Pipinjjg System Design Philosophy

7/18/2019 Pipinjjg System Design Philosophy

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SELECTION OF SUPPORTING

ARRANGEMENT FOR CRITICAL

PIPING

By

DILEEP PILLAI



PURPOSE OF STRESS ANALYSIS

The selection of suo!tin" #!!#n"e$ent is %#se& on

Piin" St!ess #n#lysis' Piping Stress Analysis is c#!!ie&

out to (

)' *ee STRESSES in the iin" +ithin its #llo+#%le

,#lues'

-' *ee REACTIONS &ue to the iin" on e.ui$entno//les +ithin thei! #llo+#%le ,#lues'

0' P!o,i&e SUITABLE SUPPORTS to t#1e the DEAD

WEIGHT of the iin" +hile !o,i&in" f!ee $o,e$ent



PROCEDURE

2 Static analysis 3

This consists of fi!st # f!ee The!$#l Run #n& # 4ei"ht &ist!i%utionRun'follo+e& %y 5#n"e! Selection' Afte! th#t the fin#l The!$#l Run+ith selecte& h#n"e! #n& #ll !est!#ints in l#ce is t#1en' The h#n"e!s #!eselecte& %#se& on the the!$#l $o,e$ents #n& the the ie +ei"ht'An#lysis is &one in such # +#y th#t the !e#ctions #t the te!$in#ls #!e1et +ithin thei! #llo+#%le ,#lues' Rest!#ints #!e use& to hel #chie,ethis #s +ell !est!ict un&ue ie $o,e$ents' 5#n"e!s #!e selecte& +ith$#!"in in $o,e$ent on %oth to #n& %otto$'

In #ll *4U sets the #n#lysis is &one in such # +#y so th#t no ie+ei"ht is t!#nsfe!!e& to the tu!%ine #n& ,#l,e no//les' To ensu!e this #s+ell #s to t#1e c#!e of the #ctu#l ie +ei"ht 6&ue to ie tole!#nces7+ith !esect to the theo!etic#l +ei"hts the iin" is flo#te& on unloc1e&s!in" h#n"e!s %efo!e connectin" to tu!%ine no//les &u!in" e!ection'



The ,#!ious static analysis otpts "ene!#te& %y us #!e(

2 Piin" st!ess chec1 #s e! co&es2 5#n"e! #n& suo!t t#%les

2 Fo!ces #n& $o$ents t#%le consistin" of (

3 Weig!t

3 Hot 6 i$$e&i#te 5ot7

3 Hot 6s#fety ,#l,es %lo+in"7

3 Col" Rela#e"

3 Col" Rela#e" 6+ith ue! c#sin" !e$o,e&8 in c#se of slit c#sin"7

The #n#lysis is &one u to the Tr$ine CG so #s to f#cilit#te st#%ility

c#lcul#tions' The !e#ctions #t the tu!%ine #!e li$ite& %y t+o c!ite!ion8

the tu!%ine st#%ility #n& the no//le st!en"th'



2 Dyna%ic analysis &

4e c#!!y out # Dyna%ic Analysis of 'S( HRH an" CRH iin" %ec#use of )ic*closing of ES+ , C+ in MS iin" #n& I+ , C+ in 5R5 iin"' A pressre s!oc*

-a.e is "ene!#te& in the iin" +hen the ,#l,e closes f#st +hich t!#,els #t the see&of soun& in the iin"' Deen&in" on the #ctu#l .al.e closing ti%e8 the %ass /lo- th!ou"h the ,#l,es #n& the piping lengt!s the /orcing /nctions #!e +o!1e& out ine#ch le"' 4ith these fo!cin" functions # .i$ration analysis of the iin" is c#!!ie&out' 4he!e,e! foun& necess#!y s!oc* a$sor$ers #!e int!o&uce& to the iin" syste$so #s not to &istu!% the st#tic #n#lysis #s +ell #s s#tisfy &yn#$ic !e.ui!e$ents'

The #n#lysis "i,es us the stresses in the iin"8 /orces an" %o%ents #t thee.ui$ents #n& !est!#ints #n& the "e/lection of the iin" #t ,#!ious oints'

The !angers #!e then once #"#in chec1e& to &ete!$ine +hethe! the e#!lie! $#!"ins !o,i&e& &u!in" st#tic #n#lysis +e!e #&e.u#te' They shoul& not to out o! %otto$ out&u!in" &yn#$ic con&itions #lso'

The restraints #!e fin#lly &esi"ne! to c#te! fo! st#tic 9 &yn#$ic lo#&s'

The #&&ition#l !e#ctions #t e)ip%ent no00les &ue to &yn#$ic con&itions #!e #lsot#1en into consi&e!#tion



St!esses

)' P!i$#!y st!esses

-' Secon&#!y st!esses



PRIMARY STRESSES

P!i$#!y st!esses #!e those st!esses c#use& %y lo#& th#t#ct continuously' They #!e not self li$itin" #n& ifyiel& st!ess is !e#che& yiel&in" +ill occu!' P!i$#!yst!esses fo! +hich the iin" is usu#lly #n#ly/e& #!e

2 De#& +ei"ht

2 P!essu!e

2 Occ#sion#l lo#&in"s such #s e#!th.u#1e #n& ste#$h#$$e! 6e#!th.u#1e in c#se the l#nt is loc#te& in #ne#!th.u#1e !one #!e#7



SECONDARY STRESSES

Secon&#!y st!esses #!e st!esses +hich #!e

self li$itin" #n& f#ilu!e occu!s %y !ee#te&

#lic#tion' The!$#l st!esses #!e secon&#!yst!esses #n& f#ilu!e occu!s th!ou"h !ee#te&

cycles #n& su%se.uent f#ti"ue'



St!ess co$#!ison #s e! co&e ANSI B0)')

Longit"inal Stresses "e to Sstaine" Loa"s

S 9 S+ :; Sh

Longit"inal Stress "e to Occasional Loa"s

S 9 S+ 9 So :; 1Sh 8 1; )')< fo! &u!#tion : )= > of o' ti$e

1; )'-= fo! &u!#tion : ) > of o' ti$e

T!er%al E#pansion Stress Range

Se :; S#

S# ; Allo+#%le St!ess R#n"e ; f 6)'-< Sc 9='-< Sh7

Sstaine" 1 T!er%al E#pansion Stress

S 9 S+ 9 Se :; 6Sh 9S#7



HANGER SELECTION

2 Hanger selections #!e $#&e %#se& on static analysis( #n& then fin#lly

chec1e& fo! "yna%ic "e/lections #s +ell'

2 +aria$le springs #!e usu#lly selecte& fo! &eflections of u to ?= $$'Beyon& ?= $$ Constant Loa" h#n"e!s #!e selecte&'

2 +aria$ility of lo#& fo! ,#!i#%le lo#& h#n"e!s #!e usu#lly 1et +ithin -<>'In Const#nt lo#& h#n"e!s the ,#!i#%ility is theo!etic#lly /e!o'

2 Hanger Loa"s consists of pipe -t8 %e"ia -t8 inslation -t #n& -t of!anger co%ponents such cl#$s8ch#nnels8tie !o&s etc'

2 +aria$le Loa" !angers #!e selecte& f!o$ @Lo#& T#%les "i,en in the5#n"e! c#t#lo"ue %y Piin" Cente!' 4hile selectin" s!in"s8 c#!e is t#1ento see th#t top #n& $otto% $#!"ins #!e #,#il#%le in #ll oe!#tin"con&itions such #s Col"8 Hot #n& Col" Rela#e"' C#!e is #lso t#1en to seeth#t &yn#$ic &eflections #!e +ithin the to #n& %otto$ $#!"ins !o,i&e&'



2 Constant Loa" !angers #!e selecte& usin" @Selection "ata2 ch#!ts of

PC' 5e!e $#!"ins #!e chec1e& fo! Col" #n& Hot con&itions #n& #lso

fo! "yna%ic $o,e$ents'

2 Rigi" spports #!e !o,i&e& u&iciously in the syste$ $#1in" the

syste$ #s !i"i& #s ossi%le +hile still 1eein" stresses in the iin" #s

+ell #s reactions #t the te!$in#l oints +ithin li$its' Ri"i& suo!ts

$#y %e tie ro" !angers8 strts o! !est!#ints $#&e of pipe

attac!%ents'

2 S!oc* A$sor$ers #!e only use& +hen it %eco$es #%solutely

necess#!y8 to #%so!% the !essu!e shoc1 +#,e "ene!#te& &ue to .uic1

closin" of ES C #n& I C' The lo#&s #!e &eci&e& %#se& on

Dyna%ic Analysis !esults











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Pipinjjg System Design Philosophy