fp707a,bondstrand marine design manual

7/25/2019 FP707A,Bondstrand Marine Design Manual

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BondstrandDesignManualfor Ma rine P iping S ys tems

FP707A (4/01) S upe rse de s FP 707


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1 Introduction1.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

1.2 Products Range and S eries . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

1.3 Sta ndards and S pecifica tions . . . . . . . . . . . . . . . . . . . . . . . . . . .2

1.4 Class ifica tion So ciety Approvals . . . . . . . . . . . . . . . . . . . . . . . . .2

1.5 Uses a nd Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

1.6 J oining Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

1.7 Fittings a nd Flang e Drillings . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

1.8 Corrosion Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

1.9 Economy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

2 Design for Expansion and Contraction2.1 Length Change d ue to Thermal Expansion . . . . . . . . . . . . . . . . .5

2.2 Length Change due to Pressure . . . . . . . . . . . . . . . . . . . . . . . . .6

2.3 Length Change due to Dynamic Loading . . . . . . . . . . . . . . . . .10

2.4 Flexible J oints, Pipe Loops, Z &L Bends . . . . . . . . . . . . . . . . .11

2.5 Design with Flexible Jo ints . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

2.6 Design with Pipe Loops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

2.7 Design using Z Loops a nd L Bends . . . . . . . . . . . . . . . . . . . . .16

3 Design for Thrust (Restrained Systems)3.1 General Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

3.2 Thrust in an Anchored Sys tem . . . . . . . . . . . . . . . . . . . . . . . . .19

3.3 Thrust d ue to Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

3.4 Thrust due to P ress ure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

3.5 Formulas for Calculating Thrusts inRestrained Pipe Lines (With Examples) . . . . . . . . . . . . . . . . . . .20

3.6 Longitudinal Stress in Pipe &Shear Stress in Adhesive . . . . . .21

4 Support Location and Spacing4.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

4.2 Abrasion Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

4.3 Spa ns Allow ing Axial Movement . . . . . . . . . . . . . . . . . . . . . . . .28

4.4 Span Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28

4.5 Suspended S ystem Restrained from Movement . . . . . . . . . . . .30

4.6 Euler and Roark Equations . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

4.7 Support of Pipe Runs C ontaining Expansion Joints . . . . . . . . .33

4.8 Support for Vertica l Runs . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38

4.9 Ca se S tudy: Vertica l Riser in Ba llas t Tank . . . . . . . . . . . . . . . . .38

5 Anchors and Support Details5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43

5.2 Details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43

6 Internal and External Pressure Design6.1 Internal Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55

6.2 External Collaps e P ressure . . . . . . . . . . . . . . . . . . . . . . . . . . . .56

7 Hydraulics7.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59

7.2 Head Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59

7.3 Formulas for Ca lculating Head Loss in Pipe . . . . . . . . . . . . . . .59

7.4 Head Loss in Fittings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61

7.5 Ca rgo Discha rge Time &Energy Sa vings . . . . . . . . . . . . . . . . .66

AppendicesA. Using Metallic P ipe Couplings to J oin Bondstrand . . . . . . . . .A.1

B. Grounding of Series 7000M Piping . . . . . . . . . . . . . . . . . . . . .B.1C. Sizing of Shipboard P iping . . . . . . . . . . . . . . . . . . . . . . . . . . .C.1D. Miscellaneous Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D.1E. Piping Support for Non-Restrained Mechanical J oints . . . . . . .E.1

Table of Contents


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1

1.1 GENERAL

Historically, offshore exploration, production platforms and ship owners have had to face the grim reality

of replac ing mo st me ta l piping two or three times d uring the a verag e life of a ve ss el or platform. This ha s

mea nt, of co urse, that piping s ystems end up cos ting s everal times that o f the original investment sincereplac ement is more expensive tha n new insta llation. When you a dd the lab or cos ts, the dow ntime a nd

the inconvenience of keeping conventional steel or alloy piping systems in safe operating condition, the

long-term adva ntag es of fibergla ss piping b eco me very obvious.

1.2 PRODUCT RANGE AND SERIES

Bondstrand provide s four distinct s eries of fila ment-wound pipe a nd fittings using continuous glas s

filam ents and thermosetting resins for marine a nd na val app lica tions:

Series 2000MA lined e poxy pipe and fittings sys tem for ap plica tions which include ba lla st lines, fresh a nd s a ltwa ter

piping, sanitary sewage, raw water loop systems and fire protection mains where corrosion resis-

tance and light weight are of paramount importance.

Series 2000M-FPA lined epoxy system covered with a reinforced intumescent coating suitable for dry service in a jet fire.

Series 2000USNAn epoxy system meeting the requirements of MIL-P-24608B (SH) for nonvital piping systems on

co mba tant a nd non-co mba tant ves se ls. Availa ble in sizes from 1 to 12 inches (25 to 300mm).

Series 5000MA lined vinylester pipe and fittings system in 2 inch diameter (50mm) for seawater chlorination.

Series 7000M

An epo xy pipe a nd fittings sys tem w ith a nti-static c ap a bilities des igned for white petroleum produc tsand applications passing through hazardous areas. Properly grounded Series 7000M prevents the

ac cumulation on the e xterior of the pipe o f da ngerous levels o f sta tic elec tricity prod uced by flow o f

fluids inside the pipe o r by a ir flow ove r the exterior of the p ipe. This is a c co mplishe d b y Amerons

pa tented method of inco rporating electrica lly c onduc tive elements into the wa ll structure of pipe a nd

fittings during ma nufacture.

PSXL3A polysiloxane-modified phenolic system for use in normally wet fire protection mains - also suitable

for confined s pa ce s a nd living q uarters d ue to low s moke a nd toxicity properties . Also a vaila ble in a

co nductive version.

PSXJ F

A polysiloxane-modified phenolic system for use in deluge piping (normally dry). PSX J F has anexterior jacket which allows the pipe to function even after 5 minutes dry exposure to a jet fire (follow

by 15 minutes w ith flow ing w a ter). Also a va ila ble in a co nduc tive version.

1.0 Introduction


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1.3 STANDARDS AND SPECIFICATIONS

Bondstrand marine pipe and fittings are designed and manufactured in accordance with the follow-

ing sta ndards a nd spec ifica tions:

MIL-P-24608A (SH)U.S. Navy sta ndards for fiberglas s piping sys tems onboa rd c omba tant and nonco mba tant ships.

ASTM (F1173)U.S. sta ndards for fiberglas s piping systems onboa rd mercha nt vesse ls, offshore production a nd

explorations units.

1.4 CLASSIFICATION SOCIETY APPROVALS

Ameron works closely with agencies worldwide to widen the scope of approved shipboard applica-

tions for fiberglass pipe s ystem s. C ertifica tes of a pproval and letters of g uida nce from the fo llow ing

agency concerning the use of Bondstrand piping on shipboard systems are currently available from

Ameron. Others are pending.

1.5 USES AND APPLICATIONS

Series 2000MApproved fo r use in a ir co oling circulating w ate r; auxiliary e q uipment co oling; ba lla st/se grega ted ba l-

la st; b rine; drainag e/sa nitary se rvice /se wa ge ; ed uca tor syste ms; elec trica l co nduit; exhaus t piping;

fire p rotec tion ma ins (IMO L3) fres h w a ter/se rvice (nonvital); inert ga s effluent; m a in eng ine c oo ling ;

pota ble wa ter; stea m co ndens a te; sound ing tubes /vent lines; a nd ta nk cleaning (sa ltwa ter system);

submersible pump column piping; raw water loop systems and drilling mud pumping systems.

Series 2000M-FPDesigned for use where pipe is vulnerable to mechanical abuse or impact or for dry deluge service.

Series 5000M

Approved for use in s ea wa ter chlorination.

Series 7000MApproved for use in ba lla st (ad ja c ent to ta nks); C. O.W. (crude oil w a shing); dec k hot air drying (c a rgo

ta nks); pe troleum ca rgo lines; portab le discha rge lines; so unding tubes /vent c argo piping; stripping

lines and all se rvice s liste d fo r Series 2000M in ha za rdo us loca tions.

American Bureau of ShippingB iro Kla sifikas i Indo nes ia

B urea u Verita s

Ca nadian Co ast G uard, S hip Sa fety Branch

Det Norske Veritas

Dutch S cheepvaa rtinspectie

DDR-S c hiffs-Revision UND-Kla ss ifikation

Germanisher Lloyd

Korea n Reg ister o f S hipping

Lloyd s Reg ister of S hippingNippon Kaiji Kyokai

P olski Rejes tr Sta tkow

Registro Italiano Navale

Register of Shipping

The Marine B oa rd of Queensla nd

United S tates C oas t Guard

USSR Register of Shipping


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PSXL3Designed and approved for use in fire protection ring mains and for services in confined spaces of

living q uarters w here flame s pread, smo ke dens ity a nd to xicity are c ritica l.

PSXJ FDesigned a nd a pproved for dry deluge s ervice where pipe may be subject to a direc tly impinging jet fire.

1.6 J OINING SYSTEMS

Bondstrand ma rine a nd na val pipe s ystem s o ffer the user a variety of joining me thods for both new

co nstruction a nd fo r total or pa rtia l replace ment o f existing meta llic pipe.

All Series:

1-to 16-inch ....................Quick-Lock stra ight /ta per ad hes ive joint;

2-to 24-inch (2000M)......Van s tone type flange s w ith mova ble fla nge rings for eas y bolt alignme nt.

1-to 36-inch ....................One-piece flanges in standard hubbed or hubless heavy-duty configuration.

2-to 36-inch ....................Viking-J ohnso n o r Dress er-type me cha nica l co uplings .

1.7 FITTINGS AND FLANGE DRILLINGS

Ameron offers fila ment-wound fittings , a da pta ble for field a ss emb ly using a dhes ive, flang ed , or rub-

ber-ga sketed m ec hanica l joints. Tees , elbo w s, reduce rs a nd other fittings provide the neede d c om-

plete piping capability.

Bondstrand marine and naval flanges are produced with the drillings listed below for easy connection

to s hipbo ard pipe s ystem s c urrently in c ommo n use. Other drillings , a s we ll a s undrilled flang es , a re

available.

ANSI B16.5 Class 150 &300;

IS O 2084 NP-10 &NP-16;J IS B 2211 5kg/c m2;

J IS B 2212 10kg/cm 2;

J IS B 2213 16kg/cm 2;

U.S . Navy MIL-F-20042

1.8 CORROSION RESISTANCE

Bondstrand pipe and fittings are manufactured by a filament-winding process using highly corrosion-

res ista nt res ins. The pipe wa lls are s trengthene d a nd reinforce d throughout w ith tough fiberglass and

ca rbon fibers (S eries 7000 only) creating a lightw eight, strong, co rros ion-resista nt pipe that meets

U.S. Coast Guard Class II and U.S. Navy MIL-P-24608A (SH) standards for offshore and most ship-

board systems.

1.9 ECONOMY

Bondstrand offshore piping and Bondstrand marine and naval pipe systems have corrosion resistance

surpass ing c opper-nickel and mo re exotic a lloys, but w ith an insta lled cos t less than c arbon steel.

Numerous shipyards have recorded their Bonds tra nd installation cos ts o n new cons truction projects and

report savings from 30 to 40 percent compared to traditional steel pipe.


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2.1 LENGTH CHANGE DUE TO THERMAL EXPANSION

Like other types of piping ma terial, in an unres tra inted co ndition, B onds trand fiberglass reinforce d

pipe c hang es its length w ith temperature. Tests show that the a mount of expa nsion varies linea rly

with temperature, in other wo rds , the c oefficient of thermal expansion in Bo nds tra nd pipe is c on-sta nt, it eq ua ls to 0.00001 inch per inch pe r deg ree Fa hrenheit (0.000018 millimete r- per millimete r

per degree centigrade).

The am ount of expans ion ca n be c a lculated b y the formula:

L = L T

where L = cha nge in length (in. or mm),

= co efficient of thermal expa nsion (in./in./ F or m m/mm/ C ),L = length of pipeline (in. or mm), and

T = c ha n ge in te mp era t ure ( F or C).

Example: Find the amount of expansion in 100 feet (30.48 meter) of Series 2000M pipe due to a

change of 90 F (50 C) in temperature:

a. English Units:

L = L T

where = 10 x 10-6 in./in./ F

T = 90 F

L = 100 ft. = 1 200 in.

L = (1200 in .) (10 x 10-6 in./in./ F) (90 F)

L = 1. 08 in.

b. Metric Units:

L = L T

where = 18 x 10-6 mm /mm / C

T = 50 C

L = 30.48 m = 30480 m m

L = (30480 mm) (18 x 10-6 mm /mm / C ) (50 C )

L = 27.4 mm

Note that 27.4 mm is eq ual to 1.08 in. which is the ca lculated thermal expansion for the s am e length

of pipe due to the sa me a mount of temperature c hange.

In normal operating tempe rature rang e, the length c hang e - tempe rature relationship ca n be repre-

sented by a straight line a s illustrated in Figure 2-1 on the ne xt pa ge .

2.0 Design for Expansion & Contraction


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2.2 LENGTH CHANGE DUE TO PRESSURE

2.2.1 Unrestrained System

S ubjec ted to a n internal pressure, a free B onds tra nd pipeline w ill expa nd its length d ue to thrust

force a pplied to the end of the pipeline. The a mount of this c hang e in the pipe length d epend s o n the

pipe wall thickness, diameter, Poissons ra tio a nd the e ffective mod ulus of e las ticity in both a xial and

circumferentia l direc tions a t operating temperature.

L = L

The first term inside the b racket is the strain ca used by press ure end thrust w hile the s ec ond term,

is the a xia l contraction due to a n expa nsion in the c ircumferentia l direc tion, the P oisson s e ffect . The

res ult is a net increa se in length w hich c an be ca lculated by the s implified formula :

L = L

w he re L = le ng th o f pipe (in. o r c m.),

p = internal pressure (psi or kg./cm 2),

lc

= P ois sons ratio for contraction in the longitudinal direction due to the

s train in the circumferentia l direc tion.

Ec

= circumferential mod ulus o f elas ticity (psi or kg./cm 2),

p ID2

4t Dm

El

p ID2

2t Dm

Ec

lc

p ID2

2t Dm

Ec

lc

p ID2

4t El Dm

El

Ec

1 2lc

Fig. 2-1

LEN

GTH

CHANGE

MM/

100MO

FPIPE

TEMPERATURE CHANGE (DEG F)

TEMPERATURE CHANGE (DEG C)

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El

= long itudinal mod ulus o f elas ticity (ps i or kg./cm 2),

Dm

= mean diameter of pipe wall = ID + t ,

ID = inside diameter of the pipe (in. or cm.), and

t = thickness of pipe wall (in . or cm.)

Example: Find the length cha nge in 10 meters o f B onds trand S eries 2000M, 8-inch pipe w hich issub jec ted to a n internal press ure o f 145 psi (10 ba rs) a t 75 F (24 C ).

a. English Units:

The phys ica l properties of the pipe c a n be found from BONDS TRAND S ERIES 2000M

P RODUCT DATA (FP 194):

lc

= 0.56

Ec

= 3,600,000 psi

El

= 1,600,000 psi

ID = 8.22 in.

t = 0.241 in.

Dm

= 8.46 in.

p = 145 psi

L = 394 in.

Note: Physical properties vary with temperature. See Bond strand Series 2000M Product Data (FP194).

Fig. 2-2


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L = (394 in.)

L = 0.147 in.

b . Metric Units :

lc

= 0.56

El

= 113490 kg/cm 2

Dm

= 21.5 cm

ID = 20.9 cm

t = 0.612 cm

p = 10 bars = 10.02 kg/cm 2

L = 1000 cm

L = (1000 cm)

L = 0. 373 cm

Table 2-I provide s the c a lcula ted leng th increa se for 100 feet (30.48 meters) of B ond stra nd S eries 2000M

P ipe c a used b y 100 psi (7 kg/cm 2) internal press ure. The Table is va lid through the temperature rang e o f

a pplica tion. (The effec t of temperature on leng th cha nge due to press ure is sma ll.)

Obta in length increas e for other pressure by us ing a direc t press ure ratio c orrec tion. For exam ple, to

find the length cha nge ca used by 150 psi pres sure in a 6-inch pipe, m ultiply 0.4 inch by the press ure

ratio 150/100 to obt a in an a mo unt of 0.6 inc h leng th increa se .

145 psi (8.22 in.)2

4 (.241 in.) (8.46 in. ) 1,600,000 psi

1,600,000 psi

3,600,000 psi1 - 2 (.56)

10.02 kg/cm2 (20.9 c m)2

4 (.612 c m) (21.5 c m ) (113490 kg/cm2)113490 kg /cm2

253105 kg /cm21 - 2 (.56)

S ize Leng th Inc rea se

(in.) (mm.) (in.) (mm)

2 50 0.2 5.0

3 80 0.3 7.8

4 100 0.3 7.6

6 150 0.4 10.2

36 900 0.4 10.2

Ta ble 2-I


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2.2.2 Restrained Systems

In the piping system, shown in Figure 2-3, all longitudinal thrusts are eliminated by the use of fixed

supports; therefore, the pipe is subjected only to load in the circumferential direction. Without the

end thrust present, the first term in the equation is dropped and the length change becomes:

L = L

w here L = leng th of pipe (in. or cm ),

p = internal pres sure (psi or kg/cm 2),

lc

= P ois sons ratio

Ec = circumferential modulus of elast ici ty, (psi or kg/cm 2)

ID = ins ide d ia mete r of the pipe (in. or cm),

t = thickness o f pipe wa ll (in. or cm),

Dm

= mean diameter of pipe wall = ID + t.

Example: Find the cha nge in length in 12 meters (39.4 feet) of restrained B onds trand S eries 2000M,

8-inch diameter pipe operating at 10 bars (145 psi) internal pressure.

a. English Units:

lc

= .56

p = 145 ps i

ID = 8. 22 in.

t = 0.241 in.

Dm

= 8.46 in.

Ec

= 3,600,000 ps i

L = 472 in.

Fig. 2-3

p ID2

2t Ec

Dm

-lc

MECHANICAL COUPLING

(Dresser Type)

W.T. BHD.

9


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L = (472 in.)(-.56)

L = -.175 in. or .175 in. red uction in leng th

b.Metric Units:

lc

= .56

p = 10.02 kg/cm 2

ID = 20.9 cm

Dm

= 21.5 c m

t = 0.612 cm

Ec

= 253105 kg/cm2

L = 1200 cm

L = (1200 cm ) (-.56)

L = - .442 cm o r .442 cm red uction in leng th

As indicated by the formula and demonstrated by the example, in a restrained installation where amec ha nic a l c oupling is use d, a pplic a tion of pres sure w ill res ult in a c ontra c tion of the pipe. This

shortening effect is found favorable in most applications where the designer can use the reduction in

length to compens ate for thermal expansion. Conversely, a llow anc es should be mad e w here o perat-

ing temperature is significa ntly lower than the tempe rature a t w hich the sys tem is installed.

2.3 LENGTH CHANGE DUE TO DYNAMIC LOADING

Piping installed on board ship is often subjected to another type of load at the supports which results

from s udden c hange of the supports rela tive loc ation. This d ynam ic load ing s hould b e a cc ounted for

in the de sign. The de gree of fluctua tion in length b etw een the tw o s upport points d epend s o n the

ships s tructural chara cte ristics, i.e., the s hip size, the s ize o f the dyna mic loa d, e tc. This type of

movement in the piping system should be considered with other length changes previously dis-

cuss ed; how ever, ca lculation of expansion a nd c ontrac tion due to dynamic loading is beyond theintended scope of this manual.

2.3.1 Equipment Vibration

Under normal circums tanc es, Bo nds trand pipe w ill sa fely a bs orb vibration from pumping if the pipe

is protected ag ainst external abras ion a t supports.

Vibration can be damaging when the generated frequency is at, or near, the natural resonance fre-

q uency o f the pipeline. This frequenc y is a function of the s upport syste m, layout ge ometry, tempe ra-

ture, mass and pipe stiffness.

145 psi (8.22 in.)2

2 (.241 in.) (8.46 in. ) 3,600,000 psi

10.02 kg/cm2 (20.9 cm)2

2 (0.612 cm) (21.5 c m) (253105 kg /cm)2

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There a re tw o principal wa ys to c ontrol exces sive stress ca used by vibration. Either insta ll, ob se rve

during operation, and add supports or restraints as required; or add an elastometric expansion joint

or other vibration a bs orber.

2.4 FLEXIBLE JOINTS, PIPE LOOPS, Z AND L TYPE BENDS

Bondstrand piping is often subjected to temperature change in operation, usually in the range of

50 F to 100 F (32 C to 82 C). S ince a piping s ystem operating a t low stress level provideslonge r service life, it is g ood prac tice to reduce the a mount of stress ca used by therma l a nd/or pres-

sure expans ion. This c a n be ac co mplished by us ing o ne or more of the follow ing:

A. Flexible J oints

a.1 Mechanical coupling (Dresser-type), or

a.2 Expansion joint.

B. P ipe Loops

C. Z type configurations or cha nge of direction at b ends.

2.5 DESIGN WITH FLEXIBLE J OINTS

Both Dresser-type c ouplings and expansion joints a re recognized as sta nda rd devices to a bs orbthermal expa nsion. They a re ea sy to use a nd c omme rcially ava ila ble.

2.5.1 Mechanical Couplings (Dresser-type)

These a re prima rily de signed to b e us ed a s m ec hanica l connec tion joints. The elas tomeric se al offers

some flexibility that will relieve thermal expansion in the pipe; however, this can only absorb a limited

a mo unt of a xia l move ment, usua lly a bo ut 3/8 in. (10mm) per co upling. Thus, m ore tha n one c oupling

must b e us ed if the expe cte d moveme nt is g rea ter than 3/8 in. (10mm).

It should be noted here that fixed supports are always required in a mechanical system. In moderate

temperature and pressure application, such as often found in ballast piping systems, the total expan-

sion of a 40-foot B onds tra nd pipe is w ithin the c oupling reco mmend ed limit. For add itional informa-

tion on mechanical type couplings see Appendix A.

2.5.2 Expansion Joints

Expansion joints are widely accepted as standard devices to relieve longitudinal thermal stress.

Unlike the mechanical coupling, this joint offers a wider range of axial movement giving more flexibili-

ty in des ign. This is a dva ntag eous in long s ec tion of pipe such a s in ca rgo piping w hich s ometimes

runs the entire length of the ship. An expansion joint is normally not needed in ballast piping system

where short sections o f pipe a re a nchored at bulkhead s.

When an expansion joint is used in the pipeline to relieve longitudinal stress, it must be fairly flexible,

such as a teflon bellows which is activated by the thrust of a low modulus material.

Support for expansion joints must be correctly designed and located to maintain controlled deflec-tion. Besides adding weight, most of these joints act as partial structural hinges which afford only

limited tra nsfer of mo ment a nd shea r. Where the expa nsion joint relies on e la stom ers of thermoplas -

tics , the structura l disc ontinuity or hinging effec t a t the joint c hang es w ith tempe rature.

When using an expansion joint in a pipeline carrying solids, consider the possibility that it could stiff-

en or fail to function due to sedimentation build up in the expansion joint. Failure of the expansion

joint could cause excessive pipe deflection. Regular schedule maintenance and cleaning of the

expansion joint is recommended to assure adequate function of the piping system.


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2.6 DESIGN WITH PIPE LOOPS

Where s pa ce is not a prima ry conc ern, expans ion loops are the preferred method for relieving the

thermal stress betw een a nchors in suspended piping s ystems since it ca n be eas ily fab rica ted using

pipe a nd elbows at the job site.

Loops should be ho rizonta l wherever pos sible to a void entrapping a ir or sediment and fa cilitate drainage.

For upwa rd loops , a ir relief va lves a id a ir remova l and improve flow. In press ure s ystem s, a irremova l for both testing a nd no rmal operation is required for sa fety.

For downward loops, air pressure equalizing lines may be necessary to permit drainage.

In both ca ses , spec ial taps a re neces sa ry for complete drainag e.

The size of the loop c a n be dete rmined b y using the Ela stic-Center Method. The c once pt is out-

lined a s follow s:

Co nsider a properly g uide d expa nsion loop a s show n in Figure 2-4. The c entroid 0 of this structure

is located at the center of the guides A and B, and the line of thrust will lie parallel to a line joining

the guides. The only force that a cts on this loop is in the x direc tion a nd c a n be found b y the eq ua-

tion.

Fx

= EI

Ix

where = total linear expansion which will be ab sorbed by the loop,

Fx

= force in the x direction,

E = modulus of elas ticity of the pipe,I = beam moment o f inert ia o f the pipe, and

Ix

= moment of inertia o f the line ab out the x axis of the ce ntroid.

Fig. 2-4

12

S ince Ix = + + =

4 2

2

2 2

2

4

2

3

4 2


15/97

Fx

= 4 EI3

S ubs tituting M = Fx

a nd

SA

= M D

2 I

and a rra nging the req uired length in terms of other know n values we obta in:

= ED1/2

S A

Where M = bending moment, ma ximum a t elbow s ,

S A = a llo w a ble s tre ss ,

D = o uts id e d ia m et er o f p ip e,

= required length of the expansion loop.

It should be noted here that similar result can be obtained using the Guided Cantilever Method of

pipe flexibility calculation.

Where=

1 F 3=

M 2=

S A 2

2 4 EI 4EI 2ED

and again=

ED1/2

SA

Ca lculation exa mple: Determine the req uired e xpans ion loop for 8-inch B onds trand S eries 2000M

piping subjected to the follow ing co ndition:

Opera ting tempera ture: 65 C (149 F)

Ins ta lla tion tempera ture: 20 C (68 F)

Total length of pipe between a nchors: 100 meter (328 f t)

From P RODUCT DATA S HEET FOR B ONDS TRAND 2000M (FP194) we ob tain at 150 F (66 C ):

Allowable bending s tress = 548 kg/cm 2 = 183 kg/cm 2 (2600 psi)

3

Therma l expa ns ion c oeffic ient = 18 x 10-6 m/m/ C (10 x 10-6 in/in/ F)

Modulus o f elasticity a t 65 C = 91,400 kg/c m2 (1,300,000 ps i)

P ipe O.D. = 22.1 c m (8.7 inc h)

First determine the total thermal expansion for the entire length of the pipe section in question:

L = L T= 18 x 10-6/ C (45 C) (100 x 102) cm

= 8.1 c m

2

13


16/97

14

Then

=ED

1/2

SA

= 8.1 c m (91,400 kg/cm2) (22.1 cm)

1/2

= 299 cm183 kg/c m2

= 2.99 meter

Ca lculation of length ca n a lso be performed in English units:

= 3.18 in (1,300,000 psi) 8.7 in

1/2

= 118 in2,600 ps i

= 9 f t. - 10 in .

w hich is e q uivalent to 2.99 meters.

1/2


17/97

15

Ta

ble2-I

Itabu

latest

he

leng

tho

floop

infee

tan

dme

ter

srequ

ire

dtoa

bsorbexpans

ion.

TABLE2-II:RE

QUIREDLENGTHFOREXPANSION

LOOP


18/97

16

2.7 DESIGN USING Z LOOPS AND L BENDS

Similarly the Z-loop and L-bends can be analyzed by the same guide cantilever method.

= Fx

3 = M 2 = SA

2

4EI 4EI 2ED

= 2 ED 1/2S

A

Fig. 2-5


19/97

17

Note: In special cases where the pipe is insulated, longer length is needed to compensate for the

stiffer loop memb ers.

The req uired length in this ca se should be a djusted by a fac tor

(EIinsulated pipe

/EIbare pipe

)1/2

which wa s d erived a s follow s:

For the same application condition:

bp=

ip

ip=

bpEI

ip/EI

bp

1/2

Loops using 90 elbow s c hange length better than those using 45 elbow s. Unlike a 90 turn, a 45

turn carries a thrust component through the turn which can add axial stress to the usual bending

stress in the pipe and fittings . Alignme nt and deflection are also d irec tly a ffected by the a ngular dis-

plac ement at 45 turns a nd d ema nd s pecial attention for support de sign and loca tion.

A 45 elbow at a free turn with the same increment of length change in each leg will be displaced 86

percent more than a 90 elbo w. The rela tive d isplac ement in the plane of a loop is a lso more of a

problem. Figure 2-6 illustrates the geometry involved.

Comparison of Displacement in 90 vs. 45 elbows caused by a Unit Length Change:

Fig. 2-6

A. Relative displacemen t of

elbows p ermitted to move

freely in a pipe run .

B. Relative displacement

configuration of loops

bp = M2

bp bp = 2 bp EI bp /2

2EIbp

M

ip= M 2

ipip = 2

ipEI

ip2

2EIip

M

1/2

1/2


20/97

18

Ta

ble2-I

IIt

abu

lates

the

le

ng

tho

floopor

ben

dinfee

tan

dm

etersrequ

ire

dtoa

bsorbexpansio

n.

TABLE2-III:REQU

IREDLENGTHFORZTYPELOOPA

NDLBEND


21/97

3.1 GENERAL PRINCIPLES

Occasionally, the layout of a system makes it impossible to allow the pipe to move freely, as for

exam ple, a ba lla st line running thw a rt-ships betw een longitudinal bulkheads . Or it ma y be nece ss a ry

to a nchor ce rta in runs o f an o therwise free s ystem . In a fully res tra ined p ipe (a nchored a ga inst mo ve-ment at both ends), the designer must deal with thrust rather than length change. Both temperature

and pressure produce thrust which must be resisted at turns, branches, reducers and ends. Knowing

the mag nitude of this thrust enab les the des igner to select sa tisfac tory a nchors and chec k the a xial

stress in pipe a nd s hea r stress in joints. Re memb er that a xia l thrust on a nchors is norma lly indepe n-

dent of anchor spac ing.

Caut ion: In restrained systems, pipe fittings can be damaged by faulty anchorage or by untimely

release of anchors. Damage to fittings in service can be caused by bending or slipping of an improp-

erly de signed or insta lled anc hor. Also , length c hang es due to creep a re induc ed by high pressures

or temperatures w hile pipe is in service . When a nchors must late r be releas ed, esp ec ia lly in long pipe

runs, temporary anchors may be required to avoid excessive displacement and overstress of fittings.

3.2 THRUST IN AN ANCHORED SYSTEM

Both temperature and pressure produce thrust, which is normally independent of anchor spacing. In

practice, the larges t c ompress ive thrust is norma lly de veloped on the first pos itive temp erature c ycle.

Subsequently, the pipe develops both compressive and tensile loads as it is subjected to tempera-

ture and pressure cycles. Neither compressive nor tensile loads, however, are expected to exceed

the thrust on the first cycle unless the ranges of the temperature and pressure change.

3.3 THRUST DUE TO TEMPERATURE

In a fully restrained Bondstrand pipe, length changes induced by temperature change are resisted at

the anc hors and co nverted to thrust. The thrust deve loped dep ends on thermal co efficient of expan-

sion, the cross-sectional area, and the modulus of elasticity.

3.4 THRUST DUE TO PRESSURE

Thrust d ue to internal pres sure in a sus pende d but restrained sys tem is theoretica lly mo re c omplica t-

ed. This is bec a use in straight, restrained pipelines w ith a ll joints a dhes ive b onde d or fla nged , the

Poisson effect produces considerable tension in the pipe wall.

As internal pres sure is a pplied, the pipe expa nds circumferentia lly a nd a t the s am e time c ontrac ts

longitudinally. This tensile force is important b ec a use it a cts to reduc e the hydrosta tic thrust o n

anchors. In lines with elbows, closed valves, reducers or closed ends, the internal pressure works on

the cross-sectional area of the ends . This thrust tends to be ab out twice as great a s the effect of

press ure o n the pipe w all.

The co ncurrent effects o f press ure a nd tempe rature must be co mbined for design of anc hors.

Similarly, on multiple pipe runs, thrusts developed in all runs must be added for the total effect on

anchors.

3.0Design for Thrust (Restrained Systems)

19


22/97

20

3.5 FORMULAS FOR CALCULATING THRUST IN RESTRAINED PIPELINES

3.5.1 Thrust Due To Temperature Change In An Anchored Line

The thrust due to temperature cha nge in a s ystem fully restra ined a ga inst length cha nge is c alculate d

by:

P = TAEl

w here P = thrust (lbf or kg),

= co efficient of thermal expans ion (in./in./ F or m/m/ C),

T = cha ng e in te mp era t ure ( F or C),

El

= long itudinal mod ulus o f ela sticity a t low er temperature (ps i or kg/cm 2),

A = averag e cross -sectional area of the pipe wall (in.2 or cm2),

S ee Ta ble 4-IV.

For example:

= 10 x 10-6in./in./ F

T = 150 F

A = 4.23 in2 for 6 inch pipe

El

= 1.6 x 106 ps i

then P = (10 x 10-6)(150)(4.23)(1.6 x 106) = 10,150 lbf. or from Ta ble 3-1

P = 6,770 x 1.5 = 10,150 lbf.

3.5.2 Thrust Due To Pressure In An Anchored System

In a fully restrained system, calculate the thrust between anchors induced by internal pressure using:

P = (-lc

)

w here P = internal press ure (ps i or kg/cm2),

ID = interna l dia mete r (in. or cm ),

El

= long itudinal mod ulus o f elas ticity (ps i or kg/cm 2),

Ec

= circum ferentia l mo dulus of elas tic ity (ps i or kg/cm 2), and

lc

= P ois sons ratio.

Note: Use elastic properties at lowest op erating temperature to calculate maximum expected thrust.

pDm

ID

2

El

Ec


23/97

21

For example, ass ume that

ID = 6.26 in.,

Dm

= 6.44 in .,

P = 100 psi.

El = 1.6 x 106 psi,

Ec

= 3.6 x 106 psi, and

lc

= 0.56

then P = (0.56) = 1,580 lbf (tens ion)

or rea d the va lue of 1,580 lbf from Ta ble 3-Il.

3.5.3 Thrust Due To Pressure On A Closed End

Where internal pres sure on a close d e nd e xerts thrust on s upports, c a lculate thrust

using:

P = p

where ID = inside diameter of the pipe (in. or cm).

Va lues a re g iven in Ta ble 3-Ill.

For example: If there is 100 psi in a 6-inch (6.26 ID) pipe, thrust is

P = x 100 = 3,080 lb f

3.6 LONGITUDINAL STRESS IN PIPE AND SHEAR STRESS IN ADHESIVE

Stress in the pipe is g iven in eac h of the abo ve ca ses by:

f =

w here f = long itudinal s tres s (ps i or kg/cm 2).

In the last example for pressure on a closed end:

f = = 728psi

The a llow ab le s tres s is one third of the longitudinal tensile s trength a t the ap propriate temperature a s

given in the Bondstrand Product Data Sheet. For Series 2000M and Series 7000M pipe the allowable

stress at 70 F is 8,500 psi/3.0 = 2830 psi (199 kg/c m2). For s hort-term effec ts suc h a s thos e result-

ing from green sea loads, a higher allowable stress may be justified.

3.14 (100) (6.44) (6.26)

2

ID2

4

3.14 (6.26)2

4

P

A

3,080

4.23

(1.6)

(3.6)


24/97

22

S hear stress in an a dhesive bonded joint is:

=

where = shea r stress in ad hesive (psi or kg/cm 2),

Dj

= joint d iama ter (in. or cm), s ee Ta ble 3-IV.

Lb

= bo nd leng th (in. or cm), see Ta ble 3-IV.

For example: In the case of 100 psi pressure on a closed end 6-inch pipe, as previously calculated:

P = 3,080 lbf

= = 67 ps i

The a llow a ble shea r stress for RP -34 a dhes ive (normally use d with S eries 2000M produc ts) is 250 psi

(17.6 kg/c m2). The a llow a ble she ar s tres s for RP -60 a dhes ive (normally use d with S eries 7000M prod -

uc ts ) is 212 ps i (14.4 kg/cm2).

P

DjL

b

3,080

3.14 (6.54) 2.25


25/97

23

TABLE 3-I

THRUST IN AN ANCHORED PIPELINE DUE TO TEMPERATURE CHANGE

FOR BONDSTRAND PIPING

Note: 1. For temperature change other than 100 F or 100 C use linear ratio forthrust.

2. Ca lculations a re ba sed on elas tic properties a t room temperature.

3. Ca lculations a re ba sed on IP S dimensions for sizes 2 to 24 inch, MCI

dimensions for 28 to 36 inch.


26/97

24

TABLE 3-II

THRUST FORCE DUE TO INTERNAL PRESSURE IN AN ANCHORED PIPELINE


Note: 1. For temperature change other than 100 psi or 10 kg/cm 2, use linear ratio for tensileforce.

2. Ca lculations a re ba sed on elas tic properties a t room temperature.

3. Ca lculations a re ba sed on IP S dimensions for sizes 2 to 24 inch, MCI dimensions for

28 to 36 inch.


27/97

25

TABLE 3-III

THRUST DUE TO PRESSURE ON A CLOSED END


Note: 1. For temperature change other than 100 psi or 10 kg/cm 2, use linear ratio for thrust.

2. Ca lculations a re ba sed on IP S dimensions for sizes 2 to 24 inch, MCI dimensions for

28 to 36 inch.


28/97

26

TABLE 3-IV

ADHESIVE BONDED JOINT DIMENSIONS

Note: 1. J oint Diameters are bas ed on IP S dimensions for sizes 2 to 24 inch, MCIdimensions for 28 to 36 inch.

2. Adhes ive b onde d joints a re a vaila ble for field joining of pipe and fittings in size

range 2 to 16 inch. Only ad hesive bo nded fla nges are a vaila ble for field joints

above 16 inch.


29/97

27

4.1 GENERAL

This s ec tion gives rec omme nda tions on plac ement of supports a nd ma ximum support spa cing.

These rec omme nda tions give minimum s upport req uirements . Add itiona l support may be neede d

where pipe is exposed to large external forces as for example, pipe on desk subject to green waveloading.

Tec hniq ues us ed in de termining s upport req uirements for Bond strand a re s imila r to those used for

carbon steel piping systems; however, important differences exist between the two types of piping.

Each requires its own unique design considerations. For example, Bondstrand averages 16 percent

of the w eight o f sc hedule 40 stee l, has a longitudinal mod ulus 14 times sma ller, a nd a thermal coeffi-

cient of expansion 50 percent larger.

4.2 ABRASION PROTECTION

Bond strand s hould be protected from external ab ras ion w here it comes in co ntact with guides and

support, pa rticularly in areas of s ignifica nt thermal expans ion, in long runs o f pipe o n w ea ther dec ks,

or in pas sa gew ays which w ould b e a ffected by dyna mic tw isting of the ships structure. Such protec-tion is achieved through the use of hanger liners, rider bars or pads made of teflon or other accept-

a ble ma teria l. Re fer to Ta ble 4-I for de ta ils.

4.0Support Location & Spacing

TABLE 4-I

PIPE HANGER LINER, RIDER BAR, OR PAD MATERIALFOR ABRASION PROTECTION


30/97

28

4.3 SPANS ALLOWING AXIAL MOVEMENT

Supports that allow expansion and contraction of pipe should be located on straight runs of pipe

where axial movement is not restricted by flanges or fittings. In general, supports may be located at

positions convenient to nearby ships structures, provided maximum lengths of spans are not

exceeded.

4.4 SPAN RECOMMENDATIONS

Recommended maximum spans for Bondstrand pipe at various operating temperatures are given in

Ta ble 4-Il. Thes e s pa ns a re intend ed fo r norma l horizont a l piping a rra nge ment s, i.e., thos e w hich

have no fittings , valves, vertica l runs, etc ., but w hich ma y include fla nges and nonuniform support

spa cings. The tab ula r values represent a c ompromise b etw een c ontinuous a nd single spa ns. When

inst a lled a t the s upport sp a cings indica ted in Ta ble 4-Il, the w eight of the p ipe full of w a ter will pro-

duc e a long-time d eflec tion o f a bout 1/2 inch, (12.7 mm), w hich is us ually a cc epta ble for appe a rance

and ad eq uate drainag e. Fully co ntinuous s pans may be used with support spac ings 20 percent

greater for this same deflection; in simple spans, support spacings should be 20 percent less. For

this purpose , co ntinuous s pa ns a re d efined a s interior spa ns (not end spa ns), w hich a re uniform in

length and free from structural rotation at supports. Simple spans are supported only at the ends and

a re either hinged or free to rota te a t the s upports. In Tab le 4-Il, recomm enda tions for support spa c-

ings for mec hanica l joints a ss ume s imple spa ns and 20 ft. (6.1m) pipe length. For a dd itiona l informa -

tion rega rding the s pec ia l prob lems involved in suppo rt and a nchoring o f pipe w ith mec hanica l joints,see Appendix E.

4.4.1 Formula for Calculating Support Spacing for Uniformly Distributed Load

Suspended pipe is often required to carry loads other than its own weight and a fluid with a specific

gravity of 1.0. Perhaps the mos t c ommo n external loa ding is therma l insulation, but the b as ic princi-

ple is the sa me for all loa ds which a re uniformly d istributed a long the pipeline. The w a y to a djust for

increased loa ds is to d ecrease the support spa cing, a nd co nversely, the wa y to ad just for dec reas ed

loads is to increase the support spacing. An example of the latter is a line filled with a gas instead of

a liq uid; and longe r spa ns a re indica ted if deflection is the c ontrolling fa cto r.

For all such loading cases, support spacings for partially continuous spans with a permissible deflec-

tion of 0.5 inch are determined using:

L = 0.258(EI)

w

1/4


31/97

29

TABLE 4-II

RECOMMENDED MAXIMUM SUPPORT SPACINGS FOR

PIPE AT 100F (38C) AND 150F (66C) OPERATING TEMPERATURES

(FLUID SPECIFIC GRAVITY = 1.0)

Note: 1. For 14- through 36-inch diame ters, load s ta bulated are for Iron P ipe S ize and are 7 to 12 percentles s tha n for Metric C a st Iron s izes . How ever, recomm ende d s pa ns a re s uitab le for either.

2. S pa n rec omme nda tions a pply to normal horizonta l piping suppo rt a rrang ements a nd are ca lculated

for a m aximum long-time de flec tion of 1/2 inch to ens ure go od a ppea rance a nd a deq uate d rainag e.

3. Includes Quick-Loc k a dhes ive bond ed joints a nd flang ed joints.

4. Maximum spa ns for mec hanica lly joined pipe a re limited to one pipe length.

5. Modulus of ela sticity for spa n ca lculations:

E = 2,100,000 (ps i)-6000 (ps i/ F) x T ( F). S ee Ta ble 4-III.


32/97

30

where L = support spa cings , ft.

(EI) = beam s t iffness (lb-in2, from Ta ble 4-Ill a nd 4-IV)

w = total uniformly distributed load (lb/in.).

In metric units:

L = 0.124

where L = support spa cings (m)

(El) = be a m s tiffnes s (kg-cm 2) (from Ta ble 4-Ill and 4-IV)

w = tota l uniformly distributed loa d (kg/m)

For example: Calculate the recommended support spacing for 6-inch Bondstrand Series

2000M pipe full of water at 150 F:

L = 0.258 16.5 ft.

4.5 SUSPENDED SYSTEM RESTRAINED FROM MOVEMENT

Anchors may be used to restrict axial movement at certain locations (see Section 5 for anchor

details). Such restriction is essential:

Where sp a c e limitations res tric t a xia l mo veme nt.

To transm it axial loa ds through loops a nd expa nsion joints.

To res tra in exces sive thrusts at turns, branches , reduc ers, and e nds

To s upport valves. This is d one not only to s upport the weight of va lves and to reduce thrust, b ut

it also prevents excessive loads on pipe connections due to torque applied by operation of

valves.

Refer to Section 3 for determining thrust in an anchored system.

(EI)

w

1/4

1,200,000 x 19.0

1.36

1/4

TABLE 4-III

MODULUS OF ELASTICITY FOR CALCULATIONS OF SUPPORT SPACINGS


33/97

31

In pipe runs anchored at both ends, a method of control must be devised in order to prevent exces-

sive lateral deflection or buckling of pipe due to compressive load. Guides may be required in conjunc-

tion with expa nsion joints to c ontrol exc es s ive de flec tion. Ta bles 4-V a nd 4-VI g ive reco mme nda tions

on guide spacing versus temperature change for marine pipe with restrained ends.

4.6 EULER AND ROARK EQUATIONS

The Euler eq uat ion is first use d to c hec k the sta bility of the res trained line.

L =

w he re L = unsup po rte d le ng th o r g uid e sp a c ing (in. o r cm ),

I = bea m mome nt of inertia (in4 or cm4) se e Ta ble 4-IV,

= coefficient of thermal expans ion (in./in./ F or m/m/ C),

A = cross -sectional area (in2

or cm2

) se e Ta ble 4-IV,

T = cha nge in temperature ( F or C).

The eq uation gives ma ximum sta ble length of a pipe c olumn when fixed end s a re a ss umed.

In Ta bles 4-V a nd 4-VI this ma ximum leng th is reduc ed by 25 perce nt to a llow for non-Euler be ha vior

near the origin of the curve.

I

T A

1/2


34/97

32

Notes:

1. Outside diamete rs approxima te thos e for iron pipe s ize, ISO International Sta nda rd 559 - 1977 and for

cast iron pipes, ISO Recommendation R13-1965 as follows:

2. Values are for composite moment of a rea of structural wa ll and liner cross -section in terms of the

structural wa ll for Series 2000M. Bea m sec ond mome nt of area is also known as bea m moment of

Inertia.

TABLE 4-IV

PIPE DIMENSIONS AND SECOND MOMENT OF AREAS (SERIES 2000M)

IRON PIPE SIZE (IPS)

METRIC IRON SIZE


35/97

Using the length developed by the Euler equation, the weight of and the physical properties at the

operating tempe rature d eflec tion of a horizonta l pipe is ca lculated using the eq uation from Ro a rk1:

y = (ta n - )

w here K = P /(El)

P = = TAE

El

= long itudinal mod ulus o f elas ticity (ps i or kg/cm 2), s ee Ta ble 4-Ill

w = uniform horizo nta l loa d (lb/in or kg/cm),

L = guide spa cing (in. or cm).

If y is less than 0.5 inch (1.27cm), the L obtained using the Euler equation is the recommended

guide spacing. If y is greate r than .5 inch (1.27cm ), c hoos e a shorter length L a nd solve the Roa rk

eq uation a ga in for y . A final length rec omme nda tion is thus de termined by tria l and error whe n y

closely approximates 0.5 inch (1.27cm).

4.7 SUPPORT OF PIPE RUNS CONTAINING EXPANSION .JOINTS

The mo dulus of elas tic ity for Bo nds trand pipe is a pproximate ly 1/14th that o f ste el pipe. Fo r this rea -

son, the force due to expansion of Bonds trand pipe is not great enough to compress most varieties

of expa nsion joints us ed in stee l piping s ystem s. B onds trand req uires ela sto meric expa nsion joints.

The use of elas tomeric expa nsion joints has so mew hat limited ma rine a pplica tions. These joints have

very limited resista nce to external force s a nd, therefore, a re not s uitab le for use in the bottom oftanks. However, it can be used for piping systems installed in the double bottoms were hydrostatic

co lla pse pres sure is not a req uirement. During the installation c areful co nsideration m ust b e g iven to

the proper support and guidance.

(1) R.J. Roark, Formulas for Stress and Strain, 3rd Edition, McGaw-Hill Book Co., New York, 1954.

-w L

2KP

2 (El)

L2

KL

4

KL

4

1/2

33


36/97

34

TABLE4-V

GUIDESPACINGVS.TEMPERATURECHANGEFOR

PIPEWITH

RESTRAINEDENDS

Note:

For

horizontalpipe,valuesbelowthelinemaybetakenfromTable4-II.Forverticalpipe,usetabulatedvalues

asshown.


37/97

TABLE4-VI

GUIDESPACING

VS.TEMPERATURECHANGEFORPIPEWITH

RESTRAINEDENDS

Note:

Forhorizontalpipe,v

aluesbelowthelinemaybetaken

fromTable4-II.Forverticalpipe,u

setabulatedvaluesasshown.

35


38/97

36

There a re a lso very distinct ad vanta ge s to these e xpans ion joints. They reduc e vibration ca used by

equipment, are very compact and lightweight, and will compensate for axial movement.

When using a n expa nsion joint to a llow movem ent be twe en a nchors, the e xpans ion joint sho uld b e

pla ce d a s c los e a s po ss ible to one a nchor or the other. The oppo site side of the expa nsion joint

sho uld ha ve a guide place d no further tha n five times the pipes diamete r from the expa nsion joint

w ith a s ec ond g uide p os itioned farther do w n the pipe. To de termine the spa cing for the sec ond

guide, find ma nufac turers spe cifica tions on force req uired to c ompress the joint a nd refer to Figure

4-1 for reco mmended spa cing.

The horizonta l line a t the top of ea ch c urve repres ents ma ximum s upport spa cing for a tota lly unre-

strained sys tem. The low er end of the c urve a lso bec omes horizonta l a t the value for ma ximum guide

spa cing for a to tally restrained s ystem . This g raph only show s va lues for pipes s ma ller than 12 inch

diameter. In large diameters, the slightly increased guide spacing is not great enough to compensate

for the added cost of the expansion joint.

The guide s pa cing for variab le end thrust as prod uced by a n expans ion joint may b e ca lculated a s

follows:

L = =

L = guide sp ac ing (in. or cm. )

F = TAEl= force of compressing a n expansion joint (lb or kg),

= co efficient of thermal expans ion (in/in/ F or m/m/ C).

El

= long itudinal modules of ela sticity at the highes t operating temperature

(ps i or kg/cm2), s ee Ta ble 4-Ill

T = cha nge in temperature ( F or C),

A = cross -sec tiona l a rea (in2 or cm2), s ee Ta ble 4-lV.

I = bea m sec ond moment of area (in4 or cm4), s ee Ta ble 4-IV.

The va lues s how n in Fig. 4-1 are c alculate d a t 100 F (38 C) and reduced by 25 percent. Within the

cross-hatched area, the pipe will crush prior to compression of the expansion joint based on a com-

press ive a llow a ble s tress of 20,000 psi (1400 kg/c m2).

I

TA

1/2

IEl

F

1/2


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FIGURE4-1

AXIALFORCECOMPRESSINGANEXPANSIONJOINT

VS.GUIDESPACING

MAXIMUMGUIDESPACING

(METERS)

(FEET)

(POUNDSFORCE)

(KILOGRAMSFORCE)

37


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4.8 SUPPORTS FOR VERTICAL RUNS

Insta ll a single s upport anyw here a long the length o f a vertica l pipe run more tha n ab out ten feet

(3mm) long. See Section 5 for suggested details. If the run is supported near its base, use loose col-

lars as guides spaced as needed to insure proper stability.

Vertica l runs less than ten feet (3mm) long ma y usua lly b e s upported a s pa rt of the horizonta l piping.

In either ca se, be sure the la yout ma kes s ufficient provision for horizonta l and ve rtica l movem ent a t

the top and b ottom turns.

In vertical pipe runs, accommodate vertical length changes if possible by allowing free movement of

fittings at either top o r bottom or bo th. For ea ch 1/8 inch (3mm) of anticipa ted vertica l length cha nge,

provide 2 feet (62cm) of horizonta l pipe b etw een the elbow and the first support, but no t less than 6 fee t

(1.9m) nor more than 20 feet (6.1m) of horizontal pipe. If the pipeline layout does not allow for

ac commo da tions of the ma ximum ca lculated length c hange, there a re tw o po ss ible resolutions:

Anchor the vertica l run nea r its b as e a nd us e intermediate g uide s a t the s pa cing sho w n in Ta bles

4-V or 4-VI, or

Anchor the vertica l run near its ba se and use intermed ia te Dress er-type co uplings a s req uired to

accommodate the calculated expansion and contraction.

Treat c olumns mo re tha n 100 feet (30m) high (either ha nging or sta nding) a s s pec ia l de signs ; supp ort

a nd provision for length cha nge a re important. The installer should b e e spe cially c areful to a void

movem ent d ue to wind o r support vibration w hile joints are c uring.

4.9 CASE STUDY: VERTICAL RISER IN BALLAST TANK

A 210,000 DWT Ta nker trade s be twe en Ala ska a nd P a nam a. S eg reg a ted b a lla st ta nks next to ca rgo

tanks are served by 16 inch (400mm) Bondstrand Series 7000M pipe with RP-60 adhesive as shown

in Figure 4-2. Maximum working pressure is 225 psi (15.5 bars). Maximum cargo temperature is

130F (54C). Minimum cargo temperature is 70F (21C). Minimum ballast water temperature in

Ala ska is 30F (-1C). Length of riser is 80 ft. (24.4m). Ambient temperature at time of pipe installation

is 70F (21C). Maximum a mbient temperature in P a nama is 110F (43C ).

4.9.1 What relative movement is expected between bottom of riser and bulkhead assum-ing no restraint on riser and no dresser-type couplings in the riser pipe?

Maximum relative movement due to temperature occurs when the steel bulkhead is at cargo temper-

ature (1300F) and the fiberglass pipe is at minimum ballast water temperature (300F); i.e. at time of

loa ding c a rgo in Alas ka.

Expans ion of bulkhead = L T= 6.38 x 10-6 (80 x 12) (130 - 70)

= 0.37 inches

Contraction of pipe = L T = 10 x 10-6(80 x 12) (70 - 30)= 0.38 inches

Tota l relative mo veme nt due to te mpe rature

= 0.37 + 0.38 = 0.75 inch

Note that p ress ure in the pipe under these c onditions w ill ca use the p ipe to lengthen a nd reduce the

relative movement between pipe and bulkhead.

Maximum rela tive mo vement d ue to pressure w ill occ ur at a mbient tempe rature d uring ba llas ting in

Panama .

38


41/97

VERTICAL RISER IN BALLAST TANK

FIGURE 4-2

39


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40

L = (80 x 12) 1-2 (.56)

= 0.53 inches o r see Tab le 2-I

Thus the ma ximum expec ted relative movement is 0.75 inch a s c aus ed b y temperature.

4.9.2 Does the pipeline layout below the riser allow enough flexibility to absorb the expect-ed relative movement?

The ed ucto r is rig idly anc hored to prevent vibra tion; the refore, the rise r support forms a Z loo p.

Interpolat ing from Ta ble 2-Ill for a leng th c ha nge of 0.75 inch, the req uired leg lengt h is 9.5 ft. S ince

the layout provides only 3 ft., there is insufficient flexibility to absorb movement.

Tw o solutions a re pos s ible:

A. Anchor the riser pipe nea r the bottom a nd provide guides as req uired to prevent buck-

ling.

B. Insert Dress er-type couplings into the riser pipe to a bs orb the expected movement.

4.9.3 Solution A: Restrain the riser pipe

Elat 30F = 2,100,000 6,000 (30) = 1,920,000 ps i

Force on anc hor, P = ElA L/L

= 1,920,000 (22.5) 0.75/(80x12)

= 33,750 lbf. due to temperature chang e

Note that pressure causes a reduction in anchor force due to temperature.

From Ta ble 3-Il, the force due to p ress ure a lone is

P = 9260 (225/100) = 20,840 lbf.

Thus the a nchor must b e d es igned for 33,750 lbf.

The guide s pa cing should be es ta blished for a c ondition of empty ba lla st ta nk in Pa nam a (110 F) and

full cargo tank a t 70 F. The pipe T = 110-70= 40 F. From Ta ble 4-VI the g uide s pa c ing is 52 fee t.

S ince the ma ximum unguided length is 30 ft., no a dd itiona l guides w ould b e required.

Check maximum tensile stress in pipe wall: In this case, assume hot cargo tank, cold ballast tank

a nd m aximum pres sure oc cur simultane ously.

f = (33,750 + 20, 840)/22.5

= 2,426 psi < 2,830 psi allowa ble

Chec k shear stress in RP 60 a dhes ive (S ee Ta ble 3-IV):

a = (33,750 + 20,840)/[ir(15.91)(4.00)]

= 273 psi > 212 psi allowa ble

Solution A is not feasible due to shear stress in adhesive.

225 (15.19)2

4 (.47) 1,6000,000 (15.66)

1.6

3.6


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41

4.9.4 Solution B: Dresser-type couplings. Contraction in riser pipe due to pressure:

L = (80 x 12) (. 56)

= 0.53 inches

Thus the tota l co ntra ction due to press ure a nd temp erature is 0.75 + 0.53 = 1.28 inches . Eac h co u-pling allows 0.375 inch movement (See Appendix A) without gasket scuffing. However, considering

the infreq uent nature of the wo rse-ca se co ndition, tw o c ouplings should be sufficient. Light d uty

anchors will be required between couplings.

The rise r bottom should b e a nchored a ga inst closed -end force. From Tab le 3-Ill, the force is:

P = 18,100 (225/100) = 40, 740 lbf.

For anchor details see Section 5.

225 (15.9)2

2(.47) 3,600,000 (15.19 + .47)


44/97

42


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43

5.1 INTRODUCTION

Proper support of fiberglass piping systems is essential far the success of marine fiberglass installa-

tions. In de aling w ith insta lla tions of fiberglass pipe b y s hipya rds , riding c rew s, a rid o w ners through-

out the wo rld, the need for a C hapter dedicated to c ommonly used installation details has bec omeevident.

The recomm enda tions and deta ils he rein are b a sed on s ound eng ineering principles a nd experience

in suc ce ss ful fiberglass piping installations. They a re offered a s a lternatives and sug ge stions for eval-

ua tion, mo difica tion a nd impleme nta tion by a q ua lified Ma rine Engineer. Ta king s hort cuts to s a ve

material or cost can cause grave consequences.

Notes: 1. Unless otherwise indica ted, d etails are co nsidered suitab le for all approved piping s ystems.

2. Deta ils a re not intended to sho w o rienta tion. Ass emb lies m ay b e inverted o r turned horizonta l for

atta chment to ship s s tructure, bulkhead or dec k. Goo d pra ctice req uires that s upport lengths in pipe

runs provide the minimum dimensions needed for clearance of nuts and bolts.

3. Loca tion, spac ing a nd des ign of hangers and steel supports a re to be d etermined by the shipyard,

nava l a rchitect, or des ign a ge ncy. The nec ess a ry properties o f fiberglass pipe a re found in Chapte rs 2,

3 and 4.

4. Fiberglas s piping systems on boa rd ships a re often des igned to a bso rb movement and length changes

a t mec ha nic a l joints. To c ontrol de flec tions, the d es igne r mus t a llow for the w eight a nd flexibility (hinge

effect) introduc ed by mec hanica l co uplings or expans ion joints. S ee Appendix E.

5. Deta iled d imens ions a re in inches a nd (mm) unless otherwise indica ted.

6. Fla nge ga skets s hall be 1/8 in. (3mm) thick, full fac e elas tomeric ga skets w ith a S hore A Duromete r

hardnes s o f 60 + 5. A S hore fluromete r hardnes s o f 50 or 60 is reco mmend ed fo r elasto meric pa ds .

7. Refer to AS TM F708 for add itiona l deta ils rega rding sta nda rd prac tice fo r des ign a nd insta llation ofrigid pipe ha ngers.

5.2 DETAILS

5.2.1 Water Tight Bulkhead Penetration, Flanged One End (Figure 51 On Following Page)

All wa ter tight b ulkhea ds a nd d ec k penetrations must b e a cc omplished in ste el and/or a non-ferrous

metal capable of being welded water tight to the steel structure and must comply with classification

societies rules. Fiberglass pipe can be attached to this penetration by a mechanical coupling

(Dres ser-type) betw een the me tallic s pool piec e a nd fiberglas s p lain end. A step do w n co upling c an

also be used when the diameter of the metallic spool piece differs from the outside diameter of the

fibe rglas s pipe.

Note: All spool piec es must b e a ligned w ith the longitudinal axis of the piping sys tem within tolera nce per-mitted by the mechanical coupling manufacturer regardless of the deck or bulkhead slope.

5.0 Anchor And Support Details


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44

5.2.2 Water Tight Bulkhead Penetration, Flanged Both Ends (Figure 52 )

The d ifference betw een this w a ter tight s pool piec e a nd the previous one is the inco rpora tion of

fla nges a t both end s o f the wa ter tight b ulkhead. This s pool piec e penetration is c ommo nly used if a

valve must be attached at the bulkhead penetration as required for design, safety reasons or classifi-

cation society rules.

The alignme nt betw een the stee l and fiberglass flang es mus t be w ithin the tolerance discus sed late r

in Paragraph 5.2.13 and shown by Figure 513. Spec ial atte ntion is req uired w hen valves a re

mounted on the flanges; lock washers shall be placed on the steel side (compressed by the nut) and

flat washers on the fiberglass side (supported by the bolt).

5.2.3 Adjustable Water Tight Bulkhead Penetration, Flanged or Plain End. (Figure 53)

This pa rticular spoo l piec e c onnec tion a llow s tac k welding a t the b ulkhea d prior to final as se mbly so

that the pipe is truly a ligned , thus relieving fa brica tion s tress es in the s ystem . Two tanks c a n bealigned simultaneo usly w ith the use of this ad justa ble bulkhead penetration for proper a lignme nt of

the fiberglass pipe a nd fittings .

Fig. 51

Fig. 52


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45

5.2.4 Anchor Supports. (Figure 54)

This pa rticular deta il use s fiberglas s sa dd le s toc k halfco lla rs to a nchor the pipe a nd prevent long itu-

dinal displa ce ment along the axis. The ga p betw een ea ch 1800 sa dd le and the fla t ba r type clamp is

1/8 in. (3mm). Thes e s teel clam ps a re fa bric a ted by the s hipya rd c onfo rming to I.P.S. o r M.C.I. out-

side d iameters.

Notes: 1. The steel clamp should fit sq uarely a ga inst the a ngle b ar support where the c lamp will be bolted.Inserts, w as hers a nd spa cers should not be used .

2. For thickness o f the steel clamps refer to Note 3 under P arag raph 5.1.

5.2.5 Pipe Anchor Using 1800 Saddle Stock Full Collar (Figure 55 On Preceding Page)

This a nchor suppo rt is a cc omplished in the sa me ma nner as Figure 54. It restricts the pipe from

a xia l moveme nt. The ad ditiona l sa dd les w ill increas e the area of co ntac t betw een the sa dd le and the

pipe to ac commo da te axial forces .

Calculations of thrust are discussed in Chapter 3. If the shear value of the adhesive to be used on a

particular sys tems is exceed ed (see Se ction 3.6), a lternate types of a nchors should be used; es pe-cially at fittings. See Figures 58 and 59 for examples.

Fig. 53

Fig. 54


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46

5.2.6 Anchor Supports Using Full Metal Clamp (Figure 56)

The flat ba r clam p is des igned to restrain the pipe from a xia l movem ent. S a dd le s toc k is insta lled on

bo th sides o f the steel clamp. In order to hold the pipe w ithout da ma ge s ee Tab le 51 below for

recomme nded s pac e betw een the bottom pa rt of the clamp a nd upper part of the c lamp.

For sma ll pipe d ia meters 16 in. (25150mm) it is us eful to us e a 1/4 thick (6mm) neoprene p a d

(Durometer A 5060) co mpresse d b etw een the pipe a nd me ta l clamp. This w ill not prevent move-

ment o f the pipe in the a xia l direc tion. To prevent mo veme nt, the pipe mus t be properly a nc hored

with sa dd le s upports using half or full co lla rs depe nding on the thrust impos ed by the hyd ros tatic

pres sure or temperature c hang e in the piping s ystem .

Notes: 1. The steel clamp should fit sq uarely a ga inst the a ngle b ar support where the c lamp will be bolted.Inserts, w as hers a nd spa cers should not be used .

2. For thickness of the s teel clamps refer to Note 3 under Pa rag raph 5.1.

Fig. 55

Clearance At Bolts

NP S (Without Liner)

(in) (mm)

1 1/8 3

11/2 1/8 3

2 1/8 3

3 1/4 6

4 1/4 6

6 3/8 10

8 3/8 10

10 1/2 12

12 1/2 12

14 5/8 16

16 5/8 16

18 5/8 16

Clearance At Bolts

NP S (Without Liner)

(in) (mm)

20 5/8 16

22 5/8 16

24 5/8 16

26 5/8 16

28 5/8 16

30 5/8 16

32 5/8 16

34 5/8 16

36 5/8 16

TABLE 5I


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47

5.2.5 Pipe Anchor Using 180Saddle Stock Full Collar (Figure 55)

This a nchor suppo rt is a cc omplished in the sa me ma nner as Figure 54. It restricts the pipe from

a xia l moveme nt. The ad ditiona l sa dd les w ill increas e the area of co ntac t betw een the sa dd le and the

pipe to ac commo da te axial forces .

Calculations of thrust are discussed in Chapter 3. If the shear value of the adhesive to be used on a

particular sys tems is exceed ed (see Se ction 3.6), a lternate types of a nchors should be used; es pe-

cially at fittings. See Figures 58 and 59 for examples.

5.2.6 Anchor Supports Using Full Metal Clamp (Figure 56)

The fla t ba r cla mp is des igned to restrain the pipe from a xia l moveme nt. S ad dle stoc k is installed on

bo th sides o f the steel clamp. In order to hold the pipe w ithout da ma ge see Ta ble 51 below for

recom mended s pac e betw een the bottom part of the clamp a nd upper part of the clamp.

For sma ll pipe d ia meters 16 in. (25150mm) it is use ful to us e a 1/4 thick (6mm) neo prene p a d

(Durome ter A 5060) co mpresse d b etw een the pipe a nd me tal clamp. This w ill not prevent move-

ment o f the pipe in the a xia l direc tion. To prevent m ovem ent, the p ipe m ust b e properly anc hored

w ith sa dd le s upports using half or full co llars d epend ing o n the thrust impose d b y the hydrosta tic

pressure or temperature c hang e in the piping s ystem .

Fig. 56

Fig. 57


50/97

5.2.7 Anchor Supports Using Flat Bar Top Half and Steel Shape Bottom (Figure 57 Previous Page)

This typ e of a ncho r suppo rt is s imila r in purpose to tha t sho w n in Figure 56. Many shipyards p refer

this type.

Caution: Dimensions of the steel clamp must provide for a loose fit around the fiberglass pipe when attached tothe steel angle shape below. If the pipe is clamped against the flat steel surface on the bottom half, the

force imposed at the ta ngential point of contac t betw een the pipe a nd steel ca n da mag e the fiberglas s

pipe. (Se e Ta ble 5I). For dia meters g rea ter than 8 inches this prob lem is less se vere d ue to increas edthic kness of the pipe w a ll. (S ee C ha pter 4, Ta ble 4IV)

Note: The sup ports s how n in Figs . 54, 55, 56 and 57 are designed to restrain axial movement of thepipe when they are fitted with 180 deg. saddles.

5.2.8 Thrust Support For 90and 45Elbows (Figure 58 on Following Page)

The thrust supp ort plate of Figure 58 is us ed w hen the hydrosta tic force or thrust in the piping s ys-

tem will exceed the shear strength of the adhesive bonded joint. It is recommended that this type of

supp ort be use d in trans ferring t he loa d from the joint direc tly into the bo dy of the fitting. The fitting

will a bs orb thrust impos ed on the piping s ystem . The suppo rt plate w ill be permanently atta ched to

the standard foundation detail produced by the shipyard with addition of a torsional support plate

bo lted d irec tly onto a fla nge o f the elbo w to prevent a to rsiona l displa ce ment of the fitting.

It is recommended that a .394 in. (10mm) thick neoprene pad with a Durometer A of 50-60 be

installed between the thrust support plate and the outside of the elbow completely covering the

inside c urved s urfac e w hich w ill co ntac t the pipe. The neoprene pa d s hould b e fully c ompress ed

against the thrust plate. If the thrust plate support cannot be made into a smooth radius, an alterna-

tive metho d is to w eld toge ther stra ight plates (Lobster-B ac k configuration). In this c a se the neo-

prene pad must be sufficiently thick so that when the pad is compressed between the fitting and the

Lobster-Back support, a full contact of the outside diameter of the pipe is accomplished with the

co mpression of the neop rene pa d. This a ss ures that the fo rce s w ill be tra nsmitted d irec tly to the

steel thrust support plate and no slippage will occur by an improperly compressed neoprene pad.

Note: It is recomme nded that a mec hanica l coupling (Dres ser-type o nly) be inco rporate d o n either side of thefitting us ing thrust s upport plate s to a llow a xial movem ent in the piping s ystem a nd relieve pa rt of the

thrust impose d on the fitting. This practice has be en used suc ce ss fully in previous insta llations. S ee

Note in Sec tion 5.2.9.

5.2.9 Thrust Support Plate For Tees (Figure 59 On Page 5.8)

The thrust supp ort plate of Figure 59 is us ed w hen the hydrosta tic force or thrust in the piping s ys-

tem will exceed the shear strength of the adhesive bonded joint. It is recommended that this type of

supp ort be use d in trans ferring t he loa d from the joint direc tly into the bo dy of the fitting. The fitting

w ill a bs orb thrust impos ed o n the piping s ys tem . The thrust supp ort pla te for the tee is simpler in

des ign tha n the previous thrust s upport for elbow s. The c onstruction is straight a nd s imple without

compound curvature and can be accomplished by rolling the plate to conform to the outside diame-

ter of the tee.

48


51/97

49

Fig. 58


52/97

The ac co mmod a tion of the neoprene pad will be the s a me a s Figure 58 with the objective to trans -

fer the thrust force of the piping s ystem into the thrust s upport pla te a nd not into the flang e or bo nd-

ed joints of the tee. Because of the geometrical configuration of the tee, a torsional plate will not be

required. All the rest of the recommendations previously discussed in Figure 58 are also applicable

to the tee support.

Note: It is ad visable to coat the U bolts which hold the e lbows a nd tees aga ins t the thrus t support p la teswith Amercoat, urethane or similar coatings to protect against corrosion, and also cushion between the

fittings and the U bolt. Another method used by some shipyards is to introduce a neoprene sleeve

around the U b olts. This Note a pplies to a ll supports using U b olts.

5.2.10 Anchor Support Plate Bolted to a Flanged Fitting (Figure 510 On Following Page)

This anc hor support is used for flang e fittings when the hydrostatic forces impos ed by the des ign o f

the piping s ystem d o not exc eed the ad hesive s hear stress va lue. (S ee S ection 3.6 of this ma nual.)

Figure 510 shows the plate pattern covering a minimum of four bolts (for all pipe sizes). Figure 5

10 shows a design used by shipyards to anchor large diameter elbows. See Note 3 on page 5.2.

5.2.11 Steel Supports for Large and Small Valves (Figure 511 On Page 5.10)

The s teel suppo rts sho w n in Fig ure 511 ap ply for va rious kinds of va lves . Va lves in sizes 4 in. a nd

under are relatively light c a n normally be supported with a single s upport. Ga te va lves and similar

large a nd heavy va lves in sizes 6 in. and up req uire tw o s upports to ac commo da te the weight and

directly transmit it to the ship s s tructure. Valves suc h as globe o r ga te valves w ith rea ch rods

extending to the above decks require double support.

S ee Ta ble 5Il below for required number of bolts in support plates.

50

Fig. 59


53/97

Flanged plates must be properly designed to support the weight of valves and transmit it directly to

the ship s structure. It is recommended that all steel components in a piping system be supported.

This w ill prevent shifting the w eight to the fibe rgla ss piping s ys tem.

TABLE 5Il

Note: Fla nges should be two -hole oriented as a gene ral prac tice in shipbuilding.

51

Fig. 510

Req uired Minimum

Number Of Bolts

Fla nge Atta che d To

S ize Support P late

20 8

22 8

24 10

26 10

28 10

30 12

32 12

34 12

36 12

Req uired Minimum

Number Of Bolts

Fla nge Atta ched To

S ize S upport P la te

1 2

11/2 2

2 2

3 4

4 4

6 4

8 4

10 6

12 6

14 6

16 6

18 8


54/97

52

5.2.12 Guidance Support for Fiberglass Pipe. Teflon Sliding Pad (Figure 512)

This s imple des ign ha s b een a do pted a lmos t universa lly for guide s in ship c ons truction. Teflon hasselflubrica ting properties w hich help to reduce friction betw een the s urfac e of the pipe a nd the

stee l without inducing a bras ion on the fibe rglas s co mponent. Teflon a lso is inert to mos t c hemicals

and petroleum d erivatives us ed in ta nk ships, w hite produc t, a nd c hemica l ca rriers. The minimum

thic kness of the te flon pa d is reco mme nde d to be 1/5 inch (5mm). Teflon thicknes s s hould be

increa se d propo rtiona lly to the large st s ize o f the piping s ys tem i.e., 1/4 inc h (6mm) for 20 inc hes a nd

a bo ve. The teflon pa d c a n be utilized (or insta lled ) in different co nfigura tions , so me s hipya rds fee l

that the teflon pad in conjunction with the holes for the U bolt will be sufficient. Others shipyards pre-

fer to have an indentation on the teflon pad to prevent any sliding in the center between the two

holes suppo rting the pa d. The third a nchor point will be in the c enter of the teflon pa d a nd the m eta l

ba r as s hown a s a n alternative on Figure 512. It is a lso recomm ended that the U bo lts b e c oated

with Amercoa t, uretha ne or hot d ip c oa ting to prevent c orros ion.

5.2.13 Maximum Flange Misalignment Allowance (Figure 513)

The Ta ble in Figure 513 shows allowable misalignment for flanges from 116 inches diameter and

from 1836 inches diameter. It is recommended that these allowances not be exceeded in order to

ac complish a proper sea l between flang es without inducing unac cepta ble stress es.

Fig. 511


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53

Fig. 513

Fig. 512


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54

5.2.14 Pipe Misalignment Between Supports (Figure 514)

The Ta ble in Figure 514 show s a llow a ble misa lignme nt for different sizes of pipe as suming 20 ft.

(6m) between supports. Figure 514 also provide s a formula to c alcula te the ma ximum misa lign-

ment betw een supports for other support spa cings .

Note: When joints are made with mechanical couplings, see manufacturers litera ture for permiss iblemisalignment.

Notes: 1. For supports spa ns other than 20 feet the total misa lignment ca n be c alculated using theabove formula

2. Misa lignme nt applica ble applica ble to any direc tion pa rallel to a xis

H = H20

x

Where

H = Total allowable

misalignment in (in.)

C = Support span in (ft.)

H20 = See Table

C2

400

Fig. 514


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6.0Internal and External Pressure Design6.1 INTERNAL PRESSURE

Pi

=

Where: Pi

= rated internal press ure, psi or kg/cm2,

s = allowa ble hoop s tress , 6000 psi. (422kg/cm2) for S eries 2000M

and 7000M Bondstrand pipe,

OD = minimum outside d iameter (in. or cm) see Tab le 4IV,

t = minimum reinforced w all thickness (in. or cm) = tt ti,

tt = minimum total thickness (in. or cm) see Tab le 4IV,

tl

= liner thickness , 0.020 in. (0.51 cm) for Se ries 2000M, ze ro for

Series 7000M.

(OD - t) = ID + t + 2tl

ID = inside diameter (in . or cm).

To c onvert p res sure in psi to ba rs, d ivide by 14.5. To c onvert pres sure in kg/cm 2 to b ars, d ivide by

1.02.

Based on the formula given above, the rated operating pressure for Series 2000M and Series 7000M

pipe is ta bulate d in Ta ble 6I. This provides long term performance in accordance with the cyclic

Hydrosta tic Design B as is (AS TM D2992, Method A) a nd provides a 4 to 1 s afety fac tor on s hortterm hydrosta tic performa nce a s req uired by propos ed AS TM Marine P iping S pec ifica tions.

Note: Fittings a nd/or mecha nica l co uplings ma y reduc e the sys tem w orking press ure be low thatshow n in Ta ble 6I. See Bond strand P roduct Da ta S heets FP168 and FP169 and c oupling ma nufac -

turers literat ure.

55

2s t

(ODt)


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TABLE 6I

Ra ted Internal Opera ting P ress ure for S eries 2000M and S eries 7000M Pipe

Rated Internal

No mina l Opera ting P res sure

Dia meter a t 2000F (930C )

in. mm ps i ba r

2 50 550 38

3 80 450 31

4 100 450 31

6 150 300 21

8 200 300 21

10 250 300 21

12 300 300 21

14 350 300 21

16 400 300 21

18 450 300 21

20 500 300 21

24 600 300 21

28 700 300 21

30 750 300 2136 900 300 21

Note: Fittings a nd flang es have a lower press ure rating than the pipe.

6.2 EXTERNAL COLLAPSE PRESSURE.

Pc

=

Where Pc

= externa l colla ps e press ure (ps i or kg/cm 2),

Ec

= effective c ircumferentia l modulus o f elasticity (ps i or kg/cm 2), s ee Ta ble

6Il,

ta

= average reinforced wa ll thickness (in. or cm), .875 is used bec ause the

minimum thickness is 87.5% of nominal.

= (tt /. 875) tl

tt

= minimum tota l thickness (in. or cm) see Ta ble 4IV,

tl

= liner thicknes s , 0.020 in. (0.51 cm) for Series 2000M, zero for S eries

7000M,

ID = pipe inside d iameter (in. or cm), see Tab le 4IV,

l

= P ois sons ratio for contraction in the circumferential direction due to

tens ile s tres s in the longitudinal direc tion, se e Ta ble 6Il,

c

= P ois sons ratio for contraction in the longitudinal direction due to the

tens ile s tres s in the c ircumferentia l direc tion, see Ta ble 6II.56

2Ec

ta3

(1-c

l) ID3


59/97

To c onvert exte rnal pres sure in ps i to b a rs, divide by 14.5. Atmo sp heric p res sure a t se a level is 14.7

ps i. To convert kg /cm2 to bars, divide by 1.02.

When installing pipe in the bottom of tanks, the pipe must resist the combined external fluid pressure

and internal suction. It is assumed that a positive displacement pump can pull a maximum of 75 per-

ce nt vac uum. The des igner should a lso a llow fo r a s a fety facto r of 3 in ac co rda nce w ith propos ed

AS TM Spe c ific a tions. Thus the a llow a ble hydros ta tic hea d, H in ft. is:

H = 2.31 11.0

Ta bula ted values of allow ab le hyd ros tatic hea d are s how n in Ta ble 6Ill on pa ge 6.6 for tempera-

tures of 1000F(380C) and 2000F(930C). For example, calculate the collapse pressure and

allowable hydrostatic head in English units for 12 inch Series 2000M pipe at 2000F:

ID = 12.35 inc h

tt

= 0.351 inch

tl

= 0.020 inch

ta

= (.351/.875) .020 = .381 inch

Pc

= = 181 ps i

H = 2.31 11.0 = 114 ft.

Or rea d the a ppropria te va lues from Ta ble 6Ill.

Table 6IlElas tic P roperties for Ca lculation o f Externa l Collap se P res sure for Se ries 2000M and 7000M Pipe

Tempera ture Ec

F C psi kg/cm2

c

l

70 21 3.15 x 106 2.21 x 105 0.56 0.37

100 38 3.06 x 106 2.15 x 105 0.57 0.38

150 66 2.90 x 106 2.04 x 105 0.60 0.39

200 93 2.20 x i06 1.55 x 105 0.70 0.41

Note: Ec is ba sed on external colla pse tests per AS TM D2924. Values of P oisson s ratio are based ontes ts per AS TM D1599

57

Pc

3.0[ ]

[ ]

2(2.20 x 106).3813

[ 1 - .7 (.41)] 12.353

181

3.0


60/97

58

TABLE 6IllExternal Collapse Pressure and Allowable Hydrostatlc Head

for Series 2000M and Series 7000M Pipe

1000F(380C ) 2000F(930c)

Nom. P ipe Colla pse Allow a ble C olla pse Allow a ble

S ize P ressure Hydros ta tic Hea d P ressure Hydros ta tlc Hea d

(in) (mm) (ps i) (B a rs ) (ft) (in) (ps i) (B a rs ) (ft) (in)

2 50 2,331 160 1,770 540 1,855 565 1,403 427

3 80 637 43.9 465 142 507 35.0 365 111

4 100 703 48.5 516 157 559 38.6 405 123

6 150 234 16.1 155 47 186 12.8 118 36

8 200 231 15.9 153 47 184 12.7 116 35

10 250 231 15.9 153 47 184 12.7 116 35

12 300 228 15.7 150 46 181 12.5 114 35

14 350 228 15.7 150 46 181 12.5 114 35

16 400 228 15.7 150 46 181 12.5 114 35

18 450 227 15.6 149 45 181 12.5 114 35

20 500 227 15.6 149 45 181 12.5 114 35

24 600 226 15.5 149 45 180 12.4 114 35

28 700 226 15.5 149 45 180 12.4 114 3530 750 226 15.5 149 45 180 12.4 114 35

36 900 225 15.5 148 45 179 12.3 112 34


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7.1 INTRODUCTION

When comparing Fiberglass and carbon steel piping systems it becomes evident that selection of

Fiberglass pipe c an result in s ignifica nt s avings due to fa vorable hydraulic properties.

7.2 HEAD LOSS

The frict iona l hea d loss in a pipe is a function of veloc ity, dens ity, and visc os ity of the fluid; a nd of

the smo othnes s of the bo re, a nd the length a nd diame ter of the pipe. Therefore, the best me a ns of

minimizing this pressure drop in a particular piping service is to minimize the internal roughness

fp707a,bondstrand marine design manual

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