8/4/2019 Jacket Pipe 010001

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Thcrm3J end reactions can be pre~icted

fo r jack ete d p iping carrying a process

fluid in an inner pipe heated by st8:1mb:.:f',jeen the pipe and jackGt

JACKETED -PIPING requires special stress anaiysis: Com-

monly used to convey very viscous pr~cess fluids in an

mner pIpe, neated by steam between the outer jacket ans!

inner pipe, thermal end reactions can be predicted. Vac-

cuum jacketing is also used as an insulator for cryogenic

fluicls and can be analyzed using the same calculation

method for heated jacketed piping.

By example, stress problems occuring with this type

of piping system will be descrihed. The example assumes

a process fluid requiring const.1nt, uniform heat not avail-

able through steam or electrical tracing systems. It further

ass,:mcs-the need for a stainless steel Lnner pipe or core

and an outer carbon steel pipe or jacket. Since both pipes

are rigidly attached to flanges in spool pi.eces and each

pire has a difTerent. thermal e~pansion _coefficient, ~xial

- str~se~ will be _an_a_ly_z_e_d_._

Example. An isometric dra\',ing of the sample problem

is shown on Fig. 1. The construction is a three inch

schedule '10 stainless steel core pipe with a four inch

schedu1e ,1 0 carbon steel jacket. The jacket covers the core

for its entire length and flanges arc used for system dis-rnantlillg. The heating medium is 180 psi-saturated stelll the uifl""ll:IJ"': in tIll: coefficieJlt of cx-

pallSi",n hct\\cI'lI t!w st;liJlIt-" eof/.' alld carboJl steel

jad:t.:t. The cIJJllpn:ssi\'c :1Il I I)

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~ v5pacers shown as a restraint

i~I II II II } - 3-in sch. 1055 core pipe

I II 1,-4in, sch,40 C stl jacketI I

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