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Mechanical Services
Performance Specification
for
GAP OutletUnit 16Newport Retail ParkNewport
Part 2
Materials andWorkmanship
Prepared for:
GAP UK
Castle Mound WayRugbyWarwickshireCV23 0WA
2nd October 2012
Ref: AD398/mech2/10.0 Issue 1.0
Alchemi Design LimitedLandmark HouseStation RoadChead le HulmeCheshireSK8 7BS
Tel: 0161 486 3332Fax: 0161 486 3336E-mail: [email protected]
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PART 2
GENERAL MATERIALS AND METHODS OF INSTALLATION
2.01 INTRODUCTION
2.02 REGULATIONS
2.03 PIPEWORK2.03.01 Pipework Materials and Valve Schedule2.03.02 Refrigeration2.03.03 Underground Mains Cold Water2.03.04 Gas
2.03.05 Condensate2.03.06 Drainage2.03.07 Domestic Pipework2.03.08 Condenser Water/LPHW2.03.09 Pipework Routes2.03.10 Pipework Supports2.03.10a. Table 1 Supports for Copper Pipework2.03.10b. Table 2 Supports for Plastic Pipework2.03.10c. Table 3 Supports for Wrought Iron and Mild Steel
Pipework2.0310d. Table 4 Supports for Drainage Pipework2.03.11 Electric Water Heaters
2.03.12
Cisterns and Cold Water Tanks2.03.13 Waste Water Pump Unit
2.04 DUCTWORK2.04.01 General2.04.02 Flexible Duc twork2.04.03 Flexible J oints2.04.04 Control Dampers2.04.05 Access Doors2.04.06 Fire Dampers2.04.07 Smoke Dampers2.04.08 Grilles, Diffusers and Louvers
2.04.09 Duct Cleanliness2.05 AIR HANDLING UNITS
2.05.01 General2.05.02 Construction
2.06 HEATER BATTERIES2.06.01 General2.06.02 Electric Type
2.07 FANS2.07.01 General2.07.02 Centrifugal Fans2.07.03 In-Line Fans
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2.08 BELT DRIVES AND GUARDS
2.08.01 Belt Drives2.08.02 Guards2.08.03 Fan Drive Pulleys
2.09 AIR FILTERS2.09.01 General2.09.02 Frames, Sea ls and Gaskets2.09.03 Panel Filters2.09.04 Bag Filters
2.10 THERMAL INSULATION2.10.01 General
2.10.02 Methods of Application2.10.03 Duc twork Insulation2.10.04 Pipework Insulation2.10.05 Vapour Barriers
2.11 VIBRATION ISOLATION AND NOISE INSULATION2.11.01 Anti-Vibration2.11.02 Noise2.11.03 Noise Insulation (Airborne Noise)
2.12 RECOVERY AND DISPOSAL OF REFRIGERANT
2.13 FLAMMABILITY2.14 PIPEWORK AND PLANT IDENTIFICATION
2.15 PAINTING AND CLEANING ON COMPLETION
2.16 PRE-COMMISSIONING, CLEANING AND FLUSHING2.16.01 Sterilisation2.16.02 Condenser Water2.16.03 Pseudonymous Bacteria
2.17 COMMISSIONING, TESTING AND HANDOVER
2.18 REDUNDANT EQUIPMENT AND SERVIC ES
2.19 OPERATING AND MAINTENANC E MANUALS
APPENDIX A DESIGN STANDARDS
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PART 2
GENERAL MATERIALS AND METHODS OF INSTALLATION
2.01 INTRODUCTION
This part of the Spec ification known as the GENERAL SPECIFICATION details the generalmaterial requirements, installation methods and the standard of workmanship on whichthe C ontract installation shall be based.
The following clauses detail the basic materials, but where materials or equipment arerequired which are not detailed herein or in the Particular Specification, then these shall
be of proven quality to British Standards, BS EN or equivalent EU standards and CEmarked, and installed in accordance with approved and accepted current practiceand manufac turers instructions.
It will be the C ontrac tors responsibility to ascertain from the manufacturers, wherenecessary, any relevant information to ensure compliance with the Specification. Ifevidence is found of non-compliance with the Specification, any remedial worknec essary as instructed by the Engineers shall be at the Contrac tors own expense.
2.02 REGULATIONS
The Mec hanical Services shall be designed and installed in accordance with therequirements of this specification and as detailed below and shall also take full accountof the following: -
a) All relevant British Standards, European Standards and Codes of Practise.
b) Health and Safety at Work Act 1974 and existing statutory Health and Safetyprovisions.
c) Health and Safety Executive Guidance Notes.
d) CIBSE Guides, Building Energy Codes and Technical Memoranda.
e) Water Authority Regulations.
f) Building Regulations.
g) Loc al Authority requirements.
h) Elec tricity at Work Regulations 1989.
i) Elec tricity Supply Regulations 1988.
j) IEE Wiring Regulations (Current Edition).
k) Construction (Design and Management) Regulations 2006.
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l) The Scottish Building Regulations (where appropriate)
Particular attention should be paid to the need to reduce the risk of Legionella and thedesign must take full account of the following publications
m) British Standard BS 6070.
n) Health and Safety Exec utive EH48, IAC (L) 27 HSG 70.
o) CIBSE TM13.
2.03 PIPEWORK2.03.01 PIPEWORK MATERIALS AND VALVE SCHEDULE
PIPEWORK MATERIALS SCHEDULESERVICE MATERIAL SPECIAL REQUIREMENTSD.H.W.S. COPPER NON-LEAD SOLDERC.W.D.S. COPPER NON-LEAD SOLDERCONDENSATE ABS AS SPECIFICATIONCHILLED WATER STEEL AS SPECIFICATIONCONDENSER WATER STEEL AS SPECIFICATIONMWS (EXTERNAL) MDPE AS SPECIFICATION
MWS (INTERNAL) COPPER NON-LEAD SOLDERGAS (INTERNAL) STEEL AS SPECIFICATIONREFRIGERATION COPPER AS SPECIFICATION
VALVE SCHEDULESERVICE MATERIAL SPECIAL REQUIREMENTSD.H.W.S. CRANE D191 ) REFER TO DOMESTICC.W.D.S. CRANE D191 ) PIPEWORK SECTIONC.W.M. CRANE D191 ) 2.0107C.H.W. CRANE D911/DM910 (IV/OP)
D920/D922/DM920(DRV)CONDENSER WATER CRANE D911/DM910 (IV/OP)
D920/D922/DM920(DRV)
Materials
All materials shall be of British Manufacture (unless otherwise stated) and shall not beinferior to the latest relevant British Standard referred to in this Spec ification as BS. Samplesof materials are to be submitted as and when requested for examination and approvalby the Consulting Engineer. Any materials not approved and/ or not in strict compliancewith this Specification or as detailed on the drawings are to be immediately removedfrom the site.
Materials shall in all cases be as specified or of other similar equal and approved
manufacture.Manufacturers rec ommendations for site storage of materials are to be closely adhered
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to, to prevent damage, deterioration or loss of materials.
Substitution of Materials and Equipment
Substitution of specified materials or plant shall not be permitted without the writtenconsent of the Consulting Engineer.
In the event of non-availability of the specified material or plant, the Contractor shallformally notify the Consulting Engineer and shall at the same time submit proposals foralternative materials for the c onsideration of the Consulting Engineer.
The Contrac tor shall give notice in good time to avoid any disruption to the regularprogress of the Contrac t works, and shall provide full details in justification of any
substitution that may be proposed.
All alternative materials and plant shall conform to the requirements of this Spec ification. The cost of any variation shall be agreed with the Consulting Engineer at the time.
2.03.02 REFRIGERATION
Refrigeration pipework shall be installed by a specialist and in accordance with currentgood prac tice.
The pipework shall be half-hard or soft tempered refrigerant quality copper inaccordance with BS 2871 Part 2, ASTM 280 and DIN 1754/8905. Soft tempered pipework
may be used where the diameter is or3
/8.
Bends shall be formed using pipe benders. The use of bend and elbow fittings should beavoided (to minimise the possibility of leaks).
All brazing of joints shall be carried out whilst passing oxygen-free nitrogen through thepipework.
It is the responsibility of the Spec ialist Installer to ensure that the pipework is adequatelyprotected during the installation to prevent the ingress of dirt and moisture. Pipework thatis delivered to site without end caps must be rejected.
Pipework must not be cut using any tool that may cause filings, as it will contaminate thesystem.
Brazing shall only be c arried out by skilled operatives in accordance with HVCA C odes of
Practice. Refnet joints shall be used in accordance with Daikin Ltd requirements. The pipework shall be sized in accordance with the manufacturer's requirements andguidelines. All pipework to be tagged at 3m intervals.
All filters, driers, thermal expansion valves, charging valves, etc., shall be included in thesystem where manufacturers rec ommendations are applicable.
All pipework shall be properly insulated with Armaflex class O insulation suitablyweatherproofed and painted to protect against degradation by UV light.
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The Contrac tor shall be responsible for providing an independently supported, suitablysized medium duty return flange cable tray for refrigerant pipework and interconnec tingcables, externally and throughout ceiling voids, etc. The pipework and cable must beindividually secured.
Where galvanised tray cannot be installed due to space restrictions the hydrozorbcushion clamp system as supplied by Dean & Wood Ltd., shall be used only with prioragreement to the Engineer. Any other support system will be rejec ted.
Where exposed to view internally, the pipework shall run in a suitably sized UPVC trunkingcontainment system.
Gauges
Pressure gauges shall be installed adjacent to the external condensing units of split andmulti-split systems to provide visual indication of refrigerant charge status.
Note: VRV condensing units shall not be fitted with gauges.
2.03.03 UNDERGROUND MAINS COLD WATER
Underground polyethylene pipework for water shall be to BS 6572 (1985) Spec ification forblue polyethylene pipes up to nominal size 63 for below ground use for potable water.
Pipes larger than nominal size 63 shall conform to WAA-SWMC information and guidancenote number 4-32-03 (ISBN 267-0305).
In all instances, the installation and jointing of polyethylene pipework shall be in strictcompliance with the Water Supply (Water Fittings) Regulations 1999 Edition and any otherrequirements of the loc al Water Company. All jointing methods must be approved bythe Consulting Engineers.
All marker plates, pipe route markers etc, shall be included by the Contractor to complywith the Water Authority requirements.
2.03.04 GAS
Underground polyethylene pipework for gas services shall be to BFP/PS/PL2 Parts 1 and 2.
In all instances the installation and jointing of polyethylene pipework shall be in strictcompliance with British Gas Publication IM/16 and any other requirements of the localGas Board.
All marker plates, pipe route markers etc. shall be included by the Contractor to complywith the G as Regulations.
2.03.05 CONDENSATE
Unless otherwise spec ified condensate pipework shall be in copper. The pipework shallbe as detailed in sec tion 2.03.06 f).
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2.03.06 DRAINAGE
a) General
The work shall conform to the Specification in all respects and be executed by fullyqualified, competent tradesmen and certified welders, in accordance with theSpecification to the satisfac tion of, and as direc ted by, the C lients Representative andthe relevant Local Authorities.
b) Relevant Codes of Practice
Attention is drawn to the following Codes of Practice where they are applicable and do
not conflict with the Specification:
BS6367: 1983 Drainage and roofs and paved areas.BS8301: 1985 Building DrainageBS5572, 1994: Code of Prac tice for Sanitary Pipework.Building Regulations (Current Edition)
c) Materials
Vertical soil, waste and ventilatingpipework 75 mm diameter and above
Cast or Ductile iron socketless pipe toBS 416/EN877 with flexible two piecemec hanical joints to BS6087.
Horizontal soil, waste and ventilatingpipework 75 mm diameter and aboveexposed or in ceiling void spa ces.
Cast or Ductile iron socketless pipe toBS416/EN877 with flexible two piecemec hanical joints to BS 6087.
Horizontal soil, waste and ventilatingpipework 75 mm diameter and above.
UPVC solvent weld or ring-sea l soc ket joints to BS 4514 or cast iron a s verticalpipework.
Vertical soil, waste and ventilatingpipework 75 mm diameter and above.
UPVC solvent weld or ring-sea l soc ket joints to BS 4514 or cast iron a s verticalpipework.
Rainwater pipework Cast of Ductile iron soc ketless pipe toBS416/EN877 with flexible two piecemechanical joints.
Vertical waste and ventilating pipeworkless than 75 mm diameter.
Copper to BSEN 1057 R250 (BS2871 Part1 Table X) capillary jointed with fittingsto BS864 Part 2. Chromium platedwhere exposed in finished areas.
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Horizontal waste and ventilating
pipework less than 75mm diameterexposed or in ceiling void spa ces.
Copper to BSEN 1057 / 2250 (BS2871
Part 1 Table X) capillary jointed withfittings to BS 864 Part 2. Chromiumplated where exposed in finishedareas.
Horizontal waste and ventilatingpipework less than 75 mm diameterconcealed other than in ceiling voids.
MUPVC to BS 5255: 1989 with solventwelded joints or copper as verticalpipework.
Overflow pipework As waste pipework
Traps: (sizes as described on projec t
drawings)
ConcealedExposed
Polypropylene to BS3943: 1979Chromium plated copper.
d) Installation
Pipework shall be installed in the positions and to the sizes shown on the drawings, instraight lines and even gradients with swept branches facing up the gradient againstthe oncoming flow.
Access fittings shall be provided on all vertical pipework at each storey level above
the spillover level of the highest appliance or terminal fitting connected to the verticalpipework on the particular storey.
Access fittings shall be provided on all horizontal pipework and at all changes ofdirec tion, gradient and level. In addition the minimum requirements for accessdescribed in BS5572 shall be met.
The locations of access fittings shall be arranged to suit the layout of the building.
J ointing material shall not projec t into the bore of pipes, fittings or applianc es.
Where pipework passes through roofs, a roof connector compatible with the roofconstruction shall be used.
All soil, waste and vent pipes shall terminate with a wire balloon guard, or proprietaryapproved vent pipe terminal to the requirements of BS 5572.
J oints between branc h soil pipes and WC pan spigots shall be made by the use of aproprietary solid WC connec tor.
Site installation works shall comply with BS5572, BS6367, the Building Regulations andthe requirements of the District Surveyor.
During the course of construction all open ends of pipework are to be sealed with atemporary cover, the contractor shall carry out regular checks to ensure that thecovers are still effective.
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Where pipes pass through floors or walls, compatible pipe sleeves shall be sized to
provide a minimum of 15 mm clearance around the pipe to be installed, in order thatthe sleeve may be packed and sealed at both ends with water and fire retardantmastic.
Firep roof sleeves shall be fitted to UPVC pipework over 50 mm where it passes throughall fire rated walls and floor slabs.
The fire sleeves shall be installed in strict ac cordance with the manufacturersinstructions and shall be the Firebreak type a s manufac tured by Caradon Terrain Ltd.
Adequate provision shall be made for expansion and contraction in all soil, waste andventilating p ipework in full ac cordance with the manufac turers' rec ommendations.
e) Cast Iron Drainage Pipework with Flexible Joints
Cast / ductile iron pipework and fittings shall be to BS416/EN877.
Copper pipework shall be fixed at centres not exceeding the minimum described inthe table under sec tion 2.0110d using brass holderbats.
Socketless pipes and fittings shall be jointed with flexible couplings, comprising cast /ductile iron clamps manufactured from metal conforming to BS1452, Grade 180,sec ured with stainless steel bolts, nuts and washers to BS3692, Grade 18/8 and syntheticrubber gaskets in ac cordance with BS2494 and a s specified in BS 6087. The joints shall
be made and torqued strictly in accordance with the manufac turers instruction.Electrical continuity couplings shall be used, to comply with the IEE wiring Regulations.
Cast iron p ipework shall be fixed using two piece zinc plated mild steel or coatedductile iron pipe clamps / brackets, bolted to flat iron hangers suspended from soffit,built-in to walls or screw to walls as appropriate and shall be fixed at centres notexceeding the minimum described in the table water section 2.03.10d.
f) Copper Drainage Pipework
Pipework up to and including 54 mm nominal size shall be copper to BSEN 1057-R250BS2871 Part 1 Table X) except where a particular table is called for the drawings orelsewhere in this spec ification. The pipework shall be assembled using copper orcopper alloy, soft solder capillary fittings to BS864: Part 2. Capillary joints shall be madein accordance with fitting manufac turers rec ommendations.
Pipes of normal bore greater than 54 mm shall be copper to BSEN 1057-R250 BS2871:Part 1 Table X) and pipework shall be a ssembled by silver brazing, using formed soc ketsand spigots and/ or suitable copper or copper alloy capillary type fittings.
Silver brazing shall be carried out in accordance with BS 1723 and Technical Note TN4issued by Copper Development Assoc iation. All joints in permanently conc ealedpipework without access shall be silver brazed.
Maintenance joints shall be provided at connections to all items of plant, valves, etc.,not provided with flanges or unions and elsewhere in the pipework system, as
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necessary, to allow for easy erection and dismantling of the installation. All
maintenance joints shall be provided in accessible positions.
Union couplings shall be c opper alloy type.
Flanges shall be c opper alloy slip-on type suitable for silver brazing to BS4504 or BS10 Tab le E. Flanges used at connections to equipment, valves, etc. shall match thoseprovided on the equipment. All flanged joints shall be made in the approved manner.
Connections between copper and ferrous pipework and equipment shall incorporatewhere possible non-metallic materials to prevent direct contact between the twometals.
Bends, springs and sets in Table X tubing, up to and including 54mm diameter, may bemade where standard fittings cannot be used or where this method will give a neaterappearance. Pulled bends or off sets which show flattening, rippling or restriction ofthe bore will not be accepted.
Fittings incorporating screwed threads to BS211 shall be jointed by systems usingmaterials and compound complying with BS5292 or P.T.F.E tape.
J oints between c opper tube and cap illary type fittings shall be made in accordancewith the manufacturers rec ommendations.
J oints between copper tube and compression type fittings shall be made in
ac cordance with the manufac turers rec ommendations.Where chromium plated pipework is called for elsewhere in this spec ifica tion orindicated on the drawings, chromium plating shall comply with BS 1224. Compressionor pre-fabrica tion only shall be used.
g) UPVC Drainage Pipework
All joints on UPVC pipework and fittings, except where expansion must be catered for,shall be solvent welded. All surfac es to be jointed shall be cleaned prior to coating thecontact surfac es with solvent weld c ement using a clean b rush.
The joint shall be assembled immediately and excess cement shall be removed, the joint shall be left to set for 12 hours before testing.
Where p ipework is to be c ut, a fine tooth saw shall be used. Pipes must be cut squa reand burrs and swarf removed.
Where it is nec essary to connect to dissimilar materials e.g. cast iron or copper, such joints shall be made using proprietary connectors in full ac cordance with themanufacturers instruc tions.
Where boss or branch connections are made to soil or waste stacks, the distancebetween the entry point and the nearest fixed point shall not be less than 500 mm.
UPVC vertica l pipework shall be fixed at c entres not exceeding the minimumdescribed in the table 2.03.10d using galvanised mild steel holderbats.
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UPVC horizonta l pipework shall be fixed at centres not exceeding the minimum'sdescribed in the relevant table using ga lvanised mild steel support brackets (orthermal movement limiters if required) on 8 mm diameter drop rods. MUPVC horizontalpipework shall be fixed with pipe clips and brackets as recommended by the pipemanufacturer.
Expansion joints in general shall be provided at a maximum of 4m centres for soilpipework and 2 metre c entres for waste pipework and between fixed points over 1.0mapart. Pipework shall not be inserted fully into expa nsion fittings. A suffic ient gap shallbe allowed to allow lateral movement of the p ipe into the soc ket of the fitting.
h) Floor Drains
Drains shall be of stainless steel construction and be supplied with a removable trap toprovide full rodding access.
The drain shall have height adjustment of 55 mm and trap seal depth of 60mm. Theunit shall have a 5mm slot width grating.
Drain outlet size shall be 110 diameter suitable for a flow rate of 0.8 l/s.
An additional clamp shall be installed where a damp proof membrane is to besec ured to the gully body.
The drain shall be type RND0-5764 as supplied by RNDO Services Ltd (Tel: 01376 563636)or equal and approved.
i) Testing
All internal and / or external pipework shall be tested with air as soon as practicableafter installation and before completion of shaft walls, access panels and suspendedceilings.
Open ends of pipe shall be fitted with plugs, one of which shall incorporate a tee-piec e for connection to an air pump and manometer. Air shall be pumped until themanometer indicated an air pressure of 38mm WG, which must remain constant for 3minutes or to Loc al Authority requirements if different.
The fac t that any pa rt of the works has been passed by test will not relieve theContrac tor of any of his obliga tions and any defec t shown by the independent finaltest. Any faults appearing during the period of maintenance shall be loc ated andmade good at the Contrac tors expense.
The Contrac tor shall provide all necessary drain / pipe stoppers and bags, forcepumps, gauges etc., to carry out the required testing.
All testing of the various installations shall be carried out in the presence of theEngineer and the Local Authority Environmental Health Inspector.
At least 48 hours notice shall be given in writing to the engineer and EnvironmentalHealth Inspector of any proposed testing.
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Any failures in the system shall be made good and the system retested, all workdisturbed thereby shall be renewed and left sound and perfec t, at the C ontrac torsexpense.
j) Sanitary Appliances
Sanitary appliances shall be supplied and fixed as detailed on the Sanitary FittingsSchedules.
Suites containing more than one component shall be obtained from a single sourcewherever possible to ensure c ompatibility. All colours including white shall be ba tchedto ensure ac curate colour matching. All metal appliances shall be supplied with tags
for electrical bonding.
Protec tive c overings shall be retained , when practical, during and after fixing.
All packing and protective wrappings, etc are to be completely removed from insideand outside of all appliances prior to Practical Completion.
Prevent use of appliances for any purpose (except testing to specification), untilprac tical completion.
k) Installation
Assemble and fix appliances and accessories so that surfaces / parts designed to fall,drain as intended.
Where masonry walls are faced with ceramic tiling, wall plugs shall be pushed beyondthe back fac e of the tiling.
Floor standing appliances shall be bedded in suitable mastic and secured with screwsand not bedded in cement mortar unless so spec ified.
Only brass or stainless steel screws shall be used throughout.
Taps and waste fittings shall be bedded using washers or a suitable mastic . Any surplusmastic shall be cleaned off immediately after installation.
Where not otherwise specified, using bedding and jointing compounds recommendedby the manufacturers of the appliances and / or ac cessories.
Where an appliance is fed with both hot and cold supplies the hot tap shall be fixedon the left hand side and the cold on the right when viewed from the front, unlessotherwise specified on the drawings.
Watertight joints between app liances and duc t or wall surfac es shall be made using a nimpermeable flexible material such as silicone rubber mastic to a matching colour.
This specification sec tion shall be read in conjunction with architec tural specification.
Ensure that noggins, bearers, etc. required to support sanitary appliances and fittings
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are accurately positioned and securely fixed.
For tiled back grounds (other than splashbacks) ensure that:
Tiling is completed before fixing applianc es.
Fixings do not overstress tiles.
Ensure that seat and lid are stable when raised.
Unless specified otherwise obtain cistern operating components from cisternmanufacturer. Ensure that ball valve matches pressure of water supply.
Fix at the height recommended by manufacturer unless otherwise specified or shownon drawings.
Ensure that overflow pipe is fixed to falls, and located to give visible warning ofdischarge. Agree position with Engineer where not shown on drawings.
Fix taps sec urely, making a watertight seal with the appliance. Place hot tap to left ofcold tap as viewed by user of applianc e.
Wastes and overflows shall be bed in waterproof jointing compound and fixed withresilient washer between appliance and backnut.
l) Sealant PointingSea lant: Silicone based to BS 5889, Type B with fungicide.Manufac turer and Reference: To be approved.Colour: White
2.03.07 DOMESTIC PIPEWORK
a) General
The domestic water services works shall comprise the supply, installation, testing,sterilisation and commissioning of the complete water mains installation to the standardsand regulations specified and indicated on the drawings.
Submit all relevant information and pay any fees or levies to the Statutory Authorities andobtain approval on the services installed as a whole.
Failure to comply with the above clauses shall be rectified until the standard or LocalAuthority requirements are met at no cost to the contract.
Copper Domestic Pipework
All copper pipework, fittings and processes of fabrication shall be 100% LEAD FREE andshall comply with the current Water Byelaws for potable water supply.
15mm diameter to 54 mm diameter shall be c opper tubing to BSEN 1057, (BS 2871, Part 1, Table X). J oints and fittings as BS 864 (kite marked), (lead content not exceeding 0.1%).
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Integral solder ring capillary fittings installed using a non-toxic flux. No end feed fitting
shall be permitted. Compression fittings type B to BS 864, pa rt 2 can be used as analternative to capillary fittings.
b) Installation Standards
Ensure that the installation of the domestic water services comply with all Statutory andLoc al Authority regulations and current British Standards, with particular referenc e to:
BS 6700 design, installation, testing and maintenance of services supplying water fordomestic use within buildings and their curtilages.
BS 8000: Part 15 Domestic Hot & C old Water Services (Workmanship on Building Sites)
c) Easements and Notices
Ensure that prior to work commencing, all nec essary easements have been obtained , allnotices sent and all fees and levies paid to the Water Authorities concerned that arelegally demandable by them.
d) Pipework Supports
All vertical or horizontal pipework shall be supported by means of brass pipe rings, as Yorkshire catalogue No. 107. With build into wall split iron stem or brass pipe ring, a s Yorkshire catalogue No. 107.
With screw to wall backplate, or by means of brass single pipe rings on appropriatelysized mild steel drop rods supported off a secondary support system comprising mildsteel channel iron and angle iron, secured by means of Unistrut fixings, or equal andapproved.
Supports for pipework with expansion couplings shall be of the guide and anchor pointtype to allow correc t operation of the expa nsion coupling. The support and a lignmentof the pipework shall be in accordance with the expansion coupling manufacturersrequirements.
Surface finishes of site cut supports to be made good, cut surfaces to be de-burredand all supports to be fixed square to major building elements, i.e. walls, floors etc.
All primary and sec ondary support systems shall comprise non-ferrous metals, ferrousmetals ga lvanised or ferrous metals painted . Ferrous metals to be painted are to bethoroughly cleaned and degreased, a rust inhibitor applied and primed with a basecoat in compliance with the recommendations of the paint manufacturer prior toapplication of finishing coats.
e) Valves
All valves shall be Water Resea rch C entre (WRC ) app roved and shall be listed in thecurrent water fittings and materials direc tory for potable use. All valves shall be non-dezincifiable.
Isolation/stop valves shall generally be positioned such that ranges of fittings can be
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isolated, individual fittings shall be provided with service valves to facilitate
maintenanc e of the individual item/fitting.
All valves unless flanged shall be compression fittings. When positioning/fitting va lvesinto the system care should be taken to allow the future removal of that valve forfuture maintenance.
Failure to comply with this clause shall be rec tified to the satisfac tion of the C onsultingEngineer at no cost to the contract.
Gates valves 15 mm to 80 mm nominal bore shall comply with BS 5154 following fullpa ttern complete with wheelheads or be lockshield pattern where indicated. Gatevalves 80 mm and larger shall be flanged ductile iron to BS 5150.
Isolation valves up to 50 mm nominal bore shall be screw down pattern to BS 1010 Part2 with crutch head.
Drain Cocks shall comply with BS 2879.
Doub le chec k valves shall comply with BS 6282: Part 1. Connections shall be to BS 2779BSP or BS 864: 2 compression a s Yorkshire SOCLA IMI type 4423 or 4421 connections toBS2779 or BS864:2 compression.
Note: Valves shall be suitable for the system pressures exerted upon them.
Servicing valves shall comply with BS 6675:1986 and shall be of the compressionrotating ball type with large handles as Yorkshire or equal and app roved .
All valves shall be c ompression fitting to BS 864: 2 (unless flanged) to facilitate easyremoval.
Ball valves shall be Equilibrium pattern and comply with BS1212, with copper ball floatto BS 1968.
Water saving valves shall be hydraulically operated valve or electronic time clocktype.
The hydraulic operated valve units installed shall be appropriate to the pressuresexerted.
Stopcoc ks shall comply with BS 1010: Part 2: 1973 with crutch hea ds.
Pressure reducing valves shall be as manufac tured by Honeywell Ref. No. D06FN orequal and approved
f) Automatic Urinal Flush Valves
Each automatic urinal flush tank shall be fitted with an approved flush control deviceutilising ceiling mounted, flush fitting, battery operated passive infra-red detection asFLUSHMATIC or equal and app roved.
All fittings shall be listed in the current edition of the WRC Fittings and Materials
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Directory.
The Contrac tor shall give attendanc e as required to permit the bonding of metalpipework to earthing c able (see Electrica l Specifica tion).
g) Electro-Magnetic Descalers
For the Inhibition of hard scale formation, an elec tro-magnetic water conditioning unitshall be installed where indicated on the drawings. Size should be as rec ommendedby the manufac turer.
The system should be WRC a pproved.
The unit shall be comprised of an electrical coil for generating the magnetic field, adesigned flow path that enables the water to cross the magnetic field line at an angleof 90 degrees, with PTFE plated body. The power supply / control box should have apolarity reversal mechanism to eliminate routing maintenance of the unit, and shouldbe connected to a 240v/1ph/50Hz supply through a fused spur.
h) External Trace Heating
All plant and equipment sited in areas subject to ambient temperatures shall beprotected by means of self-regulating trace heating tape. The tape shall comply withBS 635 1. Supply and fix all necessary equipment, cabling, etc. leaving a 1metre cabletail for connec ting to the e lectrical supply by others.
i) Expansion Couplings
Shall be as Engineering Appliances (1978) Ltd., Unit I 1, Sunbury Cross Industrial Centre,Brooklands Close, Sunbury-on-Thames, Middlesex TW16 7DX. Generally as their stainlesssteel axial expansions joint with gunmetal unions, type EA02, or similar, equal andapproved.
j) Overflow Pipes
Overflow pipes shall discharge externally where possible in conspicuous positions. Theexac t method and termination points are to be c onfirmed and agreed with the Loca lWater Authority and the C lient's Representative.
All overflows shall be water tested for soundness under working cond itions.
Where overflows discharge internal to the building, or where it may not be easilydiscernible as to the origin of the overflow, Traffolyte labels shall be affixed to, oradjacent to, the overflow at its termination to indicate the origin.
k) Mechanical Plant Connection
Mechanical plant connections shall be via a backflow prevention device suitable forthe fluid category at the point of connection and shall be in accordance with therequirements of the Water Regulations. This shall be positioned down stream of anisolating valve. No mechanical plant shall be c onnec ted to the drinking watersupplies.
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l) Cleaning Injection Point
A WRC approved injec tion point shall be installed as close to the main stopcoc k aspracticable.
2.03.08 CONDENSER WATER/LPHW
a) General
Black mild steel pipework shall be of heavy weight tube to BS 1387 (1990) and shall becoated at the manufacturer's works with a special anti-corrosive varnish.
Pipework of 65 mm diameter and above shall be welded. Pipework up to and including50 mm diameter shall be screw threaded.
Where screw joints are employed they shall have a taper thread to BS 21 (1985) and shallbe made with approved jointing compound BS 5292 (1980).
J oints on all permanently concea led or other inaccessible work shall be welded.
Screwed fittings for mild steel pipework other than sockets shall be malleable cast iron,banded or beaded pattern, conforming to BS 143 (1986) and BS 1256 (1986). Purposemade welding fittings to BS 2971 (1991) shall be used on welded pipework.
Flanged joints shall be wrought iron or annealed steel with faces machined to a truemating surface and conform to BS 4504 and be capable of maintaining the appropriatepressures spec ified .
Flanged joints shall be made with gaskets to BS 4865 Part 1 or BS 3063 as appropriate.Gaskets shall be asbestos free. Full faced joints shall be acceptable only when matedflanges are non-ferrous. Flanges shall be pulled up by steel hexagon headed nuts andbolts with steel chamfered edge washers. Bolt thread protrusion through the nut shall notexceed 5 mm when fully tightened.
Isolation and regulation valves shall be provided and installed as shown on the drawings.All valves shall have local supports to prevent undue forces from being applied to thepipework.
b) Strainers
Duplex strainers shall be fixed as shown on the drawings and be screwed or flanged forthe particular service. All strainers 50 mm and above shall have suitable drain coc ks fittedto allow the complete draining down of the strainer.
The strainers shall be malleable cast iron Airpel Delta model OW by BSS Ltd and shall bepipeline size.
The strainers shall be fitted with "100" mesh liners for the initial system operating period.After the initial operating period the strainers shall be fitted with 400 micron stainless steelperforated screen once the system is clear.
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Where control valves are fitted with integral strainers these shall be removed when theperforated screens are installed.
Note: The strainers shall only be changed from "100" mesh liners to the perforated screenupon instructions from the Engineers.
c) Non Return Valves
Malleable cast iron non-return (check) valves shall be installed in the pipelines asindicated on the drawings. The valves shall be sized so that the flow rate is above theminimum required to hold the valve wide open in a stable position. The valves shall beSeries FM 492 (Bronze Trim) PN16 as manufactured by Crane Ltd.
d) Drain Cocks
The C ontrac tor shall supply and fix 15 mm diameter drain cocks wherever necessary toallow the completed draining of the system. These shall be provided with an 8 mm BSPblack malleable cap and hose union wired on. Where pipes run under doorways and forsimilar short sec tions of pipework which do not drain to the system low points 15 mmplugged outlet tees shall be supplied and fitted. The drain coc ks shall be Crane seriesD171 MHU ball coc ks.
Where drain cocks are exposed to view external to plant rooms on copper pipeworksystems these shall be Crane figure 340.
e) Air Cocks and Air Bottles
Generally air vents shall be fitted a t all high points. Pipework which requires venting shallbe fitted with 8mm air coc ks on a ir bottles unless spec ified differently. Air bottles shall beformed from 150 mm length of tube of equal bore to the pipe which is being vented, with8 mm pipe welded into the top and taken to low level and fitted with 8 mm ball valves -Crane series D191 with T-Handle. Each valve shall be provided with a 6 mm malleableplug.
f) Test Plugs
15 mm BSP Twinlock test plugs shall be provided in the pipework at the positions shown onthe drawings. They shall be as manufac tured by Binder Engineering and be suitable forthe service specified.
All test plugs shall be fitted complete with 50 mm extension pieces to bring the test plugclear of the insulation.
2.03.09 PIPEWORK ROUTES
Pipe runs shall be installed in accordance with that shown on the drawings, thediagrammatic nature of which shall be interpreted to accord with the best practice. Fullallowance shall be made in setting out runs of piping for possible future removal ofsections for extension and routine maintenance.
Where two or more pipe runs follow the same route care must be taken to ensure that
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they are truly parallel to each other and in the case of pipes running vertically, side by
side to the surrounding structure.
Pipes that are to be insulated shall be so spaced that they can be separately insulated.Combined insulation will not be ac ceptable.
Steel tubes shall be reamed after cutting and shall be free from burrs, rust, scale and otherdefects and shall be thoroughly cleaned before erection.
Open ends left during the progress of work shall be protected by being blanked off withpurpose made metal or wood plugs or blank counter flanges. Pipework shall follow linesof walls and have a minimum grading of 1 in 250 to ensure venting and drainage.
The clearance between pipework (or the lagging) and the wall and any other fixturesshall not be less than 30 mm.
J oints shall not be made within the thickness of any wall, floor or ceiling and pipeworkshall not be embedded in the structure of floors unless specifically indicated or instructedby the Engineer.
Where tubes pass through walls, floors or ceilings, sleeves shall be provided. Tubes passingthrough floors and ceilings shall be provided with an approved type floor and ceilingplate. The sleeves shall be of the same material as the tube.
Where pipework penetrates roof sections the opening shall be suitably weathered using a
ga lvanised steel construction. A detail shall be submitted to the engineer for approval.Penetrations shall be kept to a minimum.
All sleeves shall be packed with a compressible fire resistant material.
Whilst pipework is stored on site care shall be taken to prevent the tubes from rusting andthey are to be properly racked and covered, the necessary racks and covers beingsupplied by the Contrac tor. Any installed pipework showing any evidence of corrosion orUV degradation will not be permitted to be put into service.
2.03.10 PIPEWORK SUPPORTS
All pipework shall be adequately supported.
It is the Contrac tors responsibility to provide suitable secondary steelwork that is nec essaryto ensure the correct support of the pipework.
Where subsequent expansion, settlement, vibrations and other changes in the system canoc cur, variable support brackets shall be used.
All supports must be adequate for the total load being supported and shall be so formedand fixed that proper allowance is made for longitudinal expansion and contraction,without lateral deviation, guide points are to be sited in strategic positions.
For steel tubing, clips shall be fabricated from malleable iron and for steel copper tubingthe c lips shall be fabricated from brass, copper or gunmetal.
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Holes in brackets shall be drilled not large than 3 mm greater in diameter than the bolt or
rod accepted. All suspension rods over 300 mm shall be plain mild steel rod , minimumdiameter 10 mm threaded on site with minimum thread to serve the purpose, no joints tobe made in the length of the suspension rod . Where suspension rod sec uring nuts seat ona tapered flange tapered washers shall be used under the nut. Screwed studding forsuspension rods shall not be acceptable where exposed to view. Brackets shall be sawnoff if possible. If flame-cut the edges shall be filed and ground to a smooth finish.
Vertical pipework shall be supported by the use of purpose made "U" bolts onto channeliron sections. The spacing of supports shall not exceed that in the following tab les:
Multi-pipe supports for pipes of differing sizes shall be spaced at intervals required for thesmallest pipe.
Suspended type pipe hangers and accessories shall be constructed and assembled inaccordance with BS 3974: Part 1.
The type of pipe hanger clip or hoop used shall be selected according to theapplication, special provision being made in instances where the piping or tubing issubjec t to axial movement due to thermal expansion and/or contraction.
Where it is proposed to support pipes on cantilevers of fabricated mild steel section, eitherbolted or welded. Full details of pipe supports must be submitted to the Architec t forac ceptance prior to ordering of fabrication.
Where individual fixings require cutting for the building into the building structure, theinstaller shall arrange for positions to be to be marked out on the building for acceptanceby the Architect before c utting out and fixing.
Contact between dissimilar metals must be prevented. Cast iron and mild steel pipingshall have steel supporting members actually in contact with the pipe.
Socketless pipe systems shall be supported, in accordance with manufacturers fixinginstructions, adjacent to every joint. Long sec tions of drain shall be laterally braced to thestructure with angle sec tion mild steel to prevent horizontal movement.
Angle section mild steel thrust brackets shall be fitted at vertical bends to prevent axialmovement of suspended pipes.
In undercrofts and similar where the piping system is not suspended from a slab over,support shall be supported from engineering brick piers in accordance with BS 5228,
Table 1, C20p Grade concrete bedding and haunching. Spacing to piers to be as forpipe supports.
Pipe in shafts shall be fixed with two-piece eared type holderbats bolted together withcadmium plated mild steel and nuts and screwed to shaft walls using 50 mm No. 10cadmium plated mid steel screws and plastic wall plugs.
All steel brackets and pipe shall be wire brushed clean of rust and then painted with onecoat of red oxide pa int prior to erec tion. Following erection and installation of the pipingand brackets shall be painted with one additional coat of red oxide paint.
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Exposed pipework fixed to walls in occupied areas shall be supported on brass or mild
steel pipe rings as appropriate with screw on backplates.Pipework supports shall permit free movement of pipes due to expansion and contrac tionand shall generally be arranged as near as possible to the joint, valves and on both sidesof changes in direc tion. Eac h support shall not exceed the centres given in the tab leunless otherwise indicated.
Where two or more pipes share support points spacings shall be based on the centresrequired by the smallest bore pipework.
Pipework shall not be fixed to skirting boards.
Multiple pipe runs in plant rooms and where not exposed to view shall be supported form
mild steel single or channel sections or approved proprietary system securely fixed to thebuilding structure.
Individual pipe runs in plant rooms and where not exposed to view shall be supported viaindividua l split ring type brackets sec urely fixed to the building structure.
In certain circumstanc es pipes may be suspended from larger ones. The reverse shall notbe permitted.
The total weight of vertica l pipes shall be carried at the base of the riser or as detailed onthe drawings. Branch pipes shall not be used to support vertical mains.
2.03.10a - Table 1 Supports for Copper Pipework
NominalBore of Pipe
Intervals for Horizontal Runs Intervals for VerticalRuns Bare or
InsulatedBare Insulated
Mm
1520 and 25
32 and 4050
65 and 100
m
1.21.8
2.42.43.0
m
1.21.5
1.81.82.4
m
1.82.4
3.03.03.6
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2.03.10b - Table 2 Supports for Plastic Pipework
NominalBore of Pipe
Intervals for Horizontal Runs Intervals for Vertical RunsBare or Insulated
Mm
1522 to 25
3240
50 6580
100
M
0.751.01.01.21.41.8
2.0
m
1.51.82.02.42.83.5
4.0
2.03.10c - Table 3 Supports for Wrought Iron and Mild Steel Pipework
NominalBore of Pipe
Intervals for Horizontal Runs Intervals for VerticalRuns Bare or
InsulatedBare Insulated
Mm
1520 and 25
3240 and 5065 and 80
100
m
1.82.42.73.03.63.9
m
1.82.42.42.43.03.0
m
2.43.03.03.64.54.5
2.03.10d Table 4 Supports for Drainage Pipework
PLASTIC PIPEWORK
Pipe Dia. (mm) Support Interval Horizontal Pipes(m)
Support interval Vertical Pipes (m)
32285082
110160
0.50.50.90.90.91.0
1.21.21.21.81.81.8
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COPPER PIPEWORK
Pipe Dia. (mm) Support Interval Horizontal Pipes(m)
Support interval Vertical Pipes (m)
283542546576
1.51.81.81.82.42.4
2.43.03.03.03.73.7
CAST IRON PIPEWORK
Pipe Dia. (mm) Support Interval Horizontal Pipes(m)
Support interval Vertical Pipes (m)
75100150
2.02.02.0
2.72.73.6
a) The Contrac tor is to carry out his own fixings and must provide anchors similarto the HILTI type or girder clamps where appropriate. Self drill anchors shall notbe used. Care must be taken to ensure that the fixings are located securely,
and in accordance with the Structural Engineers requirements.
b) Where prac ticable, provision for expansion and contrac tion of pipework shallbe made by changes in direc tion.
2.03.11 ELECTRIC WATER HEATERS (UP TO 50L)
Electric water heaters up to 50 litres capacity shall be of an unvented type,incorporating and supplied c omplete with unvented systems kit comprising: pressure /expansion relief valve and pre charged expansion vessel appropriately sized to suit thesystem volume. Pressure reducing a nd c hec k valves to be provided a s required.
The heater shall be constructed from corrosion resistant plastic coated or stoveenamelled steel and / or high impact resistant plastics outer casing, CFC freeexpanded polystyrene or polyurethane foam insulation a nd copper or glass lined steelinner casing rated for 6 bar max8mum working pressure.
Heating units to be replac ea ble, generally to c omply with the requirements of BS 3456:Part 2: Section 2.21: and BS EN 60335-2-73: 1997.
Heater to incorporate temperature and pressure relief valve set to open at 7 Bar and90 o C.
Water heater and pressure/temperature relief drain arrangement shall be in
ac cordance with Building Regulations Approved Document G3.
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2.03.12 CISTERNS AND COLD WATER TANKS
Cisterns and c old water storage tanks shall be of the following types as indicated: -
a) Thermo-plastics for cisterns.
b) Glass reinforced plastics (one-piece)
Thermoplastic cisterns shall comply with BS 4213 (1991).
Each cistern shall be provided with a loose cover formed in sections not exceeding 2 mlong and 1 m wide. Covers shall be of the same material as the cistern or tank body. Thetermination of vent pipes into cisterns and tanks shall permit the easy removal of the
covers.
Each cistern or tank shall be fitted with a float-operated valve suited to the pressureavailable. Cisterns and tanks shall be installed in positions that allow easy access formaintenance.
Warning and/or overflow pipes shall be twice the bore of the ball-float valve fitted or32mm size, whichever is the greater. Warning and/or overflow pipes shall be run todischarge outside the building wherever possible.
Where indicated the cistern or tank shall be complete with integral insulation with a rigidouter skin. The insulation shall also c over the base and lid.
All cisterns or tanks shall comply with all current Water Byelaws.
2.03.13 WASTE WATER PUMP UNIT
a) Toilet Waste
Note: Where pumping systems are required to serve WCs, domestic pumping systemsshall not be used.
Floor mounted sewage pumping systems shall be installed . These units shall be installed ina separate enclosure of suitable size, and with suitable maintenance access to thepumping system.
The units shall be capable of 30 m 3/h at 5 m head. They shall comprise vortex freeflowpumps with non-clogging single vane open impeller with large free passage to preventblockage. The unit shall include an 80 mm (3) discharge c onnection. The unit shall besupplied with a non-return valve on the discharge pipework, and all necessary couplingsfor all invert, discharge and vent connec tions. The discharge pipework shall be uPVCclass C or D with solvent welded joints.
The tank on the unit shall be vented to external atmosphere using 75 mm (O.D.) pipework.Durgo type air admittance valves are not ac ceptable.
The units shall be suitable for 230 V, single phase electrica l supply.
The units shall be supplied with a small pre-wired control panel which can be wall
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mounted adjac ent to the unit. The control panel shall include manual/automatic switch
and pump run/fault lamps.
The units shall be supplied with a separate high level alarm unit, which must be providedwith a separate 230V supply. The a larm shall be wired to the pump set with a 0.75mm 2 2core cable.
The units shall be the Efflu Midi 40 as supplied by Pump Technology Ltd or equal andapproved.
b) Sink Waste
Where waste pumping systems are required only to serve sinks these shall be suitable for
commercial premises.
The units shall be installed under the sinks. The units shall comprise a pump enclosed by adurable tank manufactured from polyester/glass fibre laminate, with externally smoothisophthalic polyester gel coating and resin enriched lining.
The tank shall have a 1 BSP discharge outlet. The discharge pipework shall be uPVCwith solvent welded joints. The contrac tor shall connect the waste outlet to the side ofthe tank by drilling a hole and using the appropriate tank connec tor. The contrac tor shallsupply and install a vent off the side of the tank run to external atmosphere of minimumsize 1 .
The pumps shall be capable of pumping to a head of minimum 5 m against a flow rate of10 m 3/h. The pump shall be a vertical centrifugal type of stainless steel construction,suitable for submerged operation, with a strainer base, and open impeller capable ofhandling 10 mm solids. The pump body shall be manufactured from plastic, with a GRPimpeller and stainless steel encapsulated motor.
Motors shall be fully encapsulated submersible motors with built-in overload/thermal cut-out, within a watertight (IP68) enc losure. The pump shall be supplied with a built-in levelswitch. The pump end shall include a silicon carbide mechanical seal, unaffected by dryrunning.
The waste pump shall be suitable for 230 V, single phase electrical supply. The pump shallbe the Drainmajor 60/W as supplied by Pump Tec hnology Ltd, or equal and approved.
2.04 DUCTWORK
The supply and extrac t ductwork systems shall be installed as indicated on the drawings.
2.04.01 GENERAL
In general, all ductwork shall be manufactured and installed to DW/144 Specification ofthe Heating and Ventilation C ontrac tors Assoc iation for low and high velocity/pressuresystems with the following specific requirements: -
a) The "Mez Flange" jointing system shall be used throughout. Drive cleats shall beused where additional clamping is required.
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b) All duc twork shall be detailed on suppliers' manufacturing drawings of a scale
not less than 1:20. These drawings shall include all plans, sections and deta ils asnecessary to ensure all aspects of co-ordination are allowed for. All ductworksec tions shall be individua lly numbered for identification purposes. Thedrawings shall be based on actual site dimensions and manufacturers certifieddrawings for plant and equipment. These are to be submitted to the Engineerfor approval before manufacture and installation.
c) All bends and changes in direc tion (including final bends onto grilles anddiffusers) shall be fitted with turning vanes.
d) Support rails shall be as supplied by Unistrut Mez or B.S.S. Boss Flamco. Rails shallbe selected by the ductwork Sub-Contractor to suit the duc t size and loadings.
All rail sizes shall be shown on the ductwork suppliers manufacturing drawings.
e) All suspension rods exposed to view (including false ceiling voids) shall besheradised studding. The studding shall be cut to a proper length and filedsmooth to remove all sharp edges. All cut ends shall be painted with a zincrich paint to inhibit rusting.
f) All suspension rods shall be selected by the C ontrac tor to suit the loadings andrail sizes. All rod sizes shall be shown on the ductwork supplier's drawings.Spacing of supports shall be in accordance with DW144.
g)
At each point where a duct passes through a roof or external wall a weathercravat shall be installed to the duct to ensure a weatherproof fixing.
h) Duct connec tions between individual components of an air handling assemblyand connections between an assembly and a ductwork system shall be madewith angle flanged joints.
i) Where the ductwork rests on the support brackets, the bracket must be felt/Hardwood lined to avoid vibration/condensation.
The following clauses shall apply to flat oval ductwork:
a) "Flat oval" is the term used to describe a duc t of cross-sec tion with flat opposedsides and semi-circular ends. The duct is formed from a spirally wound circularduct using a spec ial former. Apart from stiffening flat oval duc ts have thesame constructional requirements throughout the pressure ranges covered inDW144.
b) Flat oval ducts may also be formed from flat sheet with straight seams.
c) Spirally-wound flat oval duc t is accepted as airtight to the requirements ofDW144 without sealant in the seams, provided the grooved seam is tightlyformed to produce a rigid duct.
d) Wherever possible all joints shall be sea led with hea t-shrinkable tape.
e) However, where agreed with the Engineer the joint is made with sea lant, the
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ends to be jointed shall be carefully cleaned with a suitable solvent to a length
of 100 mm and sealant applied to the spigot so as to give a joint length as forthe requirement for circular duc ts. Use of excessive sealant shall be avoided.
The joint shall be fixed with permitted fastenings at 60 mm centres, on the flatsurfaces only.
f) Where the joint is made by enc losure, such as with a hea t shrinkable band orstrip, or other approved material, the makers' recommendations shall befollowed. Care should be taken to maintain close contac t between thematerial and the flat sides of the duct until the joint is completed.
g) Where conditions require the use of flanged joints, they shall be as above.
Alternatively, the duct shall be continuously welded inside the angle flange.Sealant shall be used between the duct and the spigot, and sealant or gasketbetween the angle flanges. The flanged joint shall be sec ured by bolts andnuts at 150mm centres.
h) The larger sizes of flat oval duc t are stiffened by swages. Additional tie rods arerequired, positioned as indicated in DW144.
i) Flat oval ducts with opposed sides and semi-circular ends may also be formedusing plain sheet and straight seams. Ducts so formed should follow the metalthickness and stiffening requirements spec ified for the c orresponding sizes ofrec tangular ducts, except that stiffening is nec essary on the flat sides only.
Seams and cross joints shall be sealed to ensure the necessary degree of airtightness throughout the pressure ranges covered in DW144.
The ductwork installation shall be ca rried out by a Spec ialist.
All drilling, screw fixings, etc ., assoc iated with these works shall also be carried out by theContrac tor or his Specialist.
2.04.02 FLEXIBLE DUCTWORK
Where flexible ductwork is indicated, or required between rigid ductwork and items ofequipment, the internal diameter of the flexible duct shall be equal to the externaldiameter of the rigid duct and equipment spigot. Flexible ductwork shall be kept to aminimum and shall not be used between rigid sections of ductwork to change direction.
The maximum length of any individual flexible duct shall not exceed 1.5 m unlessotherwise indicated by the Engineer. The flexible duct shall only include one change ofdirection.
The flexible duct shall have a liner and a cover of tough tear-resistant fabric equal indurability and flexibility to glass fibre fabric. The fabric shall be impregnated and coatedwith plastics. It shall be reinforced with a bonded ga lvanised spring steel, stainless steel orother approved wire helix between the liner and the cover. An outer helix of glass fibrecord or equal shall be bonded to the cover to ensure regular convolutions.
Flexible ductwork up to and including 140 mm diameter shall be secured with a doubleworm drive type hose c lip complying with BS 5315. Ductwork over 140 mm diameter shall
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be secured with a band c lip.
The leakage from any section of flexible duct shall not exceed 1% of the local designairflow rate at the loc al maximum static pressure.
Flexible ductwork shall consist of, or be externally protected by, materials having a firepenetration time of at least 15 minutes when tested in ac cordance with BS 476, Parts 20-23 (1987) and shall comply with BS 476 Part 7, Sec tion 2, clause 2.8 (Class 0: surface of verylow flange spread).
2.04.03 FLEXIBLE JOINTS
Flexible joints shall be provided on fan inlet and outlets connections and elsewhere on
duc twork where indicated. J oints shall be of the same cross-sec tional area as the matingfan inlet, outlet or duct sec tion. The centre lines of flexible joint connections shall becoaxial.
Flexible joints shall consist of, or be externally protected by, material having a firepenetration time of a t least 15 minutes when tested in ac cordance with BS 476 Parts 20-23(1987) and shall comply with BS 476 Part 7, Section 2, clause 2.8 (Class 0: surface of verylow flame spread).
2.04.04 CONTROL DAMPERS
Control dampers shall be provided where indicated on the drawings. The dampers shall
have stainless steel low profile aspect ratio blades of riveted double skin constructioncomplete with silicone treated synthetic seal with twin trailing edges to minimise airleakage. The damper shall have a double skin spigot casing with a 20 gauge galvanisedsteel formed inner frame and an 18 gauge galvanised steel formed outer frame. Theexternal casing shall have only one penetration for the control drive shaft.
The control dampers shall be of the "Aeroseal Series" as manufac tured by ActionairEquipment Ltd or equal and approved.
2.04.05 ACCESS DOORS
Removable hinged insulated access doors to DW144 Table 25 Level 2 and shall beprovided where indicated on the drawings and adjacent to all attenuators coils, firedampers and volume control dampers. They shall also be installed at changes indirec tion and be adequate to comply with clause 2.02.09 of this document. The doorshall be of twin wall deep drawn 20 gauge galvanised steel construction totallyencapsulating mineral wool insulation.
The door shall have a compressible fire resistant gasket on the door inner side to ensureair-tightness to DW144 and be complete with safety chain or hinged operation (120 o minimum opening).
The doorframe shall be of one piece deep drawn construction from 20 gauge galvanisedsteel, with pre-punched fixing holes.
The frame shall be suitable for surface mounting on the ductwork and shall be completewith an overlapped finishing edge to protec t the external duct insulation.
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The access doors shall be of the "Access/Shield" type as manufactured by ActionairEquipment Ltd or equal and approved.
2.04.06 FIRE DAMPERS
Fire dampers shall be fitted in the ductwork where indicated on the drawings and whereany ductwork passes through concrete slabs/fire compartments.
The fire dampers shall conform to BS 476: Part 20-23 (1987).
The fire dampers shall not obstruct the a irway when in the fully open position. The firedampers shall have stainless steel folding curtain blades of not less than 22 gauge. The
bottom blade shall be fitted with a manual release device to facilitate the opening of thedamper position.
A fusible link rated at 72 oC shall be mounted on the fire damper by a stainless steelbracket incorporating a quick release trigger.
The damper casing shall be completely airtight and shall be c onstructed from 16 gaugega lvanised sheet steel with continuously welded corners. The casing shall have a gasketof 32 gauge tempered stainless steel fitted between the blade ends and the casing.
All dampers shall be provided with "Installation Frames" which shall be fixed with the slaband grouted in by the Main Contractor to provide a fire barrier. The fire damper is to be
independently supported to the building fabric in all instances. The fire dampers shall be of the "Fire/Shield" type as manufactured by ActionairEquipment Ltd or equal and approved.
2.04.07 SMOKE DAMPERS
Fire/smoke dampers shall be installed within the ductwork where indicated on thedrawings and where any ductwork passes through a smoke barrier.
The fire/smoke dampers shall be fire tested to BS 476 Part 8 and be approved by theLPCB.
The damper shall have stainless steel interlocking aerofoil blades and stainless steelbearings and gasketing.
The opposed blade drive mechanism shall be totally enclosed and outside the air stream.
An externally replaceable and fusible link rated at 72 oC shall be mounted on the unit toprovide fail safe operation.
An externally replaceable electrica l self re-settable thermal link shall also be provided.
The rating/operating method of the fusible and thermal links and the mode of operationshall be as specified the particular specification.
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All dampers shall be provided with installation frames which shall be fixed to the
slab/partition and fully grouted in to provide a fire/smoke seal
The fire/smoke damper is to be independently supported in all instances.
The fire/smoke dampers shall be the smoke/shield type as manufac tured by ActionairEquipment Ltd or Advanced Air, series 1200 type or equal and approved.
2.02.08 GRILLES, DIFFUSERS AND LOUVRES
All grilles and diffusers throughout the premises must be supported from the buildingstructure and not the c eiling grid.
The grilles shall have where prac ticable secret fixings and a removable core on safetychains.
Grille boxes shall be provided with painted matt black internal finish.
Louvers shall be weather tight and provided with an insect screen in all instances andburglar bars where the opening exceeds 300 mm in any direction.
2.04.09 DUCT CLEANLINESS
The Workplace Health Safety and Welfare Regulations 1992 plac es a duty on Employers(Regulation 6) to ensure that mechanical ventilation systems including air conditioning
systems be regularly and properly cleaned and kept free from anything which maycontaminate the air.
It is therefore essential that at Practical Completion/ Handover the installed ductworksystems are internally clean in all respects with zero contamination from dust, dirt, debrisetc ., arising from the construction proc ess.
To aid this requirement all ductwork sections delivered and stored on site prior to erectionshall have sealed ends to prevent contamination.
All ductwork shall be subjec t to internal inspection on completion and any contaminationshall be removed a t the installers cost. Access must also be provided to level 2 as set outin HVCA publication DW/TM2.
2.05 AIR HANDLING UNITS
2.05.01 GENERAL
Casings shall generally be of c onstant cross-sec tional dimensions. Casings shall becomplete with internal flanged joints. Mixing sec tions, with outside air/rec irculated airconnections complete with dampers as appropriate, shall be included together withaccess sections, bulkhead light fittings and viewing panels.
Packaged plant components shall comprise a combination of the following fans, filters,cross flow plate heat exchanger, heaters and attenuators, all as described in theParticular Specification.
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Individua l components shall, in add ition to the requirements of this sec tion, comply with all
other relevant sec tions of this Specification.
Sections of packaged air handling units shall be arranged with adequate separation andgenerally to promote even air distribution across the face of a ll components.
Air handling units shall be c orrosion resistant.
J ointing methods shall ensure that air handling units are no less airtight than the relatedductwork system.
Air handling units for outdoor installation shall have a weatherproof outer casing, apitched roof constructed of watertight metal decking with water seals in all joints and
lockable access doors.
2.05.02 CONSTRUCTION
Air handling units shall be of rigid c onstruction to minimise distortion and drumming inoperation.
The casing shall be of a framed construction utilising heavy gauge steel penta-postsec tion or steel box sec tion frames fully welded a t each corner. The infill panels shall be ofa sandwich c onstruction from 16 gauge zinc coated mild steel. The panels shall have aplastic or vinyl faced outer skin and a ga lvanised inner skin.
The panels shall encapsulate 25 mm minimum thick mineral wool insulation with a densityof 60 kg/m 3. The panels shall meet Class 0 requirements and BS 476: Part 7 (1973) Fire Tests on Building Materials and Structures.
A copy of the manufac turers Class 0, BS 476: Part 7 Certificate shall be included in theMechanical Installation Operating and Maintenance Manual.
Where penta-post frames are used they shall also be insulated to the same standard asthe infill panels but using rigid type materials to prevent the migration of fibres from theinsulation.
Each panel shall be set flush into the framework and shall be seated on a 3 mm pliablegasketing to give a fully airtight seal.
Full height access doors shall be provided where necessary for inspection andmaintenance and shall be complete with safety latches that may be opened from withinthe unit. Ac cess doors shall be hinged and capable of being lifted off completely oropen through 180 o to provide a clearway for maintenance.
All other panels shall be of the lift off type for easy removal and replacement. All fansec tion access doors shall be fitted with lockable handles.
The filters shall be mounted in a purpose made housing that shall be complete withgalvanised steel filter frames and withdrawal strips.
Individual components and sections shall be assembled using proprietary and provenfastening tec hniques. Loc king devices shall be used with all fastenings that are subjec t to
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vibration.
Floor dec king suitable for 1.5 kN/m 2 loading, shall be provided to all ac cessible sec tions.
Each sec tion shall be identified by a label on the external surface indicating the contentsof the sec tion.
Unless otherwise indicated, there shall be a clearance of at least 150 mm between theunderside of the air handling unit and its base or the plant room floor.
Unless otherwise indicated each fan and drive motor shall be mounted on a commonframe or other means of support. The complete assembly shall be isolated from thecasing to prevent the transmission of vibration. Electrica l connec tions shall not inhibit free
movement of the fan and drive motor set.
Where the fan and drive motor are directly connected to the fan section casing, thecasing shall be isolated from the structure to prevent transmission of vibration. Flexible
jointing to adjac ent sections shall be provided.
All power transmission shafts, belts and pulley drives shall be guarded in accordance withSec tion 2.9 of this Specification and any Health and Safety legislation including EECdirec tives.
Vapour proof bulkhead lights shall be fitted to all sec tions having access and shall be pre-wired to an individual switch external to that section complete with engraved plate
indicating the light switch. The fans shall be pre-wired to an externally mounted isolator suitable for the area of use. The cabling internally shall be in galvanised conduit with the final connection to the fanmotor in metallic flexible conduit.
2.06 HEATER BATTERIES
2.06.01 GENERAL
Casings shall be of galvanised sheet steel not less than 1.2 mm thick with angle framing ateach end drilled ready to receive the counter flanges on the connecting ductwork.Heaters shall be supported so that their weight is not transmitted to ductwork and so thatthey can be removed without disturbing adjacent ductwork. Inspection doors shall beprovided on both the upstream and the downstream sides of the heater.
2.06.02 ELECTRIC TYPE
Electric air heaters shall consist of a number of heating elements of the enclosed typemounted in a sheet steel casing. The elements shall be so installed that they can beremoved for cleaning or renewal without dismantling ductwork. The surfac e temperatureof the elements shall not exceed 400 oC when measured in an airflow of 2.3 m/s atambient temperature. A high temperature limit device located nearest to and abovethe heating elements which is energised by the first control step shall be incorporated.
The high limit device shall incorporate a remote reset and indication for integration intothe mechanical services control panel.
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The control of electric air heaters shall be interlocked with the fan motor starters and anair flow control of the pressure type so that the heaters cannot operate unless the fan isrunning.
The number of elements in the heater shall be the same as or a multiple of the number ofsteps in the controller. All hea ters and heater sec tions of more than 3 kW loading shall bebalanced over 3 phases and the c omplete heater bank shall be arranged for balancedoperation on a 3 phase 4-wire system.
The connections from eac h element shall be taken to readily accessible extendedterminal boxes arranged for conduit/c able gland entry.
Terminals and cable entries shall be suitably sized for their respec tive cables. Each heatersection shall be separately fused and the neutral point of all 3 phase star-connectedsec tions shall be brought out to a link in the terminal box. Nea r hot areas the wiringinsulation shall be of a quality suitable for the maximum temperature.
The total resistance of the heater to airflow shall not exceed 25 Pa and the face velocityshall not exceed 6 m/s.
2.07 FANS
2.07.01 GENERAL
Fans shall be constructed to proven design standards and shall be capable ofwithstanding the pressures and stresses developed during continuous operation at theselected duty, during starting, during stopping and during speed and duty changes.Additionally, belt-driven fans shall be capable of running continuously at 10% in excess ofthe selec ted duty speed and shall have a minimum of two belts. Details of the designstandards shall be included in the Mechanical Installation Operating and MaintenanceManual.
Fans shall be installed using bolts, nuts and washers with all nuts properly locked andsec ured. All as cast bearing surfac es for bolt heads and washers shall be mac hinecounterfaced. Holding-down bolts for fans and motors shall be provided with means toprevent the bolts turning when the nuts are tightened. Fans heavier than 20 kg shall beprovided with eyebolts or other safe means of lifting.
The shaft and impeller assembly of all fans shall be statically and dynamically balancedto BS 6861 (1987). Where indicated, limits of vibration severity shall be in accordance withBS 4675: Pa rt 1 (1986).
Fan bearings shall be of a type suitable for the size, speed, loads and discharge angle ofthe fan and shall be grease/oil ball and/or roller type, oil lubricated sleeve type or sealedtype where approved and shall be included in the Mechanical Installation Operatingand Maintenance Manual. Bearing housings shall be prec ision aligned and arranged sothat bearings may be replaced without the need for realignment. Bearing housings shallbe protected aga inst the ingress of dust. For grease lubricated systems, the bearings shallbe provided with grease in the quantity and quality recommended by the bearingmanufacturer. Oil lubricated systems shall have an adequate reservoir of oil. All bearinglubricators shall be located to fac ilitate maintenanc e.
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Finishes and materials of construction shall not be affected by gases handled by the fanor the local environment.
2.07.02 CENTRIFUGAL FANS
Unless otherwise indicated, centrifugal fans consuming more than 7.5 kW at the fan shaftshall be of the backward bladed type, selected for operation at a fan total efficiency notless than 75%.
Fan casings shall be mild steel sheet, with welded or riveted joints and welded anglestiffeners, constructed to permit withdrawa l of the fan impeller. A plugged drain shall befitted at the lowest point in the casing. Permanent indica tors shall show the direc tion of
rotation of the impeller. Casings shall have ac cess panels incorporating air seals tofacilitate cleaning and maintenance of the impeller.
Impellers shall be of mild steel protec ted against corrosion or aluminium alloy. Impellercage braces shall be bolted, riveted or welded to the cage and hub. Stressed wire ofthreaded rod brac ing shall not be used. Bolted a ssemblies shall have locking devices.
Impellers of fans consuming more than 1 kW at the fan shaft shall be keyed to the driveshaft or fixed with tapered bush fittings.
Each fan impeller shall have a separate shaft. Where necessary, fan shafts shall beconnec ted with flexible couplings to ensure correc t alignment.
Each fan impeller shall be supported by an individual bearing system.
Plumber block bearings or similar split bearing housings shall be used on fans consumingmore than 4 kW at the fan shaft.Rubber bushed bearing housings with lateral deflections shall not be used on belt-drivenfans consuming more than 1 kW at the fan shaft.
Belt-driven centrifugal fans and drive motors shall be located on a common base.
2.07.03 IN-LINE FANS
Fan casings shall be rigidly constructed of mild steel protected against corrosion oraluminium alloy and shall be stiffened and braced where necessary to minimisedrumming and vibration. Mounting feet shall be provided where necessary for bolting toa base or supports. Each inlet and outlet shall terminate in a flange to BS 6339 (1983) tofac ilitate removal. Stator vanes shall be of mild steel or aluminium alloy.
Provision shall be made for inspection of the fan impeller and motor. Casings shall havean access panel incorporating an air seal to fac ilitate cleaning and maintenance. Aremovable inspection panel incorporating an air seal shall be fitted to casings 450 mmdiameter and above.
Fans connected at both ends to ducted systems shall have c ircular cross sec tion casingsthat cover the overall length of the impeller, impeller hub, motor and any inlet cones anddischarge straightening vanes.
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Impellers shall be mild steel protected against corrosion or aluminium with blades welded
or riveted to the impeller hub and shroud. Impellers with an outside d iameter 500 mm orless may be die-cast aluminium with a fitted shroud.
Electrica l connections to fans with direc t-drive motors mounted inside the c asing, shall bethrough flexible conduit to an external galvanised mild steel or plastics terminal boxsecured to the fan casing.
Fans driven by externally mounted motors shall have twin ball or roller bearing mountedsteel impeller shafts. The drives shall be so arranged to minimise air leakage and a llowaccess to pulleys and belts.
2.08 BELT DRIVES AND GUARDS
2.08.01 BELT DRIVES
Belt drives shall comply with BS 3790 (1995) and be capable of transmitting a t lea st therated power output of the driving motor with one belt removed. Unless otherwiseindicated, no less than two belts per drive shall be used and all multibelt drives shall usedmatched sets. Pulleys shall be correc tly aligned and the Contrac tor shall ensure that anyholding down bolts or fixings he provides are positioned by the Main Contrac tor to ensurecorrec t alignment. Provisions shall be made for adjustment of the tension in belt drivesand also for their alignment.
2.08.02 GUARDS
Guards shall comply with the recommenda tions contained in BSEN 953 (1988). Guardsshall be provided at all open intakes and exhausts from fans, all forms of open powertransmission systems including belt drives and drive couplings, and where indicated.
Fixed guards shall be used and they shall be installed to prevent access to dangerousparts of mac hinery. Construction and installation of guards shall ensure strength andrigidity and it shall not be possible to remove any guard or access panel without the aidof a tool.
For belt drives, the guards shall be of galvanised steel wire not less than 2.5 mm diameterattac hed to a rigid ga lvanised steel rod or angle framework. The mesh size and/ or thelocation of the guard shall prevent figure contac t with any enclosed danger point.
2.08.03 FAN DRIVE PULLEYS
Belt Driven fans shall be fitted with pulleys suitable for the belt drive used . Pulleys may usesplit taper bushings of an approved type for drives up to 30 kW. Alternatively, and in anycase above 30 kW output, pulleys shall be secured to the fan and motor shafts by keysfitted into machined keyways. Pulleys shall be keyed to the fan shaft in the overhungposition. Keys shall be easily accessible so that they can be withdrawn or tightened andthey shall be accurately fitted.
2.09 AIR FILTERS
2.09.01 GENERAL
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