tyco water sps design manual 2008
TRANSCRIPT
SINTAKOTE®
Steel pipeline systemsDesign Manual
SINTAKOTE®
Steel pipelinesystemsDesign Manual
Tyco Water Regional Marketing Offices
Divisional Office
Tyco Water Pty Ltd
ABN 75 087 415 745
1-21 Percival Road
Smithfield 2164
PO Box 141 Fairfield
New South Wales 1860
Telephone 61 2 9612 2470
Facsimile 61 2 9612 2471
www.tycowater.com
Regional Marketing Offices
Brisbane
39 Silica Street
Carole Park 4300
PO Box 162 Carole Park
Queensland 4300
Telephone 07 3712 3666
Facsimile 07 3271 3128
Sydney
1-21 Percival Road
Smithfield 2164
PO Box 141 Fairfield
New South Wales 1860
Telephone 02 9612 2470
Facsimile 02 9612 2471
Melbourne
60A Maffra Street
Coolaroo 3048
PO Box 42 Dallas
Victoria 3047
Telephone 03 9301 9115
Facsimile 03 9309 0577
Perth
70 Cleaver Terrace
Belmont 6104
PO Box 385 Cloverdale
Western Australia 6105
Telephone 08 9346 8555
Facsimile 08 9346 8501
This manual has been prepared by Tyco Water to assistqualified engineers and contractors in the selection of theCompany’s product, and is not intended to be an exhaustivestatement on pipeline design, installation or technical matters.Any conclusions, formulae and the like contained in the manualrepresent best estimates only and may be based onassumptions which, while reasonable may not necessarily becorrect for every installation.
Successful installation depends on numerous factors outsidethe Company’s control, including site preparation andinstallation workmanship. Users of this manual must checktechnical developments from research and field experience,and rely on their knowledge, skill and judgement, particularlywith reference to the qualities and suitability of the productsand conditions surrounding each specific installation.
The Company disclaims all liability to any person who relies onthe whole or any part of this manual and excludes all liabilityimposed by any statute or by the general law in respect of thismanual whether statements and representation in this manual
are made negligently or otherwise except to the extent it isprevented by law from doing so.
The manual is not an offer to trade and shall not form any partof the trading terms in any transaction. Tyco Water’s tradingterms contain specific provisions which limit the liability of Tyco Water to the cost of replacing or repairing any defectiveproduct.
SINTAKOTE®, SINTAJOINT®, SINTALOCK® and SINTAPIPE®
are registered trademarks.
© Copyright Tyco Water Pty Ltd
This manual is a publication of Tyco Water Pty Ltd, ABN 75 087 415 745 / ACN 087 415 745, and must not becopied or reproduced in whole or part without the Company’s prior written consent.
This manual is and shall remain as the Company’s property andshall be returned to the company on its request. The Company reserves the right to make changes to anymatter at any time without notice.
Steel Pipeline Systems Design Manual
First Edition 1992Second Edition 2003Third Edition 2004Fourth Edition 2008
C O N T E N T S
Section 1 Introduction 8
Section 2 Technical Specifications and Manufacturing Standards 12
Section 3 Coatings 16
Section 4 Linings 22
Section 5 Jointing Systems 26
Section 6 Design – General Considerations 32
Section 7 Pipe Data 42
Section 8 Structural Properties of Pipe 52
Section 9 Fittings 62
Section 10 Hydraulic Characteristics of Pipe and Fittings 66
Section 11 Water Hammer 76
Section 12 Anchorage of Pipelines 84
Section 13 Structural Design for Buried Pipelines 90
Section 14 Free Span and Structural Loading 102
Section 15 Appurtenance Design 114
Section 16 Typical Installation Conditions 118
Appendices 126
Appendix A Glossary 128
Appendix B SI Conversion Factors 132
Appendix C Material Properties 135
Appendix D References 136
Appendix E Standards Referenced in Text 137
Introduction
8
section1
1.1 Steel design manualOur communities today depend heavily on the continual supply ofhigh quality water for both domestic and industrial purposes.
For these applications the community requires a pipeline that willdeliver good quality water in sufficient quantity and with adequatepressure, year after year.
This must be achieved under prevalent operating conditionsembracing static and transient operating pressures and externalloads acting on the pipeline, including earth pressure and live loadsdue to vehicular traffic.
Satisfaction of these criteriaTo perform as required the pipeline system must not only becapable of being handled, transported and installed with little or no damage but also must be resistant to degradation or damagethrough corrosion, ageing and other external effects.
The community expects these criteria to be met in the mosteconomical way, that is at minimum cost over the lifetime of the pipeline.
The superior material properties of steel, combined with world-class corrosion protection systems, ensure that Tyco Water SteelPipeline Systems provide the answer for water supply and manyother applications.
1.2 HistoryThroughout Australia and the rest of the world, steel pipelines havelong been used in water supply, particularly where high pressures,difficult laying conditions or security of supply, have required thestrength and toughness of steel.
Tyco Water and its predecessors have traditionally been at theforefront of developments in the water industry. Today, Tyco Water’s products and services cover a broad range of industry needs, offering a total solution approach to its Customers. Tyco Water’s operations extend across Australia, South East Asiaand the Pacific.
1.3 ApplicationsTyco Water Steel Pipeline Systems, (TWSPS), offers products for allwater industry applications, including:
• potable water systems,
• industrial water systems,
• sewage rising mains and trunk sewers.
Products are also available for other applications including:
• slurry pipelines,
• aggressive fluids, and
• tubular piling and structural applications.
1.4 Installation trainingExtensive research has shown that by following proper installationprocedures, Tyco Water Steel Pipeline Systems can readily achieveoperational lifetimes of over 100 years.
Tyco Water and its predecessors have promoted quality pipelineinstallation through its “SINTAKOTE PIPELINES PROGRAM”. This program provides training in the installation of steel pipe andaccreditation to competent pipeline laying personnel. Most Australian water authorities now regard this as a mandatorycompetency requirement.
Tyco Water Training is a Registered Training Organisation (RTO).The course has been designed to meet some outcomes of theNTIS Unit of Competency UTWNSWS390A/02 – Construct/installdrains, pipes and associated fittings, and is accredited to theVocational Education and Training Board (NSW).
1.5 Manufacture of mild steel cement mortar lined (MSCL) pipeTyco Water Pty Ltd manufactures MSCL pipe using the spiralforming method. In this process, a coil of steel having the requiredwidth and thickness is placed on the spiral pipe-making machine,where it is uncoiled and fed continuously through the machine. The strip is formed to the required pipe diameter and continuouslywelded internally and externally using the Submerged Arc Weldingprocess. The welds so produced form a spiral, hence the name ofthe process.
The pipe so formed is then fed onto the output table where it is cutto the length required. The pipe is then removed from the machineto an area where each pipe is inspected.
After inspection, the pipe ends are machined square beforeproceeding to the pipe end-forming machine. Here the ends of thepipe are formed to produce the socket for the SINTAJOINT® rubberring joint or the spigot and socket for the Ball and Socket Joint (B & S).The SINTAJOINT end is formed by rolling the shape on the pipeends. The socket and spigot of the B & S joint are formed byexpansion. Spherical Slip-in Joint ends (SSJ) are formed byexpanding and collapsing the ends on specially made dies on thehydrostatic testing machine.
10 | S E C T I O N 1
Each pipe is then hydrostatically pressure tested. Water is pumpedinto the pipe whilst all air is purged out. When the pipe is full ofwater, the pressure is increased so as to induce a hoop stress inthe pipe shell equivalent to 90% of the nominal minimum yieldstrength (NMYS) of the steel, as required by AS1579. Note that themaximum pressure that can be applied is 8.5 MPa, as dictated bythe pressure test equipment.
After testing, the pipe is dried and the external surface is blastcleaned to remove all rust and mill scale prior to application of theexternal corrosion protection system (SINTAKOTE®). Note that forSINTAPIPE®, the internal surface of the pipe is also blast cleaned at this stage.
The pipe is then placed into a preheat oven where the temperatureof the steel is raised to processing temperature. It is then pickedup and dipped into a fluidised bath containing polyethylenepowder. On contact, the powder melts and fuses to the pipe’sexternal surface. This pipe is rotated and held in the bath until therequired coating thickness is reached. This is the SINTAKOTEfusion bonding process.
For SINTAPIPE, the internal lining and external coating operationsare carried out simultaneously.
For SSJ and B & S pipes, the external coating is set back from theends of the pipe to allow for field jointing and welding. In the caseof SINTAJOINT pipe, the external coating is carried around theends of the spigot and socket to actually cover part of the internalsurface of the pipe at each end.
After coating, pipes are cement mortar lined. The pipe is spun at high speed so as to generate a high ‘g’ force. This centrifugal force compacts the mortar around the insidesurface of the pipe whilst removing excess water from themortar. The process results in a dense and firm lining. For field assembly the lining is set back from the ends asrequired by AS1281. After the lining operation the pipe isremoved from the machine and placed on curing ramps. Each pipe is fitted with plastic end-caps in order to protectagainst the formation of shrinkage cracks, caused by rapiddrying. The SINTAKOTE is checked to ensure that no damagehas occurred and that it is free from holes in the coating, known as ‘holidays’.
The pipe is stored for a minimum period of four days to ensureadequate cure before dispatch. During this period, the plastic endcovers are retained to prevent loss of moisture from the lining.
The completed SINTAJOINT pipe is rubber ring jointed, withSINTAKOTE applied externally and around the pipe ends, allowingthe cement mortar lining to overlap the SINTAKOTE. The pipe is
completely protected with the factory applied SINTAKOTE andcement mortar lining. It requires no field joint coating or lining.
Pipes and fittings are manufactured in accordance with the relevantAustralian Standard. Each manufacturing facility operates under acertified Quality Assurance system to AS/NZS ISO 9001/9002.
Tyco Water can provide other types of coatings and linings, e.g.epoxy paint, seal coatings etc, to suit the client’s requirements.
Short runs of pipe can also be made using bending rolls to formcans that are then welded together to form specific lengths of pipe.Pipe fittings, such as mitre bends, off-takes, bifurcations etc. arealso available.
Tyco Water supplies a range of pipe from 114mm to 2500mm OD.The wall thickness ranges from 4mm to 16mm and lengths can bemade in 6, 9, 12.2 and 13.5m. Please contact your nearestRegional Marketing Office for further details.
S E C T I O N 1 | 11
Preparation of pipe ends at the end trimming station.
S E C T I O N 1
Introduction
TechnicalSpecifications &ManufacturingStandards
12
section2
2.1 Steel Pipe ManufactureSteel pipe and fittings for water pipe are manufactured in accordancewith the following Australian/New Zealand Standards:
AS 1579: “Arc welded steel pipes and fittings for water and waste water”AS/NZS 1594: “Hot-rolled steel flat products”AS/NZS 3678: “Hot-rolled structural steel plates, floor plates and slabs”
Steel pipe for the Water Industry is usually specified in wall thicknesses from 4.0 to 12.7mm. The analysis grades HA1016 andHXA1016 steel to AS/NZS 1594 are normally used. Note: 8mm wallthickness coil is now offered as HU300 steel. These materials aresupplied by the steel maker with prescribed chemical analysis limits. Themechanical property values associated with the chemical analysis havebeen identified by statistical means and are given in Table 6.5.
For a thickness greater than 12.7mm, steel to AS/NZS 3678 isusually used with a minimum yield strength (MYS) of 250 MPa.
Other grades of steel can be specified provided that the carbonequivalent (CE) calculated by using the following equation does notexceed 0.40%:
CE =%C + %Mn + %Cr+%Mo+%V + %Ni+%Cu ≤ 0.40% 6 5 15
Refer to AS 1579 for further details.
Pipe manufactured by Tyco Water must pass a mandatoryhydrostatic pressure test in accordance with AS1579, ensuringfitness for purpose and quality of manufacture.
2.2 SINTAKOTEAS 4321: “Fusion bonded medium density polyethylene coatingsand linings for pipes and fittings”.
2.3 Cement mortar liningAS 1281: “Cement mortar lining of steel pipes and fittings”.
2.4 SINTAJOINT rubber ringsAS 1646: “Elastomeric seals for waterworks purposes”.
2.5 Other materials and specificationsOther materials and specifications can be accommodated if required.Please contact your nearest Tyco Water Regional Marketing Office forfurther details.
S E C T I O N 2
Technical Specifications and Manufacturing Standards
S E C T I O N 2 | 15
Coatings
16
section3
18 | S E C T I O N 3
3.1 Brief historyA wide variety of systems have been used to provide externalcorrosion protection of steel water supply pipelines, for both aboveground and below ground installations.
Above ground treatments have consisted of various types ofindustrial paints such as inorganic zinc silicates and epoxies. Forunderground applications bitumen paints were commonly used inthe early days.
Coal tar enamel became the preferred coating in the 1950’s. Its properties were enhanced by incorporating glass fibre mat andan outer wrapping of coal tar impregnated felt. Coal tar enamelwas in common use for underground applications through the1960’s and 1970’s and into the early 1980’s.
Coal tar enamel generally performed well. However there wereoccasional problems during storage, handling and deterioration inservice. Tyco Water carried out extensive research to develop animproved system, the result of which was the introduction ofSINTAKOTE® in 1972. Once the performance of this coating wasrecognised, coal tar enamel was progressively phased out.
3.2 SINTAKOTE®
SINTAKOTE is a registered trademark. A black polyethylene coatingis fusion bonded directly to the steel pipe, hence the coating is alsoknown as Fusion Bonded Polyethylene (FBPE). Properties andperformance under various test standards are given in Table 3.1.
Features of the coating include:
• Excellent adhesion• High impact and load resistance• Excellent chemical resistance• High dielectric strength• High electrical resistivity• Low water absorption• Resistance to soil stresses• Wide service temperature range - temperatures from minus 40°C to plus 70°C have no detrimental effect on SINTAKOTE• Ability to accept cold bending of the pipe in accordance with AS 2885 without damage to the coating.
SINTAKOTE is ideally suited to below ground applications, includinginstallations where pipes must be thrust bored under roads andrailways. It is also ideal for sub-sea installations such as the protectionof tubular steel wharf piling.
SINTAKOTE is supplied in accordance with AS 4321: “Fusion-bonded medium-density polyethylene coating and lining for pipes and fittings”.
The SINTAKOTE processThe bare steel surface of the pipe is cleaned and profiled by gritblasting to ensure an excellent bond between the steel and the coating.The pipe is then heated in an oven and dipped into a fluidised bath ofpolyethylene powder that fuses directly onto the heated surface.
The recommended thickness of the coating varies with thediameter of the pipe. See Table 3.2.
The molten SINTAKOTE can be strewn with sand to provide ashear key for concrete encasement when requested.
A range of conventional fittings can be coated in a similar manneras the pipe itself to achieve the same high quality finished coating.
Quality control is maintained through routine tests for thickness,adhesion and coating continuity.
RepairsMinor damage may occur when SINTAKOTE pipe is mishandled.Such damage can be repaired using a particular method suited tothe area of the damaged section. Small areas can be repaired bythe application of a patch whereas large areas are repaired by theapplication of tapes or heat shrinkable polyethylene sleeves.Details are given in the SINTAKOTE Steel Pipeline Systems“Handling and Installation Reference Manual” available from any ofour Regional Marketing Offices.
Note: Oxygen and acetylene should not be used to heatSINTAKOTE as heating in this way can degrade SINTAKOTE.
SINTAKOTE thicknessSINTAKOTE coating and lining thicknesses conform to AS 4321. See Table 3.2 and Fig. 3.1.
Figure 3.1: Designation of SINTAJOINT joint region.
Lining
Lining
Coating
Coating
Joint region
Joint region
S E C T I O N 3 | 19
Table 3.2. – SINTAKOTE - Coating and Lining Thickness (millimetres)
Pipe outside Minimum thicknessdiameter
Coating LiningElastomeric ring
(Note 1) joint region (Note 2)
≤ 273 (250 DN) 1.6 1.0 (Note 3)
>273 ≤ 508 (500 DN) 1.8 1.0 0.8
>508 ≤ 762 (750 DN) 2.0 1.0 1.0
>762 2.3 1.0 1.0
Notes: 2 See Figure 3.1 for joint region.1 Nominal pipe sizes are shown in brackets. 3 RRJ available for ≥324mm OD.
S E C T I O N 3
Coatings
Table 3.1 – SINTAKOTE (fusion bonded medium density polyethylene) - Properties & performance
Property Test standards Typical test resultsCoating Material AS 4321 Complies
Colour Black: To impart maximum protection against UV radiation when used above ground
Service Temperature Range AS 4321 -40°C to 70°C
Thermal Stability (100°C for 100 days) AS 4321 < 35% change in MFI
Bond Strength AS 4321 5-10 N/mm
Tensile Strength at Yield AS 4321 18 MPa
Indentation Hardness ASTM D2240 61 Shore hardness D
Penetration resistance - 23°C AS 4321 0.1mm indentation- 70°C 0.2mm indentation
Thermal Conductivity ASTM C177 0.34 Wm-1 K-1
(Compression moulded specimen)
Environmental Stress Crack Resistance AS 4321 F50 >100 hrs
Density AS 4321 940 kg/m3
Water Absorption AS 4321 < 0.1% m/m water absorbed(100 days, 23°C)
Electrical Volume Resistivity IEC 60093 approx. 1019 ohm cm (1000 sec. polarisation, on base polymer)
Dielectric Strength IEC 60243 20kV/mm (on base polymer, (Specimen 3mm thick, on base polymer) without carbon black)
Impact Resistance ASTM G13, 219mm No holidays after 10 successive drops(Limestone drop test) OD coated pipe,
av. thickness 1.6mm
Impact Resistance AS 4321/ASTM G14, Mean impact strength 20J(Falling tup test) 219mm OD coated pipe,
2.3mm thick
Abrasion Resistance ASTM D4060 8mg loss due to abrasion(Tabor) (C17, 1000g, 1000 cycles)
Cathodic Disbondment AS 4321 8-14mm radial disbonded length
Chemical Resistance: SINTAKOTE is resistant to all the normal chemicals, compounds and solutions commonly encountered in waterindustry applications including muriatic acids, as well as marine organisms and compounds found in aggressive soils.
20 | S E C T I O N 3
Cathodic protectionCathodic protection (CP) is a method of providing secondarycorrosion protection to coated pipelines. High-pressure oil and gaspipelines are protected by CP as the danger and costs of leaks areso high that secondary protection is required by statutory authorities.
Most water pipelines that utilise SINTAJOINT pipes are notcathodically protected. The choice of cathodic protection for waterpipelines is one of strategic importance and cost. When usingSINTAJOINT pipe it is likely to be more cost effective not to applycathodic protection. Normal CP costs include joint bonding cables,anodes, ground-beds, transformer rectifiers and associatedinstallation and maintenance.
CP is however, completely compatible with SINTAKOTE. The high electrical resistivity of SINTAKOTE is maintained duringits life due to the very low water absorption of SINTAKOTE. Its high resistance to impact and deterioration whilst in servicemake it the ideal coating choice for critical installations where CP is deemed essential.
Handling, storing and layingSINTAKOTE pipes should be cradled and packed using appropriatedunnage.
The FBPE will remain unaffected when stored above ground over alengthy period of time due to the inbuilt ultra violet stabiliser, as wellas its high resistance to temperature.
Because of the strength, toughness and damage resistance ofSINTAKOTE the bedding, backfill composition and compactionprocedures are not as critical as those for alternative coatings.Please refer to the SINTAKOTE Steel Pipeline Systems Handling andInstallation Reference Manual for further details.
Chemical resistance SINTAKOTE is resistant to all the relevant chemicals, compoundsand solutions commonly encountered in water industry applicationsincluding muriatic acids, as well as marine organisms andcompounds found in aggressive soils.
Linings
22
section4
24 | S E C T I O N 4
4.1 GeneralFerrous potable water pipelines will corrode internally if notprotected. The rate of corrosion is generally quite low due to thelow conductivity, neutral pH and low dissolved oxygen content ofpotable water.
Internal corrosion does not usually lead to pipe failure, but canresult in head loss or reduced flow due to an increase in surfaceroughness caused by the growth of corrosion products. Waterquality can also be a problem due to increased concentrations ofiron in the water.
The predominant lining used for potable water and sewage risingmains is cement mortar lining. For sewage pipelines that are septicand produce sulphuric acid, alternative mortar linings such asCalcium Aluminate (CA), CML or SINTAPIPE can be used (see ref. 19). Note that pipelines can be designed to minimise thegeneration of sulphuric acid (see ref. 7).
Cement mortar linings are used to convey petroleum products fromships and the pipelines are usually left filled with seawater when notin use.
Other common applications include bore field collectors andground water transmission lines.
For high saline applications where total dissolved solids exceed35,000 ppm or aggressive water conveyance, customers shouldcontact Tyco Water Marketing Offices.
4.2 Cement mortar lining
HistoryCement mortar has been used to line pipe since the 1840’s when itwas introduced in France and the USA. The techniques forapplication took some time to develop and it was not until the1920’s that the process of centrifugal spinning (originally known asthe ‘Hume’ process) came into being. This process allowed therapid application of linings to the entire pipe surface by placing amixture of sand, cement and water into the pipe and rotating it athigh speed.
The centrifugal forces distribute the lining around the pipecircumference and compact it against the pipe wall. At the sametime excess water in the mixture migrates to the surface of thelining. After spinning, this excess water is removed leaving asmooth surfaced mortar with a water to cement ratio of 0.25 to0.40.
The high density, low void content and low water content results ina strong, low permeability cement mortar lining.
Current practiceThe centrifugally spun process remains the preferred lining methodtoday as it produces the highest quality lining. It is the methodused in all our steel pipe plants.
Cement mortar linings provide long-term protection at a low cost and consequently they remain the standard lining for potablewater mains.
Mechanism of corrosion protectionCement mortar linings provide active protection of the steel pipe bycreating a high pH environment, typically pH12, at the steel-mortarinterface. At pH values above approximately 9, a stable hydroxidefilm is formed on the inside steel surface. While this passive filmremains intact no corrosion occurs.
Lining appearanceWhen leaving our pipe manufacturing plants the linings maycontain superficial hairline cracks. If the pipes are stored forextended periods, say more than two months, especially in hotweather, drying shrinkage can lead to the formation of largercracks.
For potable water pipelines cracks up to 2mm wide should not berepaired as they will close and heal when immersed in water. Whenthe pipes are rewetted, the mortar typically absorbs up to 8%moisture and expands, reducing crack widths by around 50%.Further hydration closes the cracks in a process sometimesreferred to as autogenous healing.
The mechanism of high pH providing protection and the ability ofcement mortar to continue to hydrate and cure during servicemeans that minor cracks in the lining can be tolerated. However, for aggressive conveyants the 2mm maximum crack width mayneed to be reduced.
Cement mortar lining (CML) thicknessesCement mortar linings are manufactured to the thicknesses andtolerances specified in AS 1281. See Table 4.1.
Pipe OD (mm) CML (mm) Tolerance (mm) +/-
100 ≤ OD ≤ 273 9 3
273 < OD ≤ 762 12 4
762 < OD ≤1219 16 4
1219 < OD ≤ 1829 19 4
Table 4.1 - Cement mortar lining (CML) thicknesses
S E C T I O N 4 | 25
PerformanceThe dense mortar produced by our centrifugal lining processoffers good chemical resistance to potable waters and can also beused in saline and wastewater applications. Cement mortar liningusing Sulphate resistant (SR) and Calcium Aluminate (CA) cementsare resistant to the water chemistries shown in Table 4.2. Ordinarypotable cement performs similarly to SR cement, except the limiton sulphate concentration is reduced to 600 mg/L. Note thatCalcium Aluminate cement should not be used for potable waterpipelines. When the water chemistry is outside these limits, pleasediscuss with a Tyco Water Regional Marketing Office.
Bitumen seal coatHigh pH can develop in water, especially in small diameter cementmortar lined pipelines, where the water is aggressive and the flowrate is low, resulting in a long residence time. To overcome this potential problem seal coatings have beendeveloped to restrict leaching from the cement mortar lining.
Pipes can be supplied with cement mortar lining and bitumen sealcoat if required. This must be specified at time of quotation.
Handling, storing, layingCement mortar lined pipes should be handled with due care.Mistreatment, poor handling and unloading practice can result inlining damage.
Details of repair are given in the SINTAKOTE Steel PipelineSystems Handling and Installation Reference Manual, available fromany of our Tyco Water Regional Marketing Offices.
4.3 SINTAPIPE®
SINTAPIPE® is a registered trademark. SINTAKOTE is applied to both the outside and the bore of rubber ring jointed steel pipe to make SINTAPIPE. Possible because of innovation in the fusion bonding processes, it provides a wide range ofopportunities for steel pipe options for aggressive water applications.
SINTAPIPE properties and performance under various teststandards are given in Table 3.1.
S E C T I O N 4
Linings
Chemical species Tolerable TolerableConcentration Concentrationfor SR Cement for CA Cement
Sulphate, SO42-(mg/L) 6000 max no limit
Magnesium, Mg2+(mg/L) 300 max no limit
Free aggressive carbon dioxide, CO2(mg/L) 30 no limit
pH(mg/L) 6.0 min 4.0 min
Ammonium, NH4+(mg/L) 30 max no limit
Calcium, Ca2+(mg/L) 1.0 min no limit
Hydrogen Sulphide, 0.5 max 10 maxH2S (ppm)
Table 4.2 - Chemical resistance of cement mortar linings
JointingSystems
26
section5
28 | S E C T I O N 5
5.1 GeneralPipes can be supplied with any of the joint configurationsdescribed below. A variety of mechanical jointing systems to suitspecialist requirements can also be supplied.
Jointing systems for fittings can also be specified in theseconfigurations. They are however, subject to geometrical andpractical considerations.
Clients are advised to contact Tyco Water Regional MarketingOffices to discuss detailed requirements.
5.2 SINTAJOINT Advantages of rubber ring joints (RRJ) over welded joints includefaster laying rates, less field plant and maintenance, and speedierbackfilling as this can be done immediately after the joint has beenlaid and checked.
In the case of SINTAJOINT pipe, no joint corrosion protection isnecessary. Therefore minimal excavation at joints is required,allowing trenching to proceed without interruption. See Figure 5.1.
SINTAJOINT is available from 324mm to 1829mm outside diameterfor pipes and fittings. Each joint provides angular deflection up toapproximately 3° depending on diameter. See Graph 5.1.
Due to its insulating properties, the joint is ideal for applicationswhere induced current may be a design consideration, for example,within power transmission easements.
“Deep entry” SINTAJOINTTo accommodate abnormal angular rotation and axialdisplacements, rubber ring joints can be supplied with a modifiedsocket profile featuring a deeper, wider throat. Design Engineersshould contact one of the Tyco Water Regional Marketing Offices todiscuss detailed requirements.
An example of this joint application is in mine subsidence areaswhere ground strain can be high, typically in the range of 3 to 7 mm/m.
Laying SINTAJOINT pipeRecommended practices for laying rubber ring joint steel pipes areprovided in the SINTAKOTE Steel Pipeline Systems Handling andInstallation Reference Manual.
Figure 5.1 - SINTAJOINT rubber ring joint
Figure 5.3 - Spherical slip-in joint
Figure 5.2 - SINTALOCK joint
Figure 5.4 - Ball and socket joint
test point
Figure 5.5 - Butt joint with collar Figure 5.6 - Plain butt joint
S E C T I O N 5 | 29
S E C T I O N 5
Jointing Systems
Design engineers in particular should be familiar with thesepractices for consideration in design.
SINTALOCK
Tyco Water's SINTALOCK joint consists of a restrained rubber ringjoint and external fillet weld. With no need to enter pipes forwelding or lining reinstatement, safety is increased and corrosionprotection enhanced. SINTALOCK also eliminates the need forthrust blocks, drastically reducing construction time. SINTALOCKis available for 324-1440mm outside diameter pipe. It will suitpipes containing a wall thickness of ≤ 10mm. Each joint providesan angular deflection of up to 1.1º. For allowable operatingpressures of SINTALOCK, see Table 7.2.
5.3 Welded jointsWelded joints ensure 100% structural integrity. Where an internaland external weld is used they can also permit a pneumatic test ofthe weld integrity in the field during construction. Complete internaland external circumferential welds are necessary however, and adrilled and tapped hole accessing the air space between thewelds must also be provided for an air nozzle to be attached. The weld is then daubed with a soap solution and the annuluspressurised to around 100 kPa. The welds are then examined forbubbles of escaping air and rectified if necessary. For largepipelines this test can assure integrity as construction progresseseliminating the time and cost of a major hydrostatic field test. See Figure 5.4 for a typical arrangement.
The integrity of spherical slip-in and ball and socket welded joints may be assessed by this test. See Tyco Water’s SteelPipeline Systems Handling and Installation Manual for furtherdetails.
Spherical slip-in joint (SSJ)This pipe joint is available in sizes 168 to 1422mm OD, in wallthicknesses up to 12mm, with angular deflections of up to 3° availablein the smaller diameters. Deflections are based on proprietarycalculations and can be obtained from your nearest Tyco WaterRegional Marketing Office. Field welding may be carried out internallyas well as externally in pipes large enough to provide adequateinternal access. Generally, pipes above 813mm OD will allow this. SeeFigure 5.3.
Ball and socket joint (B&S)This pipe joint is available in sizes ≤ 806mm OD and allows 3ºdeflection per joint prior to welding. See Figure 5.4. Graph 5.1 - SINTAJOINT RRJ angular deflections
100
0.5º
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
1600
1700
1800
1500
1º1.5º2º2.5º3º3.5º
Tem
pora
ry c
onst
ruct
ion
defle
ctio
n
Per
man
ent d
efle
ctio
n
OD
. Out
side
dia
met
er in
mill
imet
res
θ Deflection angle in degrees
θ
Butt joint with collarSquare end preparation is required. Pipes and collar are easy to alignand the configuration is often used in closing lengths. See Figure 5.5.
It can also be used for smaller diameter pipes to eliminate internalgaps in cement mortar lining.
Butt joint The plain butt joint may be satisfactorily welded from one side usinga root fill and hot-pass method, if required, provided that the joint isNDT inspected in accordance with AS/NZS 1554. Note that pipe ends must be bevelled to achieve a reasonable weld,and the ends of the cement mortar lining must have been prepared.
This method is particularly useful for small diameter pipes whereinternal reinstatement of the cement mortar lining cannot beperformed by hand. See Figure 5.6.
5.4 Flanged jointsFlanged joints are completely rigid and should not be used forapplications where movement of the pipeline is expected, unlessspecial provision is made to accommodate it by, for example, theinclusion of expansion joints.
Flanged joints are used mainly for above ground applications, e.g. pumping stations, water and sewage treatment plants and forindustrial pipework. They are also used to facilitate the installationand removal of valves in SINTAJOINT and welded pipelines and forvalve bypass arrangements.
For assembly of flanged joints no field welding or other specialequipment is required. Flange dimensions are normally inaccordance with AS 4087 and are currently supplied in Class 16,Class 21 or Class 35.
For access covers and other blank flange joints Tyco Waterrecommends the use of o-ring type gaskets because of their lowrequirement for assembly stress and trouble free operation. O-ringflanged joints have these same advantages in other flanged jointsituations but it must be remembered that the use of o-ring typeflanges requires full knowledge of all of the mating components toavoid a joint situation with two o-ring groove ends joining eachother. The correct matching is shown in Figure 5.8.
Where it is not possible or desirable to use o-ring type flanges, TycoWater recommends the use of raised face steel flanges. See Figure 5.7.The use of flat-faced steel flanges is not preferred except when themating flange is cast iron. This situation may occur at a pumphousing, but current practice is for most pipeline components to bemanufactured in wholly steel or ductile iron. Experience has shown
that flat-faced flanges are generally more susceptible to sealingproblems and successful sealing is heavily dependent uponassembly technique.
Where the required flange sizes are larger than DN 1200 or areoutside the normal pressure rating, special flanges must bedesigned. In this situation o-ring type flanges are recommended asbeing the best option for medium to high pressure situations.
GasketsGaskets may be either elastomeric or compressed fibre type.Elastomeric gaskets are only recommended for the Class 16flanges. Compressed fibre gaskets are recommended for Class 21and Class 35 flanges. Compressed fibre gaskets can also be usedwith Class 16 flanges but will require the use of high strength boltsbecause of the higher initial compression necessary.
Table 5.1 details the recommended type of gasket and bolt to beused for various classes of raised face steel flanges. Generally fullface gaskets (that incorporate holes for the flange bolts) can beused with raised face flanges as only the raised face area inside thebolt holes is clamped. The full face gasket enables better location ofthe gasket compared to a ring type gasket. (If rigid compressedfibre type gaskets are used the use of ring type gaskets is normal).
For other liquids, temperatures or pressures contact a Tyco WaterRegional Marketing Office.
S E C T I O N 5 | 31
S E C T I O N 5
Jointing Systems
Table 5.1 - Recommended gasket composition for transportation ofgeneral domestic liquids including brine and sewage
Fig 5.8 Matched o-ring type flangesFig 5.7 Raised face type flanges
Maximum Maximum GasketOperating Pressure Temperature Composition
MPa °C
1.6 50Solid EPDM Rubber
3mm thick
3.5 80
Composite fibre1.5mm thick
TEADIT NA1000C6327 or equivalent
Design –GeneralConsiderations
32
32 | S E C T I O N 1
section6
34 | S E C T I O N 6
6.1 Safe designLong-term safety of buried pipelines will be achieved if, at the designstage, the following are known with a fair degree of confidence:
• the properties of the pipe material and of the pipe itself, asspecified by standards and warranted by the manufacturer.
• the loads that the pipeline will be subjected to, as determined byadequate design methods, based on accepted theories andexperimental evidence.
• the environment in which the pipeline will operate including itschemical nature and temperature.
However, 100% confidence in accessing the conditions above is unachievable at reasonable cost. The Engineer thus uses a design safety factor in matching the pipe minimum strength to the expected loads.
The real safety factor of the buried pipeline is usually larger than thedesign safety factor because:
(i) the pipe minimum characteristics are generally exceeded, and
(ii) the design method includes criteria which are conservative.
Greater confidence in the design and its performance is thus justifiedknowing the formal factors of safety are associated with minimumproduct performance criteria and conservative design procedures.
6.2 Check list for pipeline designIn order to establish the diameter and wall thickness of a pipeline itis necessary to consider a number of interrelated factors.
In some cases the operating pressure and flow requirements willdetermine these dimensions. On other occasions such factors asexternal loading, soil stability and type, conditions of support(above ground, bridge crossings, river crossings) as well as axialforces may influence the calculations and necessitate some local oroverall increase in wall thickness.
In certain situations the design operating criteria alone may result ina diameter to wall thickness ratio considered too high formechanical stability of the pipe during manufacture, handling andinstallation.
Design Supply Construct Operate & Maintain
Location Compaction Availability Handling Water quality
Route Jointing Lead time Storage Operating costs
Topography Fittings Product standards Bedding Cleaning
Geology Air valves Quality AS/NZS ISO 9001/9002 Jointing Air Valves
Flow requirements Isolating valves Delivery period Backfill Repairs
Future boosting Scour tees Transport Compaction Spares
Diameter Anchor blocks Handling Field test Availability
Velocity Product standards Storage Repairs Cut-ins/branches
Headloss Quality AS/NZS ISO 9001/9002 Seasonality Temperature Exposure
Pressure External corrosion UV radiation Anchor blocks
Water hammer Internal corrosion Seasonality Reinstatement
External loads Seasonality Economics
Cover Temperature Finance
Traffic UV radiation Net present value
Water table Economics
Bedding Finance
Backfill Net present value
Table 6.1- Checklist of typical design factors
S E C T I O N 6 | 35
S E C T I O N 6
Design — General Considerations
The additional wall thickness specified to overcome this representsa major benefit should a need arise to increase pipeline pressureand boost flow some time after the line has been in service.
Integration of the numerous design principles is complicated andrequires a systematic approach to optimise the design in terms ofperformance and cost effectiveness.
A comprehensive design will consider factors of pipelinecomponent supply, construction, operation and maintenance andaccount for their effect on the viability, benefits and cost of theproject.
6.3 General design procedure for buriedpipelines
1) Define pipeline
RouteLengthProfileJointing type
Several solutions are normally possible andalternatives will need to be assessedfinancially or economically.
Consider demand growth, staging,boosting.
Pipeline jointing system RRJ or weldedmay affect profile, design flexibility andpressure limitation.
Section 6.2 and Table 6.1Section 6.3Section 5 and Table 7.1
H Y D R A U L I C D E S I G N O F P I P E L I N E SACTION COMMENTS DESIGN MANUAL REFERENCES
2) Trial HGL
Identify boundary andintermediate HGL limits ofoperation.Trial possible HGL'S
Normally set by defined existing limitations:free water surface levels, terrain etc.Ignore fittings losses.Flow velocities generally between1 and 2 m/sHeadlosses generally 2 to 7 m/km.
3) Solve for
diameter, given flow and headloss or flow, given headloss anddiameter or headloss, given flowand diameter.
Identify optimum alternative.
For pumped systems match "systemcurve" with pump characteristics andoptimum duty point.
Section 10.1, 10.2Graph 10.1Examples Section 10.5
4) Define maximum pressure
Add fittings and appurtenanceheadlosses.Static headPump shut off headPRV setting
Consider a range of operating conditions.
Check HGL always above pipe level.
Fittings losses see Section 10.4 and Table 10.1
Appurtenances see Section 15
Recommended maximum internalpressures see Section 8.2
Table 6.2 is a checklist of some factors to consider for a typical pipeline.
36 | S E C T I O N 6
5) Estimate steel wall thickness
t = PD/2f
Check D/t < 165 for CML pipe,increase it if not
Maximum static working stress[f = 0.72 MYS]
D/t <165 for manufacturing, lining andhandling considerations.
Section 8
6) Select available pipe
Closest boreClosest steel wall thickness
Check availability and lead time ofselection with your nearest Tyco Water Regional Marketing Office.
Section 7.1
7) Check water hammer
P = 2ft/D ort = PD/2f
From simple checks to full computermodelling.Increase t, reselect pipe if necessary.
Allowable working pressure.
Allowable wall stress[f = 0.90 MYS]
Simple water hammer check vs fullanalysis. Increasing wall thicknessincreases surge peaks - check designchanges
Table 7.1Section 8.2Section 11
8) Refine HGL and hammer analyses
Finalise hydraulic appurtenancedesign, fittings etc.
Check final HGL and hammer analyses
Detailed design of selected size. See texts and referencesListed in Appendix D.
9) Define structural deflection limits The maximum allowable deflection of asingle hardnesss RRJ pipeline ranges from2.3-4%, depending upon OD and WallThickness.
The maximum allowable deflection of adual hardness RRJ pipeline (OD>1200)ranges from 3.5-4%, depending upon ODand Wall Thickness
The maximum allowable deflection of CMLwelded pipelines = 0.00014x MYS x D/t.
0.00014 x MYS x D/t must not exceed 4%.
Section 13.5Table 13.4, 13.5Table 8.2
10) Determine maximum load (Pmax) fordeflection limit.
Select a trial installation design trenchwidth and depth
Section 16.1, 16.2Table 13.3
S T R U C T U R A L D E S I G N O F P I P E L I N E SACTION COMMENTS DESIGN MANUAL REFERENCES
S E C T I O N 6 | 37
12) Determine maximum allowablebuckling pressure (qmax) and criticalbuckling pressure.
Consider buried and exposed ring bucklingstability.
Section 13.7
13) Calculate design buckling pressure (q)
q ≤ qmax
Consider worst load case for buckling.
Usually (dead load + vacuum) or(dead + live load).
If q > qmax increase pipe teq and/orsoil modulus E’.
Section 13.7
14) Structural design complete
Specify pipeline.
Specify pipe dimensions andinstallation design.
15) Grades Consider air entrapment. Section 6.6
17) Anchorage of pipelines Anchorage should be considered forall rubber ring jointed pipelines.
Include field test pressure anchorageperformance.
Section 12.
16) Valves Consider requirements for:
Air valves
Scour valves
Isolating valves
Section 6.7
18) Cathodic protection Secondary protection Section 3.2
O P E R AT I O N A L C O N S I D E R AT I O N SACTION COMMENTS DESIGN MANUAL REFERENCES
11) Calculate design load (P)
P < Pmax
Consider worst load case for deflection.
Usually (dead + live load) pipe emptyduring construction.
If P > Pmax, increase pipe teq and/or soilmodulus E’.
Section 13.2
S E C T I O N 6
Design — General Considerations
38 | S E C T I O N 6
years % Interest Rate or Discount Rate
n 1 2 3 4 5 6 7
5 4.8534 4.7135 4.5797 4.4518 4.3295 4.2124 4.1002
10 9.4713 8.9826 8.5302 8.1109 7.7217 7.3601 7.0236
15 13.8651 12.8493 11.9379 11.1184 10.3797 9.7122 9.1079
20 18.0456 16.3514 14.8775 13.5903 12.4622 11.4699 10.5940
25 22.0232 19.5235 17.4131 15.6221 14.0939 12.7834 11.6536
30 25.8077 22.3965 19.6004 17.2920 15.3725 13.7648 12.4090
35 29.4086 24.9986 21.4872 18.6646 16.3742 14.4982 12.9477
40 32.8347 27.3555 23.1148 19.7928 17.1591 15.0463 13.3317
45 36.0945 29.4902 24.5187 20.7200 17.7741 15.4558 13.6055
50 39.1961 31.4236 25.7298 21.4822 18.2559 15.7619 13.8007
55 42.1472 33.1748 26.7744 22.1086 18.6335 15.9905 13.9399
60 44.9550 34.7609 27.6756 22.6235 18.9293 16.1614 14.0392
80 54.8882 39.7445 30.2008 23.9154 19.5965 16.5091 14.2220
100 63.0289 43.0984 31.5989 24.5050 19.8479 16.6175 14.2693
years % Interest Rate or Discount Rate
n 1 2 3 4 5 6 7
5 0.95147 0.90573 0.86261 0.82193 0.78353 0.74726 0.71299
10 0.90529 0.82035 0.74409 0.67556 0.61391 0.55839 0.50835
15 0.86135 0.74301 0.64186 0.55526 0.48102 0.41727 0.36245
20 0.81954 0.67297 0.55368 0.45639 0.37689 0.31180 0.25842
25 0.77977 0.60953 0.47761 0.37512 0.29530 0.23300 0.18425
30 0.74192 0.55207 0.41199 0.30832 0.23138 0.17411 0.13137
35 0.70591 0.50003 0.35538 0.25342 0.18129 0.13011 0.09366
40 0.67165 0.45289 0.30656 0.20829 0.14205 0.09722 0.06678
45 0.63905 0.41020 0.26444 0.17120 0.11130 0.07265 0.04761
50 0.60804 0.37153 0.22811 0.14071 0.08720 0.05429 0.03395
55 0.57853 0.33650 0.19677 0.11566 0.06833 0.04057 0.02420
60 0.55045 0.30478 0.16973 0.09506 0.05354 0.03031 0.01726
80 0.45112 0.20511 0.09398 0.04338 0.02018 0.00945 0.00446
100 0.36971 0.13803 0.05203 0.01980 0.00760 0.00295 0.00115
Table 6.4 - Present value of an annuity
Table 6.3 - Present value of a single sum
S E C T I O N 6 | 39
6.4 Economic appraisalAs well as the physical aspects of pipeline design a combination ofinterrelated economic decisions must be taken, including pipelinediameter selection and choice of pipeline material. The objective isusually to minimise total cost (initial cost, operation and maintenancecosts) by selecting the alternative that results in the least life-cycle cost.
Factors influencing the economic decision include:
• Initial cost of pipeline components• Initial installation costs• Cost to increase capacity in future• Maintenance costs• Cost of pipeline replacement• Initial cost of pumping stations• Annual power costs• Projected life of pipeline
DCF methodsIt is generally considered that discounted cash flow (DCF)methods should be used in order to provide a rational basis forevaluating and ranking investment options.These DCF methods take account of both the magnitude and timingof expected cash costs each year in the life of a project. Cash flowsare discounted at a predetermined real discount rate. The resultingpresent worth of the DCF is the basis for comparing alternatives.
For diameter selection total present value of alternatives can beobtained by adding present capital cost to net present value of futurecosts (eg. annual pumping costs, maintenance, scheme replacement).
Table 6.2 enables the calculation of present values of future capital cost:Factors for calculating present value of a single sum.The present value of $1 in n years time, when discounted atinterest rate ri per annum is:(1+ri )–n where ri = % interest rate/100
Table 6.3 enables the calculation of present values of annualoperating costs.
Real discount rateThe discount rate used has a major effect on the result of present
value calculations, and various rates should be used to provide asensitivity analysis on any project.(See Table 6.4 - Present value of an annuity)
The present value of $1 per annum for n years when discounted atinterest rate ri per annum is:(1-(1+ri)
-n)/ri ri = % interest rate/100
The amount per annum to redeem a loan of $1 at the end of n yearsand provide interest on the outstanding balance at ri per annum canbe determined from the reciprocals of values in this table.
6.5 Properties of steelSteel water pipe manufactured to AS 1579 is normally manufacturedfrom AS/NZS 1594 analysis grade HA1016 & HXA1016 steel coil orflat plate to AS/NZS 3678 Grade 250. HA1016 & HXA1016 issupplied by the steel maker with prescribed chemical analysis limits.
HA1016 & HXA1016 mechanical property limits are not guaranteedby the steel maker, but the statistical distributions associated withthe chemical analysis limits are accurately known from historicaldata. Minimum mechanical property values associated with theselimits have been identified and are included in Table 6.5.
Yield strength performance of the steel to make the pipe is assuredby the hydrostatic test of each pipe after manufacture to 90% MYS(minimum yield strength).
The hydrostatic factory test not only proves minimum steel strengthbut also tests the welding and ultimate fitness for purpose.
Steel to other grades and specifications can be supplied if required.See Section 2.1.
For pipe that is not hydrostatically tested in accordance with AS 1579, the design pressure rating of the pipe must be includedin the design. The wall thickness of pipes that are non-hydrostatically tested shall be no less than 8.0mm. If pipes arenot hydrostatically pressure tested, then all welds shall be 100%non-destructively tested in accordance with AS 1554.1, categorySP, and the maximum hoop stress at the rated pressure shall notexceed 0.50 of the specified minimum yield stress of the steel.Other typical properties include:
Thickness Min. yield strength Min. tensile strength Product Standard Gradet mm MPa MPa t ≤ 6 300 400 AS/NZS 1594 HA1016
6 ≤ t ≤ 8 300 400 AS/NZS 1594 HXA1016t = 8 300 400 AS/NZS 1594 HU300
8 < t ≤ 12.7 250 350 AS/NZS 1594 HXA1016 t > 12.7 250 350 AS/NZS 1594 250
Table 6.5 - Steel strength
S E C T I O N 6
Design — General Considerations
• Modulus of elasticity:Est = 207,000 MPa
• Linear coefficient of thermal expansion: a = 12 x 10-6 mm/mm/°C
• Thermal conductivity:k = 47 W/(m°C)
• Density:p = 7850 kg/m3
• Melting temperature:approx 1520 °C
• Poisson ratio:v = 0.27
6.6 Air entrapmentIn a water supply pipeline air must beevacuated in order for the main to be filledand function properly.
Air can be brought into the pipeline underpressure should pump glands or inlet pipenot be properly sealed.
Dissolved air can be liberated at pointswhere the pressure is lower, and movealong the pipeline to accumulate at highpoints.
The pipeline profile should be designed tofacilitate expulsion of air at predeterminedhigh points where a release valve can belocated.
Entrained air in a pipeline can give rise to:• Drop in flow rate through a reduction inbore area caused by trapped air pocketsat line peaks, changes of slope, blind endsor low pressure zones near fittings.• Increase in energy requirement inpumped mains. A 1% by volume of airbubbles can lower pump efficiency by15%.• Water hammer due to inflow of waterinto the collapsing volume of a large airpocket.• 'White water' turbidity due to entrainedmicroscopic bubbles. Although the airclears slowly, consumer complaints mayresult on aesthetic grounds and theresulting interference with industrialprocesses such as filtration.
S E C T I O N 6 | 41
S E C T I O N 6
Design — General Considerations
Some suggestions to assist in the expulsion of air:• If possible give the pipeline a uniform gradient of at least 2 to 3in 1000 to help air rise.• Where practicable avoid too many changes of slope.• If the pipeline has several high points, minimum gradient shouldbe 2 to 3 in 1000 in rising sections and 4 to 6 in 1000 indescending sections.• On level ground, pipelines should be laid with artificial highpoints since a level pipeline may develop high points as a result ofearth settlement.
6.7 Valves
Air valvesAir valves and anti-vacuum valves should be located at the highpoints on the pipeline to release accumulated air, or to allow air toenter should a partial vacuum occur.
Supplementary air valves may be installed before stop valves andnon-return valves where these are liable to be closed duringdraining and refilling of the pipeline. Consideration should be givento the placement of air valves at intervals of 500m to 1000m overlong ascending lengths of pipeline.
Scour valvesScour valves are necessary to allow sediment to be flushed outand to enable the pipeline to be drained for maintenance andrepair work, particularly on valve equipment. They should belocated on invert scour tees at low points and between isolatingvalves on the pipeline. The location of these valves is ofteninfluenced by the need to dispose of the scour water.
Their size depends on the maximum time the pipeline may be outof service, and the maximum disposal flow available, for examplesewer lines.
If sewers are used for disposal, measures should be taken toensure backflow is prevented.
In parallel lines scour valves can be interconnected to allow bottomcharging of the empty line. This minimises air entrainment.
Isolating valvesIsolating or sectioning valves are used to isolate sections of apipeline in an emergency or for maintenance.
They should be located at high or low points. High points aregenerally more accessible, however low point located valves allowshorter pipeline lengths to be drained.
In parallel lines with twin isolating valves, cross connections fromupstream of the valve on one line to downstream of the valve onthe other allow greater flexibility in operation.
On large pipelines, isolating valves may be actuator driven to closeon detection of abnormally high flow rates caused by accidentalline rupture. Detection devices include pitot-static tubes, orificeplates or venturi meters.
6.8 Determination of wall thicknessTo establish the appropriate steel wall thickness the followingfactors must be taken into account.
Internal pressure, including consideration for water hammer (surge pressure).
External pressure, including earth fill pressure, atmospheric andhydraulic pressure, trench loading pressure and where applicableinternal part or full vacuum.
Structural loading, for example beam loading stresses in aboveground pipes and saddle stresses at supports.
Practical requirements, such as pipe rigidity during manufacturehandling and laying.
6.9 Axial loadsA welded pipeline is axially restrained. Internal pressure willtherefore cause longitudinal tension due to Poisson's effect.Thermal expansion or contraction can also cause axial loads. Pipe"beam bending" due to uneven bedding, differential settlement orsoil subsidence is another cause of axial loading.
At pipe bends, forces are generated by the internal pressure anddirection changes if velocity and volumes are significant. If notdirectly absorbed in thrust blocks these become axial loads actingon the pipeline. High hydrostatic loads may arise at valves or blankends and if not restrained in thrust blocks may cause additionallongitudinal stresses in the pipeline.
All structures securing the pipeline must be adequately designed tocarry these loads in service and also during the hydrostatic testingof the pipeline when high temporary loads may be created by theincreased test head.
Pipe Data
42
section7
44 | S E C T I O N 7
7.1 Preferred sizes and dimensionsTable 7.1 contains a comprehensive range of pipe diameters andwall thicknesses supplied by Tyco Water.
For details of pipe diameters and wall thicknesses most readily availableand for pipe diameters in excess of 2200mm nominal bore, clients areadvised to contact Tyco Water Regional Marketing Offices.
Steel wall thicknessesPlease note steel wall thicknesses shown in Table 7.1 represent platethicknesses supplied by the steel maker as “preferred thicknesses”.
Intermediate and greater wall thicknesses can be supplied butthese may incur additional costs and longer lead times.
7.2 Hydraulic boresHydraulic bores are given in Table 7.1 with CML bores based onmean cement mortar lining thicknesses given in Table 4.1.
7.3 Pipe massesTo calculate masses per metre for pipes with dimensions notincluded in the tables use the following formulae:
Plain steel shell: M1 = 0.02466(D-t)t kg/m
Cement mortar lining: M2 = 0.00755T(D-2t-T) kg/m
SINTAKOTE: M3 = 0.00295Dts kg/m
where:D = outside diameter of steel shell mmt = steel wall thickness mm
T = cement mortar lining thickness mmts = SINTAKOTE thickness mm
Approximate material densities used in these formulae are:Steel: 7850 kg/m3
Cement mortar: 2400 kg/m3
SINTAKOTE: 940 kg/m3
7.4 Pipe lengthsPipes are normally supplied in 6, 9, 12.2 and 13.4m effective laying lengths.
Minimum length is usually 6 metres, such pipes being used tofacilitate road crossings in busy areas as well as to allow minorchanges in direction without the need to provide fittings.
Lengths in excess of 13.5 metres can be manufactured upon request.
7.5 Buoyant weights (empty, closed submerged weight)Table 7.1 lists masses of water filled pipes and buoyant weights ofpipes. Where buoyant weight values are negative, precautionsshould be taken against flotation effects on empty pipelines,particularly during construction. The density of water used in thecalculation of these tables is 1000 kg/m3.
7.6 Rated/test pressuresAll pipe manufactured to AS 1579 is hydrostatically proof tested inthe factory. See Section 8.2 for more information.
S E C T I O N 7 | 45
S E C T I O N 7
Pipe Data
WaterFilled Bouyant
Empty Pipe Pipe WeightOD WT Test Pressure Rated Pressure SK CML Bore SKCL UCCL SKCL SKCL Tonnes per Pipe, SKCL(mm) (mm) (Mpa) (m) (Mpa) (m) (mm) (mm) CML kg/m kg/m kg/m kN/m 6m 9m 12m 13.5m114 4.8 8.5 866 6.8 693 1.6 9 86 19.9 19.4 25.8 0.1 0.1168 5.0 8.5 866 6.8 693 1.6 9 140 31.0 30.2 46.4 0.1 0.2 0.3190 5.0 8.5 866 6.8 693 1.6 9 162 35.3 34.4 55.9 0.1 0.2 0.3219 5.0 8.5 866 6.8 693 1.6 9 191 41.0 40.0 69.6 0.0 0.2 0.4240 5.0 8.5 866 6.8 693 1.6 9 212 45.1 44.0 80.4 0.0 0.3 0.4257 5.0 8.5 866 6.8 693 1.6 9 229 48.5 47.2 89.6 0.0 0.3 0.4273 5.0 8.5 866 6.8 693 1.6 9 245 51.6 50.3 98.7 -0.1 0.3 0.5290 5.0 8.5 866 6.8 693 1.8 12 256 61.0 59.4 112.4 -0.1 0.4 0.5324 4.0 6.7 680 5.3 544 1.8 12 292 60.8 59.1 127.8 -0.2 0.4 0.5324 4.5 7.5 765 6.0 612 1.8 12 291 64.6 62.9 131.1 -0.2 0.4 0.6324 5.0 8.3 849 6.7 680 1.8 12 290 68.4 66.7 134.4 -0.2 0.4 0.6324 6.0 8.5 866 6.8 693 1.8 12 288 76.0 74.2 141.1 -0.1 0.5 0.7337 4.0 6.4 653 5.1 523 1.8 12 305 63.4 61.6 136.4 -0.3 0.4 0.6337 4.5 7.2 735 5.8 588 1.8 12 304 67.3 65.5 139.9 -0.2 0.4 0.6337 5.0 8.0 817 6.4 653 1.8 12 303 71.3 69.5 143.3 -0.2 0.4 0.6337 6.0 8.5 866 6.8 693 1.8 12 301 79.1 77.3 150.2 -0.1 0.5 0.7356 4.0 6.1 618 4.9 495 1.8 12 324 67.1 65.2 149.5 -0.3 0.4 0.6356 4.5 6.8 696 5.5 557 1.8 12 323 71.2 69.4 153.1 -0.3 0.4 0.6356 5.0 7.6 773 6.1 618 1.8 12 322 75.4 73.5 156.8 -0.3 0.5 0.7356 6.0 8.5 866 6.8 693 1.8 12 320 83.8 81.9 164.1 -0.2 0.5 0.8406 4.0 5.3 542 4.3 434 1.8 12 374 76.8 74.6 186.6 -0.5 0.5 0.7406 4.5 6.0 610 4.8 488 1.8 12 373 81.6 79.4 190.8 -0.5 0.5 0.7 1.0406 5.0 6.7 678 5.3 542 1.8 12 372 86.4 84.2 195.0 -0.4 0.5 0.8 1.0406 6.0 8.0 813 6.4 651 1.8 12 370 95.9 93.8 203.4 -0.4 0.6 0.9 1.2406 8.0 8.5 866 6.8 693 1.8 12 366 114.9 112.8 220.1 -0.2 0.7 1.0 1.4419 4.0 5.2 525 4.1 420 1.8 12 387 79.3 77.1 196.9 -0.6 0.5 0.7 1.0419 4.5 5.8 591 4.6 473 1.8 12 386 84.3 82.1 201.2 -0.5 0.5 0.8 1.0419 5.0 6.4 657 5.2 525 1.8 12 385 89.2 87.0 205.6 -0.5 0.5 0.8 1.1419 6.0 7.7 788 6.2 631 1.8 12 383 99.1 96.9 214.3 -0.4 0.6 0.9 1.2419 8.0 8.5 866 6.8 693 1.8 12 379 118.7 116.5 231.5 -0.2 0.7 1.1 1.4457 4.0 4.7 482 3.8 385 1.8 12 425 86.7 84.3 228.5 -0.8 0.5 0.8 1.0457 4.5 5.3 542 4.3 434 1.8 12 424 92.1 89.7 233.3 -0.7 0.6 0.8 1.1457 5.0 5.9 602 4.7 482 1.8 12 423 97.6 95.1 238.0 -0.7 0.6 0.9 1.2457 6.0 7.1 723 5.7 578 1.8 12 421 108.4 106.0 247.5 -0.6 0.7 1.0 1.3457 8.0 8.5 866 6.8 693 1.8 12 417 129.9 127.4 266.4 -0.4 0.8 1.2 1.6502 4.0 4.3 439 3.4 351 1.8 12 470 95.5 92.8 268.9 -1.0 0.6 0.9 1.1502 4.5 4.8 493 3.9 395 1.8 12 469 101.5 98.8 274.1 -1.0 0.6 0.9 1.2 1.4502 5.0 5.4 548 4.3 439 1.8 12 468 107.4 104.8 279.4 -0.9 0.6 1.0 1.3 1.5
Table 7.1 Pipe Data
Note:
1) See Table 6.5 for associated steel grades and relevant minimum yield strength and minimum tensile strength values.
2) For further sizes please contact your local Tyco Water regional marketing office.
46 | S E C T I O N 7
Key:OD = Outside diameter of the steel pipe shell. Does not include SINTAKOTE thicknessWT = Thickness of steelSK = Thickness of SINTAKOTE external coatingCML = Thickness of cement mortar liningSKCL = SINTAKOTE cement mortar liningUCCL = Uncoated cement mortar liningRated Pressure = Maximum allowable operating internal pressure for SINTAJOINT and welded joint pipelinesTest Pressure = Maximum internal pressure each SINTAJOINT and welded joint pipe is tested to during manufacturing
WaterFilled Bouyant
Empty Pipe Pipe WeightOD WT Test Pressure Rated Pressure SK CML Bore SKCL UCCL SKCL SKCL Tonnes per Pipe, SKCL
(mm) (mm) (Mpa) (m) (Mpa) (m) (mm) (mm) CML kg/m kg/m kg/m kN/m 6m 9m 12m 13.5m502 6.0 6.5 658 5.2 526 1.8 12 466 119.4 116.7 289.8 -0.8 0.7 1.1 1.4 1.6502 8.0 8.5 866 6.8 693 1.8 12 462 143.1 140.4 310.6 -0.6 0.9 1.3 1.7 1.9508 4.0 4.3 433 3.4 347 1.8 12 476 96.6 93.9 274.5 -1.1 0.6 0.9 1.2 1.3508 4.5 4.8 488 3.8 390 1.8 12 475 102.7 100.0 279.8 -1.0 0.6 0.9 1.2 1.4508 5.0 5.3 542 4.3 433 1.8 12 474 108.7 106.1 285.1 -0.9 0.7 1.0 1.3 1.5508 6.0 6.4 650 5.1 520 1.8 12 472 120.8 118.1 295.7 -0.8 0.7 1.1 1.4 1.6508 8.0 8.5 867 6.8 693 1.8 12 468 144.8 142.1 316.8 -0.6 0.9 1.3 1.7 2.0559 4.0 3.9 394 3.1 315 2.0 12 527 106.9 103.6 324.9 -1.4 0.6 1.0 1.3 1.4559 4.5 4.3 443 3.5 354 2.0 12 526 113.6 110.3 330.8 -1.3 0.7 1.0 1.4 1.5559 5.0 4.8 492 3.9 394 2.0 12 525 120.3 117.0 336.6 -1.3 0.7 1.1 1.4 1.6559 6.0 5.8 591 4.6 473 2.0 12 523 133.6 130.3 348.3 -1.1 0.8 1.2 1.6 1.8559 8.0 7.7 788 6.2 630 2.0 12 519 160.1 156.8 371.6 -0.9 1.0 1.4 1.9 2.2610 4.5 4.0 406 3.2 325 2.0 12 577 124.2 120.6 385.5 -1.7 0.7 1.1 1.5 1.7610 5.0 4.4 451 3.5 361 2.0 12 576 131.5 127.9 391.9 -1.6 0.8 1.2 1.6 1.8610 6.0 5.3 541 4.2 433 2.0 12 574 146.1 142.5 404.7 -1.5 0.9 1.3 1.8 2.0610 8.0 7.1 722 5.7 578 2.0 12 570 175.1 171.5 430.1 -1.2 1.1 1.6 2.1 2.4610 9.5 7.0 714 5.6 572 2.0 12 567 196.7 193.1 449.1 -1.0 1.2 1.8 2.4 2.7648 4.5 3.8 382 3.0 306 2.0 12 615 132.0 128.2 428.9 -2.0 0.8 1.2 1.6 1.8648 5.0 4.2 425 3.3 340 2.0 12 614 139.8 136.0 435.8 -1.9 0.8 1.3 1.7 1.9648 6.0 5.0 510 4.0 408 2.0 12 612 155.3 151.5 449.4 -1.7 0.9 1.4 1.9 2.1648 8.0 6.7 680 5.3 544 2.0 12 608 186.3 182.4 476.4 -1.4 1.1 1.7 2.2 2.5648 9.5 6.6 672 5.3 538 2.0 12 605 209.3 205.5 496.6 -1.2 1.3 1.9 2.5 2.8660 4.5 3.7 375 2.9 300 2.0 12 627 134.5 130.6 443.1 -2.1 0.8 1.2 1.6 1.8660 5.0 4.1 417 3.3 334 2.0 12 626 142.5 138.6 450.1 -2.0 0.9 1.3 1.7 1.9660 6.0 4.9 500 3.9 400 2.0 12 624 158.3 154.4 463.9 -1.8 0.9 1.4 1.9 2.1660 8.0 6.5 667 5.2 534 2.0 12 620 189.8 185.9 491.5 -1.5 1.1 1.7 2.3 2.6660 9.5 6.5 660 5.2 528 2.0 12 617 213.3 209.4 512.1 -1.3 1.3 1.9 2.6 2.9700 4.5 3.5 354 2.8 283 2.0 12 667 142.8 138.7 492.1 -2.4 0.9 1.3 1.7 1.9700 5.0 3.9 393 3.1 315 2.0 12 666 151.3 147.1 499.4 -2.3 0.9 1.4 1.8 2.0700 6.0 4.6 472 3.7 377 2.0 12 664 168.1 163.9 514.2 -2.2 1.0 1.5 2.0 2.3700 8.0 6.2 629 4.9 503 2.0 12 660 201.5 197.4 543.5 -1.8 1.2 1.8 2.4 2.7700 9.5 6.1 623 4.9 498 2.0 12 657 226.5 222.4 565.3 -1.6 1.4 2.0 2.7 3.1700 12.0 7.7 786 6.2 629 2.0 12 652 267.9 263.8 601.6 -1.2 1.6 2.4 3.2 3.6711 5.0 3.8 387 3.0 310 2.0 12 677 153.7 149.5 513.5 -2.4 0.9 1.4 1.8 2.1711 6.0 4.6 465 3.6 372 2.0 12 675 170.7 166.6 528.4 -2.3 1.0 1.5 2.0 2.3711 8.0 6.1 619 4.9 495 2.0 12 671 204.8 200.6 558.2 -1.9 1.2 1.8 2.5 2.8711 9.5 6.0 613 4.8 490 2.0 12 668 230.1 225.9 580.4 -1.7 1.4 2.1 2.8 3.1711 12.0 7.6 774 6.1 619 2.0 12 663 272.2 268.0 617.3 -1.3 1.6 2.4 3.3 3.7762 5.0 3.5 361 2.8 289 2.0 12 728 164.9 160.4 580.9 -2.9 1.0 1.5 2.0 2.2762 6.0 4.3 433 3.4 347 2.0 12 726 183.2 178.7 597.0 -2.7 1.1 1.6 2.2 2.5762 8.0 5.7 578 4.5 462 2.0 12 722 219.7 215.2 629.0 -2.4 1.3 2.0 2.6 3.0762 9.5 5.6 572 4.5 458 2.0 12 719 247.0 242.5 652.8 -2.1 1.5 2.2 3.0 3.3762 12.0 7.1 722 5.7 578 2.0 12 714 292.2 287.7 692.4 -1.7 1.8 2.6 3.5 3.9
S E C T I O N 7
Pipe Data
WaterFilled Bouyant
Empty Pipe Pipe WeightOD WT Test Pressure Rated Pressure SK CML Bore SKCL UCCL SKCL SKCL Tonnes per Pipe, SKCL
(mm) (mm) (Mpa) (m) (Mpa) (m) (mm) (mm) CML kg/m kg/m kg/m kN/m 6m 9m 12m 13.5m
800 5.0 3.4 344 2.7 275 2.3 16 758 197.0 191.5 648.0 -3.1 1.2 1.8 2.4 2.7800 6.0 4.1 413 3.2 330 2.3 16 756 216.2 210.7 664.8 -2.9 1.3 1.9 2.6 2.9800 8.0 5.4 550 4.3 440 2.3 16 752 254.4 249.0 698.4 -2.5 1.5 2.3 3.1 3.4800 9.5 5.3 545 4.3 436 2.3 16 749 283.0 277.6 723.4 -2.2 1.7 2.5 3.4 3.8800 12.0 6.8 688 5.4 550 2.3 16 744 330.4 325.0 764.9 -1.7 2.0 3.0 4.0 4.5813 5.0 3.3 339 2.7 271 2.3 16 771 200.2 194.7 666.8 -3.2 1.2 1.8 2.4 2.7813 6.0 4.0 406 3.2 325 2.3 16 769 219.7 214.2 684.0 -3.0 1.3 2.0 2.6 3.0813 7.0 4.6 474 3.7 379 2.3 16 767 239.2 233.7 701.0 -2.8 1.4 2.2 2.9 3.2813 8.0 5.3 542 4.3 433 2.3 16 765 258.7 253.2 718.1 -2.6 1.6 2.3 3.1 3.5813 9.5 5.3 536 4.2 429 2.3 16 762 287.7 282.2 743.5 -2.3 1.7 2.6 3.5 3.9813 12.0 6.6 677 5.3 542 2.3 16 757 335.9 330.4 785.8 -1.9 2.0 3.0 4.0 4.5914 6.0 3.5 361 2.8 289 2.3 16 870 247.6 241.4 841.7 -4.1 1.5 2.2 3.0 3.3914 7.0 4.1 422 3.3 337 2.3 16 868 269.6 263.4 861.0 -3.9 1.6 2.4 3.2 3.6914 8.0 4.7 482 3.8 385 2.3 16 866 291.5 285.3 880.2 -3.6 1.7 2.6 3.5 3.9914 10.0 4.9 502 3.9 402 2.3 16 862 335.2 329.0 918.5 -3.2 2.0 3.0 4.0 4.5914 12.0 5.9 602 4.7 482 2.3 16 858 378.7 372.5 956.6 -2.8 2.3 3.4 4.5 5.1960 6.0 3.4 344 2.7 275 2.3 16 916 260.3 253.7 918.9 -4.6 1.6 2.3 3.1 3.5960 8.0 4.5 459 3.6 367 2.3 16 912 306.4 299.9 959.3 -4.2 1.8 2.8 3.7 4.1960 10.0 4.7 478 3.8 382 2.3 16 908 352.4 345.9 999.6 -3.7 2.1 3.2 4.2 4.8960 12.0 5.6 573 4.5 459 2.3 16 904 398.2 391.7 1039.7 -3.3 2.4 3.6 4.8 5.4972 6.0 3.3 340 2.7 272 2.3 16 928 263.6 257.0 939.6 -4.8 1.6 2.4 3.2 3.6972 8.0 4.4 453 3.6 362 2.3 16 924 310.3 303.7 980.5 -4.3 1.9 2.8 3.7 4.2972 10.0 4.6 472 3.7 378 2.3 16 920 356.9 350.3 1021.3 -3.8 2.1 3.2 4.3 4.8972 12.0 5.6 566 4.4 453 2.3 16 916 403.3 396.7 1061.9 -3.4 2.4 3.6 4.8 5.41016 8.0 4.3 433 3.4 347 2.3 16 968 324.6 317.7 1060.2 -4.8 1.9 2.9 3.9 4.41016 10.0 4.4 451 3.5 361 2.3 16 964 373.4 366.5 1102.9 -4.4 2.2 3.4 4.5 5.01016 12.0 5.3 542 4.3 433 2.3 16 960 421.9 415.0 1145.4 -3.9 2.5 3.8 5.1 5.71035 8.0 4.2 425 3.3 340 2.3 16 987 330.8 323.8 1095.5 -5.1 2.0 3.0 4.0 4.51035 10.0 4.3 443 3.5 355 2.3 16 983 380.5 373.4 1139.0 -4.6 2.3 3.4 4.6 5.11035 12.0 5.2 532 4.2 425 2.3 16 979 429.9 422.9 1182.3 -4.1 2.6 3.9 5.2 5.81067 8.0 4.0 413 3.2 330 2.3 16 1019 341.2 333.9 1156.3 -5.5 2.0 3.1 4.1 4.61067 10.0 4.2 430 3.4 344 2.3 16 1015 392.4 385.2 1201.2 -5.0 2.4 3.5 4.7 5.31067 12.0 5.1 516 4.0 413 2.3 16 1011 443.5 436.3 1245.9 -4.5 2.7 4.0 5.3 6.01085 8.0 4.0 406 3.2 325 2.3 16 1037 347.0 339.7 1191.2 -5.7 2.1 3.1 4.2 4.71085 10.0 4.1 423 3.3 338 2.3 16 1033 399.2 391.8 1236.8 -5.2 2.4 3.6 4.8 5.41085 12.0 5.0 507 4.0 406 2.3 16 1029 451.1 443.8 1282.3 -4.7 2.7 4.1 5.4 6.11125 8.0 3.8 391 3.1 313 2.3 16 1077 360.0 352.4 1270.6 -6.3 2.2 3.2 4.3 4.91125 10.0 4.0 408 3.2 326 2.3 16 1073 414.1 406.5 1317.9 -5.8 2.5 3.7 5.0 5.61125 12.0 4.8 489 3.8 391 2.3 16 1069 468.1 460.4 1365.1 -5.2 2.8 4.2 5.6 6.31200 8.0 3.6 367 2.9 294 2.3 16 1152 384.4 376.3 1426.2 -7.4 2.3 3.5 4.6 5.21200 10.0 3.8 382 3.0 306 2.3 16 1148 442.2 434.1 1476.8 -6.8 2.7 4.0 5.3 6.01200 12.0 4.5 459 3.6 367 2.3 16 1144 499.8 491.7 1527.2 -6.3 3.0 4.5 6.0 6.71219 8.0 3.5 361 2.8 289 2.3 16 1171 390.6 382.3 1467.0 -7.7 2.3 3.5 4.7 5.3
S E C T I O N 7 | 47
WaterFilled Bouyant
Empty Pipe Pipe WeightOD WT Test Pressure Rated Pressure SK CML Bore SKCL UCCL SKCL SKCL Tonnes per Pipe, SKCL(mm) (mm) (Mpa) (m) (Mpa) (m) (mm) (mm) CML kg/m kg/m kg/m kN/m 6m 9m 12m 13.5m1219 9 3.3 339 2.7 271 2.3 16 1169 420.0 411.7 1492.7 -7.4 2.5 3.8 5.0 5.71219 10 3.7 376 3.0 301 2.3 16 1167 449.3 441.0 1518.4 -7.1 2.7 4.0 5.4 6.11219 12 4.4 452 3.5 361 2.3 16 1163 507.9 499.6 1569.6 -6.5 3.0 4.6 6.1 6.91283 8 3.4 343 2.7 275 2.3 19 1229 439.3 430.6 1625.0 -8.5 2.6 4.0 5.3 5.91283 10 3.5 358 2.8 286 2.3 19 1225 501.1 492.4 1679.1 -7.9 3.0 4.5 6.0 6.81283 12 4.2 429 3.4 343 2.3 19 1221 562.7 554.0 1733.0 -7.2 3.4 5.1 6.8 7.61283 16 5.6 572 4.5 458 2.3 19 1213 685.3 676.6 1840.4 -6.0 4.1 6.2 8.2 9.31290 8 3.3 341 2.7 273 2.3 19 1236 441.7 432.9 1640.9 -8.6 2.7 4.0 5.3 6.01290 10 3.5 356 2.8 284 2.3 19 1232 503.9 495.1 1695.3 -8.0 3.0 4.5 6.0 6.81290 12 4.2 427 3.3 341 2.3 19 1228 565.8 557.1 1749.6 -7.4 3.4 5.1 6.8 7.61290 16 5.6 569 4.5 455 2.3 19 1220 689.2 680.4 1857.6 -6.1 4.1 6.2 8.3 9.31404 10 3.2 327 2.6 261 2.3 19 1346 549.1 539.6 1971.3 -9.9 3.3 4.9 6.6 7.41404 12 3.8 392 3.1 314 2.3 19 1342 616.7 607.2 2030.4 -9.2 3.7 5.6 7.4 8.31422 10 3.2 323 2.5 258 2.3 19 1364 556.2 546.6 2016.7 -10.2 3.3 5.0 6.7 7.51422 11 3.5 355 2.8 284 2.3 19 1362 590.5 580.9 2046.7 -9.9 3.5 5.3 7.1 8.01422 12 3.8 387 3.0 310 2.3 19 1360 624.7 615.1 2076.6 -9.5 3.7 5.6 7.5 8.41440 10 3.1 319 2.5 255 2.3 19 1382 563.4 553.6 2062.7 -10.5 3.4 5.1 6.8 7.61440 12 3.8 382 3.0 306 2.3 19 1378 632.7 623.0 2123.4 -9.9 3.8 5.7 7.6 8.51440 16 5.0 510 4.0 408 2.3 19 1370 770.9 761.1 2244.2 -8.5 4.6 6.9 9.3 10.41451 10 3.1 316 2.5 253 2.3 19 1393 567.7 557.9 2091.0 -10.7 3.4 5.1 6.8 7.71451 12 3.7 379 3.0 303 2.3 19 1389 637.7 627.8 2152.2 -10.1 3.8 5.7 7.7 8.61451 16 5.0 506 4.0 405 2.3 19 1381 776.9 767.0 2274.0 -8.7 4.7 7.0 9.3 10.51500 10 3.0 306 2.4 245 2.3 19 1442 587.2 577.0 2219.5 -11.7 3.5 5.3 7.0 7.91500 12 3.6 367 2.9 294 2.3 19 1438 659.5 649.3 2282.8 -11.0 4.0 5.9 7.9 8.91500 16 4.8 489 3.8 391 2.3 19 1430 803.6 793.4 2408.8 -9.6 4.8 7.2 9.6 10.81575 10 2.9 291 2.3 233 2.3 19 1517 617.0 606.3 2423.5 -13.2 3.7 5.6 7.4 8.31575 12 3.4 349 2.7 280 2.3 19 1513 693.0 682.3 2490.0 -12.4 4.2 6.2 8.3 9.41575 16 4.6 466 3.7 373 2.3 19 1505 844.4 833.7 2622.5 -10.9 5.1 7.6 10.1 11.41600 10 2.8 287 2.3 229 2.3 19 1542 626.9 616.0 2493.4 -13.7 3.8 5.6 7.5 8.51600 12 3.4 344 2.7 275 2.3 19 1538 704.1 693.3 2561.0 -12.9 4.2 6.3 8.4 9.51600 16 4.5 459 3.6 367 2.3 19 1530 858.0 847.2 2695.6 -11.4 5.1 7.7 10.3 11.61626 10 2.8 282 2.2 226 2.3 19 1568 637.2 626.2 2567.2 -14.2 3.8 5.7 7.6 8.61626 12 3.3 339 2.7 271 2.3 19 1564 715.7 704.7 2635.9 -13.5 4.3 6.4 8.6 9.71626 16 4.4 451 3.5 361 2.3 19 1556 872.2 861.2 2772.8 -11.9 5.2 7.8 10.5 11.81750 12 3.1 315 2.5 252 2.3 19 1688 771.1 759.2 3007.8 -16.1 4.6 6.9 9.3 10.41750 16 4.1 419 3.3 336 2.3 19 1680 939.8 927.9 3155.3 -14.5 5.6 8.5 11.3 12.71829 12 3.0 301 2.4 241 2.3 19 1767 806.3 793.9 3257.3 -18.0 4.8 7.3 9.7 10.91829 16 3.9 401 3.1 321 2.3 19 1759 982.8 970.4 3411.7 -16.2 5.9 8.8 11.8 13.31981 12 2.7 278 2.2 222 2.3 19 1919 874.1 860.7 3764.9 -21.8 5.2 7.9 10.5 11.81981 16 3.6 370 2.9 296 2.3 19 1911 1065.6 1052.2 3932.4 -19.9 6.4 9.6 12.8 14.42159 12 2.5 255 2.0 204 2.3 19 2097 953.5 938.9 4405.5 -26.7 5.7 8.6 11.4 12.92159 16 3.3 340 2.7 272 2.3 19 2089 1162.6 1147.9 4588.3 -24.6 7.0 10.5 14.0 15.7
48 | S E C T I O N 7
Key:OD = Outside diameter of the steel pipe shell. Does not include SINTAKOTE thicknessWT = Thickness of steelSK = Thickness of SINTAKOTE external coatingCML = Thickness of cement mortar liningSKCL = SINTAKOTE cement mortar liningUCCL = Uncoated cement mortar liningRated Pressure = Maximum allowable operating internal pressure for SINTAJOINT and welded joint pipelinesTest Pressure = Maximum internal pressure each SINTAJOINT and welded joint pipe is tested to during manufacturing
S E C T I O N 7 | 49
50 | S E C T I O N 7
Table 7.2. SINTALOCK joint rated pressure
Note: For further sizes please contact your local Tyco Water regional marketing office.
SINTALOCKPipe Wall Steel Rated Steel RatedOD Thickness Yield Pressure Yield Pressure
WT(mm) (mm) (MPa) (MPa) (MPa) (MPa)324 4.5 300 3.0 350 3.5324 5.0 300 3.3 350 3.9324 6.0 300 4.0 350 4.7337 4.5 300 2.9 350 3.4337 5.0 300 3.2 350 3.7337 6.0 300 3.8 350 4.5356 4.5 300 2.7 350 3.2356 5.0 300 3.0 350 3.5356 6.0 300 3.6 350 4.2406 4.5 300 2.4 350 2.5406 5.0 300 2.7 350 3.1406 6.0 300 3.2 350 3.7419 4.5 300 2.3 350 2.4419 5.0 300 2.6 350 3.0419 6.0 300 3.1 350 3.6457 4.5 300 2.1 350 2.2457 5.0 300 2.4 350 2.8457 6.0 300 2.8 350 3.3457 8.0 300 3.8 350502 4.5 300 1.9 350 2.0502 5.0 300 2.2 350 2.2502 6.0 300 2.6 350 3.0502 8.0 300 3.4 350508 4.5 300 1.9 350 2.0508 5.0 300 2.1 350 2.2508 6.0 300 2.6 350 3.0508 8.0 300 3.4 350559 4.5 300 1.7 350 1.8559 5.0 300 1.9 350 2.0559 6.0 300 2.3 350 2.7559 8.0 300 3.1 350610 4.5 300 1.6 350 1.7610 5.0 300 1.8 350 1.8610 6.0 300 2.1 350 2.5610 8.0 300 2.8 350648 4.5 300 1.5 350 1.6648 5.0 300 1.7 350 1.7648 6.0 300 2.0 350 2.3648 8.0 300 2.7 350648 9.5 250 2.6 350
Pipe Wall Steel Rated Steel RatedOD Thickness Yield Pressure Yield Pressure
WT(mm) (mm) (MPa) (MPa) (MPa) (MPa)660 4.5 300 1.5 350 1.5660 5.0 300 1.6 350 1.7660 6.0 300 2.0 350 2.3660 8.0 300 2.6 350660 9.5 250 2.6 350700 4.5 300 1.4 350 1.4700 5.0 300 1.5 350 1.6700 6.0 300 1.9 350 2.2700 8.0 300 2.5 350711 5.0 300 1.5 350 1.6711 6.0 300 1.8 350 2.1711 8.0 300 2.4 350711 9.5 250 2.4 350762 5.0 300 1.4 350 1.5762 6.0 300 1.7 350 1.8762 8.0 300 2.3 350800 5.0 300 1.4 350 1.4800 6.0 300 1.6 350 1.7800 8.0 300 2.2 350813 5.0 300 1.3 350 1.4813 6.0 300 1.6 350 1.7813 7.0 300 1.9 350813 8.0 300 2.1 350813 9.5 250 2.1 350914 6.0 300 1.4 350 1.5914 7.0 300 1.7 350914 8.0 300 1.9 350914 10.0 250 2.0 350960 6.0 300 1.4 350 1.4960 8.0 300 1.8 350960 10.0 250 1.9 350972 6.0 300 1.3 350 1.4972 8.0 300 1.8 350972 10.0 250 1.9 3501016 8.0 300 1.7 3501016 10.0 250 1.8 3501035 8.0 300 1.7 3501035 10.0 250 1.7 3501067 8.0 300 1.6 3501067 10.0 250 1.7 350
SINTALOCK
S E C T I O N 7 | 51
S E C T I O N 7
Pipe Data
Pipe Wall Steel RatedOD Thickness Yield Pressure
WT(mm) (mm) (MPa) (MPa)1085 8.0 300 1.61085 10.0 250 1.71125 8.0 300 1.51125 10.0 250 1.61200 8.0 300 1.41200 10.0 250 1.51219 8.0 300 1.41219 9.0 250 1.31219 10.0 250 1.5
Pipe Wall Steel RatedOD Thickness Yield Pressure
WT(mm) (mm) (MPa) (MPa)1283 8.0 300 1.31283 10.0 250 1.41290 8.0 300 1.31290 10.0 250 1.41404 10.0 250 1.31422 10.0 250 1.31422 11.0 250 1.41440 10.0 250 1.3
StructuralPropertiesof Pipe
52
section8
54 | S E C T I O N 8
8.1 StandardsA list of applicable Australian Standards used in steel pipe designand specification is included in Section 2.
8.2 Recommended maximum internalpressuresAll pipe manufactured to AS 1579 is hydrostatically proof tested inthe factory to 90% MYS. Table 7.1 lists recommended maximumrated pressures for SINTAJOINT and welded joint pipes.
Pressure formulaThe Barlow formulae given below were used to calculate themaximum test and maximum working pressures respectively,shown in Table 7.1.
a) Strength test pressure Pt = 0.90 (2 MYS x t) = 1.25 PrDo
b) Rated pressure Pr = 0.72 (2 MYS x t)Do
c) Hoop stress σh = PtDo or = PrDo2t 2t
wherePt = field test internal pressures MPaPr = internal pressure MPat = steel wall thickness mmDo = outside diameter of steel shell mmσh = hoop stress MPaMYS = minimum yield strength MPa
The lining has been ignored in the calculation of pressures for CMLpipe. The steel shell is assumed to act alone.
Steel strengthThe Nominal Minimum Yield Strength (NMYS) values used for thethicknesses given in Table 8.1 are given in Table 6.5.
Table 8.1 - Maximum recommended steel hoop stresses
Steel hoop stress σh
The maximum recommended steel hoop stresses at variousservice pressures are given in Table 8.1.
Rated pressure refers to the maximum hydrostatic pressure atwhich the pipe or fitting is suitable for sustained operation,including an allowance for transient pressures.
The recommended maximum field test pressure is limited to the Manufacturing Proof Test as defined in AS 1579 (90% ofMYS). Typically the field test pressure would be 1.25 x maximumworking pressure.
Hydrostatic pressure limitsThe hydrostatic pressures calculated on the basis of the allowable steelhoop stresses given in Table 8.1 are subject to the following limits:Pt = 8.5 MPaPr = 6.8 MPa
The limits apply principally to pipe with D/t ratios less than 50 andrarely occur. They are set in consideration of the practicality ofachieving the test pressures necessary to reach the relevant steelwall proving stress.
8.3 Ring stiffnessCorrectly designed and installed buried flexible pipes deflect underload, to be restrained by passive pressure from the surroundingsoil. See Figure 8.1.
The installation is a composite pipe-soil structure acting integrallyto carry imposed loads.
The degree to which the pipe depends on the soil for support is afunction of the ring stiffness of the pipe. Ring stiffness is alsorequired to resist buckling.
For the purpose of calculating ring stiffness of pipes, the outsidediameter has been used. This simplifies calculation and givesconservative values.
Stiffness as a function of DA common form of calculating ring stiffness, as a function ofdiameter, SD, is:SD = E I x 106 N/m/m
Dm3
whereSD = ring bending stiffness measured in N/m of deflection per mof pipe N/m/mE = Modulus of elasticity for the steel or composite steel-cementmortar lining MPa t = steel wall thickness mmI = second moment of area of the pipe wall section per unit lengthof pipe
= t3 mm4/mm12
Category Maximum Recommended Steel Hoop Stress
(%MYS) (MPa)t ≤ 8mm 8 < t ≤ 16mm
Manufacture Proof / 90 270 225 Strength Test Pressure, Pt
Rated Pressure, Pr 72 216 180
S E C T I O N 8 | 55
Δ
% Deflection = Δ / Dm
Bedding reaction
Pipe section afterbackfill and compaction
loading
Pipe section before backfill and
compaction
S E C T I O N 8
Structural Properties of Pipe
Figure 8.1 - Flexible pipe deflection
Pipe Type Pipe OD range CML Design Limit Maximum field measurement
mm Pipe body Joint
Welded Pipe 114 - 2500 No The lesser of 0.00014 x SMYS* x D/t and 5% Design Limit Design Limit
Welded Pipe 114 – 2500 Yes The lesser of 0.00014 x SMYS* x D/t and 4% Design Limit Design Limit
RRJ-S Pipe 324 – 1290 Yes The lesser of 0.00014 x SMYS* x D/t and 4% Design Limit 80% of Design Limit
(for 648mm, reducing to 2.8% for 1290mm)
RRJ-S Sintalock 324 – 1440 Yes The lesser of 0.00014 x SMYS* x D/t and 4% Design Limit 80% of Design Limit
(for 648mm, reducing to 2.5% for 1440mm)
RRJ-D Pipe 1200 - 1829 Yes The lesser of 0.00014 x SMYS* x D/t and 4% Design Limit 80% of Design Limit
Dm = mean diameter of pipe = D-t mmD = pipe outside diameter mm
Simplified, this can also be expressed asSD = E x ( t )3 x 106
12 Dm
an inverse function of the Dm /t ratio.This is the ring stiffness that is used in the deflection analysis ofburied pipes.
Moduli for elasticityYoung's Modulus for steel is taken as 207,000 MPa.Young's Modulus for cement mortar lining is taken as 21,000 MPa.
Transformed sectionYoung's Modulus for the composite steel-cement mortar lining isaccounted for by transforming the cement mortar lining thickness tothe equivalent thickness of steel using the ratio of respective moduli.
teq = t + T (Ecl ) mmEst
whereteq = transformed pipe wall thickness mm
t = steel pipe wall thickness mmT = cement lining thickness mmEcl = Young’s Modulus for cement mortar = 21,000 GPaEst = Young’s Modulus for steel = 207,000 GPa
Thus
teq = t + 0.1 T mm
This transformation is not meant to account for the cementlined steel shell acting as a monolithic composite. A stricttransformation to account for this structural action wouldassume perfect bonding at the cement-steel interface andintegral ring action of the cement mortar lining. The transformedsection would be a 'T' shape and have a much greater second moment of area.
The simplified teq transformation above results in a conservativeestimate of the stiffness contribution by the cement mortar lining.
Table 8.3 lists stiffness values as functions of radius and diameterfor bare steel shells and composite cement mortar lined steelshells. Dm /t ratios are also listed for reference, included in table 8.3.
Table 8.2 - Summary of deflections for steel pipe
Note: 1) Field measurements should only be made at positions where at least half a pipe length is buried either side of the measurement position
2) The joint region is ± 150mm from either side of the pipe joint
* Specified Minimum Yield Strength (SMYS) or Nominal Minimum Yield Strength (NMYS)
56 | S E C T I O N 8
8.4 Critical buckling pressureThe critical buckling pressure, Pcr for unsupported pipe issometimes required to assess structural stability under loads thatmay give rise to unsupported buckling of the pipe, due toaccidental removal of the soil support. Probability of such an eventand its inclusion as a performance criterion must be assessed bythe Design Engineer.
Pcr required to cause buckling of an unsupported pipe can be
calculated using the Timoshenko buckling equation.
Pcr = 24 SD x 10-3 kPa
FS (1-ν2)
wherePcr = critical external pressure required to cause buckling kPaFS = a factor of safety, normally equal to 2.5SD = pipe ring stiffness as a function of the diameter N/m/mν = Poisson’s Ratio = 0.27
This equation ignores the assistance of soil support (see Section13.6.)
Table 8.3 lists critical buckling pressures described above for baresteel shells and composite cement mortar lined steel shells.
Out of round effectsRing buckling resistance of unsupported pipe will be reduced bythe degree of out of roundness or deflection reached immediatelyprior to the onset of buckling. The reduction may be calculatedfrom:
SDcr = E I x 106 N/m/mDB
3
The crown radius of curvature and the corresponding diameter ofthe deformed pipe can be calculated fromDB = D (1 + Df x Δ )
D
whereDB = pipe diameter deformed mmD = pipe diameter undeformed mmΔ = pipe deflection mmDf = shape factor (ref Sect. 13.4 )
3.33 x 10-6 (SDL ) + 0.00136E’
1.11 x 10-6 (SDL ) + 0.000151E’
E’ = effective combined soil modulus MPa
8.5 Beam section propertiesIn beam bending analyses and Table 14.1 the contribution to beamstiffness by the cement mortar lining has been ignored. The sectionproperties of steel shell only have been used.
Actual short term beam deflections will thus be smaller thancalculated, however long term deflections are likely to be realiseddue to creep of the CML.
The contribution of SINTAKOTE to structural properties is negligibleand has been ignored.
The second moment of area I, of the steel shell for beam bendingis calculated from:I = π x (D4-d4) mm4
64
= πrm3t
where I = the second moment of area of the pipe cross section mm4
D = outside diameter of the pipe mmd = inside diameter of the pipe mm
rm= pipe mean radius = (D-t) mm2
The elastic section modulus Z, of the steel shell for beam bendingis calculated from:Z = p (D4-d4) mm3
(32 D)
= 2 x ID
= πrm2t
where Z = the elastic section modulus mm3
D = outside diameter of the pipe mmd = inside diameter of the pipe mm
rm = pipe mean radius = (D-t) mm2
p = density kg/m3
Table 8.3 lists the section properties I and Z described above forbare steel shells.
=
Table 8.3 – Structural properties of steel pipes
S E C T I O N 8
Structural Properties of Pipe
S E C T I O N 8 | 57
Pipe Dimensions Pipe Shell Composite shell and liningShell CML SK Ring Stiffness Beam bending Ring Stiffness
OD t T ts Dm/t SD Pcr I x 106 Z x 103 teq Dm/teq SD Pcrmm mm mm mm N/m/m kPa mm4 mm3 mm N/m/m kPa114 4.8 9 1.6 22.8 1,465,025 15,170 2 43 5.7 19.2 2,453,272 25,403168 5.0 9 1.6 32.6 497,893 5,156 8 101 5.9 27.6 818,055 8,471190 5.0 9 1.6 37.0 340,552 3,526 12 131 5.9 31.4 559,538 5,794219 5.0 9 1.6 42.8 220,018 2,278 19 176 5.9 36.3 361,496 3,743240 5.0 9 1.6 47.0 166,148 1,720 25 212 5.9 39.8 272,987 2,827257 5.0 9 1.6 50.4 134,740 1,395 31 244 5.9 42.7 221,383 2,292273 5.0 9 1.6 53.6 112,020 1,160 38 277 5.9 45.4 184,052 1,906290 5.0 12 1.8 57.0 93,146 965 45 313 6.2 46.0 177,595 1,839324 4.0 12 1.8 80.0 33,691 349 51 318 5.2 61.5 74,020 766324 4.5 12 1.8 71.0 48,196 499 58 356 5.7 56.1 97,949 1,014324 5.0 12 1.8 63.8 66,424 688 64 393 6.2 51.5 126,646 1,311324 6.0 12 1.8 53.0 115,867 1,200 76 467 7.2 44.2 200,219 2,073337 4.0 12 1.8 83.3 29,898 310 58 344 5.2 64.0 65,685 680337 4.5 12 1.8 73.9 42,761 443 65 385 5.7 58.3 86,904 900337 5.0 12 1.8 66.4 58,923 610 72 426 6.2 53.5 112,344 1,163337 6.0 12 1.8 55.2 102,745 1,064 85 507 7.2 46.0 177,543 1,838356 4.0 12 1.8 88.0 25,313 262 68 385 5.2 67.7 55,612 576356 4.5 12 1.8 78.1 36,195 375 77 431 5.7 61.7 73,559 762356 5.0 12 1.8 70.2 49,863 516 85 477 6.2 56.6 95,070 984356 6.0 12 1.8 58.3 86,904 900 101 567 7.2 48.6 150,170 1,555406 4.0 12 1.8 100.5 16,994 176 102 502 5.2 77.3 37,335 387406 4.5 12 1.8 89.2 24,287 251 114 563 5.7 70.4 49,358 511406 5.0 12 1.8 80.2 33,440 346 127 623 6.2 64.7 63,757 660406 6.0 12 1.8 66.7 58,219 603 151 742 7.2 55.6 100,602 1,042406 8.0 12 1.8 49.8 140,091 1,451 198 975 9.2 43.3 213,061 2,206419 4.0 12 1.8 103.8 15,446 160 112 536 5.2 79.8 33,936 351419 4.5 12 1.8 92.1 22,073 229 126 600 5.7 72.7 44,858 464419 5.0 12 1.8 82.8 30,388 315 139 665 6.2 66.8 57,938 600419 6.0 12 1.8 68.8 52,892 548 166 792 7.2 57.4 91,398 946419 8.0 12 1.8 51.4 127,214 1,317 218 1,041 9.2 44.7 193,476 2,003457 4.0 12 1.8 113.3 11,876 123 146 639 5.2 87.1 26,092 270457 4.5 12 1.8 100.6 16,966 176 164 716 5.7 79.4 34,479 357457 5.0 12 1.8 90.4 23,350 242 181 793 6.2 72.9 44,519 461457 6.0 12 1.8 75.2 40,618 421 216 945 7.2 62.6 70,187 727457 8.0 12 1.8 56.1 97,571 1,010 284 1,244 9.2 48.8 148,393 1,537502 4.0 12 1.8 124.5 8,939 93 194 773 5.2 95.8 19,639 203502 4.5 12 1.8 110.6 12,766 132 217 866 5.7 87.3 25,944 269502 5.0 12 1.8 99.4 17,564 182 241 960 6.2 80.2 33,488 347502 6.0 12 1.8 82.7 30,535 316 287 1145 7.2 68.9 52,764 546502 8.0 12 1.8 61.8 73,262 759 379 1508 9.2 53.7 111,422 1,154508 4.0 12 1.8 126.0 8,623 89 201 791 5.2 96.9 18,946 196508 4.5 12 1.8 111.9 12,315 128 225 888 5.7 88.3 25,027 259508 5.0 12 1.8 100.6 16,943 175 250 983 6.2 81.1 32,304 335
58 | S E C T I O N 8
Pipe Dimensions Pipe Shell Composite shell and liningShell CML SK Ring Stiffness Beam bending Ring Stiffness
OD t T ts Dm/t SD Pcr I x 106 Z x 103 teq Dm/teq SD Pcrmm mm mm mm N/m/m kPa mm4 mm3 mm N/m/m kPa508 6.0 12 1.8 83.7 29,453 305 298 1,173 7.2 69.7 50,895 527508 8.0 12 1.8 62.5 70,656 732 393 1,545 9.2 54.3 107,459 1,113559 4.0 12 2 138.8 6,458 67 268 960 5.2 106.7 14,188 147559 4.5 12 2 123.2 9,220 95 301 1,077 5.7 97.3 18,737 194559 5.0 12 2 110.8 12,681 131 334 1,194 6.2 89.4 24,179 250559 6.0 12 2 92.2 22,033 228 398 1,425 7.2 76.8 38,072 394559 8.0 12 2 68.9 52,796 547 525 1,879 9.2 59.9 80,297 831610 4.5 12 2 134.6 7,081 73 392 1,286 5.7 106.2 14,390 149610 5.0 12 2 121.0 9,737 101 435 1,425 6.2 97.6 18,565 192610 6.0 12 2 100.7 16,910 175 519 1,701 7.2 83.9 29,220 303610 8.0 12 2 75.3 40,483 419 685 2,246 9.2 65.4 61,569 638610 9.5 12 2 63.2 68,300 707 807 2,647 10.7 56.1 97,589 1,011648 4.5 12 2 143.0 5,899 61 471 1,453 5.7 112.9 11,989 124648 5.0 12 2 128.6 8,111 84 522 1,610 6.2 103.7 15,464 160648 6.0 12 2 107.0 14,081 146 623 1,923 7.2 89.2 24,332 252648 8.0 12 2 80.0 33,691 349 823 2,541 9.2 69.6 51,240 531648 9.5 12 2 67.2 56,817 588 971 2,996 10.7 59.7 81,182 841660 4.5 12 2 145.7 5,581 58 497 1,507 5.7 115.0 11,342 117660 5.0 12 2 131.0 7,673 79 551 1,671 6.2 105.6 14,630 151660 6.0 12 2 109.0 13,320 138 659 1,996 7.2 90.8 23,017 238660 8.0 12 2 81.5 31,865 330 870 2,637 9.2 70.9 48,463 502660 9.5 12 2 68.5 53,730 556 1,026 3,110 10.7 60.8 76,771 795700 4.5 12 2 154.6 4,672 48 594 1,698 5.7 122.0 9,496 98700 5.0 12 2 139.0 6,423 67 659 1,882 6.2 112.1 12,246 127700 6.0 12 2 115.7 11,147 115 787 2,249 7.2 96.4 19,262 199700 8.0 12 2 86.5 26,653 276 1,041 2,973 9.2 75.2 40,535 420700 9.5 12 2 72.7 44,923 465 1,228 3,507 10.7 64.5 64,187 665700 12.0 12 2 57.3 91,531 948 1,534 4,382 13.2 52.1 121,828 1,262711 5.0 12 2 141.2 6,128 63 691 1,943 6.2 113.9 11,683 121711 6.0 12 2 117.5 10,633 110 825 2,321 7.2 97.9 18,375 190711 8.0 12 2 87.9 25,421 263 1,091 3,069 9.2 76.4 38,662 400711 9.5 12 2 73.8 42,843 444 1,287 3,621 10.7 65.6 61,215 634711 12.0 12 2 58.3 87,277 904 1,609 4,525 13.2 53.0 116,166 1,203762 5.0 12 2 151.4 4,971 51 851 2,234 6.2 122.1 9,477 98762 6.0 12 2 126.0 8,623 89 1,018 2,671 7.2 105.0 14,901 154762 8.0 12 2 94.3 20,604 213 1,346 3,533 9.2 82.0 31,336 324762 9.5 12 2 79.2 34,709 359 1,589 4,170 10.7 70.3 49,593 514762 12.0 12 2 62.5 70,656 732 1,987 5,215 13.2 56.8 94,043 974800 5.0 16 2.3 159.0 4,291 44 986 2,465 6.6 120.5 9,870 102800 6.0 16 2.3 132.3 7,444 77 1,179 2,947 7.6 104.5 15,128 157800 8.0 16 2.3 99.0 17,778 184 1,560 3,900 9.6 82.5 30,720 318800 9.5 16 2.3 83.2 29,940 310 1,842 4,605 11.1 71.2 47,759 495800 12.0 16 2.3 65.7 60,919 631 2,305 5,762 13.6 57.9 88,680 918813 5.0 16 2.3 161.6 4,088 42 1,035 2,547 6.6 122.4 9,401 97
S E C T I O N 8 | 59
S E C T I O N 8
Structural Properties of Pipe
Pipe Dimensions Pipe Shell Composite shell and liningShell CML SK Ring Stiffness Beam bending Ring Stiffness
OD t T ts Dm/t SD Pcr I x 106 Z x 103 teq Dm/teq SD Pcrmm mm mm mm N/m/m kPa mm4 mm3 mm N/m/m kPa813 6.0 16 2.3 134.5 7,090 73 1,238 3,045 7.6 106.2 14,408 149813 7.0 16 2.3 115.1 11,300 117 1,439 3,539 8.6 93.7 20,955 217813 8.0 16 2.3 100.6 16,931 175 1,638 4,030 9.6 83.9 29,256 303813 9.5 16 2.3 84.6 28,510 295 1,934 4,758 11.1 72.4 45,478 471813 12.0 16 2.3 66.8 58,001 601 2,421 5,955 13.6 58.9 84,432 874914 6.0 16 2.3 151.3 4,977 52 1,763 3,858 7.6 119.5 10,115 105914 7.0 16 2.3 129.6 7,930 82 2,050 4,486 8.6 105.5 14,705 152914 8.0 16 2.3 113.3 11,876 123 2,335 5,110 9.6 94.4 20,522 213914 10.0 16 2.3 90.4 23,350 242 2,900 6,345 11.6 77.9 36,447 377914 12.0 16 2.3 75.2 40,618 421 3,457 7,564 13.6 66.3 59,127 612960 6.0 16 2.3 159.0 4,291 44 2,045 4,260 7.6 125.5 8,721 90960 8.0 16 2.3 119.0 10,236 106 2,709 5,644 9.6 99.2 17,689 183960 10.0 16 2.3 95.0 20,120 208 3,365 7,011 11.6 81.9 31,405 325960 12.0 16 2.3 79.0 34,987 362 4,013 8,360 13.6 69.7 50,931 527972 6.0 16 2.3 161.0 4,133 43 2,123 4,368 7.6 127.1 8,400 87972 8.0 16 2.3 120.5 9,859 102 2,813 5,788 9.6 100.4 17,036 176972 10.0 16 2.3 96.2 19,376 201 3,494 7,190 11.6 82.9 30,244 313972 12.0 16 2.3 80.0 33,691 349 4,167 8,574 13.6 70.6 49,045 5081016 8.0 16 2.3 126.0 8,623 89 3,216 6,331 9.6 105.0 14,901 1541016 10.0 16 2.3 100.6 16,943 175 3,996 7,866 11.6 86.7 26,447 2741016 12.0 16 2.3 83.7 29,453 305 4,767 9,383 13.6 73.8 42,875 4441035 8.0 16 2.3 128.4 8,154 84 3,401 6,573 9.6 107.0 14,089 1461035 10.0 16 2.3 102.5 16,018 166 4,227 8,168 11.6 88.4 25,003 2591035 12.0 16 2.3 85.3 27,842 288 5,043 9,744 13.6 75.2 40,530 4201067 8.0 16 2.3 132.4 7,437 77 3,729 6,990 9.6 110.3 12,850 1331067 10.0 16 2.3 105.7 14,607 151 4,635 8,688 11.6 91.1 22,800 2361067 12.0 16 2.3 87.9 25,385 263 5,531 10,367 13.6 77.6 36,953 3831085 8.0 16 2.3 134.6 7,070 73 3,923 7,231 9.6 112.2 12,217 1271085 10.0 16 2.3 107.5 13,886 144 4,876 8,988 11.6 92.7 21,674 2241085 12.0 16 2.3 89.4 24,129 250 5,819 10,726 13.6 78.9 35,124 3641125 8.0 16 2.3 139.6 6,337 66 4,376 7,780 9.6 116.4 10,951 1131125 10.0 16 2.3 111.5 12,444 129 5,441 9,673 11.6 96.1 19,424 2011125 12.0 16 2.3 92.8 21,620 224 6,494 11,545 13.6 81.8 31,472 3261200 8.0 16 2.3 149.0 5,215 54 5,318 8,864 9.6 124.2 9,011 931200 10.0 16 2.3 119.0 10,236 106 6,614 11,024 11.6 102.6 15,978 1651200 12.0 16 2.3 99.0 17,778 184 7,897 13,162 13.6 87.4 25,880 2681219 8.0 16 2.3 151.4 4,973 51 5,577 9,149 9.6 126.1 8,594 891219 9.0 16 2.3 134.4 7,098 74 6,258 10,267 10.6 114.2 11,597 1201219 10.0 16 2.3 120.9 9,761 101 6,936 11,380 11.6 104.2 15,236 1581219 12.0 16 2.3 100.6 16,952 176 8,282 13,588 13.6 88.8 24,677 2561283 8.0 19 2.3 159.4 4,261 44 6,508 10,145 9.9 128.8 8,075 841283 10.0 19 2.3 127.3 8,362 87 8,097 12,622 11.9 107.0 14,091 1461283 12.0 19 2.3 105.9 14,518 150 9,671 15,075 13.9 91.4 22,563 2341283 16.0 19 2.3 79.2 34,739 360 12,773 19,911 17.9 70.8 48,643 504
60 | S E C T I O N 8
Pipe Dimensions Pipe Shell Composite shell and liningShell CML SK Ring Stiffness Beam bending Ring Stiffness
OD t T ts Dm/t SD Pcr I x 106 Z x 103 teq Dm/teq SD Pcrmm mm mm mm N/m/m kPa mm4 mm3 mm N/m/m kPa1290 8.0 19 2.3 160.3 4,192 43 6,616 10,257 9.9 129.5 7,944 821290 10.0 19 2.3 128.0 8,225 85 8,231 12,762 11.9 107.6 13,861 1441290 12.0 19 2.3 106.5 14,280 148 9,831 15,242 13.9 91.9 22,194 2301290 16.0 19 2.3 79.6 34,170 354 12,986 20,133 17.9 71.2 47,845 4951404 10.0 19 2.3 139.4 6,368 66 10,632 15,146 11.9 117.1 10,731 1111404 12.0 19 2.3 116.0 11,051 114 12,704 18,097 13.9 100.1 17,176 1781422 10.0 19 2.3 141.2 6,128 63 11,050 15,541 11.9 118.7 10,326 1071422 11.0 19 2.3 128.3 8,173 85 12,129 17,059 12.9 109.4 13,182 1361422 12.0 19 2.3 117.5 10,633 110 13,203 18,570 13.9 101.4 16,526 1711440 10.0 19 2.3 143.0 5,899 61 11,478 15,941 11.9 120.2 9,941 1031440 12.0 19 2.3 119.0 10,236 106 13,715 19,049 13.9 102.7 15,909 1651440 16.0 19 2.3 89.0 24,469 253 18,134 25,186 17.9 79.6 34,262 3551451 10.0 19 2.3 144.1 5,765 60 11,744 16,188 11.9 121.1 9,715 1011451 12.0 19 2.3 119.9 10,003 104 14,035 19,345 13.9 103.5 15,547 1611451 16.0 19 2.3 89.7 23,911 248 18,557 25,579 17.9 80.2 33,481 3471500 10.0 19 2.3 149.0 5,215 54 12,984 17,312 11.9 125.2 8,788 911500 12.0 19 2.3 124.0 9,047 94 15,518 20,690 13.9 107.1 14,061 1461500 16.0 19 2.3 92.8 21,620 224 20,524 27,365 17.9 82.9 30,272 3131575 10.0 19 2.3 156.5 4,500 47 15,045 19,104 11.9 131.5 7,584 791575 12.0 19 2.3 130.3 7,806 81 17,984 22,837 13.9 112.4 12,133 1261575 16.0 19 2.3 97.4 18,647 193 23,796 30,217 17.9 87.1 26,110 2701600 10.0 19 2.3 159.0 4,291 44 15,777 19,722 11.9 133.6 7,232 751600 12.0 19 2.3 132.3 7,444 77 18,861 23,577 13.9 114.2 11,569 1201600 16.0 19 2.3 99.0 17,778 184 24,959 31,199 17.9 88.5 24,893 2581626 10.0 19 2.3 161.6 4,088 42 16,564 20,374 11.9 135.8 6,888 711626 12.0 19 2.3 134.5 7,090 73 19,803 24,358 13.9 116.1 11,019 1141626 16.0 19 2.3 100.6 16,931 175 26,208 32,236 17.9 89.9 23,707 2451750 12.0 19 2.3 144.8 5,678 59 24,727 28,259 13.9 125.0 8,824 911750 16.0 19 2.3 108.4 13,552 140 32,742 37,420 17.9 96.9 18,976 1961829 12.0 19 2.3 151.4 4,969 51 28,254 30,896 13.9 130.7 7,723 801829 16.0 19 2.3 113.3 11,856 123 37,424 40,923 17.9 101.3 16,602 1721981 12.0 19 2.3 164.1 3,905 40 35,955 36,300 13.9 141.7 6,069 631981 16.0 19 2.3 122.8 9,312 96 47,648 48,105 17.9 109.8 13,039 1352159 12.0 19 2.3 178.9 3,012 31 46,614 43,181 13.9 154.5 4,681 482159 16.0 19 2.3 133.9 7,179 74 61,805 57,254 17.9 119.7 10,053 104
Fittings
62
section9
64 | S E C T I O N 9
9.1 Preferred sizes, dimensions andtypical configurationsFittings are normally fabricated from pipe. Pipe wall, coating andlining thicknesses, and outside diameters are therefore inaccordance with Table 7.1.
Table 9.1, Figure 9.1 and Figure 9.2 depict a range of cost effectivefitting configurations manufactured by Tyco Water. Whilst thesesizes are preferred, Tyco Water can make any size that is required.
9.2 SINTAJOINT fittingsSINTAJOINT fittings are available in sizes 324mm OD to 1829mmOD and allow construction of a complete rubber ring joint pipelinesystem. This eliminates welding entirely. In particular, no joint reinstatement or field joint overwrap of anykind is required and over excavation of the trench at joints forwrapping access is unnecessary.
Tapers, tees and air valves or scour off-takes are also available.
9.3 Welded joint SINTAKOTE fittings Most welded joint fittings are available with SINTAKOTE, fusionbonded polyethylene coating.
Typical fitting dimensions are shown in Table 9.1. Changes inpipeline direction can be achieved by the appropriate combinationof joint deflection and specified bends.
Figure 9.1 Typical Fittings
Tee Angled Branch Y– Piece
Q
d
PM N
30 min.
USS
d
Mitred Bends
Figure 9.2 Typical Reducers
Concentric Reducer
150mm ~4.5 x (D1 – D2) 150mm
150mm ~4.5 x (D1 – D2) 150mm
D1
D1
Eccentric Reducer
D2
D2
S E C T I O N 9 | 65
Diameter Mitred Bends Tee Angle Branch Y - Piece
δ = 22.5o 22.5o < δ ≤ 45o 45o < δ ≤ 90o (30o minimum) (45o)
DN mm M mm N mm R1 mm P mm R2 mm Q mm S mm U mm S mm U mm
200 300 360 500 650 500 325 250 850 250 825
250 375 360 500 650 500 350 250 1,000 250 890
300 375 380 550 700 550 375 250 1,100 250 950
350 450 420 650 800 650 400 250 1,200 250 1,025
400 450 465 750 900 750 425 250 1,300 250 1,100
450 450 485 800 950 800 450 250 1,400 250 1,150
500 450 525 900 1,050 900 475 300 1,500 300 1,225
550 525 565 1,000 1,150 1,000 525 300 1,650 300 1,300
600 525 610 1,100 1,250 1,100 575 300 1,800 300 1,350
650 525 650 1,200 1,350 1,200 625 300 1,900 300 1,425
700 525 690 1,300 1,450 1,300 675 300 2,000 300 1,500
750 600 710 1,350 1,500 1,350 750 300 2,100 300 1,550
800 600 755 1,450 1,600 1,450 775 300 2,200 300 1,600
900 600 815 1,600 1,750 1,600 825 350 2,400 400 1,750
1000 750 900 1,800 1,950 1,800 875 400 2,600 400 1,850
1100 750 980 2,000 2,150 2,000 925 400 2,800 400 2,000
1200 825 1,065 2,200 2,350 2,200 975 500 3,000 500 2,150
1300 825 1,105 2,300 2,450 2,300 1,025 500 3,200 500 2,275
1400 825 1,190 2,500 2,650 2,500 1,075 500 3,400 500 2,400
1500 825 1,270 2,700 2,850 2,700 1,125 600 3,600 600 2,550
1600 900 1,355 2,900 3,050 2,900 1,175 600 3,800 600 2,675
1700 900 1,395 3,000 3,150 3,000 1,225 600 4,000 600 2,800
1800 900 1,500 3,250 3,400 3,250 1,275 600 4,200 600 2,950
1900 900 1,560 3,400 3,550 3,400 1,325 600 4,400 600 3,050
2000 900 1,645 3,600 3,750 3,600 1,375 600 4,600 600 3,200
2100 900 1,725 3,800 3,950 3,800 1,425 600 4,800 600 3,325
9.4 Special fittingsTyco Water can fabricate and supply special fittings in addition tothose indicated to suit your specific needs, for example: expansionjoints, ring girders and support assemblies and complex fittings likebifurcations and trifurcations.
Technical assistance is readily available on request in connection with any problems relating to pipe specials. Although not illustrated we can also supply plate flanges to suit various specifications.
Table 9.1 Fitting configurations manufactured by Tyco Water.Note:
1) Mitred bend radii designed to restrict stress concentration at inside leg to max of 1.25 times hoop stress in pipe.
2) Q may need to be increased when crotch plate reinforcement is used.
S E C T I O N 9
Fittings
HydraulicCharacteristicsof Pipe & Fittings
66
section10
68 | S E C T I O N 1 0
The flow capacity of a pipeline depends on the head driving theflow, the diameter and length of the pipe, the condition of theinterior surface of the pipe and the number and type of fittings inthe line.
The flow velocity in water supply pipes usually does not exceed 3 m/s and is often below 1.5 m/s. At high flow velocities there isa risk of cavitation occurring at discontinuities in the pipeline,such as bends, joints, tees etc. To avoid this, the recommendedmaximum flow velocities are:
4 m/s for CML pipelines
6 m/s for FBPE pipelines
10.1 Colebrook-White formulaA number of formulae exist for calculation of friction losses along apipeline.
The Colebrook-White formula below is the most recently developedand is regard internationally as the most accurate basis forhydraulic design.
v = -2 2gdSg. log10 ( k + 2.51ν )
3.7d d 2gdSg
where: v = flow velocity m/s g = acceleration due to gravity 9.81 m/s2
d = internal diameter of pipe m Sg = hydraulic gradient (head loss/unit length) m/m k = linear measure of roughness m ν = kinematic viscosity of water
= 0.11425 x 10-5 at 15° Celsius m2/s
10.2 k valuesThe recommended value of k for cement mortar lined steel pipes is0.01 to 0.06mm as per Table 2 of AS 2200 (2006) “Design chartsfor water supply and sewerage.”
Experiments carried out by Tyco Water in collaboration with theWater Research Laboratory - University of NSW, at the State Rivers& Water Supply Commission of Victoria Hydraulic ExperimentalStation, resulted in a k value of 0.01mm with water at 20°C for newcement lined steel pipe. Therefore values of k in the lower range ofthe variation shown in Table 2 of AS 2200 (2006) should be chosenwhen determining head losses.
For SINTAPIPE, k values are of the order of 0.003 to 0.015mm perAS 2200, but the actual value taken should represent any film thatmay build up on the surface.
10.3 Flow chart for mild steel cementmortar lined pipePipe flow friction charts provide a convenient graphical means ofsolving the Colebrook-White formula and are sufficiently accuratefor most practical purposes.
Recommended values of k for new steel pipelines are:0.003 mm for SINTAPIPE0.03 mm for CML pipe and CML seal coated pipe
Graphs 10.1 and 10.2 are based on the Colebrook – Whiteformula, using k values of 0.003 and 0.03mm, and indicate thehydraulic gradient along a straight run of pipe.
Where the number of fittings is high compared with pipe length headlosses can be calculated using minor loss coefficients from Table 10.1.
Bringing water to wine – Barossa Valley, South Australia.
√√
S E C T I O N 1 0 | 69
S E C T I O N 1 0
Hydraulic Characteristics of Pipe and Fittings
Type of fittings KL Type of fittings KL
1) Entry losses 5) Sudden enlargementsSharp edged entrance 0.50 Inlet dia:Outlet dia.-Re-entrant entrance 0.80 4:5 0.15Rounded entrance 0.25 3:4 0.20Bellmouthed entrance 0.05 2:3 0.35Footvalve and strainer 2.50 1:2 0.60
1:3 0.802 )Radiused bends 1:5 and over 1.00Elbows(R/D - 0.5 approx) 22.5° 0.20 6) Sudden contractions
45° 0.40 Inlet dia:Outlet dia.-90° 1.00 5:4 0.15
4:3 0.20Close radius bends 3:2 0.30(R/D - 1 approx.) 22.5° 0.15 2:1 0.35
45° 0.30 3:1 0.4590° 0.75 5:1 and over 0.50
Long radius bends 7) Tapers(R/D - 2 to 7) 22.5° 0.10 Flow to small end = 0
45° 0.20 Flow to large end90° 0.40 Inlet dia.: Outlet dia.
4:5 0.03Sweeps 3:4 0.04(R/D - 8 to 50) 22.5° 0.05 1:2 0.12
45° 0.1090° 0.20 8) Valves
Gate valve - fully open 0.123) Tees - 25% closed 1.00Flow in line 0.35 - 50% closed 6.00Line to branch or branch - 75% closed 24.00to line:-
sharp-edged 1.20 Globe valve 10.00radiused 0.80 Right angle valve 5.00
Reflux valve 1.00
4) Angle branchesFlow in line 0.35 9) Exit lossesLine to branch or branch to line:- Sudden enlargement 1.0030° angle 0.40 Bellmouthed outlet 0.2045° angle 0.6090° angle 0.80
Table 10.1 - Pipeline fittings loss coefficients
70 | S E C T I O N 1 0
Graph 10.1 – Pipe flow and head loss , k = 0.003
Hydraulic gradient in percent
Dis
char
ge ‘Q
’ in
litre
s/se
cond
Velocity ‘v’ in metres/second
Inte
rnal
dia
met
er ‘d
’ in
mill
imet
res
S E C T I O N 1 0 | 71
Graph 10.2 – Pipe flow and head loss , k = 0.03
Hydraulic gradient in percent
Dis
char
ge ‘Q
’ in
litre
s/se
cond
Velocity ‘v’ in metres/second
Inte
rnal
dia
met
er ‘d
’ in
mill
imet
res
S E C T I O N 1 0
Hydraulic Characteristics of Pipe and Fittings
S E C T I O N 1 0 | 73
74 | S E C T I O N 1 0
10.4 Pipeline fittings lossesValues of KL given in Table 10.1 are taken from Skeat (ref 8) andrelated to head loss by the equation:
HL = KLv2
2g m
where
HL = head loss in metres head of water mv = flow velocity m/sg = acceleration due to gravity 9.81 m/s2
KL = minor loss coefficient
Mitred bendsMitred bends are less efficient hydraulically than radiused bends,however they can be readily fabricated to suit specific geometricalneeds.
Loss coefficients vary markedly with Reynolds number (R) andnormally, to a lesser extent, with inlet and outlet arrangements andsurface roughness.
Single mitresThe coefficients given below are defined at a Reynolds number of106, with long and hydraulically smooth inlet and outlet pipes. Miller(ref 9, chapter 8) gives correction factors for other inlet:outletarrangements and roughness.
Composite mitresThe equivalent circular arc re, needed for re/d values, can becalculated using:re =(a)cot(90)2 2n
wherere = equivalent radius mma = centreline length mmn = number of individual mitres
90° Composite bend KL
90° re /dComposite
Bend 1.0 1.5 2.0 3.0 4.0
2 x 45° 0.45 0.35 0.31 0.35 0.40
3 x 30° 0.42 0.33 0.27 0.21 0.23
4 x 22.5° 0.40 0.31 0.25 0.19 0.19
Other anglesCoefficients for combinations of two single mitres can be derivedfrom:
KLE = (KL1 + KL2) x Cbb
WhereCbb = headloss coefficient factor for bends
KLE = Effective headloss coefficient
KL1 = headloss coefficient bend 1
KL2 = headloss coefficient bend 2
re/d 1 2 3
Cbb 0.82 0.73 0.78
Reynolds number correctionThe following factors derived from Miller (ref 9) can be used toadjust for Reynolds number variation.
θ° 111/4 221/2 45 60 90
K1 0.03 0.07 0.30 0.50 1.15
θ°
θ°
Table 10.2
Figure 10.1
Figure 10.2
Table 10.3
Table 10.4
S E C T I O N 1 0 | 75
R x103 50 100 200 500 1000 5000
re/d
1 1.5 1.25 1.0 1.0 1.0 1.0
1.5 1.6 1.4 1.25 1.0 1.0 1.0
>2 1.65 1.5 1.3 1.15 1.0 0.8
Reynolds numberR = vd = vdρ
ν μ
wherev = water velocity m/sd = inside diameter of pipe mmν = kinematic viscosity m2/s μ = dynamic viscosity kg/m/s ρ = density kg/m3
10.5 Flow calculation examples
Example 1. Find d given discharge Q and hydraulicgradient SgDetermine the diameter of pipe required to discharge 1000litres/second if pipeline length is 5km of CML pipe and the availablehead is 15 metres.
Hydraulic gradient is 15/5000 = 0.3%
From Graph 10.2 an internal diameter of 800mm is required.
From Table 7.1 select a 914mm OD x 6mm wall thickness pipewith 16mm thick cement mortar lining.
(Actual mean bore = 870mm)
From Table 7.1 permissible working head for this pipe is 289 metres.
From Graph 10.2 flow velocity is 2.1m/s - well within normal limits.
Example 2. Find Sg given Q and d.Determine the friction head when pumping 600 litres per second alonga 15km pipeline consisting of 750mm nominal bore MSCL pipe.
Pipe 762mm OD
Steel wall thickness 6mm
Mean bore from Table 7.1 = 726mm
From Graph 10.2 hydraulic gradient is 0.18%
Head loss over 15km = 15000 x (0.18/100) = 27 m
From Graph 10.2 flow velocity is 1.50m/s - well within normal limits.
Example 3. Find Q given d and Sg.Given an existing 5km, 900NB MSCL pipeline between tworeservoirs with an elevation difference of 20m.
Find the maximum flow rate.
From Table 7.1 mean bore of 914mm OD x 8mm steel wallthickness, with 16mm CML pipeline = 866mm.
Hydraulic gradient = 20/5000 = 0.4%
From Graph 10.2 flow rate = 1420 l/s, velocity = 2.4m/s - wellwithin acceptable limits.
S E C T I O N 1 0
Hydraulic Characteristics of Pipe and Fittings
Table 10.5
Water Hammer
76
section11
78 | S E C T I O N 1 1
11.1 General formulaThe formula used to establish the wall thickness required toaccommodate internal pressure is the Barlow formula (refer also toSection 8.2):
t = PDo
2σall
wheret = steel wall thickness mm
P = internal design pressure MPa
Do = outside diameter of pipe mm
σall = allowable hoop stress MPa
11.2 Steel stressIt is recommended that σall should not exceed 72% of theminimum yield strength (MYS) of the steel, under hydrostatic orsteady state working pressure.
Where a detailed hydrodynamic analysis is carried out the effect oftransient surge pressures together with static pressure may betaken to 90% of the MYS.
11.3 Water hammerWater hammer is caused by a sudden change of flow velocity in apipeline, causing shock waves to travel upstream and downstreamfrom the point of origin.
The shock waves cause increases and decreases in pressure asthey travel at the speed of sound through the fluid along thepipeline.
Their reflection and interaction can lead to significant changes inpressure above and below those prevailing in the static or steadystate operation of the pipeline.
Potential water hammer problems should be investigated at thedesign stage. They are caused by events such as
• rapid valve closure
• sudden pump stoppage (e.g. power failure)
• improper operation of surge control devices
Gravity MainsFor gravity mains, water hammer effects arise commonly throughrapid valve closure.
Valve closure within the reflection period Tr will permit shock wavesof closure to be generated prior to the return of the first reflectedshock wave to the valve.
The maximum potential pressure rise will then be generated by theinteraction of all possible shock waves. Valve closure in a periodgreater than Tr reduces the maximum surge.
Surge estimate for rapid valve closure
Joukowsky Method
For the case of a steel pipeline of length L metres, undergoinginstantaneous valve closure or a valve closure within the reflectionperiod Tr seconds, the resulting pressure rise can be estimated byJoukowsky's formula:
Δh = avg m
or
Δp = av1000 MPa
where:L = length of pipeline mTr = reflection period = 2L/a sΔh = head rise above normal operating head mΔp = pressure rise above normal operating pressure MPaa = pressure wave velocity (celerity) m/s
= 1440
{1+ 1 (d )}0.5
100 tv = velocity of flow m/sg = acceleration due to gravity 9.81 m/s2
d = pipe internal diameter mmt = pipe wall thickness mm
Note: this formula applies to steel pipelines only.
ExampleConsider a 610mm OD x 5mm thick- SINTAKOTE (SK) CML RRJ-pipeline, 2 km in length with a normal operating head of 90m and aflow of 160 l/s. What is the maximum surge pressure that will occurif sudden valve closure occurs.
OD, pipe outside diameter = 610 mmt, steel wall thickness = 5 mmT, cement mortar lining thickness = 12 mmd, inside diameter of lined pipe = 576 mm
celerity a = 1440/{1+576/(100 x 5)}0.5 = 981.6 m/s
Determine flow velocity
v = Q/A
S E C T I O N 1 1 | 79
Where Q = flow rate m3/sv = velocity m/sA = bore area of lined pipe m2
v = 160 x 10-3/[π( 0.576/2)2] = 0.614 m/s
This velocity is well within acceptable limits.
Pressure rise above normal operating pressure
h = av/g = 981.6 x 0.614/9.81 = 61.44 m
Total head on pipe (sum of static and surge pressure)
= 90+61.44 = 151.44
P = Total head x g / gamma w
P = 151.44 x 9.81 / 1000 = 1.49 m
Therefore pipe wall hoop stress
s =PDo
2t
s = 1.49 x 610 / (2 x 5) = 90.62
Reflection period Tr = 2 x 2000/981.6 = 4.07 s
As the pressure rise computed above is well below the workingpressure of steel pipelines, the period for critical closure does not needto be determined. It has been calculated to illustrate the procedure ashigh velocity/head conditions should always be checked.
Allievi MethodFor water hammer caused by slowly opening or closing valves (To > 2L/a) an approximation of the pressure change may be madeusing a formula similar to Allievi's. This formula assumes that fromthe time the first reflective wave returns to the valve until it is fullyclosed, the pressure remains unchanged and that the effectiveopening area of the valve is changed rectilinearly.
H = 1+ n ( n ± n2+4 )Ho 2
The plus is associated with the pressure rise in closing the valve,the minus with pressure drop at the time of opening.
where
n = Lvo
(TogHo)
H = head after valve operation m
Ho = head under constant flow conditions m
vo = velocity under constant flow conditions m/s
L = pipeline length m
To = time for valve closing or opening s
g = acceleration due to gravity = 9.81 m/s2
ExampleFor the previous example assume
To = 5 x 2L/a
Ho = 90m
n = 2000 x 0.61/(5 x 4.07 x 9.81 x 90) = 0.0679
H/Ho = 1+0.5 x 0.0679(0.0679±√(0.06792+4))
= 1.0703 or 0.9344
H = 96.32m or 84.09m
The maximum pressure rise in this case is 7 metres, significantlyless than the 61.44 metres calculated using Joukowsky's equation.
The examples above show that a valve in a flowing pipeline should beclosed slowly, and particularly for the last 10% of closure, Skeat (ref. 8)recommends the last 10% of valve closure should take at least 10xTr.
Pumped mainsFor pumped mains water hammer effects can develop throughpump start up or stoppage.
The pressure rise during pump start up will not exceed themaximum head value on the HQ characteristic curve for thepump. However, the positive surge along the full pipe length willexceed the normal operating hydraulic grade line. This conditionshould be closely examined for long pipelines and particularlywhere thinner walled pipe has been selected away from thepumping facilities.
The sudden stoppage of pumps, such as caused by power failure,is a common cause of water hammer problems. Potentially moredamaging conditions are likely if water column separation occurs.The subsequent rejoining of water columns may cause pressuresurges sufficient to damage the pipeline. Where no separationoccurs, the maximum positive pressure at the pump delivery pointwill not exceed twice the normal operating pressure.
Typical surge profiles are shown in Figure 11.1. Locations A and Bare potential zones of column separation should the maximumnegative surge drop below the pipeline.
S E C T I O N 1 1
Water Hammer
√
MPa
80 | S E C T I O N 1 1
Figure 11.1 - Typical surges in a pumped system
Surge estimate for pump stoppage and start upA useful means for estimating surges in a pumped system is bysurge diagrams.
ExampleAn example has been analysed to demonstrate this method. Thefollowing steady state conditions have been assumed:
OD, pipe outside diameter = 406 mmt, steel wall thickness = 5 mmT, CML = 12 mmpipe length = 10,000 mflow = 102 l/svelocity = 0.94 m/scelerity = 1090 m/sstatic lift = 120 mfriction headloss = 20 mpumping head = 140 m
A surge diagram shows the system resistance curve representedas hydraulic levels and velocities.
The pressure change per unit velocity change is derived fromJoukowsky's formula, namely:
Δh = aΔv g s
The pressure change equates to 111 metres for a 1 m/s velocitychange in this example. It has been assumed that thepump/motor rotational moment of inertia is insignificant, and nocolumn separation occurs over the pipeline length.
The pump stoppage condition is shown in Graph 11.1.
Prior to stoppage, the system operating point is at the intersectionof the system resistance and pump curve (a). Upon stoppage,both the pressure and flow velocity drop (b). The minimumpressure occurs when the velocity falls to zero (c).
The velocity then reverses and the pressure increases (d). Themaximum reverse velocity occurs at the intersection with the
S E C T I O N 1 1 | 81
system resistance curve (e). The flow velocity reduces andpressures increase due to the water column coming to rest againstthe pump's check valve (f). The maximum pressure occurs whenthe flow comes to rest (g).
The cycles of pressure and velocity-change continue until thesystem flow comes to rest at the static head condition (h).
The pump start up condition is shown in Graph 11.2.
Prior to pump start, the system operating point is at the static headcondition (a). Upon pump start up both the pressures and flowvelocities increase (b). The pressure increases to a maximum at theintersection with the pump curve (c). Then there is a drop inpressure but the flow velocities continue to increase (d).
The flow velocity continues to increase with pressures fluctuatingbetween the system resistance and pump curve (e). The systemeventually settles at the normal operating condition at theintersection of the system resistance curve and pump curve (f).
General recommendationIt is suggested that a detailed surge analysis be undertaken if there is a possibility of column separation or pipe flow velocitiesexceed 1 m/s in systems where appurtenances may suffer damage under high head.
Water hammer protection devicesThe selection of protection devices in a system should be basedon an adequate water hammer analysis. Indiscriminate selectionmay in fact exacerbate an existing water hammer problem.There are positive and negative surges present to be considered.It may be necessary to control both or either one for a particular
system. This assessment will become apparent during the waterhammer analysis.A water hammer problem may be solved by installing a single orcombination of protection devices. Some of the commonly usedprotection devices available are summarised below.
FlywheelEffective for pipeline lengths up to about 1000 metres. Theydampen the negative surge upon pump stoppage andconsequently dampen the associated positive surge.
Surge towerConsists of an open ended tower. Mainly used in gravity systems,particularly hydroelectric schemes. They can be used in low headpumping systems where the height does not become excessive.They dampen both positive and negative surges.
Air vesselA pressure vessel containing air and water. They dampen bothpositive and negative surges. Their use is usually limited by cost.
One way surge tankA tank connected to the pipeline by a check valve. Allows waterentry into the pipeline following negative surge.
Pressure relief valveUsed to dampen positive surges. Can be spring loaded or pilotoperated. The pilot operated type is usually preferred wherepressure release is instant and valve closure is slow.
Computer programmesA number of companies lease out computer programmes toenable rapid, economical and accurate water hammer analysis.They are ideal in modelling the incorporation of protection devicesas described above, due to the inherent hydraulic complexity ofthese controls.
Care should be exercised in using these programmes however, andit is advisable that experienced operators be consulted to ensurerealistic modelling.
Further readingThe following references are recommended for further information:Parmakian (ref 14), Streeter (ref 15), Pickford (ref 16), Watters (ref 17), Webb (ref 18).
S E C T I O N 1 1
Water Hammer
82 | S E C T I O N 1 1
Graph 11.1 - Pump stoppage
Velocity in metres per second
S E C T I O N 1 1 | 83
Graph 11.2 - Pump start up
Velocity in metres per second
S E C T I O N 1 1
Water Hammer
Anchorage of Pipelines
84
section12
86 | S E C T I O N 1 2
12.1 Calculation of thrustAll pressure pipelines with unanchored flexible joints requireanchorages at changes of diameter, direction, tees, valves andblank ends to resist the thrusts developed by the internal pressures.
These static thrusts act in the directions shown in Figure 12.1.
The additional dynamic thrust associated with a change in directionof the moving water can usually be ignored unless the watervelocity is extremely high.
It is imperative that thrust restraints be designed with capacity forthe maximum pressure to which the pipeline system will besubjected. This includes field test pressure and any transientpressures associated with operation.
The magnitude of static thrusts can be calculated as follows:
At blank ends and junctions
Ts = AP x 103 kN
At bends
Re = 2Tssinθ kN2
where
A = cross sectional area based on pipe OD pluscoating thickness m2
P = internal pressure MPa
Ts = static thrust kN
Re = resultant thrust at pipe bend kN
θ = angle of deflection of bend degrees
See Table 12.1 for values of static thrusts at typical fittings over arange of pipe diameters.
See Section 12.2 for typical thrust block arrangements.
Notes:• Calculations based on pipe outside diameter, steel OD + 2 xSINTAKOTE thickness.• Thrust values rounded to nearest kN.• Dividing the above values by the safe bearing load of thesurrounding soil will give the area of the thrust block in m2.
Example:A 1200mm nominal diameter pipe at 45° bend with an internalpressure of 1.0 MPa.
Static thrust = 960 kN
Soil allowable bearing pressure = 48 kN/m2
Thus area required = 960/48 = 20.0 m2
12.2 Typical thrust block arrangements
Horizontal thrustThe thrust developed must be transferred to the undisturbed earth ofthe trench wall by anchor blocks poured against an appropriate area.
Horizontal anchor blocks must distribute thrust forces over the totalbearing area of the block so as not to exceed the safe bearingpressure of the trench wall, thus ensuring the stability of the pipelineunder test and working pressures. See Figure 12.2.
Typical values for safe bearing pressures of various undisturbedsoils based on horizontal thrust at 0.6 metres depth are given inTable 12.2.
Vertical thrustDownward thrusts are transferred to the undisturbed ground byanchor blocks in the same manner as horizontal thrusts. Upwards
Figure 12.2 - Anchor blocks horizontal planeFigure 12.1 - Static thrust diagram
Anchor block for horizontal bend
Anchor block for horizontal taperAnchor block for horizontal tee
Ts
Ts
Ts
TsTs
θ
θ2
Re
Re =2TsSin–
S E C T I O N 1 2 | 87
thrusts are counteracted by the mass of the concrete anchorblocks. See Figure 12.3.
Where the water table in the area is likely to reach the level of theanchor block the submerged mass of the block should be used inthe calculation to determine the anchor block size.
Gradient thrustPipes laid at a gradient between 1 in 10 and 1 in 6 should beanalysed for anchor block requirement. Rubber ring jointed pipeslaid on steep slopes require restraint to prevent relative movementof the individual pipes due to the component of the pipe mass andcontents acting along the direction of the gradient. See Figure 12.3.
Frictional resistance between the pipeline coating and the backfillmaterial counteract a portion of the sliding thrust. Thrust blocksshould be designed to take the balance of the force.
12.3 Alternative to anchor blocks
Thrust blocks are not required in a welded pipeline since theunbalanced force is transmitted into the pipeline in the form oflongitudinal stress. Where a rubber ring joint pipeline is involved, asimilar situation can be achieved by providing a number of weldedjoints on each side of a fitting where a change of direction occurs.To consider this alternative the frictional resistance of the pipeline inthe soil must be checked to determine the number of welded jointsnecessary to produce an effective anchoring embedment length.
Friction Factor μThe AWWA (ref 11) states coefficients of friction μ, between soil andsteel pipe coatings are generally in the range 0.25 to 0.40.
No data has been published for fusion bonded polyethylene andhence extensive experimental work was carried out by Tyco Waterto determine the appropriate range of values.
Results can be summarised as follows:• Where sand backfill or low clay content contact the coating, afriction coefficient of 0.32 is appropriate.• For sand backfill using SINTAKOTE pipe with a factory appliedsand coating, a friction coefficient of 0.50 is appropriate.• Where clay soils are in contact with the coating, a frictioncoefficient of 0.16 should be used. Note that clay would notnormally be placed directly against the pipe surface.
These values should provide a reasonable degree of conservatismin designing the required length of pipeline to be welded togenerate adequate restraint.
OD Thrust developed per MPa internal pressuremm kN
Blank end 90° Bend 45° Bend 22.5° Bend 11.25° Bend
219 31 44 24 12 6
324 71 100 54 28 14
610 283 400 216 110 55
762 442 625 338 172 87
1016 785 1,111 601 306 154
1200 1,131 1,599 866 441 222
1422 1,539 2,177 1,178 601 302
1626 2,011 2,843 1,539 785 394
1829 2,545 3,599 1,948 993 499
Soil type Safe bearing pressure kPa
Soft clay 24
Sand 48
Sand and gravel 72
Sand and gravel bonded with clay 96
Shale 240
Table 12.1 - Static thrust values
Figure 12.3 - Anchor blocks to resist upward and gradient thrust
Table 12.2 - Safe soil bearing pressures
Anchor block for vertical slope Anchor block for vertical bend
S E C T I O N 1 2
Anchorage of Pipelines
S E C T I O N 1 2 | 89
Anchorage lengthThe length of pipe required to balance these forces can be deducedfrom
L = PA (1-cosθ) x 103
μ(2Wd+Ww+Wp)
whereL = pipeline length to be anchored m
P = internal pressure MPa
A = cross sectional area based onpipe OD + coating thickness m2
θ = angle of deflection of bend degrees
μ = soil friction coefficient
Wd = weight of backfill kN/m
Ww = weight of water in pipe kN/m
Wp = weight of pipe kN/m
12.4 Examples of thrust calculationsGiven a pipe diameter of 559mm x 5mm wall thickness, and 12mmcement lining thickness and SINTAKOTE thickness of 2 mmthickness giving a pipe OD of 563mm.
Example 1. Bearing areaDetermine the lateral bearing area and anchor block size, for ahorizontal 90° bend in a pipeline and with an internal pressure of 2 MPa laid in shale.
Re= 2PA sin(θ/2) x 103
= 2 x 2 x π x (0.563/2)2 x sin (90/2) x 103
= 704.13 kN
Bearing pressure for shale = 240 kN/m2
∴Thrust block bearing area = 2.94 m2
Example 2. Embedment lengthDetermine the length of welded pipe required on each side of the90° bend in example 1 above, to avoid the need for a thrust block.
Assume that the pipe is buried under 1 metre of clayey sand, atrench 0.8m wide at pipe crown level with clay having a density of1800 kg/m3.Length of pipe required to carry the out of balance force in thedirection of the pipe.
L = PA(1-cosθ) x 103 / [μ (2Wd +Ww +Wp)]
whereρ = soil density (see Table13.1) kg/m3
D = pipe outside diameter mH = height of ground surface above top of pipe m
thereforeWd = weight of soil prism above pipe
= 9.81ρDH/1000= 9.81 x 1800 x 0.563 x 1.0/1000= 9.960 kN/m
Ww = weight of water in pipe= π (0.525/2)2 x 9.81 x 1000/1000= 2.124 kN/m
Wp = weight of pipe (refer Table 7.1 pipe masses)
= 120 x 9.81/1000= 1.177 kN/m
μ = 0.32henceL = 2π/4 x (0.563)2 x (1-cos90) x 103/[0.32(2 x 9.960+2.124+1.177)]
= 67.0 mIf each pipe is 12m long, then 5 joints are required to be welded.
Incorporating bend reactionIn the above calculations, the soil reaction at the bend has not beenincluded. If it were, the number of joints that have to be weldedcould be reduced.
Say the bearing pressure of clayey-sand equals 96 kPa and safetyfactor is 0.8.
Assume the length of pipe under bearing pressure is 3 diametersi.e. 1.69m long.
∴ Force available at the pipe face
= 1.69 x 0.563 x 96 x 0.8
= 73.1 kN
∴ pipe length to be welded is
= (2π/4 x (0.563)2 x (1-cos90) x 103 -73.1 x sin(90/2) / [0.32(2 x 9.96 + 2.124 + 1.177)]
= 57.3 m
= 4 joints to be welded
Note:When the backfill depth to trench width ratio is > 10, considerationshould be given to a reduction in the weight of soil on the pipe. Forsuch an analysis using Marston's theory, designers should consultSpangler and Handy (ref 3) and AS 2566.1.
S E C T I O N 1 2
Anchorage of Pipelines
StructuralDesign forBuried Pipelines
90
section13
13.1 General considerations and procedureThe following design procedures are based on flexible pipebehaviour under load. Lateral support is generated by the passiveresistance of the soil, contributing to the load carrying performanceof the pipe.
A pipe placed in a trench must be strong enough to withstand allexternal loads which may act on it. In some instances, particularlywhen the internal pressure is low, these external loads maydetermine the wall thickness of the pipe in satisfying ring stiffnessrequirements.
Performance aspectsThe performance of the selected pipe is checked principally in two ways:
1. Ring deflection by verifying that the unpressurised pipe undertrench backfill, other superimposed distributed loads and traffic loadswill not suffer excessive ring deflection.
2. Ring buckling by verifying whether the pipe has adequate shellstability or resistance to buckling to resist local external loads andinternal vacuum loads.
The combined effects of ring bending stress due to externalpressures and hoop stress due to internal pressure are generally notsignificantly greater than the effects of internal pressure alone. As aresult, hoop stress only is normally adequate for determination of wallthickness.
In addition it may be necessary to assess axial and beam bendingloads. In rubber ring joint pipes correctly placed in a trench, the axialand bending loads are small and not usually taken into account.
The following methods of load calculation and performanceassessment are recommended for their ease of application andproven track record in practice.
Load calculationCalculation of soil loads is based on Marston's theory (ref 6) forflexible pipe.
Calculation of traffic wheel load effects is based on work byBoussinesq (ref 10) and the Bridge Design Code – Section Two –Design Loads – Austroads (1992).
It is to be noted that the transient loads from internal vacuum andsurface live loadings are not usually considered simultaneously.
Loads from groundwater and internal vacuum are hydrostatic innature and do not generally affect pipe ring deflection, but a checkshould be made to ensure ring buckling stability of the shell.
Compaction and effective combined soil modulus E’
Depending on the ring deflection and surface settlementconsiderations of the installation, different levels of compaction canbe specified to achieve the necessary effective combined soilmodulus E’.
As a guide, non trafficable installations such as in open field wouldrequire compaction to achieve 60% density index in cohesionlessmaterials or 90% dry density ratio in cohesive materials.
Trafficable installations such as under road pavement may requirecompaction to achieve 70% density index in cohesive materials or95% dry density ratio in cohesive soils.
92 | S E C T I O N 1 3
Symbol Description
GW Well-graded gravels, gravel-sand mixtures, little or no fines
GP Poorly graded gravels, gravel sand mixtures, little or no fines
GM Silty gravels, poorly graded gravel-sand-silt mixtures
GL Clayey gravels, poorly graded gravel-sand-clay mixtures
SW Well-graded sands, gravely sands, little or no fines
SP Poorly graded sands, gravely sands, little or no fines
SM Silty sands, poorly graded-silt mixtures
SC Clayey sands, poorly graded sand-clay mixtures
ML Inorganic silts & very fine sand, silty or clayey fine sands
CL Inorganic clays of low to medium plasticity
MH Inorganic silts, micaceous or diatomaceous fine sandy or silty soils, elastic silts
CH Inorganic clays of high plasticity, fat clays
OL Organic silts and organic silt-clays of low plasticity
OH Organic clays of medium to high plasticity
Pt Peat and other highly organic soils
Table 13.2 - Unified Soil Classification
Source: Classification of Soils for Engineering Purposes. ASTM Standard D2487-9, ASTM, Philadelphia, Pa. (1969).
Material Unified Soil WeightClassification symbol kN/m3
(see Table 13.2)
Saturated clay CL, CH, ML, MH 21
Normal clay CL, CH, ML, MH 19
Clayey sand GM, SM, SC 18
Loose granular sand GW, SW, GP, SP 15
Table 13.1 - Density of backfill materials
S E C T I O N 1 3 | 93
Deflection calculationA variety of methods have been developed for the evaluation of thestructural strength of the pipe as well as the external loads actingon the pipe. A popular formula for calculation of pipe ring deflectionis that developed by MG Spangler and later modified by Watkinsand Spangler at the Iowa State University.
Other methods of deflection estimation are available and vary in theirdegree of sophistication. Some require extensive calculation usingcomputer programmes which require numerous soil parameters tobe either estimated or measured in the field for input to the analysis.
The degree of sophistication is questionable given the intrinsicvariability of soil parameters, the difficulty in their consistentestimation, their often time dependent nature and the propensityfor soil-pipe structures to be disturbed during their service life.
Generally, the Spangler-Watkins formula is preferred because of itsextensive history of successful application, ease of use andunderstanding.
Ring buckling stabilityThe ring buckling stability check where depth of cover is equal toor less than 0.5m is carried out using Timoshenko’s equation. Forcover greater than 0.5, the Moore equation, which yields similarfactors of safety to those obtained from using the moreconventional formulae based on Luscher’s equation, is adopted.
Timoshenko’s equation predicts a buckling resistance pressure fora condition of uniform external pressure without allowance for soil
support, whereas Moore’s equation is valid only where external soilsupport is present.
13.2 Design loads due to trench andembankment fillA rapid method of estimating the earth load on a flexible pipe dueto trench and embankment fill is to assume that it is equal to theweight of the earth prism directly above the pipe:wg = γ H
wherewg = vertical design load pressure at top of pipe due to soil dead load kPa γ = assessed unit weight of trench fill or embankment fill kN/m3
H = cover, vertical distance between the top of the pipe and the finished surface ≤ 10D mD = pipe outside diameter m
For H > 10D results may be conservative.
Embankment conditionFor embankment condition the settlement ratio is assumed to bezero, that is settlement of the soil columns beside the pipe isassumed equal to the settlement of the soil column above the pipe.
Deep trench or embankmentFor deeper trenches and embankments, say H/B > 10,consideration should be given to side wall friction. For such ananalysis designers should consult AS 2566.1
S E C T I O N 1 3
Structural Design for Buried Pipelines
Connecting a cable across a joint on a cathodically protected SINTAJOINT pipeline.
94 | S E C T I O N 1 3
Graph 13.1 – Average load intensity
90
80
70
60
50
40
30
20
10
0
Cover Height (m)
Legend:
= Single lane = HLP 320 loading
= Multiple lanes = HLP 400 loading
0.5 0.7 1 2 4 6 8 10
Aver
age
Load
Inte
nsity
, Wq
(kPa
)
S E C T I O N 1 3 | 95
Design Loads due to superimposed loads.The design load due to a superimposed dead load shall bedetermined as follows:
• for uniformly distributed loadswgs = u = load per unit area, kPa
• for concentrated dead or live loads, it shall be determined byapplication of either- the Boussinesq theory in Spangler and Hardy, or- the distribution method described in section 13.3.
13.3 Superimposed Live Loads
Aircraft and railwaysFor aircraft, the appropriate superimposed live loads relatedinformation may be obtained from the relevant authority. For railways,the superimposed live loads may be obtained from AS 4799.
Road vehiclesUnless otherwise specified by the regulatory authority, road vehicleloads shall be taken as given in AUSTROADS Bridge Design Code– Section 2 and the average intensity of the design load (wq), forthese loadings is shown in Graph 13.1. (This load distributionincludes the effect of the tyre footprint)
Where the cover (H) is less than 0.4 m, a wheel or track load shallbe considered to act at the top of the pipe on an area equal to thecontact area of such load.
Where the depth of fill over a pipe is 0.4 m or more, a wheel or track
load shall be uniformly distributed at the top of the pipe, over an areasimilar to the contact area of such load, and with sides equal to 1.45H greater than the sides of the contact area. See Fig 13.1.
Where the surcharge from loads overlap, the total load shall beconsidered as uniformly distributed over the area defined by theoutside limits of the combined areas See Fig 13.1.
On the basis of these assumptions, the average intensity of thedesign live load at the top of the pipe due to multiple wheel ortrack vehicle loads, including impact effects, is calculated from thefollowing equation:
wq = ΣPα(L1L2) kPa
where
α = 1.4 – 0.15H but not less than 1.1 = impact effects
ΣP= sum of wheel loads kN
L1 = total wheel footprint width (Graph 13.1) m
L2 = total wheel footprint length (Graph 13.1) m
Construction and other equipmentAppropriate wheel or track loads for construction and otherequipment shall be obtained from the manufacturer of theequipment. Distribution and intensity of loading shall be determinedas shown above under Road Vehicles.
Note: Construction loads may be applied for cover heights lessthan the final cover height.
Figure 13.1 – Distribution of Wheel and Track Loads
Plane at top of pipe
Finished surface
L1 = ΣG + b + 1.45H if load prisms overlapor ( b + 1.45H ) if no overlap
L2 = a + 1.45H
S E C T I O N 1 3
Structural Design for Buried Pipelines
96 | S E C T I O N 1 3
13.4 Deflection CalculationsThe predicted vertical deflection of a buried pipe shall satisfy thefollowing equation:Δy ≤ ΔyallD DwhereΔy = K x 10-3 ( wg +wgs+wq) D 8 x 10-6 x SD + 0.061 x E’
whereΔy = pipe vertical deflection mΔyall = allowable pipe vertical deflection m
SD = E I x 106 N/m/mDm
3
K = 0.1 (bedding constant)E’ = ζ E’e MPa
ζ = 1.44 Δf+( 1.44 - Δf ) x ( E’e )E’n
E’e = embedment soil modulus (ref Table 13.3) MPaE’n = native soil modulus MPa
Δf = ( B/De – 1 ) ≤ 1.441.154 + 0.444 ( B/De -1)
B = Width of the trench at the pipe spring line m
De = D = Pipe outside diameter m
13.5 Acceptable deflection limits
Welded joint pipeFor mild steel cement mortar lined pipes with welded joints a safedeflection limit can be taken as the lesser of 0.00014 x SMYS XD/t(%) and 4% of the pipe diameter, see Table 8.2 and Table 13.4.
Compaction
Low <----------------------------> High
RD (%)
- 85 90 95 100
ID (%)
- 50 60 70 80
Standard Penetration Test - Number of Blows
≤4 >4 ≤14 >14 ≤24 >24 ≤50 >50
Gravel single size GW 5 7 7 10 14
Gravel graded GW 3 5 7 10 20
Sand and coarse-grained soil GP, SW, SP and 1 3 5 7 14with less than 12% fines GM-GL, GC-SC
Coarse-grained soil with more GM, GC, SC, SM and NA 1 3 5 10than 12% fines GM-SC, GC-SC
Fine-grained soil (LL<50%) with medium CL, ML, ML-CL, NA 1 3 5 10to no plasticity and containing more than CL-CH, ML-MH25% coarse-grained particles
Fine-grained soil (LL<50%) with medium to CI, CL, ML, ML-CL, NA NA 1 3 7no plasticity and containing less than CL-CH, ML-MH25% coarse-grained particles :
Fine-grained soil (LL>50%) CH, MH and CH-MH NA NA NA NA NAwith medium to high plasticity
NA = Soils in these categories require special engineering analysis to determine required density, moisture content and compaction.RD = Dry density ratio (ref AS 1289, 5.4.1 and 14.2) ID = Density index (ref AS 1289, 5.6.1 and 14.2)
Soil Description Soil Classification
Table 13.3 - Embedment (E’e) and native (E’n) soil moduli
This limit is recommended to avoid possible repetitive flexing of thepipe to an extent which could cause the cement mortar lining tofray at cracks.
It should be noted that a reduction in the deflection can in mostcases be achieved by improving the pipe bedding conditions inlocalities where the pipe will be subject to traffic loads and notnecessarily by selecting a pipe with greater wall thickness.
Rubber ring joint pipeThe maximum allowable deflection of a single hardnesss RRJpipeline ranges from 2.3-4%, depending upon OD and WallThickness (See Table 8.2 and Table 13.4).
The maximum allowable deflection of a dual hardness RRJ pipeline(OD>1200) ranges from 3.5-4%, depending upon OD and WallThickness (See Table 8.2 and Table 13.4).
Ring Bending StrainRing bending strain εb can be calculated from:
εb = Df (Δy) x t ≤ εb allD D
whereεb all = allowable ring bending strainDf = shape factor
= 3.333 x 10-6 ( SD ) + 0.00136E’
1.11 x 10-6 ( SD ) + 0.000151E’
εb all = 0.001449 for t ≤ 8= 0.001208 for t > 8
(At 100% MYS, ε = σ / Efor t ≤ 8, MYS = 300 Mpa ∴ε = 300 /207000 = 0.001449for t > 8 MYS = 250 MPa ∴ε = 250 /207000 = 0.001208)
Internal PressureThe applied internal pressure Pw shall not exceed the maximumallowable pressure Pr , i.e.
Pw ≤ Pr
Pr can be obtained from Table 8.1
DesignThe design of buried pipes with respect to trench design, backfillmaterial, compaction, loadings, etc depends on pipe materialstiffness, diameter, wall thickness, the allowable deflection limit, etc.Calculations of pipe deflection should be undertaken in accordancewith AS/NZS 2566, and compared against the allowable deflectionlimits.
Extensive testing undertaken by Tyco Water Technologies hasdetermined that a maximum safe allowable deflection limit of 4% of
the pipe outside diameter can be used for mild steel cementmortar lined pipes. This limit is to avoid significant cracking of thecement mortar lining.
The allowable deflection must also be within acceptable limits ofring bending stress in the steel pipe shell. This limit is determined by:
Stress limit = 0.00014 x (SMYS or NMYS) x D/t
For low D/t pipes (high stiffness) this deflection limit may be below4%. In those situations the stress limit will apply.
Additionally the limit for RRJ-S pipes is reduced for pipe sizesabove 660mm OD.
Table 13.4 gives the allowable deflection limits for buried mild steelcement mortar lined pipes. The limits should be used inconjunction with AS/NZS 2566 to determine the suitability of thetrench design, compaction, loadings, etc. Limits for pipe diametersoutside the range given in Table 13.4 can be provided on request.
It should be noted that these design limits are applicable to trenchdesign only, and do not apply to the field inspection of rubber ringjointed pipes. The higher stiffness in the joint region of rubber ringjointed pipes means that there is reduced deflection, andaccordingly reduced limits apply.
Field inspectionThe deflection limits for the field inspection of welded joints are thesame as those used for design. However for rubber ring jointedpipes a lower limit applies to the joint area, due to the stiffeningaffect of the joint, see Table 8.2.
13.6 Combined LoadingThe response to the combined external load and internal pressuremust satisfy
Pw + rc εb ≤ 1ηpPall ηb εb all η
whereηp = ηb = η = 1.39 (ref Table 2.1 AS 2566.1)
rc = re-rounding effect= 1- ( Pw ) for Pw ≤ 3.0 Mpa, or
3= 0 for Pw > 3.0 Mpa
S E C T I O N 1 3 | 97
S E C T I O N 1 3
Structural Design for Buried Pipelines
13.7 Ring buckling stabilityA buried pipeline may collapse or buckle from elastic instabilityresulting from loads or deformations.
The total of all loads should not be greater than the allowablebuckling pressure.
Maximum allowable buckling pressure
The allowable buckling pressure qall can be calculated from:
(i) For H ≥ 0.5m, the greater of
qall 1 = 24 SD x 10-3 or kPaFS (1-ν2)
qall 2 =(SD x 10-6)1/3. (E’)2/3 x 103 kPa
FS
(ii) For H < 0.5m
qall 1 = 24 SD x 10-3 kPaFS (1-ν2)
where
FS = factor of safety= 2.5 unless specified otherwise
H = height of ground surface above top of pipe m
External loads and combinationsThe summation of appropriate external loads including externalpressure and internal vacuum must satisfy the following equations:
• for H ≥ Hw
γ (H - Hw) + ( γL + γsub) x (De /2 + Hw) + wgs + wq + qv ≤ qall
where
Hw = height of water surface above top of pipe m
γsub = (ρs -1) γρs
γ = assessed unit weight of trench or embankment fill kN/m3
γL = assessed unit weight of liquid external to the pipe= 10.0 for water kN/m3
qv = internal vacuum kPa
Note: where ρs is not known, assume ρs = 2.65
i.e γsub = 0.623 γ
• for H < Hw
γL (De /2 + Hw) + γsub (De /2 + Hw) + wgs + wq + qv ≤ qall
Note: where the possibility of concurrent application of live loadsand vacuum is unlikely, the lesser of the terms wq and qv may beomitted from the equations above.
S E C T I O N 1 3 | 99
S E C T I O N 1 3
Structural Design for Buried Pipelines
S E C T I O N 1 3 | 101
Pipe Wall Maximum Allowable Pipe Deflection, mm
OD Thickness SSJ, B&S RRJ-S RRJ-D
Sintalock
(mm) (mm) (%) (%) (%)
324 5 2.7 2.7
324 6 2.3 2.3
337 5 2.8 2.8
337 6 2.4 2.4
356 5 3.0 3.0
356 6 2.5 2.5
406 5 3.4 3.4
406 6 2.8 2.8
419 5 3.5 3.5
419 6 2.9 2.9
457 5 3.8 3.8
457 6 3.2 3.2
508 5 4.0 4.0
508 6 3.6 3.6
559 5 4.0 4.0
559 6 3.9 3.9
610 5,6 4.0 4.0
648 5,6 4.0 4.0
648 8 3.4 3.4
660 5,6 4.0 4.0
660 8 3.5 3.5
700 5,6 4.0 3.9
700 8 3.7 3.9
711 5,6 4.0 3.9
711 8 3.7 3.7
762 5,6,8 4.0 3.8
800 6,8 4.0 3.7
813 6,8 4.0 3.7
Pipe Wall Maximum Allowable Pipe Deflection, mm
OD Thickness SSJ, B&S RRJ-S RRJ-D
Sintalock
(mm) (mm) (%) (%) (%)
914 6,8 4.0 3.5
960 8 4.0 3.4
960 10 3.4 3.4
1016 8 4.0 3.3
1016 10 3.6 3.3
1035 8 4.0 3.3
1035 10 3.6 3.3
1067 8 4.0 3.2
1067 10 3.7 3.2
1085 8 4.0 3.2
1085 10 3.8 3.2
1125 8 4.0 3.1
1125 10 3.9 3.1
1200 8,10 4.0 2.9 4.0
1200 12 3.5 3.5
1219 8,10 4.0 2.9 4.0
1219 12 3.6 3.6
1290 10 4.0 2.8 4.0
1290 12 3.8 3.8
1404 10,12 4.0 4.0
1422 10,12 4.0 4.0
1440 10,12 4.0 4.0
1500 10,12 4.0 4.0
1575 10,12 4.0 4.0
1626 12 4.0 4.0
1750 12 4.0 4.0
1829 12 4.0 4.0
S E C T I O N 1 3
Structural Design for Buried Pipelines
Table 13.4 Maximum Allowable Pipe Deflection for Design of SKCL Buried Pipe
Key:
RRJ-S = Single hardness rubber ring joint
RRJ-D = Dual hardness rubber ring joint
Free Span & StructuralLoading
102
section14
104 | S E C T I O N 1 4
14.1 General considerationsDue to its high tensile strength, steel pipe is well suited to aboveground installations, enabling longer spans and fewer supportsthan are possible with other materials.
SupportsAbove ground pipelines can be supported in a number of waysdepending on such factors as pipe size, the span required andeconomics.
Where the pipe itself acts as a structural span, it may besupported on suitably padded saddles which may be fixed onpiers attached to hangers or cantilevers.
SaddlesThe angle of the contact area of saddles usually varies from 90° to 120°, with the latter being a convenient design. For equal load,the larger the contact angle the lower the saddle stresses.
Saddle supports cause critical points of stress in the steel pipe walladjacent to the saddle edges. The critical stresses are practicallyindependent of the width of the saddle and accordingly the saddlewidth may be determined by the design width of the pier orcantilever. In the case of hangers the saddle width is determinedby the choice of materials at the pipe-saddle interface.
Should overstress be encountered it is often more economical toincrease the wall thickness of the pipe than to provide stiffeningrings, especially where diameter of the pipes is 900 mm or less.This thickening may apply to the entire span or for a distance eachside of the saddle support of approximately two pipe diametersplus the width of the saddle.
Pipes should be held in each saddle by steel hold-down strapsbolted to the main structural support.
Pipe-saddle interfaceDepending on the coating finish specified for the pipe and thefrequency of any movement relative to the saddle, the interfacemay require padding.
Where coating damage is inconsequential padding is unnecessary.When coatings are to be protected in installation and againstlocalised stress a neoprene pad is recommended.
Where the pipe saddle interface must accommodate sliding, anarrangement of suitable materials must be considered. These include PTFE, teflon and aluminium. In this case thearrangement should ensure that the sliding capacity is maintained, free of possible contamination by grit or dust. Multiple strips in the padding combination may be necessary.
Sag pocketsWhere it is required to completely drain intermittently supportedpipelines, care must be taken to avoid sag pockets. To eliminatesuch pockets, each downstream support level must be lower thanthe adjacent upstream support by an amount that exceeds the sagof the pipe between the supports.
A convenient rule is to ensure the elevation of one end is higherthan the other by an amount equal to four times the deflectioncalculated at the mid span of the pipe. The required gradient, Mbetween supports is thus calculated:
M = 4y
L
whereM = Gradienty = deflection mmL = span mm
General design considerationsIt should be remembered that the theory of flexure applies to apipe supported at intervals, held circular at and between supportsand completely filled with water.
If the pipe is only partially filled and the cross section betweensupports becomes out of round, the maximum fibre stress isconsiderably greater than indicated by the ordinary flexure formula,being highest for the half filled condition. See Schorer (ref 12).
When determining the actual position of the support centres itshould be remembered that lengths of individual pipes are subjectto manufacturing tolerances. (Refer to AS 1579).
In beam bending analyses and Table 14.1 the contribution to beamstiffness by the cement mortar lining has been ignored. The sectionproperties of steel shell only have been used.
Actual short term beam deflections will thus be smaller thancalculated, however long term deflections are likely to be realiseddue to creep of the CML. The weight component of SINTAKOTEhas also been ignored in these analyses and Table 14.1.
14.2 Maximum span for welded jointpipelinesA welded joint pipeline supported on saddles is treated as acontinuous beam as shown below. It is recommended that weldedjoints between supports be fully welded, either by full butt weld orby double-weld lap joints. If joints at supports are thus fully weldedthe pipeline is assumed to act strictly as a continuous beam.
When single welded lap joints are employed at or near supports,
S E C T I O N 1 4 | 105
the analysis conservatively assumes the joint is not absolutely rigidand allows some moment redistribution. This effectively reducesbending moment on the joint and the maximum allowable span.
Above ground rubber ring jointed pipe supported by saddles is treatedas a simply supported beam and is considered in the next section.
Consider a welded joint pipeline. This can be treated as a built-in beam.
Bending moment at A and B - MA = MB = w L2 Nm12
Bending moment at C - MC = w L2 Nm24
where
w = (M1 +M2 +MW) x 9.81 N/mM1 = unit mass of steel shell
= 0.02466 (D – t) t kg/mM2 = unit mass of cement mortar lining
= 0.00755 ( D – 2t – T)T kg/mMW = unit mass of water, pipe full
= p (D - 2t -2T)2 kg/m
4000where
D = outside diameter of pipe mmt = steel wall thickness mmT = cement mortar lining thickness mmL = span mPs = saddle reaction Np = density = 1000 kg/m3 (for water) kg/m3
Maximum bending stressThe maximum bending stress σB , occurs at A and B:
σB = 1000 MB MPaZ
whereZ = elastic section modulus of pipe
= π ( D4 – d4 ) mm3
32 D= π r2 t mm3
D = outside diameter of pipe mm
d = inside diameter of pipe mmt = wall thickness mmr = pipe mean radius = (D-t) mm
2
Cracking and spalling of Cement Lining in steel pipes occurs whenthe longitudinal bending stress in the pipe reaches 80 MPa.Therefore a tentative maximum longitudinal bending stress of80 MPa has been used in the following analysis. This limit can bechanged by the designer to suit particular requirements. Correctionfactors are included to achieve this.
By substituting MB = wL2/12 in the bending stress equation formaximum moments at A and B and rearranging we have:
L1 = ( 12 σB Z )1/2 m
1000 w
= ( 12 x 80 x Z )1/2
1000 (M1 +M2 +MW) x 9.81 m
= ( 0.09786 Z )1/2
M1+M2+MW m
This equation holds for fully welded pipe, that is a pipe with either a full butt weld or a double weld lap joint. For spans withpipes jointed at supports with only one weld, for example, a single welded lap joint, the above equation is modified to:
L2 = ( 0.08155 Z )1/2
M1+M2+MW m
to reduce the structural bending load on the single circumferential weld.
If the allowable bending stress required is other than 80 MPa, theresultant value of “L” in the above equations should be multipliedby the appropriate correction factor:
For example, if new value of σB = 65 MPathen the correction factor = (65/80)1/2 = 0.90
The recommended maximum spans for continuous fully welded (buttwelded or double lap welded) and single lap welded cement mortarlined pipe are given in Table 14.1. This table takes into account thetotal weight of pipes full of water with a density of 1000 kg/m3.
Spans have been calculated allowing for a maximum bending stress of80 MPa. This may be increased if higher bending stresses are allowableon a project. However, it is important that deflection, buckling andother stresses (Poisson, temperature and saddle stresses) also bechecked before deciding on the acceptable span.
Note: the contribution of CML to the section modulus isconservatively taken to be zero.
Figure 14.1 – Supported Beam
W
A C B
L
Ps Ps
S E C T I O N 1 4
Free Span and Structural Loading
106 | S E C T I O N 1 4
14.3 Maximum span for simplysupported pipelinesWhere SINTAJOINT pipelines adjoin a fully welded span or wherespan support joints allow angular rotation, the span is regarded asbeing simply supported. Hence the moment at the support isminimum and taken to be zero while the maximum bendingmoment occurs at the mid-point of the span and is equal to:
MC = wL2 Nm8
Hence the span can be calculated by using the equation:
L3 = ( 0.0652 Z )1/2
M1+M2+MW m
In this equation the allowable bending stress is taken as 80 MPa. If the allowable stress is other than 80 MPa the resultant value of L3
should be multiplied by the correction factor shown in Section 14.2.
The recommended maximum spans for simply supported pipelinesare provided in Table 14.1. Once the span is determined,deflection, buckling and Poisson, temperature and saddle stressesshould be checked.
Above ground SINTAJOINT pipesIt is recommended that with above ground rubber ring jointedpipelines, a support be located behind each socket, see figure 14.2.
Pipes must be fixed to supports with metal straps so that axialmovement due to expansion or contraction resulting from temperaturevariations is taken up at individual joints along the pipeline. In additionjoints should be assembled with spigots withdrawn 4mm to 5mm toaccommodate these thermal movements.
Pipes supported in this way are capable of free deflection andaxial movement at the joints which can accommodate any normalmovement of the pipe support. Purpose-designed anchoragemust be able to resist thrusts developed by internal pressure atbends, tees and other thrust fittings.
Suspended spans are not recommended for SINTAJOINT pipes.
Safe span for SINTAJOINT pipesSINTAJOINT pipe with diameters up to DN600 with effectivelengths of 13.5m are satisfactory for simply supported spansusing a single pipe. For sizes above DN600, shorter spans orspecial tolerance pipes are required to avoid sealing problemscaused by shear loads at the joints. In this size range adviceshould be sought from Tyco Water’s marketing offices.
14.4 DeflectionIn the case of a simply supported pipe, for example, a SINTAJOINT
at supports, the mid span deflection can be determined from:
δ = 5wL4
384 E I
whereδ = deflection mmw = [(M1 +M2 +MW) x 9.81]/ 1000 N/mmL = span of simply supported pipe mmE = Young’s modulus for steel
= 207,000 MPa
I = π (D4 - d4 ) = π Rav t mm4
64
D = external diameter of the pipe mmd = internal diameter of the pipe mmRav = pipe mean radius = (D-t)/2 mmt = pipe wall thickness mm
In the case of a pipe with single welded lap joints at supports, themid span deflection is determined from:
δ = 3 w L4 mm384 E I
For a pipe with butt welded or double welded lap joints at supportsthe mid span deflection is determined from:
δ = w L4 mm 384 E I
Pipe deflection should be kept within 1/360 span.
14.5 Mid span stressesStresses in the pipe between pipe supports are
• Longitudinal stresses, from a combination of- beam bending- temperature stress- Poisson stress (for welded pipes)- saddle friction (for unrestrained pipes)
• Circumferential stress from hoop stress due to internal pressure
Figure 14.2 - Pier support for above ground SINTAJOINT pipelines
Bearing material toaccomodateexpansion
movement wherenecessary
Hold down over bearing material
The equivalent stress (σe) based on Hencky-Mises failure theory iscalculated from the resultant longitudinal (σL) and circumferential(σc) stresses as follows
σe = (σL.2 + σc.2 - σL.σc) 0.5
This stress should not exceed 55% of the material yield stress.Also beam bending stress should not exceed 80MPa to avoid riskof spalling the cement mortar lining.
14.6 Stresses at pipe supportsStresses at pipe supports are
• Longitudinal stresses, from a combination of- beam bending- temperature stress- Poisson stress (for welded pipes)- saddle friction (for unrestrained pipes)
• Circumferential stresses from a combination of
- hoop stress from internal pressure- localised stress at the tip of the saddle support
The equivalent stress (σe) based on Hencky-Mises failure theory iscalculated from the resultant longitudinal (σL) and circumferential(σc) stresses as follows
σe = (σL.2 + σc.2 - σL.σc) 0.5
At the saddle support, this stress should not exceed the materialyield stress. It is not necessary to provide a safety factor becausetests have shown that because this is a very localised condition,the resulting design will have a factor of safety of 2.
Note: Stresses should be calculated for both pipe full with nopressure and pipe full with internal pressure conditions.
Also beam bending stress should not exceed 80MPa to avoid riskof spalling the cement mortar lining.
Where ring girders are used to stiffen the pipe at the supports,additional stresses need to be considered. Refer AWWA M11 (ref 11).
S E C T I O N 1 4 | 107
S E C T I O N 1 4
Free Span and Structural Loading
108 | S E C T I O N 1 4
S E C T I O N 1 4 | 109
14.7 Localised saddle stressThe localised saddle stress (σs) is a circumferential bending stresswhich tends to decrease as the pipe pressure increases.Therefore the critical condition is usually with the pipe full and nointernal pressure.
σs = kPs x loge(ro)t2 t
whereσs = localised saddle stress MPak = factor = 0.02 - 0.00012 (θs – 90)θs = saddle angle degreesPs = total load on saddle or saddle reaction Nt = pipe wall thickness mmro = outside radius of pipe mm
14.8 Hoop and Poisson stressesThe internal pressure results in a circumferential hoop stress (σh) inthe pipe,
whereσh = PD
2t
In the case of axially restrained, that is welded joint pipelines, theinternal pressure results in a longitudinal stress due to the Poissoneffect.
The Poisson stress = νσh
where
ν = Poisson’s ratio = 0.27
14.9 Temperature stressTemperature changes induce stress in axially restrained pipelines.The difference between the temperature at which the pipeline wasconstructed and the service temperature should be considered,the stress (σT) induced being estimated by
σT = E α ΔT MPa
where
E = Young’s modulus for steel= 207,000 MPa
α = coefficient of linear expansion for steel= 12 x 10-6 mm/mm/°C
ΔT = difference between pipeline operating and installation
Temperature °C
14.10 Saddle frictionFor unrestrained pipes (rubber ring jointed or welded with anexpansion joint) relatively small longitudinal stresses are calculatedas follows
Stress due to friction resistance at pipe saddle = μ(Ww + Wp)Lπ(D + t)t
where
μ = friction coefficient between surfaces of pipe and saddleWw + Wp = unit weight of pipe full of waterL = span length
Stress due to friction resistance in the expansion joint = (Ref 11)
Stress due to internal pressure acting on end of pipe at expansionjoint = p
S E C T I O N 1 4
Free Span and Structural Loading
110 | S E C T I O N 1 4
Table 14.1 - Maximum span for Simply Supported MSCL pipe. (Bending stresses only)
Section Dimensions Component Masses Second Safe Spanmoment Section Fully Single Lap Simply
Steel Shell CML SK Steel CML Water Total Mass of area Modulus Welded Weld SupportedOD t T ts M1 M2 Mw MTOT I x 106 Z x 103 L1 L2 L3
mm mm mm mm kg/m kg/m kg/m kg/m mm4 mm3 m m m114 4.8 9 1.6 12.9 6.5 5.9 25.3 2 43 12.9 11.8 10.5168 5.0 9 1.6 20.1 10.1 15.4 45.6 8 101 14.7 13.5 12.0190 5.0 9 1.6 22.8 11.6 20.6 55.0 12 131 15.3 13.9 12.4219 5.0 9 1.6 26.4 13.6 28.6 68.6 19 176 15.8 14.4 12.9240 5.0 9 1.6 29.0 15.0 35.3 79.3 25 212 16.2 14.8 13.2257 5.0 9 1.6 31.1 16.2 41.2 88.4 31 244 16.4 15.0 13.4273 5.0 9 1.6 33.0 17.3 47.1 97.4 38 277 16.7 15.2 13.6290 5.0 12 1.8 35.1 24.3 51.4 110.9 45 313 16.6 15.2 13.6324 4.0 12 1.8 31.6 27.5 66.9 126.0 51 318 15.7 14.3 12.8324 4.5 12 1.8 35.5 27.5 66.5 129.4 58 356 16.4 15.0 13.4324 5.0 12 1.8 39.3 27.4 66.0 132.7 64 393 17.0 15.5 13.9324 6.0 12 1.8 47.1 27.2 65.1 139.3 76 467 18.1 16.5 14.8337 4.0 12 1.8 32.8 28.7 73.0 134.6 58 344 15.8 14.4 12.9337 4.5 12 1.8 36.9 28.6 72.5 138.1 65 385 16.5 15.1 13.5337 5.0 12 1.8 40.9 28.5 72.1 141.5 72 426 17.2 15.7 14.0337 6.0 12 1.8 49.0 28.4 71.1 148.5 85 507 18.3 16.7 14.9356 4.0 12 1.8 34.7 30.4 82.4 147.6 68 385 16.0 14.6 13.0356 4.5 12 1.8 39.0 30.4 81.9 151.3 77 431 16.7 15.2 13.6356 5.0 12 1.8 43.3 30.3 81.4 154.9 85 477 17.4 15.8 14.2356 6.0 12 1.8 51.8 30.1 80.4 162.2 101 567 18.5 16.9 15.1406 4.0 12 1.8 39.7 35.0 109.8 184.4 102 502 16.3 14.9 13.3406 4.5 12 1.8 44.6 34.9 109.2 188.7 114 563 17.1 15.6 14.0406 5.0 12 1.8 49.4 34.8 108.6 192.9 127 623 17.8 16.2 14.5406 6.0 12 1.8 59.2 34.6 107.5 201.3 151 742 19.0 17.3 15.5406 8.0 12 1.8 78.5 34.2 105.2 217.9 198 975 20.9 19.1 17.1419 4.0 12 1.8 40.9 36.1 117.6 194.7 112 536 16.4 15.0 13.4419 4.5 12 1.8 46.0 36.1 117.0 199.0 126 600 17.2 15.7 14.0419 5.0 12 1.8 51.0 36.0 116.4 203.4 139 665 17.9 16.3 14.6419 6.0 12 1.8 61.1 35.8 115.2 212.0 166 792 19.1 17.5 15.6419 8.0 12 1.8 81.1 35.4 112.8 229.3 218 1,041 21.1 19.2 17.2457 4.0 12 1.8 44.7 39.6 141.8 226.1 146 639 16.6 15.2 13.6457 4.5 12 1.8 50.2 39.5 141.1 230.8 164 716 17.4 15.9 14.2457 5.0 12 1.8 55.7 39.4 140.5 235.6 181 793 18.2 16.6 14.8457 6.0 12 1.8 66.7 39.2 139.1 245.1 216 945 19.4 17.7 15.9457 8.0 12 1.8 88.6 38.9 136.5 263.9 284 1,244 21.5 19.6 17.5502 4.0 12 1.8 49.1 43.7 173.4 266.2 194 773 16.9 15.4 13.8502 4.5 12 1.8 55.2 43.6 172.7 271.5 217 866 17.7 16.1 14.4502 5.0 12 1.8 61.3 43.5 171.9 276.7 241 960 18.4 16.8 15.0502 6.0 12 1.8 73.4 43.3 170.5 287.2 287 1,145 19.8 18.0 16.1502 8.0 12 1.8 97.5 42.9 167.6 308.0 379 1,508 21.9 20.0 17.9508 4.0 12 1.8 49.7 44.2 177.9 271.8 201 791 16.9 15.4 13.8508 4.5 12 1.8 55.9 44.1 177.1 277.1 225 888 17.7 16.2 14.5
S E C T I O N 1 4 | 111
S E C T I O N 1 4
Free Span and Structural Loading
Section Dimensions Component Masses Second Safe Spanmoment Section Fully Single Lap Simply
Steel Shell CML SK Steel CML Water Total Mass of area Modulus Welded Weld SupportedOD t T ts M1 M2 Mw MTOT I x 106 Z x 103 L1 L2 L3
mm mm mm mm kg/m kg/m kg/m kg/m mm4 mm3 m m m508 5.0 12 1.8 62.0 44.0 176.4 282.4 250 983 18.5 16.9 15.1508 6.0 12 1.8 74.3 43.9 174.9 293.0 298 1,173 19.8 18.1 16.2508 8.0 12 1.8 98.6 43.5 171.9 314.1 393 1,545 21.9 20.0 17.9559 4.0 12 2.0 54.7 48.8 218.0 321.6 268 960 17.1 15.6 14.0559 4.5 12 2.0 61.5 48.7 217.2 327.5 301 1,077 17.9 16.4 14.6559 5.0 12 2.0 68.3 48.7 216.4 333.3 334 1,194 18.7 17.1 15.3559 6.0 12 2.0 81.8 48.5 214.7 345.0 398 1,425 20.1 18.4 16.4559 8.0 12 2.0 108.7 48.1 211.4 368.3 525 1,879 22.3 20.4 18.2610 4.5 12 2.0 67.2 53.4 261.3 381.9 392 1,286 18.1 16.6 14.8610 5.0 12 2.0 74.6 53.3 260.4 388.3 435 1,425 18.9 17.3 15.5610 6.0 12 2.0 89.4 53.1 258.6 401.1 519 1,701 20.4 18.6 16.6610 8.0 12 2.0 118.8 52.7 255.0 426.5 685 2,246 22.7 20.7 18.5610 9.5 12 2.0 140.7 52.5 252.4 445.5 807 2,647 24.1 22.0 19.7648 4.5 12 2.0 71.4 56.8 296.9 425.1 471 1,453 18.3 16.7 14.9648 5.0 12 2.0 79.3 56.7 295.9 431.9 522 1,610 19.1 17.4 15.6648 6.0 12 2.0 95.0 56.5 294.0 445.5 623 1,923 20.6 18.8 16.8648 8.0 12 2.0 126.3 56.2 290.2 472.6 823 2,541 22.9 20.9 18.7648 9.5 12 2.0 149.6 55.9 287.3 492.8 971 2,996 24.4 22.3 19.9660 4.5 12 2.0 72.7 57.9 308.6 439.2 497 1,507 18.3 16.7 15.0660 5.0 12 2.0 80.8 57.8 307.6 446.2 551 1,671 19.1 17.5 15.6660 6.0 12 2.0 96.8 57.6 305.7 460.0 659 1,996 20.6 18.8 16.8660 8.0 12 2.0 128.6 57.3 301.8 487.6 870 2,637 23.0 21.0 18.8660 9.5 12 2.0 152.4 57.0 298.8 508.2 1,026 3,110 24.5 22.3 20.0700 4.5 12 2.0 77.2 61.5 349.2 487.9 594 1,698 18.5 16.8 15.1700 5.0 12 2.0 85.7 61.4 348.2 495.3 659 1,882 19.3 17.6 15.7700 6.0 12 2.0 102.7 61.2 346.1 510.0 787 2,249 20.8 19.0 17.0700 8.0 12 2.0 136.5 60.9 341.9 539.3 1,041 2,973 23.2 21.2 19.0700 9.5 12 2.0 161.8 60.6 338.8 561.2 1,228 3,507 24.7 22.6 20.2700 12.0 12 2.0 203.6 60.2 333.7 597.5 1,534 4,382 26.8 24.5 21.9711 5.0 12 2.0 87.0 62.4 359.8 509.3 691 1,943 19.3 17.6 15.8711 6.0 12 2.0 104.3 62.2 357.7 524.2 825 2,321 20.8 19.0 17.0711 8.0 12 2.0 138.7 61.9 353.4 554.0 1,091 3,069 23.3 21.3 19.0711 9.5 12 2.0 164.3 61.6 350.3 576.2 1,287 3,621 24.8 22.6 20.2711 12.0 12 2.0 206.8 61.2 345.1 613.1 1,609 4,525 26.9 24.5 21.9762 5.0 12 2.0 93.3 67.0 416.0 576.4 851 2,234 19.5 17.8 15.9762 6.0 12 2.0 111.9 66.9 413.8 592.5 1,018 2,671 21.0 19.2 17.1762 8.0 12 2.0 148.7 66.5 409.2 624.5 1,346 3,533 23.5 21.5 19.2762 9.5 12 2.0 176.3 66.2 405.8 648.3 1,589 4,170 25.1 22.9 20.5762 12.0 12 2.0 221.9 65.8 400.2 687.9 1,987 5,215 27.2 24.9 22.2800 5.0 16 2.3 98.0 93.5 451.0 642.6 986 2,465 19.4 17.7 15.8800 6.0 16 2.3 117.5 93.3 448.7 659.4 1,179 2,947 20.9 19.1 17.1800 8.0 16 2.3 156.2 92.8 443.9 692.9 1,560 3,900 23.5 21.4 19.2800 9.5 16 2.3 185.2 92.4 440.4 718.0 1,842 4,605 25.1 22.9 20.4
112 | S E C T I O N 1 4
Section Dimensions Component Masses Second Safe Spanmoment Section Fully Single Lap Simply
Steel Shell CML SK Steel CML Water Total Mass of area Modulus Welded Weld SupportedOD t T ts M1 M2 Mw MTOT I x 106 Z x 103 L1 L2 L3
mm mm mm mm kg/m kg/m kg/m kg/m mm4 mm3 m m m800 12.0 16 2.3 233.2 91.8 434.5 759.5 2,305 5,762 27.2 24.9 22.2813 5.0 16 2.3 99.6 95.1 466.6 661.3 1,035 2,547 19.4 17.7 15.8813 6.0 16 2.3 119.4 94.8 464.2 678.5 1,238 3,045 21.0 19.1 17.1813 7.0 16 2.3 139.1 94.6 461.8 695.5 1,439 3,539 22.3 20.4 18.2813 8.0 16 2.3 158.8 94.3 459.4 712.6 1,638 4,030 23.5 21.5 19.2813 9.5 16 2.3 188.2 94.0 455.8 738.0 1,934 4,758 25.1 22.9 20.5813 12.0 16 2.3 237.0 93.4 449.8 780.3 2,421 5,955 27.3 24.9 22.3914 6.0 16 2.3 134.3 107.0 594.2 835.5 1,763 3,858 21.3 19.4 17.4914 7.0 16 2.3 156.6 106.8 591.4 854.8 2,050 4,486 22.7 20.7 18.5914 8.0 16 2.3 178.7 106.5 588.7 874.0 2,335 5,110 23.9 21.8 19.5914 10.0 16 2.3 222.9 106.1 583.3 912.3 2,900 6,345 26.1 23.8 21.3914 12.0 16 2.3 266.9 105.6 577.9 950.4 3,457 7,564 27.9 25.5 22.8960 6.0 16 2.3 141.2 112.6 658.7 912.4 2,045 4,260 21.4 19.5 17.4960 8.0 16 2.3 187.8 112.1 652.9 952.8 2,709 5,644 24.1 22.0 19.7960 10.0 16 2.3 234.3 111.6 647.2 993.1 3,365 7,011 26.3 24.0 21.5960 12.0 16 2.3 280.5 111.1 641.5 1033.2 4,013 8,360 28.1 25.7 23.0972 6.0 16 2.3 142.9 114.0 676.0 933.0 2,123 4,368 21.4 19.5 17.5972 8.0 16 2.3 190.2 113.6 670.2 973.9 2,813 5,788 24.1 22.0 19.7972 10.0 16 2.3 237.2 113.1 664.4 1014.7 3,494 7,190 26.3 24.0 21.5972 12.0 16 2.3 284.1 112.6 658.7 1055.3 4,167 8,574 28.2 25.7 23.01016 8.0 16 2.3 198.9 118.9 735.6 1053.3 3,216 6,331 24.3 22.1 19.81016 10.0 16 2.3 248.1 118.4 729.5 1096.0 3,996 7,866 26.5 24.2 21.61016 12.0 16 2.3 297.1 117.9 723.5 1138.5 4,767 9,383 28.4 25.9 23.21035 8.0 16 2.3 202.6 121.2 764.7 1088.5 3,401 6,573 24.3 22.2 19.81035 10.0 16 2.3 252.8 120.7 758.5 1132.0 4,227 8,168 26.6 24.3 21.71035 12.0 16 2.3 302.7 120.2 752.4 1175.3 5,043 9,744 28.5 26.0 23.21067 8.0 16 2.3 208.9 125.0 815.1 1149.1 3,729 6,990 24.4 22.3 19.91067 10.0 16 2.3 260.7 124.5 808.7 1193.9 4,635 8,688 26.7 24.4 21.81067 12.0 16 2.3 312.2 124.1 802.4 1238.6 5,531 10,367 28.6 26.1 23.41085 8.0 16 2.3 212.5 127.2 844.2 1183.8 3,923 7,231 24.4 22.3 20.01085 10.0 16 2.3 265.1 126.7 837.7 1229.5 4,876 8,988 26.7 24.4 21.81085 12.0 16 2.3 317.5 126.2 831.2 1274.9 5,819 10,726 28.7 26.2 23.41125 8.0 16 2.3 220.4 132.0 910.5 1262.9 4,376 7,780 24.6 22.4 20.01125 10.0 16 2.3 275.0 131.6 903.8 1310.3 5,441 9,673 26.9 24.5 21.91125 12.0 16 2.3 329.4 131.1 897.1 1357.5 6,494 11,545 28.8 26.3 23.51200 8.0 16 2.3 235.2 141.1 1041.8 1418.0 5,318 8,864 24.7 22.6 20.21200 10.0 16 2.3 293.5 140.6 1034.6 1468.6 6,614 11,024 27.1 24.7 22.11200 12.0 16 2.3 351.6 140.1 1027.4 1519.0 7,897 13,162 29.1 26.6 23.81219 8.0 16 2.3 238.9 143.4 1076.4 1458.7 5,577 9,149 24.8 22.6 20.21219 9.0 16 2.3 268.5 143.1 1072.8 1484.4 6,258 10,267 26.0 23.7 21.21219 10.0 16 2.3 298.1 142.9 1069.1 1510.1 6,936 11,380 27.2 24.8 22.21219 12.0 16 2.3 357.2 142.4 1061.8 1561.4 8,282 13,588 29.2 26.6 23.81283 8.0 19 2.3 251.5 179.0 1185.7 1616.3 6,508 10,145 24.8 22.6 20.2
S E C T I O N 1 4 | 113
S E C T I O N 1 4
Free Span and Structural Loading
Section Dimensions Component Masses Second Safe Spanmoment Section Fully Single Lap Simply
Steel Shell CML SK Steel CML Water Total Mass of area Modulus Welded Weld SupportedOD t T ts M1 M2 Mw MTOT I x 106 Z x 103 L1 L2 L3
mm mm mm mm kg/m kg/m kg/m kg/m mm4 mm3 m m m1283 10 19 2.3 313.9 178.5 1178.0 1670.4 8,097 12,622 27.2 24.8 22.21283 12 19 2.3 376.1 177.9 1170.3 1724.3 9,671 15,075 29.2 26.7 23.91283 16 19 2.3 499.9 176.7 1155.0 1831.7 12,773 19,911 32.6 29.8 26.61290 8 19 2.3 252.9 180.0 1199.2 1632.2 6,616 10,257 24.8 22.6 20.21290 10 19 2.3 315.6 179.5 1191.5 1686.6 8,231 12,762 27.2 24.8 22.21290 12 19 2.3 378.2 178.9 1183.8 1740.8 9,831 15,242 29.3 26.7 23.91290 16 19 2.3 502.7 177.7 1168.4 1848.8 12,986 20,133 32.6 29.8 26.61404 10 19 2.3 343.8 195.8 1422.2 1961.8 10,632 15,146 27.5 25.1 22.41404 12 19 2.3 411.9 195.2 1413.8 2020.9 12,704 18,097 29.6 27.0 24.21422 10 19 2.3 348.2 198.4 1460.5 2007.1 11,050 15,541 27.5 25.1 22.51422 11 19 2.3 382.7 198.1 1456.2 2037.1 12,129 17,059 28.6 26.1 23.41422 12 19 2.3 417.2 197.8 1451.9 2067.0 13,203 18,570 29.7 27.1 24.21440 10 19 2.3 352.6 201.0 1499.3 2052.9 11,478 15,941 27.6 25.2 22.51440 12 19 2.3 422.6 200.4 1490.6 2113.6 13,715 19,049 29.7 27.1 24.21440 16 19 2.3 561.9 199.3 1473.4 2234.5 18,134 25,186 33.2 30.3 27.11451 10 19 2.3 355.4 202.6 1523.3 2081.2 11,744 16,188 27.6 25.2 22.51451 12 19 2.3 425.8 202.0 1514.5 2142.3 14,035 19,345 29.7 27.1 24.31451 16 19 2.3 566.2 200.8 1497.1 2264.1 18,557 25,579 33.2 30.4 27.11500 10 19 2.3 367.4 209.6 1632.3 2209.3 12,984 17,312 27.7 25.3 22.61500 12 19 2.3 440.3 209.0 1623.3 2272.6 15,518 20,690 29.8 27.2 24.41500 16 19 2.3 585.5 207.9 1605.2 2398.6 20,524 27,365 33.4 30.5 27.31575 10 19 2.3 385.9 220.3 1806.5 2412.8 15,045 19,104 27.8 25.4 22.71575 12 19 2.3 462.5 219.8 1797.0 2479.3 17,984 22,837 30.0 27.4 24.51575 16 19 2.3 615.1 218.6 1778.0 2611.8 23,796 30,217 33.6 30.7 27.51600 10 19 2.3 392.1 223.9 1866.5 2482.6 15,777 19,722 27.9 25.5 22.81600 12 19 2.3 469.9 223.4 1856.9 2550.1 18,861 23,577 30.1 27.5 24.61600 16 19 2.3 625.0 222.2 1837.6 2684.8 24,959 31,199 33.7 30.8 27.51626 10 19 2.3 398.5 227.7 1930.0 2556.2 16,564 20,374 27.9 25.5 22.81626 12 19 2.3 477.6 227.1 1920.2 2624.9 19,803 24,358 30.1 27.5 24.61626 16 19 2.3 635.2 225.9 1900.6 2761.8 26,208 32,236 33.8 30.9 27.61750 12 19 2.3 514.3 244.9 2236.7 2995.9 24,727 28,259 30.4 27.7 24.81750 16 19 2.3 684.2 243.7 2215.6 3143.5 32,742 37,420 34.1 31.2 27.91829 12 19 2.3 537.7 256.2 2451.0 3244.9 28,254 30,896 30.5 27.9 24.91829 16 19 2.3 715.3 255.1 2428.9 3399.2 37,424 40,923 34.3 31.3 28.01981 12 19 2.3 582.7 278.0 2890.8 3751.5 35,955 36,300 30.8 28.1 25.11981 16 19 2.3 775.3 276.9 2866.8 3918.9 47,648 48,105 34.7 31.6 28.32159 12 19 2.3 635.3 303.5 3452.0 4390.8 46,614 43,181 31.0 28.3 25.32159 16 19 2.3 845.5 302.4 3425.7 4573.6 61,805 57,254 35.0 32.0 28.6
AppurtenanceDesign
114
section15
15.1 IntroductionTees, laterals and bifurcations provide a means of dividing or unitingflow in pipelines. These fittings do not have the same resistance tointernal pressure as straight pipe of a similar size.
Not all appurtenances need reinforcement, because the wallthickness used is generally thicker than that required for pressureconsiderations. However, if a pipe is operating at or near thedesign pressure the strength of the fitting should be checked andreinforced if necessary.
Generally, reinforcement is made available by the addition of alocalised thickening of the pipe, called a collar reinforcement.Other times a thicker wall pipe may be used, called a wrapperplate design, or in the case of bifurcations and tees, crotch platesmay be necessary.
This section only deals with the design of reinforcements of nozzleshaving a d/D ratio ≤ 0.7 and a PDV value ≤ 6000. For ratios of d/Dgreater than 0.7, refer to AWWA M11 – Manual of Water SupplyPractices - Steel Pipe – A guide for Design and Installation.
15.2 Design methodThe method generally adopted for reinforcements of nozzles is the“Area - Replacement” method. Here the area of the wall removedfrom the pipe so as to attach the fitting is replaced by means of acollar, welded to the outside surface of the pipe. The area removedis based on the maximum width of the opening measured along thelongitudinal axis of the pipe, multiplied by the pipe wall pressurethickness required. Any excess area available in the pipe wall aswell as any excess area available in the branch wall for a distance of
2.5ty normal to the main pipe surface but measured from thesurface of the reinforcing collar, must be taken into consideration.
Consider the following:
PDV = 5.7087Pd2
≤ 6000(D sin2 θ )
P = design pressure MPaD = outside diameter of the pipe mmd = outside diameter of the branch mmθ = angle of the nozzle degreesTy = main pipe wall thickness mmty = branch pipe wall thickness mmM = factor (see Table 15.1)
Theoretical wall thickness of the main pipe:
Tr = PD mm2σall
Theoretical wall thickness of the branch:
tr = Pd mm2σall
Area removed:
AR = M Tr (d-2ty ) mm2
sinθ
Area available as excess
AA = (d-2ty) (Ty –Tr ) + 5ty ( ty - tr ) mm2
sinθ
Reinforcement areaAW = AR – AA mm2
= 2wT
116 | S E C T I O N 1 5
Figure 15.1 – Reinforcement of Openings
d /SIN θ
θ
Minimum reinforcement thickness T
w = d mm2 sinθ
T = AW = AWsinθ2w d mm
The overall width W, of the collar should not be less than 1.67d/sinθ
and should not exceed 2.0d/sinθ, i.e the collar edge width w, shouldbe within 0.333d/sinθ ≤ w ≤ 0.5d/sinθ. Collar edge width in thecircumferential direction should not be less than the longitudinal edgewidth. Nozzles should not be placed on the pipe weld seams.
In Fig. 15.1, the area Ty (d-2ty) / sinθ represents the section of themain pipe removed for the branch opening. The hoop tension dueto pressure that would be taken by the area removed must becarried by the total areas represented by 2wT and 5ty (ty – tr ), or2.5ty (ty – tr ) on each side of the branch.
Table 15.1- PDV values and M factors for d/D ratios
15.3 Example of a calculation fordetermination of reinforcement size.Consider a pipe having a diameter of 914mm and a wall thickness of6 mm with a design pressure of 2 MPa, with a branch 610mmdiameter by 5mm wall thickness set at an angle of 75°. Pipe materialhas a MYS of 300 MPa and the allowable stress σall = 0.7 MYS
PDV= 5.7087 x 2 x 6102 / (914 sin2 75 )= 4982 < 6000
M factor from Table 15.1 = 0.00025 x 4982 = 1.25( Note: if θ = 60°, PDV = 6224 > 6000. Refer to AWWA – M11 )
σH = 2 x 914 / (2 x 6 ) = 152.3 MPaσall = 0.72 x 300 = 216.0 MPad/D = 610/914 = 0.67 < 0.7 ( O.K.)Ty = 6 mmty = 5 mmTr = (2 x 914)/(2 x 216) = 4.23 mm tr = (2 x 610)/(2 x 216) = 2.82 mm
Theoretical reinforcement area ( Area removed )AR = 1.25 x 4.23 x (610-2 x 5)/ sin75 = 3284 mm2
Area available as excessAA = (610-10)/sin75 x (6-4.23)+5 x 5(5-2.82)
= 1110 mm2
Reinforcement areaAW = 3284-1110 = 2174 mm2
Minimum reinforcement thickness TT = 2174 sin 75 / 610 = 3.44 say 4.0 mm
Reinforcement widthw = 2174/(2 x 4) = 271.8 mm
Minimum allowable widthwmin = d/(3sinθ) = 610 / ( 3 x sin 75 ) = 211 mm, therefore use 272 width
Overall reinforcement widthW = 2w + d / sinθ = 2 x 272+610/sin75 = 1176 mm from 4mm thick plate.
S E C T I O N 1 5 | 117
PDV d/D M factor
4000 – 6000 ≤ 0.7 0.00025PDV
< 4000 ≤ 0.7 1.0
S E C T I O N 1 5
Appurtenance Design
TypicalInstallationConditions
118
section16
120 | S E C T I O N 1 6
16.1 Trench conditionsThese installations are suitable for SINTAKOTE welded steelpipelines and SINTAJOINT rubber ring joint (RRJ) steel pipelines asdescribed.
The following terms and their definitions are referred to in thissection. See Figure 16.1.
Bedding - the zone between the foundation and the bottom of the pipe
Haunch support – the part of the side support below the spring line of the pipe
Side Support - the zone between the bottom and the top of the pipe
Overlay – the zone between the side support and either the trench fill or the embankment fill
Trench Fill – fill material placed over the overlay for the purpose offilling the trench
Trench widthThe trench width should be as narrow as practicable consistentwith the need to ensure:• Proper laying and jointing of the pipe• Application of joint wrapping if relevant• Where a change of direction is being made using the lateraldeflection permissible at the joints, the trench should besufficiently wide to allow the joint to be made in line and then thepipe laterally deflected• Where the virgin soil does not provide the pipe with the requiredside support, the trench must be wide enough to allow theselected back-fill to be placed and compacted in such a mannerwhich will adequately spread the load into the surrounding ground
Common size backhoe/excavator bucket widths are 300, 450,600, 750, 900, 1100 and 1200mm.
As a guide, the following trench minimum widths are reasonable:
OD + 400mm for pipe diameters ≤ 450mm
OD + 600mm for pipe diameters > 450mm, ≤ 900mm
OD + 700mm for pipe diameters > 900mm, ≤ 1500mm
OD + 0.5 x OD mm for pipe diameters > 1500mm, ≤ 4000mm
Trench depthThe depth of the trench will depend on a number of factors apartfrom pipe diameter. Other considerations include:• External loadings. Pipes usually have a greater depth of coverwhen subject to vehicle loading
• Location of other services, particularly in urban areas• Future change in levels due to road re-grading or other civil works
The minimum depth of cover recommended is 0.6m provided noneof the other considerations require a greater depth. In rock, thetrench should be excavated to ensure that at least 50mm ofcompacted bedding is achieved under the pipe after it is bedded.
Where an unstable sub-grade condition unable to support the pipeis encountered, an additional depth should be excavated andbackfilled as discussed below.
Bedding Bedding provides support to the pipeline enabling it to withstandexternal loads. The higher the external loading (depth of trenchplus any vehicle loading) the greater the degree of carenecessary with the backfill in this zone. Any part of the trenchexcavated below grade unintentionally or because of rockyground should be backfilled to grade with a thoroughlycompacted approved material.
In the case of additional depth due to unstable sub-grade the extradepth should be backfilled with crushed stone or other suitablematerial to achieve a satisfactory trench bottom.
For open field loading where traffic and superimposed loading willbe low, the bedding angle (total depth of bedding) can be limitedto approximately 70°. For roadways or heavy traffic andsuperimposed loads total depth of compacted bedding may needto be increase to the spring line (centre line) of the pipe to increasethe bedding angle to 180°, maximise support and minimisedeflection. See Spangler & Handy (ref 3).
In order to prevent damage to SINTAKOTE a compacted zone of50 mm below the pipe should comprise non-cohesive native soil,imported fill or sand such that the maximum particle size does notexceed 13.2 mm.
SINTAJOINT ( RRJ ) pipelinesBellholes should be excavated in the foundation to prevent thesocket from bearing on the foundation.
SINTAKOTE welded joint pipelinesConstruction holes should be excavated at the joint to facilitatewelding and coating reinstatement. Bedding should then be restored.
Haunch support, side support and overlayIt is essential that backfill for haunch support, side support andoverlays be well compacted between the sides of the pipe and thetrench. Particular care should be taken in compacting the materialunder the haunches of the pipe.
The backfill should be built up in layers evenly on both sides of the
S E C T I O N 1 6 | 121
pipe. Whilst the depth of such layers should be established at thecommencement of the laying for any particular material to be used,it should not normally exceed 150 mm. Backfilling in layers shouldproceed until 150 mm above the top of the pipe or as otherwisespecified where vehicular traffic is encountered.
Backfill provides material to support the pipe and prevent sharpobjects imparting high loads onto the pipeline coating. The materialused should be non-cohesive native soil with no particles largerthan 25mm, or imported sand or gravel of nominal size not largerthan 20mm with the maximum size not to exceed 25mm.
When select backfill or bedding is used with pipes which are to becathodically protected, the material should not be too high inelectrical resistivity as this will reduce the effectiveness of theprotection. Generally, sand or native soil is suitable. Stone andgravel can be too high in resistivity. Hence a graded mix of sandand gravel should be used on cathodically protected lines whereimported backfill is required.
Compaction should achieve the effective combined soil modulus E’.
Non-cohesive soilsCohesionless soils are often specified for bedding and side supportareas of buried conduits.
They offer the advantages of
• ease of placement and handling• minimum compactive effort• free draining behaviour• minimum settlement• non shear stress memory• maximum density over a wide moisture content range• high shear strength
• anchorage friction
For situations where trench water flow is possible, cross trenchdams keyed into trench walls should be constructed to preventerosion of backfill and bedding.
Trench fillThe trench can then be topped up with convenient fill. Wherenecessary it should be compacted to achieve the appropriaterelative density for pavement support. The extent of compactiondepends on the allowable future surface settlement. Under roads,pavements and in certain other areas the load bearing capacity ofthe ground surface is important and fill must be compacted inlayers all the way to the surface.
Where the trench is across open land the compaction requirementsare not normally so important and the surface can usually be builtup to a degree to allow for some future settlement.
The material used would normally be the excavated trench materialbut where a high degree of compaction is needed in poor naturalground, imported material may be required.
16.2 CompactionCompaction increases the density of the soil resulting in greaterbearing capacity, stability and reduced permeability and settlement.Void space is reduced and interparticle contact is increasedresulting in higher internal friction.
Generally, non cohesive soils require less compactive effort toachieve a given density as the interparticle cohesive forces to beovercome in rearranging the soil are a minimum.
Vibratory compaction uses equipment which incorporates vibration,normally by means of a rotating eccentric weight. The vibration
S E C T I O N 1 6
Typical Installation Conditions
Figure 16.1 - Definition of terms
Trench wall
Embedmentzone
Springline of pipe
Finished surface
Trench Embankment
Trench fill
Overlay
Sidesupport
Bedding
Haunchsupport
Haunchsupport
Embedmentzone
Springline ofpipe
Top of embankment(finished surface)Embankment fill
CLCL
S E C T I O N 1 6 | 123
jostles adjacent particles and allows their relative movement tosettle together in a denser state.
The three main factors to be considered in compaction are:• soil type• moisture content• compaction method and energy input
Soil classificationA commonly referred system of soil classification is the United Soil Classification System (USCS). Soils are categorised by this system in 15 groups identified by name and letter symbols.(ref Table 13.2)
GradationThe gradation of a soil is a measure of the size and distribution ofthe constituent particles. This is assessed by sieving the samplethrough a series of screens of increasing fineness. The retainedmaterial on each screen is expressed as a percentage of totalsample weight. These figures, when plotted on a graph show thegradation of the material. Refer to Graph 16.1.
A well graded material covers a wide range of particles filled bysmaller ones. Higher densities are more easily achieved with wellgraded materials than uniformly graded materials.
Density index - non cohesive soilsDensity index ID is a measure of compaction used for non cohesive(low fines) soils, and is specified in AS 1289.5.6.1 as:
ID = γmax (γ – γmin ) x 100%γ (γmax – γ min )
where γmax = maximum dry soil density kN/m3
γmin = minimum dry soil density kN/m3
γ = measured dry soil density kN/m3
= 100ϕ(100 + wt)
ϕ = measured wet soil density kN/m3
wt = measured soil moisture content %
γmin is determined by drying and pulverising the soil to a single grainsize and pouring with minimum disturbance into a container of aknown volume. The sample is then weighed and γmin determined.
γmax is determined after compaction with a drop hammer, tamperor vibrator.
Dry density ratio - cohesive soilsDry density ratio (RD) is a measure of compaction used forcohesive soils and is specified in AS 1289.5.4.1 as:
RD = 100γγ
r
Where:γ = measured dry soil density kN/m3
γr = maximum dry density (adjusted for oversize material,
where applicable) kN/m3
as assigned or determined in the compaction test.
Compaction equipmentThe most common forms of compaction equipment used inpipeline construction are vibratory plate compactors and vibratorytampers. Their use depends very much on the surface loads to becarried by the installation. This load carrying capacity depends onthe structural stiffness of the pipe and the degree of soil beddingand side support compaction achieved.
Very dry sand and gravel can be vibrated into place at a density ofover 90% providing it contains little or no silt.
Sluicing and dumpingWhere the material is of a granular nature and drains quickly, analternative to using compacting equipment is to flood the backfillwith water. Using this method with coarse sand a 60% relativedensity can be achieved, whilst with fine sand a 50% relativedensity should be attained.
100
90
80
70
60
50
40
30
20
Per
cent
pas
sing
0.0001 0.001 0.01 0.1 1 10 100
Particle size in mm
Clay Silt Sand Gravel Cobbles
Silt
Clay
Uniformlygraded
sand
Wellgradedsand
Road basematerial
U.S. standard sieves40 10 1.1/2"
200 100 50 30 16 8 4 3/8"3/4" 3" 6" 12"
Graph 16.1 - Sieve analysis
S E C T I O N 1 6
Typical Installation Conditions
124 | S E C T I O N 1 6
Clean selected aggregate will usually achieve 60% relative densityor better by simply dumping around the pipe.
16.3 Backfill prior to hydrostatic field testWhen laying pipelines it is normal practice to place some backfill on the pipes to prevent movement during hydrostatic testing.
In the case of flexible jointed pipelines such fill is essential toprevent any joint movement during the subsequent operations.
Where the pipeline has welded joints the fill is usually placed on the barrel portion of the pipe only, leaving the joints exposed forexamination during the hydrostatic test.
In a rubber ring joint pipeline, sufficient fill should be placed oneach pipe following its installation to prevent joint movement duringpositioning of adjacent pipes.
There is no need to leave flexible joints exposed provided the layingis carried out strictly in accordance with the recommended layingpractice. Refer to Tyco Water Steel Pipeline Systems Handling andInstallation Manual.
Measurement of soil compactionStandard tests are available for determining the density ofcompacted soil. These tests are outlined in AS 1289 – E3. An experienced engineer can usually tell the density from hisfootmarks on the soil. If he has to back-kick the soil with the cornerof his heel to leave an impression then the density is probablygreater than 95%. A heel corner impression while walking probablyindicates a soil density of 90%. A full heel imprint may indicate adensity above 80% whilst a full footprint would suggest a density of only 70%.
16.4 Hydrostatic field test.A pipeline is subjected to a hydrostatic field test primarily to checkthat all joints are watertight. At the same time the test checks theintegrity of all fittings and appurtenances, as well as constructionwork such as anchorages.
Where concrete anchor blocks are installed, allow at least 7 daysfor the concrete to cure before any test is carried out.
If the pipeline section to be tested is not provided with valves thenthe ends must be fitted with bulkheads. Such bulkheads musthave attachments to allow passage of the incoming water andoutgoing air.
Hydraulic jacks may be inserted between the temporary anchorsand sealed ends in order to take up any horizontal movement of the
temporary anchors. All outlets should be plugged prior to testing.
Air valves should be properly located and checked to ensure theyare operational. If permanent air vents are not provided at all highpoints, the contractor should install corporation cocks at all suchpoints to expel air during filling of the line.
Filling prior to tests.Cement mortar lined pipe should be completely filled with water andallowed to stand for 24 hours or longer to permit maximumabsorption of water by the lining, although experience has shownthat 4-5 days soaking is more beneficial in reducing this effect afterfilling. Lines should be flushed at hydrants, scours and dead ends.
Filling should be done slowly to prevent water hammer and toensure all the air is allowed to escape. Additional water should beadded to replace that absorbed by the cement mortar lining. It isgood practise to do a final manual bleed of the line prior to startingthe pressure test.
Test measurementTest pressure should be measured at the lowest point of thesection under test, or a static head allowance between the lowestpoint and the point of measurement should be made to ensure thatthe required test pressure is not exceeded.
The field test pressure specified must accommodate the ratedpressure of fittings and appurtenances.
Test method• It is recommended that initially the field test be carried out on asmall section (200m) of the pipeline laid first to confirm that layingpractises are effective.
• Pressure testing should not be carried out during wet weather.
• Pump in water until the test pressure is reached. The field testpressure is normally specified in the relevant contract documents.The test pressure should lie between the allowable operatingpressure of the pipeline, and no more than 125% of the allowableoperating pressure. It is good practise to allow the system time tostabilise at the test pressure before starting the test. This periodcan be utilised to check and tighten bolted fittings, flanges etc. thatshow signs of leaking.
• The test pressure should be maintained for at least 2 hours.
• During pressure testing all field joints which have not beenbackfilled shall be clean, dry and accessible for inspection.
• If the pressure has dropped at the end of the test period thequantity of water (make up volume) required to increase thepressure to the original test pressure should be established.
S E C T I O N 1 6 | 125
• The test should be repeated a number of times with any makeup volume being measured.
• It is normal for a pressure drop to occur due to;- entrapped air going into solution- water being absorbed into the cement mortar lining- weeping at valve seats, fittings and appurtenances- movement of pipe under pressure- changes in pipe temperature
• A generally accepted make-up volume rate is;
Q = 0.00014 DLH
Where Q = make up water rate litres / hour
D = pipe diameter mm
L = test pipeline length km
H = mean test head m
• If the specified make-up volume is exceeded;- ensure all air has been expelled- check all valves for closure and sealing- check all mechanical joints, gibaults and flanges. Bolts should beuniformly tight and full sealing achieved.
• If subsequent testing results in unacceptable make up volume,the ground above the pipeline should be inspected for signs ofobvious leakage. A bar probe may be be used to detect thelocation of any leaks. If none are apparent the line should be testedin halves with the failing section being subsequently halved untilthe leak is located.
• The pressure test shall be considered satisfactory if:- there is no failure of any anchor block, pipe, fitting, valve, joint orany other pipeline or service component- there is no visible leakage, and- the maximum acceptable loss rate is not exceeded
After test• It is important to ensure that proper arrangements are madefor the disposal of water from the pipeline after the test, and thatall consents which may be required from land owners andoccupiers, and from river drainage and water authorities havebeen obtained.
16.5 Pneumatic test of welded joints.Welded joint pipe (Spherical Slip-in and Ball and Socket joints) can betested for integrity of the field welding by an air pressure test.
This can only be done however if an external and internal weldare executed. An air hole must also be drilled into the sealed
annulus between the welds and tapped for air nozzleattachments.
The weld is then daubed with a soap solution and the annuluspressurised to around 100kPa. The welds are then examinedfor bubbles of escaping air and rectified if necessary.
For large pipelines this test can assure the integrity asconstruction progresses eliminating the time and cost of amajor hydrostatic field test.
16.6 Backfill following hydrostatic field testAfter a section of a pipeline has passed the field pressuretest to the satisfaction of the Supervising Engineer, the trenchshould be completely backfilled as soon as possible.
In badly drained ground or where heavy rain is expected,finished sections should not be left unfilled as there is a riskthe pipeline could be moved by floatation.
16.7 Commissioning of water pipelines.Prior to hydrostatic testing care must be taken to ensureremoval of any solid material from the inside of the pipelineincluding rubbish, dirt, welding stubs and other foreignmatter.
This may be achieved by placing a swab or pig through the lineor in the case of larger diameter pipes, by operators travellingthrough the line.
Only soft foam swabs (with no scouring pad attachments)should be used on seal coated pipelines.
A pipeline which will carry potable water should be sterilisedwith chlorinated water in accordance with the Water Agency’srequirements.
After standing for the prescribed period the water should betested for residual chlorine to ensure sterilisation has beenachieved. Potable water may then be used to replace thechlorinated water. The pipeline is not to be put into serviceuntil bacteriological tests of water delivered at the end of thepipeline show that a satisfactory potable standard has beenattained.
Note that exit water may not be suitable for disposal todrains.
S E C T I O N 1 6
Typical Installation Conditions
Appendices
126
appendix ABCD&E
128 | A P P E N D I X
Symbol Reference Unitα thermal coefficient of linear expansion of steel 12 x 10-6 mm/mm/°Cα impact factor for live loadsδ beam deflection mmεb predicted bending strain εb all allowable bending strainθ angular deflection at pipe joint or at mitre cut or pipe bend degreesθ angle of nozzle to main pipe degrees θs saddle angle degreesγ unit weight of trench or embankment fill kN/m3
γ measured dry soil density kN/m3
γL assessed unit weight of liquid external to pipe kN/m3
γsub submerged unit weight of trench or embankment fill kN/m3
γmin minimum dry soil density kN/m3
γmax maximum dry soil density kN/m3
γr maximum soil dry density assigned/determined in compaction test kN/m3
η factor of safety for combined external load and internal pressureηb factor of safety for ring bending strain ηp factor of safety for internal pressureμ soil/pipe surface friction factor μ dynamic viscosity of water kg/m. s ν kinematic viscosity of water ( 0.11425 x 10-5 at 15°C ) m2 /s ν Poisson’s ratio ( 0.27 for steel )ρ measured wet soil density kg/m3
ρs specific gravity of soil particle ( = 2.65 or determined value) kg/m3
σb bending stress MPaσc circumferential stress MPaσe equivalent stress MPaσh hoop stress MPaσT temperature stress MPaσs saddle stress MPaσL longitudinal stress MPaζ Leonhardt correction factorΔ pipe deflection m or mmΔf design factorΔh head rise above normal operating head mΔp pressure rise above operating pressure MPaΔy predicted vertical deflection of pipe in ground mΔy all allowable vertical deflection of pipe in ground mΔT change in temperature °C a pressure wave velocity m/sa centre line length on bend mitre mmA cross area of pipe based on OD m2
AA area available as excess mm2
AR area removed mm2
AW reinforcement area mm2
A P P E N D I X A
Glossary
A P P E N D I X | 129
bedding the layer of material directly under the pipe backfill the material at the sides and the set cover layer above and in contact with the pipeB&S ball and socket joint B trench width at pipe crown mC the element carbonCE carbon equivalentCML cement mortar liningCbb headloss coefficient factor for bendsCu the element copperCP cathodic protectionCr the element chromiumcover the depth of material H, from pipe crown to surface level md pipe inside diameter m or mmD, De ,Do pipe outside diameter m or mmDm pipe mean diameter (D-t) m or mmDB deformed pipe diameter m or mmD/t outside diameter to pipe wall thickness ratioDCF discounted cash flowDN nominal diameter m E’ effective combined soil modulus MPaE’e embedment soil modulus MPaE’n native soil modulus MPaE modulus of elasticity for the steel or composite steel-cement mortar liningEst Young’s modulus for steel 207,000 MpaEcl Young’s modulus for cement mortar lining 21,000 MpaFBPE fusion bonded polyethyleneFS factor of safetyG gradientg acceleration due to gravity 9.81 m/s2
H height of ground surface above pipe mH head after valve operation mHo head under constant flow condition mHw height of water surface above the top of the pipe mHL head loss in meters head of water mHGL hydraulic grade lineI second moment of area of the pipe wall per unit length mm4/mm I elastic moment of inertia of the pipe mm4
ID inside diameter of pipe mmID Density index of non – cohesive soil %k saddle factor K bedding constantk thermal conductivity of steel 47 W/(m°C)k linear measure of bore roughness for the Colebrook-White formula mKL minor loss coefficientKLE minor loss coefficient
A P P E N D I X A
Glossary
130 | A P P E N D I X
KL1 minor loss coefficientKL2 minor loss coefficientL length dimension or length of pipeline m or mmL pipe span as a beam m or mm L1 length of the base of the live load distribution measured perpendicular to the direction
of travel of the vehicle at the top of the pipe mL2 length of the base of the live load distribution measured parallel to the direction of
travel of the vehicle at the top of the pipe m M factor for design of off-takesM1 unit mass of the steel shell kg/mM2 unit mass of the cement mortar lining kg/mM3 unit mass of Sintakote kg/m MA bending moment at point A NmMB bending moment at point B NmMC bending moment at point C NmMn the element manganeseMo the element molybdenumMTOT total mass of water filled pipe kg/mMW unit mass of water in pipe kg/m MSCL mild steel cement linedMTP manufacture test pressure MPaMYS minimum yield strength MPaNi the element nickel NPV nett present valuen number of yearsn number of individual mitres or a ratio in Allievi’s equationOD outside diameter mm P live wheel load, ∑P is the sum of the individual wheel loads kNP internal pressure MPaPt manufacture proof test or strength test pressure MPaPr field test pressure or rated pressure MPaPcr critical external pressure required to cause buckling kPaPW applied internal pressure MPaPWall allowable internal pressure MPaPs saddle reaction N PE plain ended pipePDV pressure/diameter valuePRV pressure reducing valve(s)pH -log (H+)qall allowable buckling pressure kPaqall1 allowable buckling pressure based on pipe alone kPaqall2 allowable buckling pressure based on pipe/embedment interaction kPaqv internal vacuum kPaQ flow rate or discharge l/s or m3/sR radius of bend or outside diameter radius of pipe m or mmRe resultant thrust at pipe bend kN
A P P E N D I X A
Glossary
R Reynolds numberRD Dry density ratio of cohesive soil %RRJ rubber ring jointr outside radius of pipe mmre equivalent circular arc on composite mitres mm ri interest raterc re-rounding effectrm mean radius (= (D-t) / 2 ) mmSg hydraulic gradient m/mSr ring-bending stiffness as a function of radius N/m/mSD ring-bending stiffness as a function of diameter N/m/mSDcr critical ring buckling resistance due to out of roundness N/m/mSSJ spherical slip-in jointSK SINTAKOTESR sulphate resistant cementT cement mortar lining thickness mmT reinforcement collar minimum thickness mmTr reflection period s To time for valve opening or closing sTs static thrust at blank ends and junctions kNTQM total quality managementtrench fill the material placed over the backfillt steel wall thickness mmts thickness of Sintakote mmTy main pipe wall thickness mmty branch wall thickness mmTR theoretical main pipe wall thickness mmtR theoretical branch wall thickness mmteq transformed pipe wall thickness mmUV ultra violetu superimposed, uniformly distributed dead load at finished surface kPav flow velocity m/svo flow velocity under steady state conditions m/sV the element vanadiumw reinforcement collar edge width mmWd weight of backfill kN/mWw weight of water in pipe kN/mWp weight of pipe kN/m wg vertical design load pressure at top of pipe due to soil dead loads kPawgs design load due to superimposed dead load kPawq vertical design load due to surface applied live load kPawt measured soil moisture content %w unit weight of pipe (steel, lining and water) N/my pipe deflection as a beam mmZ elastic section modulus of pipe mm3
A P P E N D I X | 131
A P P E N D I X A
Glossary
132 | A P P E N D I X
Quantity Unit Conversion FactorLength 1in 25.4 mm
1ft 0.3048 m1yd 0.9144 m1 fathom 1.8288 m1 chain 20.1168 m1 mile 1.60934 km1 international nautical mile 1.852 km1 UK nautical mile 1.85318 km
Area 1in2 6.4516 cm2
1 ft2 0.092903 m2
1 yd2 0.836127 m2
Volume 1 UK minim 0.0591938 cm3
1 UK fluid drachm 3.55163 cm3
1UK fluid ounce 28.4131 cm3
1 US fluid ounce 29.5735 cm3
1 US liquid pint 473.176 cm3
1 US dry pint 550.610 cm3
1 Imperial pint 568.261 cm3
1 UK gallon 4.54609 dm3
1 US gallon 3.78541 dm3
1 in3 16.3871 cm3
1 ft3 0.0293168 m3
1 yd3 0.764555 m3
2nd Moment of Area 1 in4 41.6231 cm4
Moment of Inertia 1 lb ft2 0.0421401 kg m2
1 slug ft2 1.35582 kg m2
Mass 1 grain 64.7989 mg1 dram (avoir.) 0.00177185 kg1 drachm (apoth.) 0.00388793 kg1 ounce (troy or apoth.) 0.0311035 kg1 oz (avoir.) 28.3495 g1 lb 0.45359237 kg1 slug 14.5939 kg1 sh cwt (US hundredweight) 45.3592 kg1 cwt (UK hundredweight) 50.8023 kg1 UK ton 1016.05 kg1 short ton 907.185 kg
Mass per Unit Length 1 lb/yd 0.496055 kg/m1 UK ton/mile 0.631342 kg/m1 UK ton/1000yd 1.11116 kg/m1 oz/in 1.11612 kg/m1 lb/in 1.48816 kg/m1 lb/in 17.8580 kg/m
Mass per Unit Area 1 oz/ft2 0.305152 kg/m2
1 lb/ft2 4.88243 kg/m2
1 lb/in2 703.070 kg/m2
1 UK ton/mile2 3.92290x10-4 kg/m2
Density 1lb/ft3 16.0185 kg/m3
1lb/UK gal 99.7763 kg/m3
1 lb/US gal 119.826 kg/m3
A P P E N D I X B
SI Conversion Factors
Quantity Unit Conversion FactorDensity 1slug/ft3 515.379 kg/m3
1ton/yd3 1328.94 kg/m3
1lb/in3 27.6799 Mg/m3
Specific 1in3/lb 36.1273 cm3/kgvolume 1ft3/lb 0.0624280 m3/kg
Velocity 1in./min 0.042333 cm/s1 ft/min 0.00508 m/s1ft/s 0.3048 m/s1mile/h 1.60934 km/h1UK knot 1.85318 km/h1International knot 1.852 km/h
Acceleration 1ft/s2 0.3048 m/s2
Mass flow rate 1lb/h 1.25998x10-4 kg/s1UK ton/h 0.282235 kg/s
Force (weight) 1dyne 10-3 N1pdl (poundal) 0.138255 N1ozf (ounce) 0.278014 N1lbf 4.44822 N1kgf 9.80665 N1tonf 9.96402 kN
Force (weight) 11bf/ft 14.5939 N/mper unit length 1lbf/in 175.127 N/m
1tonf/ft 32.6903 kN/m
Force (weight) 1pdl/ft2 1.48816 N/m2
per unit area (pressure) 1lbf/ft2 47.8803 N/m2
1mm Hg 133.322 N/m2
1in H20 249.089 N/m2
1ft H20 2989.07 N/m2
1in.Hg 3386.39 N/m2
1lbf/in2 6.89476 kN/m2
1bar 105 N/m2
1 std. atmosphere 101.325 kN/m2
1tonf/ft2 107.252 kN/m2
1 mm H20 9.8067 N/m2(=1g)
Specific wt 1 lbf/ft3 157.088 N/m3
1 lbf/UK gal 978.471 N/m3
1 tonf/yd3 13.0324 kN/m3
1 lbf/in3 271.447 kN/m3
Moment, torque 1 ozf in (ounce-force inch) 0.00706155 Nmor couple 1 pdl ft 0.0421401 Nm
1 lbf in 0.112985 Nm1 lbf ft 1.35582 Nm1 ton ft 3037.03 Nm
A P P E N D I X | 133
A P P E N D I X B
SI Conversion Factors
134 | A P P E N D I X
Quantity Unit Conversion FactorEnergy 1erg 10-7 Jor heat 1horsepower hour 2.68452 MJor work 1 therm = 10 cal 4.1855 MJ
1therm = 1 00 000 Btu 105.506 MJ1cal 4.1868 J1 Btu 1.05506 kJ1kWh 3.6 MJ
Power 1hp= 550 ft lbf/s 0.745700 kW1 metric horsepower (ch, PS) 735.499 W
Specific heat 1 Btu/lb deg F1 cal/g deg C 4.1868 kJ/kg K
Heat flow rate 1Btu/h 0.293071 W1kcal/h 1.163 W1 cal/s 4.1868 W
Intensity of heat flow rate 1 Btu/ft2h 3.15459 W/m2
Electric stress 1 kV/in. 0.039370 kV/mm
Dynamic viscosity 1 1b/ft s 1.48816 kg/m s
Kinematic viscosity 1 ft2/s 929.03 stokes
Calorific value or specific enthalpy 1 Btu/ft3 37.2589 kJ/m3
1 Btu/lb 2.326 kJ/kg1 cal/g 4.1868 J/g1 kcal/m3 4.1868 kJ/m3
Specific entropy 1 Btu/lb°R 4.1868 kJ/kg K
Thermal Conductivity 1 cal cm/cm2 s deg C 41.868 W/m K1Btu ft/ft2 h deg F 1.73073 W/m K
Gas constant 1ft lbf/lb °R 0.00538032 kJ/kg K
Plane angle 1rad (radian) 57.2958°1degree 0.0174533 rad = 1.1111 grade1minute 2.90888x10-4 rad = 0.0185 grade1second 4.84814x10-6 rad = 0.0003 grade
Velocity of rotation 1rev/min 0. 1 04720 rad/sBased on Ramsay and Taylor: SI Metrication: Easy to Use Conversion Tables (Chambers).
1 N/mm2 = 1 MPa1 psi = 6.9 kPa1kg = 2.2 lb1” = 25.4 mm1 UK gallon = 4.55 litre1kg = 9.81 N
1 UK gallon = 1.2 US gallon1m3 = 1000 litre(=1kl)1 Joule = 1 Nm1 kN/m = 1 N/mm1 atmosphere = 101.325 kPa =10.33m head
of water = 1 bar = 760 cm Hg
Common Approximate Conversions
A P P E N D I X B
SI Conversion Factors
SteelModulus of elasticity 207,000 MPaLinear Coefficient of thermal expansion 12x10-6 mm/mm °CThermal conductivity 47 W/(m °C)Density 7850 kg/m3
Melting range 1510 – 1524 °CPoisson ratio 0.27
SINTAKOTEDensity approx 940 kg/m3
Cement Mortar LiningModulus of elasticity approx 21,000 MPaDensity approx 2,400 kg/m3
SoilDensity (see Table 13.1)Bearing pressures (see Table 12.2)Moduli of soil reaction - E'e and E’n (see Table 13.3)
Saline waters TDS(mg/l)
fresh water < 500marginal 500 to 1000brackish 1000 to 3000Saline waters > 3000sea water 35000
A P P E N D I X | 135
A P P E N D I X C
Material Properties
136 | A P P E N D I X
1. Luscher, U
"Buckling of Soil surrounded tubes"
Jour. Soil Mech & Foundations Division
ASCE 92:6:213, 215 (Nov 1966)
2. Molin, Jan
"Principles of calculation for underground plastic pipes – calculation of loads, deflection, strain"
International Organization for Standardization
ISO Bulletin 2:10:21 (Oct 1971)
3. Spangler MG, Handy RL
"Soil Engineering", 4th edition
Harper & Row, New York, 1982
4. Clarke NWB
"Buried Pipelines - A manual of structural design and installation"
MacLaren and Sons, London,1968
5. Compston DG, Cray P, Schofield AN, Shann CD
"Design and construction of buried thin-wall pipes"
Construction Industry Research and Information Association
CIRIA UK Report 78, July 1978
6. Marston, Anson
"The theory of external loads on closed conduits in the light of the latest experiments"
Proc. Ninth Annual Meeting Highway Res. Board. Dec 1929
7. Melbourne and Metropolitan Board of Works
"Hydrogen Sulphide Control Manual"
Technological Standing Committee on Hydrogen Sulphide
Corrosion in Sewerage Works. Dec 1989
8. Skeat, WO (Ed)
Institution of Water Engineers
"Manual of British Water Engineering Practice", Third Edition
Heffer & Sons, Cambridge, 1961
9. Miller DS
"Internal flow systems". Second ed.
BHRA, 1990
10. Boussinesq, J
"Application des Potentiels a l Etude de l Equilibre et du Mouvement des Solids Elastiques”
Gauthier-Villars, Paris, 1885
11. AWWA
Manual of water supply practices
M11 "Steel pipes – a guide for design and installation"
12. Schorer, H
"Design of large pipelines"
Trans. ASCE, 88:1011 (1933)
13. Ligon, JB and Mayer, GR
"Coefficient of friction for pipe coating materials"
Pipe Line Industry
42 (2) PP 51-54, Feb 1975
14. Parmakian, J
"Water Hammer Analysis"
Dover, New York, 1963
15. Streeter, VL and Wylie, EB
"Fluid Transients"
McGraw-Hill, New York, 1978
16. Pickford, J
"Analysis of Water Surge"
Gordon and Breach, New York, 1969
17. Watters, GZ
"Modern Analysis and Control of Unsteady Flow in Pipelines"
Anne Arbor, Michigan, 1980
18. Webb, TH
"Water Hammer Control in Pipelines 1981"
James Hardie, Sydney, 1981
19. WSAA
Technical Notes
TN6 "Guidelines for the use of cement mortar linings in sewerageapplications"
A P P E N D I X D
References
AS 1281 Cement Mortar Lining of Steel Pipes and Fittings
AS 1289 – E1.2 Method of Testing Soil for Engineering Purposes – determination of dry density / moisture content relation of soil using standard compaction.
AS 1289 – E3 Method of Testing Soil for Engineering Purposes – determination of the field dry density of a soil
AS 1289.5.4.1 Method of Testing Soil for Engineering Purposes – dry density moisture variation and moisture ratio
AS 1289.5.6.1 Method of Testing Soil for Engineering Purposes – density index method for a cohesionless material
AS/NZS 1554 Structural Steel Welding
AS 1579 Arc Welded Steel Pipes and Fittings for Water and Waste-Water
AS/NZS 1594 Hot Rolled Steel Flat Products
AS 1646 Elastomeric Seals for Waterworks Purposes
AS 2129 Flanges for Pipes, Valves and Fittings
AS 2200 Design Charts for Water Supply and Sewerage
AS/NZ S2566.1 Buried Flexible Pipelines – Structural Design
AS 2885 Pipelines – Gas and Liquid Petroleum
AS/NZS 3678 Structural Steel – Hot-rolled Plates, Floor-plates and Slabs
AS 4087 Metallic Flanges for Water-works Purposes
AS 4321 Fusion – bonded Medium – density Polyethylene Coatings and Linings for Pipes and Fittings
AS 4799 Installation of Underground Utility Services and Pipelines Within Railway Boundaries
AS/NZS ISO 9001 Model for Quality Assurance
ASTM C177 Standard Test Method for Steady State Heat Flux Measurements and Thermal Transmission Properties by means of the Guarded-Hot-Plate Apparatus
ASTM D2240 Standard Test Method for Rubber Property – durometer hardness
ASTM D2487.9 Classification of Soils for Engineering Purposes
ASTM D4060 Standard Test Method for Abrasion Resistance of Organic Coatings by the Tauber Abraser
ASTM G8 Standard Test Methods for Cathodic Disbondment of Pipeline Coatings
ASTM G13 Standard Test Method for Impact Resistance of Pipeline Coatings (Limestone drop test)
ASTM G14 Standard Test Method for Impact Resistance of Pipeline Coatings (Falling weight test)
IEC 60093 Methods of Test for Volume Resistivity and Surface Resistivity of Solid Electrical Insulating Materials
IEC 60243 Electrical Strength of Insulating Materials – test methods – tests at power frequencies
A P P E N D I X | 137
A P P E N D I X E
Standards Referenced in Text
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