Piping Inspection Code Inspection, Repair, Alteration, and Rerating of In-service Piping Systems API 570 SECOND EDITION, OCTOBER 1998 ADDENDUM 1, FEBRUARY 2000 ADDENDUM 2, DECEMBER 2001 ADDENDUM 3, AUGUST 2003 ADDENDUM 4, JUNE 2006 Copyright American Petroleum Institute Provided by IHS under license with API Licensee=Chevron Corp/5!"#$$!%% &ot 'or (esale) %$/%#/"%%* %+5,+5" -. &o reproduction or networ0ing permitted without license 'rom IHS --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
Copyright American Petroleum Institute Provided by IHS under license with API Licensee=Chevron Corp/5!"#$$!%% &ot 'or (esale) %$/%#/"%%* %+5,+5" -. &o reproduction or networ0ing permitted without license 'rom IHS --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
Piping Inspection Code Inspection, Repair, Alteration, and Rerating of In-service Piping Systems Downstream Segment API 570 SECOND EDITION, OCTOBER 1998 ADDENDUM 1, FEBRUARY 2000 ADDENDUM 2, DECEMBER 2001 ADDENDUM 3, AUGUST 2003 ADDENDUM 4, JUNE 2006 Copyright American Petroleum Institute Provided by IHS under license with API Licensee=Chevron Corp/5!"#$$!%% &ot 'or (esale) %$/%#/"%%* %+5,+5" -. &o reproduction or networ0ing permitted without license 'rom IHS --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
SPECIAL N!ES API p!"#$%&#'() (*$*))%+#" %--+*)) p+'!"*.) '/ % *(*+%" (%&+* #& +*)p*$& &' p%+&#$"%+ $#+$.)&%($*), "'$%", )&%&*, %(- /*-*+%" "%) %(- +*"%&#'() )'"- !* +*#**- API #) ('& (-*+&%#( &' .**& &* -&#*)&' '/ *.p"'*+), .%(/%$&+*+), '+ )pp"#*+) %+( %(- p+'p*+" &+%#( %(- *#p &*#+ *.p"'**), %(- '&*+) *p')*-, $'($*+(#( *%"& %(- )%/*& +#)) %(- p+*$%&#'(), ('+ (-*+&%#( &*#+ '!"#%&#'() (-*+ "'$%", )&%&*, '+ /*-*+%" "%) I(/'+.%&#'( $'($*+(#( )%/*& %(- *%"& +#)) %(- p+'p*+ p+*$%&#'() #& +*)p*$& &' p%+&#$"%+ .%&*+#%") %(- $'(-#&#'() )'"- !* '!&%#(*- /+'. &* *.p"'*+, &* .%(/%$&+*+ '+ )pp"#*+ '/ &%& .%&*+#%", '+ &* .%&*+#%" )%/*& -%&% )**& N'&#( $'(&%#(*- #( %( API p!"#$%&#'( #) &' !* $'()&+*- %) +%(&#( %( +#&, ! #.p"#$%&#'( '+ '&*+#)*, /'+ &* .%(/%$&+*, )%"*, '+ )* '/ %( .*&'-, %pp%+%&), '+ p+'-$& $'*+*- ! "*&&*+) p%&*(& N*#&*+ )'"- %(&#( $'(&%#(*- #( &* p!"#$%&#'( !* $'()&+*-
%) #()+#( %('(* %%#()& "#%!#"#& /'+ #(/+#(*.*(& '/ "*&&*+) p%&*(& G*(*+%"", API )&%(-%+-) %+* +*#**- %(- +*#)*-, +*%+.*-, '+ #&-+%( %& "*%)& **+ :* *%+) S'.*&#.*) % '(*;&#.* *&*()#'( '/ p &' &' *%+) #"" !* %--*- &' &#) +*#* $$"* T#) p!"#$%&#'( #"" (' "'(*+ !* #( *<*$& :* *%+) %/&*+ #&) p!"#$%&#'( -%&* %) %( 'p*+%&#* API )&%(-%+- '+, *+* %( *&*()#'( %) !**( +%(&*-, p'( +*p!"#$%&#'( S&%&) '/ &* p!"#$%&#'( $%( !* %)$*+&%#(*- /+'. &* API S&%(-%+-) D*p%+&.*(&, =&*"*p'(* >202? 682;8000@ A $%&%"' '/ API p!"#$%&#'() %(- .%&*+#%") #) p!"#)*- %((%"" %(p-%&*- %+&*+" ! API, 1220 S&+**&, N, %)#(&'(, DC 20005, )&%(-%+-) %p#'+ T#) -'$.*(& %) p+'-$*- (-*+ API )&%(-%+-#%&#'( p+'$*-+*) &%& *()+* %pp+'p+#%&* ('&#:$%&#'( %(- p%+&#$#p%&#'( #( &* -**"'p.*(&%" p+'$*)) %(- #) -*)#(%&*- %) %( API )&%(-%+- *)&#'() $'($*+(#( &* #(&*+p+*&%&#'( '/ &* $'(&*(& '/ &#) )&%(-%+- '+ $'..*(&) %(- *)&#'() $'($*+(#( &* p+'$*-+*) (-*+ #$ &#) )&%(-%+- %) -**"'p*)'"- !* -#+*$&*- #( +#&#( &' &* -#+*$&'+ '/ &* S&%(-%+-) D*p%+&.*(&, A.*+#$%( P*&+'"*. I()&#&&*, 1220 S&+**&, N, %)#(&'(, DC 20005 R**)&) /'+ p*+.#))#'( &' +*p+'-$* '+ &+%()"%&* %"" '+ %( p%+& '/ &* .%&*+#%" p!"#)*- *+*#( )'"- %")' !* %--+*))*- &' &* -#+*$&'+ API )&%(-%+-) %+* p!"#)*- &' /%$#"#&%&* &* !+'%- %%#"%!#"#& '/ p+'*(, )'(*(#(**+#( %(- 'p*+%&#( p+%$&#$*) T*)* )&%(-%+-) %+* ('& #(&*(-*- &' '!#%&* &* (**- /'+ %pp"#( )'(- *(#(**+#( -.*(& +*%+-#( *( %(- *+* &*)* )&%(-%+-) )'"- !* &#"#*- T* /'+."%&#'( %(- p!"#$%&#'( '/ API )&%(-%+-) #) ('& #(&*(-*- #( %( % &' #(#!#& %('(* /+'. )#( %( '&*+ p+%$&#$*) A( .%(/%$&+*+ .%+#( *#p.*(& '+ .%&*+#%") #( $'(/'+.%($* #& &* .%+#( +*#+*.*(&) '/ %( API )&%(-%+- #) )'"*" +*)p'()#!"* /'+ $'.p"#( #& %"" &* %pp"#$%!"* +*#+*.*(&) '/ &%& )&%(-%+- API -'*) ('& +*p+*)*(&, %++%(&, '+ %+%(&** &%& )$ p+'-$&) -' #( /%$& $'(/'+. &' &* ""%pp"#$%!"* API )&%(-%+- All rights reserved. No part of this work may be reproduced, stored in a retrieval system, or transmitted by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission from the publisher. Contact the Publisher, API Publishing Services, !!" # Street, N.$., $ashington, %.C. !"""&. C'p+#& 1998, 2000, 2001, 2003, 2006 A.*+#$%( P*&+'"*. I()&#&&* Copyright American Petroleum Institute Provided by IHS under license with API Licensee=Chevron Corp/5!"#$$!%% &ot 'or (esale) %$/%#/"%%* %+5,+5" -. &o reproduction or networ0ing permitted without license 'rom IHS --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
#RE$RD I& #) &* #(&*(& '/ API &' **p &#) p!"#$%&#'( p &' -%&* A"" p#p#( ))&*. '(*+) %('p*+%&'+) %+* #(#&*- &' +*p'+& &*#+ *p*+#*($*) #( &* #()p*$&#'( %(- +*p%#+ '/ p#p#( ))&*.) *(**+ )$ *p*+#*($*) .% )*)& % (**- /'+ +*#)#( '+ *p%(-#( &* p+%$&#$*)
)*& /'+& #( API 570 T#) *-#&#'( '/ API 570 )p*+)*-*) %"" p+*#') *-#&#'() '/ API 570, Piping Inspection Code' Inspection, (epair, Alteration, and (erating of In)service Piping Systems. E%$ *-#&#'(, +*#)#'(, '+ %--*(-% &' &#) API )&%(-%+- .% !* )*- !*#((#( #& &* -%&* '/ #))%($* )'( '( &* $'*+ p%* /'+ &%& *-#&#'(, +*#)#'(, '+ %--*(-% E%$ *-#&#'(, +*#)#'(, '+ %--*(-%, &' &#) API )&%(-%+- !*$'.*) *<*$&#* )# .'(&) %/&*+ &* -%&* '/ #))%($* /'+ *#p.*(& &%& #) +*+%&*-, +*$'()&+$&*-, +*"'$%&*-, +*p%#+*-, .'-#:*- >%"&*+*-?, #()p*$&*-, %(- &*)&*- p*+ &#) )&%(-%+- D+#( &* )#;.'(& &#.* !*&**( &* -%&* '/ #))%($* '/ &* *-#&#'(, +*#)#'(, '+ %--*(-% %(- &* *<*$&#* -%&*, &* )*+ )%"" )p*$#/ &' #$ *-#&#'(, +*#)#'(, '+ %--*(-%, &* *#p.*(& #) &' !*, +*+%&*-, +*$'()&+$&*-, +*"'$%&*-, +*p%#+*-, .'-#:*>%"&*+*-?, #()p*$&*- %(- &*)&*- API p!"#$%&#'() .% !* )*- ! %('(* -*)#+#( &' -' )' E*+ *<'+& %) !**( .%-* ! &* I()&#&&* &' %))+* &* %$$+%$ %(- +*"#%!#"#& '/ &* -%&% $'(&%#(*- #( &*. '**+, &* I()&#&&* .%*) (' +*p+*)*(&%&#'(, %++%(&, '+ %+%(&** #( $'((*$&#'( #& &#) p!"#$%&#'( %(- *+*! *p+*))" -#)$"%#.) %( "#%!#"#& '+ +*)p'()#!#"#& /'+ "')) '+ -%.%* +*)"&#( /+'. #&) )* '+ /'+ &* #'"%&#'( '/ %( /*-*+%", )&%&*, '+ .(#$#p%" +*"%&#'( #& #$ &#) p!"#$%&#'( .% $'(H#$& S*)&*- +*#)#'() %+* #(#&*- %(- )'"- !* )!.#&&*- &' "" &* -#+*$&'+ '/ &* S&%(-%+-) D*p%+&.*(&, A.*+#$%( P*&+'"*. I()&#&&*, 1220 S&+**&, N, %)#(&'(, DC 20005, )&%(-%+-%p#'+ ### Copyright American Petroleum Institute Provided by IHS under license with API Licensee=Chevron Corp/5!"#$$!%% &ot 'or (esale) %$/%#/"%%* %+5,+5" -. &o reproduction or networ0ing permitted without license 'rom IHS --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
Copyright American Petroleum Institute Provided by IHS under license with API Licensee=Chevron Corp/5!"#$$!%% &ot 'or (esale) %$/%#/"%%* %+5,+5" -. &o reproduction or networ0ing permitted without license 'rom IHS --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
CN!EN!S P%*
1 SCOPE 1;1
1.1 General Application. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 1.2 Specific Applications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 13 "%
F#&(*));/'+;)*+#$* 1;1 2 REFERENCES 2;1 3 DEFINITIONS 3;1 "& 4 ONERUSER INSPECTION ORGANIATION 4;1
4.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 4.2 API Authorized Piping Inspector Qualification and Certification . . . . . . . . . . . 4-1 4.3 esponsi!ilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1 "&
5 INSPECTION AND TESTING PRACTICES 5;1
5.1 Risk-Based Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1 ".2 Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . "-1
5.3 "% Inspection for Specific Types of Corrosion and Cracking . . . . . . . . . . . . . . . . . 5-1 ".4 #$pes of Inspection and Sur%eillance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . "-&"." #hic'ness (easure)ent *ocations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . "+ "%".& #hic'ness (easure)ent (ethods. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . "-,".+ "% Pressure #esting of Piping S$ste)s. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . "-,
5.8 "" Material Verification and Traceaility. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-! 5.! Inspection o f Val"es. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-! 5.1# "& Inspection of $elds In-ser"ice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1# 5.11 Inspection of %langed &oints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1# ' %R()*(+C, + (/T(+T 0% I+S(CTI0+ . . . . . . . . . . . . . . . . . . . . . . . . . . . '-1 &.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . &-1 "' &.2 Piping Ser%ice Classes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . &-1 &.3 Inspection Inter%als . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . &-2 &.4 tent of /isual ternal and C0I Inspections . . . . . . . . . . . . . . . . . . . . . . . . . &-2 "' &." tent of #hic'ness (easure)ent Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . &-2 &.& tent of S)all-ore Auiliar$ Piping and #hreaded-Connections Inspections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . &-3 7 INSPECTION DATA EKAUATION, ANAYSIS, AND RECORDING 7;1
+.1 "% Corrosion ate eter)ination. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +-1
2. Ma4i6 llo7ale $ orking r ess6re eterination . . . . . . . . . . . . . . . . . . 2-1 +.3 etire)ent #hic'ness eter)i nation "%
7;2 "&
2. ssessent of Inspection %indings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2- +." Piping Stress Anal$sis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +-2
2.' "% Reporting and Records for iping S yste Inspection . . . . . . . . . . . . . . . . . . . . 2- 8 REPAIRS, ATERATIONS, AND RERATING OF PIPING SYSTEMS 8;1
,.1 epairs and Alterations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ,-1 "& ,.2 "& elding and 5ot #apping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ,-2 ,.3 erating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ,3 Copyright American Petroleum Institute Provided by IHS under license with API Licensee=Chevron Corp/5!"#$$!%% &ot 'or (esale) %$/%#/"%%* %+5,+5" -. &o reproduction or networ0ing permitted without license 'rom IHS --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
P%*
9 INSPECTION OF BURIED PIPING 9;1
9.1 Types and Methods of Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-1 6.2 7re8uenc$ and tent of Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2
9.3 Repairs to Buried Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-3 94 R*$'+-) 9; 3 APPENDIL A "& INSPECTOR CERTIFICATION A;1 APPENDIL B "& TECNICA INUIRIES B;1 APPENDIL C ELAMPES OF REPAIRS C;1 APPENDIL D ELTERNA INSPECTION CECIST FOR PROCESS PIPING D;1 F#+*) 5;1 Tp#$%" I(*$&#'( P'#(& P#p#( C#+$#& 5;2 C;1 E($#+$"*.*(& R*p%#+ S"*** C; 1 C;2 S.%"" R*p%#+ P%&$*) C;2 T%!"*) 6;1 R*$'..*(-*- M%#.. I()p*$&#'( I(&*+%") 6;3 "' 6;2 R*$'..*(-*- E&*(& '/ CUI I()p*$&#'( F'""'#( K#)%" I()p*$&#'( 6;3 7;1 T' E%.p"*) '/ &* C%"$"%&#'( '/ M%#.. A""'%!"* '+#( P+*))+* >MAP? I"")&+%&#( &* U)* '/ &* C'++')#'(
"% %"/;#/*
C'($*p& 7; 3 9;1 F+**($ '/ I()p*$&#'( /'+ B+#*- P#p#( #&'& E<*$&#* C%&'-#$ P+'&*$&#'( 9;2
iping Inspection Code9Inspection: Repair: lteration: and Rerating of In-ser%ice Piping S$ste)s
1 Scope 1.1
GENERAL APPLICATION
1.1.1
Coverage
API "+9 co%ers inspection repair alteration and rerating procedures for )etallic piping s$ste)s that ha%e !een in-ser%ice. 1.1.2
Intent
API "+9 :as de%eloped for the petroleu) refining and che)ical process industries !ut )a$ !e used :here practical for an$ piping s$ste). It is intended for use !$ organizations that )aintain or ha%e access to an authorized inspection agenc$ a repair organization and technicall$ 8ualified piping engineers inspectors and ea)iners all as defined in Section 3. 1.1.3
Limitations
API "+9 shall not !e used as a su!stitute for the srcinal construction re8uire)ents go%erning a piping s$ste) !efore it is placed in-ser%ice; nor shall it !e used in conflict :ith an$ pre%ailing regulator$ re8uire)ents. 1.2
SPECIFIC APPLICATIONS
1.2.1
Included Fluid Services
cept as pro%ided in 1.2.2 API "+9 applies to piping s$ste)s for process fluids h$drocar!ons and si)ilar fla))a!le or toic fluid ser%ices such as the follo:ing< a. !. c. d. e.
a: inter)ediate and finished petroleu) products. a: inter)ediate and finished che)ical products. Catal$st lines. 5$drogen natural gas fuel gas and flare s$ste)s. Sour :ater and hazardous :aste strea)s a!o%e threshold li)its as defined !$ =urisdictional regulations.
f. 5azardous che)icals a!o%e th reshold li)its as defi ned !$ =urisdictional regulations.
1.2.2
Excluded and Optional Piping Systems
#he fluid ser%ices and classes of piping s$ste)s listed !elo: are ecluded fro) the specific re8uire)ents of API "+9 !ut )a$ !e included at the o:ner>s or user>s ?o:ner@user>s option. a. 7luid ser%ices that are ecluded or optional include the follo:ing< 1. 5azardous fluid ser%ices !elo: threshold li)its as defined !$ =urisdictional regulations. 2. ater ?including fire protection s$ste)s stea) stea)-condensate !oiler feed :ater and Categor$ fluid ser%ices as defined in AS( 31.3. !. Classes of piping s$ste)s that are ecluded or optional are as follo:s< 1. Piping s$ste)s on )o%a!le structures co%ered !$ =urisdictional regulations including piping s$ste)s on truc's ships !arges and other )o!ile e8uip)ent. 2. Piping s$ste)s that are an integral part or co)ponent of rotating or reciprocating )echanical de%ices such as pu)ps co)pressors tur!ines generators engines and h$draulic or pneu)atic c$linders :here the pri)ar$ design considerations and@or stresses are deri%ed fro) the re8uire)ents de%ice. 3. functional Internal piping or tu!ingof of the fired heaters and !oilers including tu!es tu!e headers return !ends eternal crosso%ers and )anifolds. 4. Pressure %essels heaters furnaces heat echangers and other fluid handling or processing e8uip)ent including internal piping and connections for eternal piping. ". Plu)!ing sanitar$ se:ers process :aste se:ers and stor) se:ers. &. Piping or tu!ing :ith an outside dia)eter not eceeding that of BPS . +. Bon)etallic piping and pol$)eric or glass-lined piping. 1.3
FITNESS-FOR-SERVICE
91 #his inspection code recognizes fitness-for-ser%ice concepts for e%aluating in-ser%ice degradation of pressure containing co)ponents. API P "+6 pro%ides general re8uire)ents and detailed assess)ent procedures for specific t$pes of degradation that are referenced in this code. Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199
Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
2-1 SECIO! 2"#EFE#E!CES
#he )ost recent editions of the follo:ing standards codes and specifications are cited in this code. API "19 Pressure /essel Inspection Code Pu!l 2291 Procedures for elding or 5ot #apping on 8uip)ent Containing 7la))a!les P "+4 Inspection of Piping S$ste) Co)ponents P "+, (aterial /erification Progra) for Be: and isting Piping S$ste)s P "+6 7itness-for-ser%ice P &"1 Cathodic Protection of A!o%eground Petroleu) Storage #an's P +"9 (anage)ent of Process 5azards Std "6, /al%e Inspection and #esting Guide for Inspection of efiner$ 8uip)ent Chapter II ?#his docu)ent :ill !e replaced !$ API P "+1 Conditions Cuasing eterioration or 7ailures currentl$ under de%elop)ent. API "+9 Inspector Certification a) od$ of Eno:ledge AS( 1 1&.34 /al%esF7langed #hreaded and elding nd 31.3 Process Piping 31G (anual for eter)ining the e)aining Strength of Corroded Pipelines oiler and Pressure /essel Code Section /III i%isions 1 and 2; Section I, ASB#2 SB#-#C-1A Personnel Qualification and Certification in Bondestructi%e #esting CP-1,6 Standard for Qualification and Certification of Bondestructi%e #esting Personnel AS#(3 G"+ (ethod for 7ield (easure)ent of Soil esisti%it$ 0sing the enner 7ourelectrode (ethod BAC4 P91&6 Control of ternal Corrosion on 0nderground
or Su!)erged (etallic Piping S$ste)s P91+9 Protection of Austenitic Stainless Steels fro) Pol$thionic Acid Stress Corrosion Crac'ing uring Shutdo:n of efiner$ 8uip)ent P92+4 5igh-%oltage lectrical Inspection of Pipeline Coatings Prior to Installation P92+" Application of Hrganic Coatings to the ternal Surface of Steel Pipe for 0nderground Ser%ice B7PA" +94 Identification of the 7ire 5azards of (aterials 1AS( International #hree Par' A%enue Be: or' Be: or' 1991&-"669 :::.as)e.org. 91 99 91 2#he A)erican Societ$ for Bondestructi%e #esting 1+11 Arlingate *ane P.H. o 2,"1, Colu)!us Hhio 4322,-9"1, :::.asnt.org. 3A)erican Societ$ for #esting and (aterials 199 arr 5ar!or ri%e est Conshohoc'en Penns$l%ania 1642,-26"6 :::.ast).org. 4BAC International 449 South Cree' ri%e 5ouston #eas ++9,4 :::.nace.org. "Bational 7ire Protection Association 1 atter$)arch Par' P.H. o 6191 Quinc$ (assachusetts 922&6-6191 :::.nfpa.org. Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
3-1 SECIO! 3"$EFI!IIO!S
7or the purposes of this standard the follo:ing definitions appl$. 3.1alteration; A ph$sical change in an$ co)ponent that has design i)plications affecting the pressure containing capa!ilit$ or flei!ilit$ of a piping s$ste) !e$ond the scope of its srcinal design. #he follo:ing are not considered alterations< co)para!le or duplicate replace)ents and the addition
of s)all-!ore attach)ents that do not re8uire reinforce)ent or additional support. 3. applicale code; #he code code section or other recognized and generall$ accepted engineering standard or practice to :hich the piping s$ste) :as !uilt or :hich is dee)ed !$ the o:ner or user or the piping engineer to !e )ost appropriate for the situation including !ut not li)ited to the latest edition of AS( 31.3.
3.3 SM( B31.3; A shortened for) of AS( 31.3 Process Piping pu!lished !$ the A)erican Societ$ of (echanical ngineers. AS( 31.3 is :ritten for design and construction of piping s$ste)s. 5o:e%er )ost of the technical re8uire)ents on design :elding ea)ination and )aterials also can !e applied in the inspection rerating repair and alteration of operating piping s$ste)s. hen AS( 31.3 cannot !e follo:ed !ecause of its ne: construction co%erage ?such as re%ised or ne: )aterial specifications inspection re8uire)ents certain heat treat)ents and pressure tests the piping engineer or inspector shall !e guided !$ API "+9 in lieu of strict confor)it$ to AS( 31.3. As an ea)ple of intent the phrase Jprinciples of AS( 31.3K has !een e)plo$ed in API "+9 rather than Jin accordance :ith AS( 31.3.K 3.4 authorized inspection agenc$< efined as an$ of the follo:ing< a. #he inspection organization of the =urisdiction in :hich the piping s$ste) is used. !. #he inspection organization of an insurance co)pan$ that is licensed or registered to :rite insurance for piping s$ste)s. c. An o:ner or user of piping s$ste)s :ho )aintains an inspection organization for acti%ities relating onl$ to his e8uip)ent and not for piping s$ste)s intended for sale or resale. d. An independent inspection organization e)plo$ed !$ or under contract to the o:ner or user of piping s$ste)s that are used onl$ !$ the o:ner or user and not for sale or resale. e. An independent inspection organization licensed or recognized !$ the =urisdiction in :hich the piping s$ste) is used and e)plo$ed !$ or under contract to the o:ner or user. 3." authorized piping inspector< An e)plo$ee of an authorized inspection agenc$ :ho is 8ualified and certified to perfor) the functions specified in API "+9. A nondestructi%e ?B ea)iner is not re8uired to !e an authorized piping inspector. hene%er the ter) inspector is used in API "+9 it refers to an authorized piping inspector. 3.' a64iliary piping; Instru)ent and )achiner$ piping
t$picall$ s)all-!ore secondar$ process piping that can !e isolated fro) pri)ar$ piping s$ste)s. a)ples include flush lines seal oil lines anal$zer lines !alance lines !uffer gas lines drains and %ents. 3.2critical c
3.8C*I; Corrosion under insulation including stress corrosion crac'ing under insulation. 3.!deadlegs; Co)ponents of a piping s$ste) that nor)all$ ha%e no significant flo:. a)ples include the follo:ing< !lan'ed !ranches lines :ith nor)all$ closed !loc' %al%es lines :ith one end !lan'ed pressurized du))$ support legs stagnant control %al%e !$pass piping spare pu)p piping le%el !ridles relief %al%e inlet and outlet header piping pu)p tri) !$pass lines high-point %ents sa)ple points drains !leeders and instru)ent connections. 3.1# defect; An i)perfection of a t$pe or )agnitude eceeding the accepta!le criteria. 3.11 design te)perature of a piping s$ste) co)ponent< #he te)perature at :hich under the coincident pressure the greatest thic'ness or highest co)ponent rating is re8uired. It is the sa)e as the design te)perature defined in AS( 31.3 and other code sections and is su!=ect to the sa)e rules relating to allo:ances for %ariations of pressure or te)perature or !oth. ifferent co)ponents in the sa)e piping s$ste) or circuit )a$ ha%e different design te)peratures. In esta!lishing the design te)perature consideration shall !e gi%en to process fluid te)peratures a)!ient te)peratures heating and cooling )edia te)peratures and insulation. 3.1 e4ainer; A person :ho assists the inspector !$ perfor)ing specific nondestructi%e ea)ination ?B on piping s$ste) co)ponents !ut does not e%aluate the results of those ea)inations in accordance :ith API "+9 unless specificall$ trained and authorized to do so !$ the o:ner or user. #he ea)iner need not of !e the 8ualified :ith "+9 or !e an e)plo$ee o:ner in oraccordance user !ut shall !eAPI trained and 8ualified in the applica!le procedures in :hich the ea)iner is in%ol%ed. In so)e cases the ea)iner )a$ !e re8uired to hold other certifications as necessar$ to satisf$ o:ner or user re8uire)ents. a)ples of other certification that )a$ !e re8uired are SB#-#C-1A or CP-1,6; or AS 1 elding Inspector certification. #he ea)iner>s e)plo$er 9& Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
3-2 API "+9 shall )aintain certification records of the ea)iners e)plo$ed including dates and results of personnel 8ualifications and shall )a'e the) a%aila!le to the inspector.
3.13
3.1' in=ection point; *ocations :here relati%el$ s)all 8uantities of )aterials are in=ected into process strea)s to control che)istr$ or other process %aria!les. In=ection points do not include locations :here t:o process strea)s =oin ?)iing tees. a)ples of in=ection points include chlorine in refor)ers :ater in=ection in o%erhead s$ste)s pol$sulfide in=ection in catal$tic crac'ing :et gas antifoa) in=ections inhi!itors and neutralizers. 3.12 in-ser"ice; efers to piping s$ste)s that ha%e !een placed in operation as opposed to ne: construction prior to !eing placed in ser%ice. piping inspector. 3 ; An 3..1 18 ! i=n 6s rip se dcicto tiron ; Aauthorized legall$ constituted go%ern)ent ad)inistration that )a$ adopt rules relating to piping s$ste)s.
3.# le"el ridle; A le%el gauge glass piping asse)!l$ attached to a %essel. 3.21 )ai)u) allo:a!le :or'ing pressure< >M$?; #he )ai)u) internal pressure per)itted in the piping s$ste) for continued operation at the )ost se%ere condition of coincident internal or eternal pressure and te)perature ?)ini)u) or )ai)u) epected during ser%ice. It is the sa)e as the design pressure as defined in AS( 31.3 and other code sections and is su!=ect to the sa)e rules relating to allo:ances for %ariations of pressure or te)perature or !oth.
3. i4ing t ee; A piping co)ponent that co)!ines t:o process strea)s of differing co)position and@or te)perature. 3.3 MT; (agnetic-particle testing. 3. +(; Bondestructi%e ea)ination. 3.5 +S; Bo)inal pipe size ?follo:ed :hen appropriate !$ the specific size designation nu)!er :ithout an inch s$)!ol. 3.' on-strea; Piping containing an$ a)ount of process fluid. 3.2 o7ner@6ser; An o:ner or user of piping s$ste)s :ho eercises control o%er the operation engineering inspection repair alteration testing and rerating of those piping s$ste)s.
3.2, o:ner@user inspector< An authorized inspector e)plo$ed !$ an o:ner@user :ho has 8ualified either !$ :ritten ea)ination under the pro%isions of Section 4 and Appendi A of API "+9 or has 8ualified under the pro%isions of A.2 and :ho )eets the re8uire)ents of the =urisdiction.
3.! T; A li8uid-penetrant testing. 3.3# pipe; A pressure-tight c$linder used to con%e$ a fluid or to trans)it a fluid pressure and is ordinaril$ designated JpipeK in applica!le )aterial specifications. ?(aterials designated Jtu!eK or Jtu!ingK in the specifications are treated as pipe :hen intended for pressure ser%ice. 3.31 piping circ6it; A section of piping that has all points eposed to an en%iron)ent of si)ilar corrosi%it$ and that is of si)ilar design conditions and construction )aterial. Co)ple process units or piping s$ste)s are di%ided into piping circuits to )anage the necessar$ inspections calculations and record 'eeping. hen esta!lishing the !oundar$ of a particular piping circuit the inspector )a$ also size it to pro%ide a practical pac'age for record 'eeping and perfor)ing field inspection. 3.3 piping engineer; Hne or )ore persons or organizations accepta!le to the o:ner or user :ho:ith are e%aluating 'no:ledgea!le and eperienced in the engineering affecting disciplines associated )echanical and )aterial characteristics the integrit$ and relia!ilit$ of piping co)ponents and s$ste)s. #he piping engineer !$ consulting :ith appropriate specialists should !e regarded as a co)posite of all entities necessar$ to properl$ address a technical re8uire)ent. 3.33 piping syste; An asse)!l$ of interconnected piping that is su!=ect to the sa)e set or sets of design conditions and is used to con%e$ distri!ute )i separate discharge )eter control or snu! fluid flo:s. Piping s$ste) also includes pipe-supporting ele)ents !ut does not include support structures such as structural fra)es and foundations. 3.34 pri)ar$ process piping< Process piping in nor)al acti%e ser%ice that cannot !e %al%ed off or if it :ere %al%ed off :ould significantl$ affect unit opera!ilit$. Pri)ar$ process piping nor)all$ includes all process piping greater than BPS 2.
3.35 $AT; post:eld heat treat)ent. 3.3' rene7al; Acti%it$ that discards an eisting co)ponent and replaces it :ith ne: or eisting spare )aterials of the sa)e or !etter 8ualities as the original co)ponent. 3.32 repair; #he :or' necessar$ to restore a piping s$ste) to a condition suita!le for safe operation at the design conditions. If an$ of the restorati%e changes result in a change of design te)perature or pressure the re8uire)ents for rerating 1A)erican elding Societ$ ""9 B.. *eLeune oad (ia)i 7lorida 3313". Cop$right A)erican Petroleu) Institute
Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
PIPIBG IBSPC#IHB CHFIBSPC#IHB PAI A*#A#IHB AB A#IBG
H7 IB-S/IC PIPIBG SS#(S 3-3 also shall !e satisfied. An$ :elding cutting or grinding operation on a pressurecontaining piping co)ponent not specificall$ considered an alteration is considered a repair. 3.3, repair organization< An$ of the follo:ing< a. An o:ner or user of piping s$ste)s :ho repairs or alters his or her o:n e8uip)ent in accordance :ith API "+9. !. A contractor :hose 8ualifications are accepta!le to the o:ner or user of piping s$ste)s and :ho )a'es repairs or alterations in accordance :ith API "+9. c. Hne :ho is authorized !$ accepta!le to or other:ise not prohi!ited !$ the =urisdiction and :ho )a'es repairs in accordance :ith API "+9. 3.3! rerating; A change in either or !oth the design te)perature or the )ai)u) allo:a!le :or'ing pressure of a piping s$ste). A rerating )a$ consist of an increase a decrease or a co)!ination of !oth. erating !elo: srcinal design conditions is a )eans to pro%ide increased corrosion allo:ance. 3.# secondary pro cess p iping; S)all-!ore ?less than or e8ual to BPS 2 process piping do:nstrea) of nor)all$ closed !loc' %al%es. 3.41 s)all-!ore piping ?SP< Piping that is less than or e8ual to BPS 2.
3. soil-to-air >S@? interface; An area in :hich eternal corrosion )a$ occur on partiall$ !uried pipe. #he zone of the corrosion :ill %ar$ depending on factors such as )oisture o$gen content of the soil and operating te)perature. #he zone generall$ is considered to !e fro) 12 inches ?39" )) !elo: to & inches ?1"9 )) a!o%e the soil surface. Pipe running parallel :ith the soil surface that contacts the soil is included. 3.3 spool; A section of piping enco)passed !$ flanges or other connecting fittings such as unions. 3. teper erittleent; A loss of ductilit$ and notch toughness in suscepti!le lo:-allo$ steels such as 1 1@4 Cr and 21@4 Cr due to prolonged eposure to high-te)perature ser%ice M+99N7 O 19+9N7 ?3+9NC O "+"NC. 3.5 teporary re pairs; epairs )ade to piping s$ste)s in order to restore sufficient integrit$ to continue safe operation until per)anent repairs can !e scheduled and acco)plished :ithin a ti)e period accepta!le to the inspector or piping engineer.
3.' test point; An area defined !$ a circle ha%ing a dia)eter not greater than 2 inches ?"9 )) for a line dia)eter not eceeding 19 inches ?2"9 )) or not greater than 3 inches ?+" )) for larger lines. #hic'ness readings )a$ !e a%eraged :ithin this area. A test point shall !e :ithin a thic'ness )easure)ent location. 3.2 t
TMs?; esignated areas on piping s$ste)s :here periodic inspections and thic'ness )easure)ents are conducted. 3.8 $%MT; et fluorescent )agnetic-particle testing. 3.! alloy aterial; An$ )etallic )aterial ?including :elding filler )aterials that contains allo$ing ele)ents such as chro)iu) nic'el or )ol$!denu) :hich are intentionall$ added to enhance )echanical or ph$sical properties and@or corrosion resistance. 3."9 )aterial %erification progra)< A docu)ented 8ualit$ assurance procedure used to assess )etallic allo$ )aterials ?including :eld)ents and attach)ents :here specified to %erif$ confor)ance :ith the selected or specified allo$ )aterial designated !$ the o:ner@user. #his progra) )a$ include a description of )ethods for allo$ )aterial testing ph$sical co)ponent )ar'ing and progra) record-'eeping. 3."1 positi%e )aterial identification ?P(I testing< An$ ph$sical e%aluation or test of a )aterial to confir) that the )aterial :hich has !een or :ill !e placed into ser%ice is consistent :ith the selected or specified allo$ )aterial designated !$ the o:ner@user. #hese e%aluations or tests )a$ pro%ide 8ualitati%e or 8uantitati%e infor)ation that is sufficient to %erif$ the no)inal allo$ co)position. 3."2 fitness-for-ser%ice assess)ent< A )ethodolog$ :here!$ fla:s and conditions contained :ithin a structure are assessed in order to deter)ine the integrit$ of the structure for continued ser%ice. 3."3 industr$-8ualified 0# shear :a%e ea)iner< A person :ho possesses an ultrasonic shear :a%e 8ualification fro) API or an e8ui%alent 8ualification appro%ed !$ the o:ner@user. 3.5 off-site piping; Piping s$ste)s not included :ithin the plot ?!atter$ li)its of a process unit such as a h$drocrac'er an eth$lene crac'er or a crude unit. a)ples of offsite piping include tan' far) paiping and other lo:er conse8uence piping outside the li)its of the process unit. 3.55 on-site piping; Piping s$ste)s included :ithin the plot li)its of process units such as a h$drocrac'er an eth$lene crac'er or a crude unit. 3."& corrosion specialist< A person accepta!le to the o:ner@user :ho is 'no:lega!le and eperienced in the specific process che)istries corrosion degradation )echanis)s
)aterial selection and other corrosion )itigation )ethods corrosion )onitoring techni8ues and their i)pact on process e8uip)ent. 3."+ pressure design thic'ness< (ini)u) thic'ness :ithout corrosion allo:ance !ased on design code calculations for pressure. 99 91 93 9& 9& Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
3-4 API "+9
3.58 re6ired t
4-1 SECIO! %"O&!E#'(SE# I!SPECIO! O#)*!I+*IO!
4.1
GBA*
An o:ner@user of piping s$ste)s shall eercise control of the piping s$ste) inspection progra) inspection fre8uencies and )aintenance and is responsi!le for the function of an authorized inspection agenc$ in accordance :ith the pro%isions of API "+9. #he o:ner@user inspection organization also shall control acti%ities relating to the rerating repair and alteration of its piping s$ste)s. 4.2
A0#5HI PIPIBG IBSPC#H
QUALIFICATION AND CERTIFICATION Authorized piping inspectors shall ha%e education and eperience in accordance :ith Appendi A of this inspection code. Authorized piping inspectors shall !e certified in accordance :ith the pro%isions of Appendi A. hene%er the ter) inspector is used in this code it refers to an authorized piping inspector.
4.3
SPHBSII*I#IS
4!" O#ner$User An o:ner@user organization is responsi!le for de%eloping docu)enting i)ple)enting eecuting and assessing piping inspection s$ste)s and inspection procedures that :ill )eet the re8uire)ents of this inspection code. #hese s$ste)s and procedures :ill !e contained in a 8ualit$ assurance inspection )anual or :ritten procedures and shall include< a. Hrganization and reporting structure for inspection personnel. !. ocu)enting and )aintaining inspection and 8ualit$ assurance procedures. c. d. e. f.
ocu)enting and reporting inspection and test results. Correcti%e action for inspection and test results. Internal auditing for co)pliance :ith the 8ualit$ assurance inspection )anual. e%ie: and appro%al of dra:ings design calculations and specifications for repairs alterations and reratings.
g. nsuring thatare allcontinuousl$ =urisdictional)et. re8uire)ents for piping inspection repairs alterations and rerating h. eporting to the authorized piping inspector an$ process changes that could affect piping integrit$. i.
#raining re8uire)ents for inspection personnel regarding inspection tools techni8ues and technical 'no:ledge !ase.
=.
Controls necessar$ so that onl$ 8ualified :elders and procedures are used for all repairs and alterations. '. Controls necessar$ so that onl$ 8ualified nondestructi%e ea)ination ?B personnel and procedures are utilized. l.
Controls necessar$ so that onl$ )aterials confor)ing to the applica!le section of the AS( Code are utilized for repairs and alterations.
). Controls necessar$ so that all ins pection )easure)ent and test e8ui p)ent are properl$ )aintained and cali!rated. n. Controls necessar$ so that the :or' of contract inspection or repair organizations )eet the sa)e inspection re8uire)ents as the o:ner@user organization. o. Internal auditing re8uire)ents for the 8ualit$ cont rol s$ste) for pressure-relie%ing de%ices.
4!% Piping Engineer #he piping engineer is responsi!le to the o:ner@user for acti%ities in%ol%ing design engineering re%ie: anal$sis or e%aluation of piping s$ste)s co%ered !$ API "+9.
4!! Repair Organi&ation #he repair organization shall !e responsi!le to the o:ner@user and shall pro%ide the )aterials e8uip)ent 8ualit$ control and :or')anship necessar$ to )aintain and repair the piping s$ste)s in accordance :ith the re8uire)ents of API "+9. 4!4 Authori&ed Piping Inspector hen inspections repairs or alterations are !eing conducted on piping s$ste)s an authorized piping inspector shall !e responsi!le to the o:ner@user for deter)ining that the re8uire)ents of API "+9 on inspection ea)ination and testing are )et and shall !e directl$ in%ol%ed in the inspection acti%ities. #he authorized piping inspector )a$ !e assisted in perfor)ing %isual inspections !$ other properl$ trained and 8ualified indi%iduals :ho )a$ or )a$ not !e certified piping inspectors. Personnel perfor)ing nondestructi%e ea)inations shall )eet the 8ualifications identified in 3.12 !ut need not !e authorized piping inspectors. 5o:e%er all ea)ination results )ust !e e%aluated and accepted !$ the authorized piping inspector. 4!' OtherPersonne( Hperating )aintenance or other personnel :ho ha%e special 'no:ledge or epertise related to particular piping s$ste)s shall !e responsi!le for pro)ptl$ )a'ing the inspector or piping engineer a:are of an$ unusual conditions that )a$ de%elop and for pro%iding other assistance :here appropriate. 9& 9& 9& 9& 9& 9& Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
"-1 SECIO! ,"I!SPECIO! *!$ ESI!) P#*CICES
".1
ISE-AS IBSPC#IHB
Identif$ing and e%aluating potential degradation )echanis)s are i)portant steps in an assess)ent of the li'elihood of a piping failure. 5o:e%er ad=ust)ents to inspection strateg$ and tactics to account for conse8uences of a failure should also !e considered. Co)!ining the assess)ent of li'elihood of failure and the conse8uence of failure are essential ele)ents of ris'-!ased inspection ?I. hen the o:ner@user chooses to conduct a I assess)ent it )ust include a s$ste)atic e%aluation of !oth the li'elihood of failure and the associated conse8uence of failure in accordance :ith API P ",9. #he li'elihood assess)ent )ust !e !ased on all for)s of degradation that could reasona!l$ !e epected to affect piping circuits in an$ particular ser%ice. a)ples of those degradation )echanis)s include< internal or eternal )etal loss fro) an identified for) of corrosion ?localized or general all for)s of crac'ing including h$drogen assisted and stress corrosion crac'ing ?fro) the inside or outside surfaces of piping and an$ other for)s of )etallurgical corrosion or )echanical degradation such as fatigue e)!rittle)ent creep etc. Additionall$ the effecti%eness of the inspection practices tools and techni8ues utilized for finding the epected and potential degradation )echanis)s )ust !e e%aluated. #his li'elihood of failure assess)ent should !e repeated each ti)e e8uip)ent or process changes are )ade that could significantl$ affect degradation rates or cause pre)ature failure of the piping. Hther factors that should !e considered in a I assess)ent conducted in accordance :ith API P ",9 include< appropriateness of the )aterials of construction; piping circuit design conditions relati%e to operating conditions; appropriateness of the design codes and standards utilized; effecti%eness of corrosion )onitoring progra)s; and the 8ualit$ of )aintenance and inspection Qualit$ Assurance@Qualit$ Control progra)s. 8uip)ent failure data and infor)ation :ill also !e i)portant infor)ation for this assess)ent. #he conse8uence assess)ent )ust consider the potential incidents that )a$ occur as a result of fluid release including eplosion fire toic eposure en%iron)ental i)pact and other health effects associated :ith a failure of piping. It is essential that all I assess)ents !e thoroughl$ docu)ented in accordance :ith API P ",9 clearl$ defining all the factors contri!uting to !oth the li'elihood and conse8uence of a piping failure. ".2
PPAA#IHB
ecause of the products carried in piping s$ste)s safet$ precautions are i)portant :hen the s$ste) is inspected particularl$ if it is opened for ea)ining internal surfaces.
Procedures for segregating piping s$ste)s installing !lan's ?!linds and testing tightness should !e an integral part of safet$ practices. Appropriate safet$ precautions shall !e ta'en !efore an$ piping s$ste) is opened and !efore so)e t$pes of eternal inspection are perfor)ed. In general the section of piping to !e opened should !e isolated fro) all sources of har)ful li8uids gases or %apors and purged to re)o%e all oil and toic or fla))a!le gases and %apors. efore starting inspection inspection personnel should o!tain per)ission to :or' in the %icinit$ fro) operating personnel responsi!le for the piping s$ste). Protecti%e e8uip)ent shall !e :orn :hen re8uired !$ regulations or !$ the o:ner@user. Bondestructi%e testing e8uip)ent used for inspection is su!=ect to the operating facilit$>s safet$ re8uire)ents for electrical e8uip)ent. In general inspectors should fa)iliarize the)sel%es :ith prior inspection results and repairs in the piping s$ste)s for :hich the$ are responsi!le. In particular the$ should !riefl$ re%ie: the histor$ of indi%idual piping s$ste)s !efore )a'ing an$ of the inspections re8uired !$ API "+9. ?See Section , of API P "+4 for supple)entar$ reco))ended practices. A general o%er%ie: of the t$pes of deterioration and failure )odes eperienced !$ pressure containing e8uip)ent is pro%ided in API P "+6 Appendi G. ".3
IBSPC#IHB 7H SPCI7IC #PS H7
CORRO)ION AND CRAC*IN+ Bote< 7or )ore thorough and co)plete infor)ation see API I Chapter II. ach o:ner@user should pro%ide specific attention to the need for inspection of piping s$ste)s that are suscepti!le to the follo:ing specific t$pes and areas of deterioration< a. In=ection points. !. eadlegs. c. Corrosion under insulation ?C0I. d. Soil-to-air ?S@A interfaces. e. Ser%ice specific and localized corrosion. f. rosion and co rrosion@erosion. g. n%iron)ental crac'ing. h. Corrosion !eneath linings and deposits. i. 7atigue crac'ing. =. Creep crac'ing. '. rittle fracture. l. 7reeze da)age. Hther areas of concern are noted in I Chapter II and Section & of API P "+4.
51#1!
In2ectionPoints
In=ection points are so)eti)es su!=ect to accelerated or localized corrosion fro) nor)al or a!nor)al operating conditions. #hose that are )a$ !e treated as separate inspection circuits and these areas need to !e inspected thoroughl$ on a regular schedule. 93 93 93 91 99 Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
"-2 API "+9 hen designating an in=ection point circuit for the purposes of inspection the reco))ended upstrea) li)it of the in=ection point circuit is a )ini)u) of 12 inches ?399 )) or three pipe #he dia)eters upstrea)do:nstrea) of the in=ection is greater. reco))ended li)itpoint of the:hiche%er in=ection point circuit is the second change in flo: direction past the in=ection point or 2" feet ?+.& ) !e$ond the first change in flo: direction :hiche%er is less. In so)e cases it )a$ !e )ore appropriate to etend this circuit to the net piece of pressure e8uip)ent as sho:n in 7igure "-1. #he selection of thic'ness )easure)ent locations ?#(*s :ithin in=ection point circuits su!=ect to localized corrosion should !e in accordance :ith the follo:ing guidelines< a. sta!lish #(*s on appropriate fittings :ithin the in=ection point circuit. !. sta!lish #(*s on the pipe :all at the location of epected pipe :all i)pinge)ent of in=ected fluid. c. #(*s at inter)ediate locations along the longer straight piping :ithin the in=ection point circuit )a$ !e re8uired. d. sta!lish #(*s at !oth the upstrea) and do:nstrea) li)its of the in=ection point circuit. #he preferred )ethods of inspecting in=ection points are radiograph$ and@or ultrasonics as appropriate to esta!lish the )ini)u) thic'ness at each #(*. Close grid ultrasonic )easure)ents or scanning )a$ !e used as long as te)peratures are appropriate. 7or so)e applications it is !eneficial to re)o%e piping spools to facilitate a %isual inspection of the inside surface. 5o:e%er thic'ness )easure)ents :ill still !e re8uired to deter)ine the re)aining thic'ness.
uring periodic scheduled inspections )ore etensi%e inspection should !e applied to an area !eginning 12 inches ?399 )) upstrea) of the in=ection nozzle and continuing for at least ten pipe dia)eters do:nstrea) of the in=ection point. Additionall$ )easure and record the thic'ness at all #(*s :ithin the in=ection point circuit. 51#1"
.eadlegs #he corrosion rate in deadlegs can %ar$ significantl$ fro) ad=acent acti%e piping. #he inspector should )onitor :all thic'ness on selected deadlegs including !oth the stagnant 7igure 1F#$pical In=ection Point Piping Circuit
Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
PIPIBG IBSPC#IHB CHFIBSPC#IHB PAI A*#A#IHB AB A#IBG
H7 IB-S/IC PIPIBG SS#(S "-3 end and at the connection to an acti%e line. In hot piping s$ste)s the high-point area )a$ corrode due to con%ecti%e currents set up in the deadleg. Consideration should !e gi%en to re)o%ing deadlegs that ser%e no further process purpose. 51#1#
Corrosion 3nder Insulation
ternal inspection of insulated piping s$ste)s should include a re%ie: of the integrit$ of the insulation s$ste) for conditions that could lead to corrosion under insulation ?C0I
and for signs of ongoing C0I. Sources of )oisture )a$ include rain :ater lea's condensation and deluge s$ste)s. #he )ost co))on for)s of C0I are localized corrosion of car!on steel and chloride stress corrosion crac'ing of austenitic stainless steels. #his section pro%ides guidelines for identif$ing potential C0I areas for inspection. #he etent of a C0I inspection progra) )a$ %ar$ depending on the local cli)ateF:ar)er )arine locations )a$ re8uire a %er$ acti%e progra); :hereas cooler drier )id-continent locations )a$ not need as etensi%e a progra). 51#1#1!
Insulated Piping Systems Susceptible to
CUI Certain areas and t$pes of piping s$ste)s are potentiall$ )ore suscepti!le to C0I including the follo:ing< a. Areas eposed to )ist o%erspra$ fro) cooling :ater to:ers. !. Areas eposed to stea) %ents. c. Areas eposed to deluge s$ste)s. d. Areas su!=ect to process spills ingress of )oisture or acid %apors. e. Car!on steel piping s$ste)s including those insulated for personnel protection operating !et:een 2"N7 O 2"9N7 ?O4NC 129NC. C0I is particularl$ aggressi%e :here operating te)peratures cause fre8uent or continuous condensation and •
re-e%aporation of at)ospheric )oisture. f. Car!on steel piping s$ste)s that nor)all$ operate in-ser%ice a!o%e 2"9N7 ?129NC !ut are in inter)ittent ser%ice. g. eadlegs and attach)ents that protrude fro) insulated piping and operate at a different te)perature than the operating te)perature of the acti%e line. h. Austenitic stainless steel piping s$ste)s operating !et:een 1"9N7 O 499N7 ?&"NC O 294NC. ?#hese s$ste)s are suscepti!le to chloride stress corrosion crac'ing. i. /i!rating piping s$ste)s that ha%e a tendenc$ to inflict da)age to insulation =ac'eting pro%iding a path for :ater ingress. =. Stea) traced piping s$ste)s that )a$ eperience tracing lea's especiall$ at tu!ing fittings !eneath the insulation. '. Piping s$ste)s :ith deteriorated coatings and@or :rappings. 51#1#1"
Common Locations on Piping Systems
Susceptible to C3I
#he areas of piping s$ste)s listed in ".3.3.1 )a$ ha%e specific locations :ithin the) that are )ore suscepti!le to C0I including the follo:ing< a. All penetrations or !reaches in the insulation =ac'eting s$ste)s such as< 1. eadlegs ?%ents drains and other si)ilar ite)s. 2. Pipe hangers and other supports. 3. andpipe fittings ?irregular insulation surfaces. 4. /al%es olted-on shoes. ". Stea) tracer tu!ing penetrations. !. #er)ination of insulation at flanges and other piping co)ponents. c. a)aged or )issing insulation =ac'eting. d. Insulation =ac'eting sea)s located on the top of horizontal piping or i)properl$ lapped or sealed insulation =ac'eting. e. #er)ination of insulation in a %e rtical pipe. f. Caul'ing that has hardened has separated or is )issing. g. ulges or staining of the insulation or =ac'eting s$ste) or )issing !ands. ?ulges )a$ indicate corrosion product !uildup. h. *o: points in s$ste) piping s$ste)s that ha%e a 'no:n !reach in the insulation including lo: points in long unsupported piping runs. i.
Car!on or lo:-allo$ steel flanges !olting and other co)ponents under insulation in high-allo$ piping s$ste)s. *ocations :here insulation plugs ha%e !een re)o%ed to per)it piping thic'ness )easure)ents on insulated piping should recei%e particular attention. #hese plugs should !e pro)ptl$ replaced and sealed. Se%eral t$pes of re)o%a!le plugs are co))erciall$ a%aila!le that per)it inspection and identification of inspection points for future reference.
51#14
SoiltoAir Inter'ace
Soil-to-air ?S@A interfaces for !uried piping :ithout ade8uate cathodic protection shall !e included in scheduled eternal piping inspections. Inspection at grade should chec' for coating da)age !are pipe and pit depth )easure)ents. If significant corrosion is noted thic'ness )easure)ents and eca%ation )a$ !e re8uired to assess :hether the corrosion is localized to the S@A interface or )a$ !e )ore per%asi%e to the !uried s$ste). #hic'ness readings at S@A interfaces )a$ epose the )etal and accelerate corrosion if coatings and :rappings are not properl$ restored. If the !uried piping has satisfactor$ cathodic protection as deter)ined !$ )onitoring in accordance :ith Section 6 eca%ation is re8uired onl$ if there is e%idence of coating or :rapping da)age. If the !uried piping is uncoated at grade consideration should !e gi%en
to eca%ating & inches to 12 inches ?1"9 )) to 399 )) deep to assess the potential for hidden da)age. At concrete-to-air and asphalt-to-air interfaces of !uried piping :ithout cathodic protection the inspector should loo' Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S "-4 API "+9 --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
for e%idence that the caul'ing or seal at the interface has deteriorated and allo:ed )oisture ingress. If such a condition eists on piping s$ste)s o%er 19 $ears old it )a$ !e necessar$ to inspect for corrosion !eneath the surface !efore resealing the =oint. 51#15
ServiceSpeci'ic and Locali6ed Corrosion
An effecti%e inspection progra) includes the follo:ing three ele)ents :hich help identif$ the potential for ser%ice specific and localized corrosion and select appropriate #(*s< a. An inspector :ith 'no:ledge of the ser%ice and :here corrosion is li'el$ to occur. !. tensi%e use of nondestructi%e ea)ination ?B. c. Co))unication fro) operating personnel :hen process upsets occur that )a$ affect corrosion rates. A fe: ea)ples of :here this t$pe of corrosion )ight !e epected to occur include the follo:ing< a. o:nstrea) of in=ection points and upstrea) of product separators such as in h$droprocess reactor effluent lines. !. e:-point corrosion in condensing strea)s such as o%erhead fractionation. c. 0nanticipated acid or caustic carr$o%er fro) processes into nonallo$ed piping s$ste)s or caustic carr$o%er into steel piping s$ste)s that are not post:eld heat treated. d. A))oniu) salt condensation locations in h$droprocess strea)s. e. (ied-phase flo: and tur!ulent areas in acidic s$ste)s. f. (ied grades of car!on steel piping in hot corrosi%e oil ser%ice M4"9N7 ?239NC or higher te)perature and sulfur content in the oil greater than 9." percent !$ :eight. Bote that nonsilicon 'illed steel pipe such as A-"3 and API "* )a$ corrode at higher rates than does silicon 'illed steel pipe such as A-19& especiall$ in high-te)perature sulfidic en%iron)ents. g. 0nderdeposit corrosion in slurries cr$stallizing solutions or co'e producing fluids. h. Chloride carr$o%er in catal$tic refor)er regeneration s$ste)s.
i.
5ot-spot corrosion on piping :ith eternal heat tracing. In ser%ices that !eco)e )uch )ore corrosi%e to the piping :ith increased te)perature such as caustic in car!on steel corrosion or stress corrosion crac'ing ?SCC can occur at hot spots that de%elop under lo:-flo: conditions.
51#1*
7rosion and Corrosion/7rosion
rosion can !e defined as the re)o%al of surface )aterial !$ the action of nu)erous indi%idual i)pacts of solid or li8uid particles. It can !e characterized !$ groo%es rounded holes :a%es and %alle$s in a directional pattern. rosion usuall$ occurs in areas of tur!ulent flo: such as at changes of direction in a piping s$ste) or do:nstrea) of control %al%es :here %aporization )a$ ta'e place. rosion da)age is usuall$ increased in strea)s :ith large 8uantities of solid or li8uid particles flo:ing at high %elocities. A co)!ination of corrosion and erosion ?corrosion@erosion results in significantl$ greater )etal loss than can !e epected fro) corrosion or erosion alone. #his t$pe of corrosion occurs at high-%elocit$ and high-tur!ulence areas. a)ples of places to inspect include the follo:ing< a. o:nstrea) of control %al%es especiall$ :hen flashing is occurring. !. o:nstrea) of orifices. c. o:nstrea) of pu)p discharges. d. At an$ point of flo: direction change such as the inside and outside radii of el!o:s. e. o:nstrea) of piping configurations ?such as :elds ther)o:ells and flanges that produce tur!ulence particularl$ in %elocit$ sensiti%e s$ste)s such as a))oniu) h$drosulfide and sulfuric acid s$ste)s. Areas suspected of ha%ing localized corrosion@erosion should !e inspected using appropriate B )ethods that :ill $ield thic'ness data o%er a :ide area such as ultrasonic scanning radiographic profile or edd$ current. 51#1,
7nvironmentalC rac0ing
Piping s$ste) construction )aterials are nor)all$ selected to resist the %arious for)s of stress corrosion crac'ing ?SCC. 5o:e%er so)e piping s$ste)s )a$ !e suscepti!le to en%iron)ental crac'ing due to upset process conditions C0I unanticipated condensation or eposure to :et h$drogen sulfide or car!onates. a)ples of en%iron)ental crac'ing include< a. Chloride SCC of austenitic stainless steels due to )oisture and chlorides under insulation under deposits under gas'ets or in cre%ices. !. Pol$thionic acid SCC of sensitized austenitic allo$ steels due to eposure to sulfide )oisture condensation or o$gen.
c. Caustic SCC ?so)eti)es 'no:n as caustic e)!rittle)ent. d. A)ine SCC in piping s$ste)s that are not stress relie%ed. e. Car!onate SCC. f. SCC in en%iron)ents :here :et h$drogen sulfide eists such as s$ste)s containing sour :ater. g. 5$drogen !listeringsuspects and h$drogen inducedthat crac'ing ?5IC da)age. hen the inspector or is ad%ised specific circuits )a$ !e suscepti!le to en%iron)ental crac'ing the inspector should schedule supple)ental inspections. Such inspections can ta'e the for) of surface B Mli8uid-penetrant testing ?P# or :et fluorescent )agnetic-particle testing ?7(# or ultrasonics ?0#. here a%aila!le suspect spools )a$ !e re)o%ed fro) the piping s$ste) and split open for internal surface ea)ination. If en%iron)ental crac'ing is detected during internal inspection of pressure %essels and the piping is considered e8uall$ suscepti!le the inspector should designate appropriate Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
PIPIBG IBSPC#IHB CHFIBSPC#IHB PAI A*#A#IHB AB A#IBG
H7 IB-S/IC PIPIBG SS#(S "-" piping spools upstrea) and do:nstrea) of the pressure %essel for en%iron)ental crac'ing inspection. hen the potential for en%iron)ental crac'ing is suspected in piping circuits inspection of selected spools should !e scheduled prior to an upco)ing turnaround. Such inspection should pro%ide infor)ation useful in forecasting turnaround )aintenance. 51#1$
Corrosion 8eneath Linings and .eposits
If eternal or internal coatings refractor$ linings and corrosionresistant linings are in good condition and there is no reason to suspect a deteriorated condition !ehind the) it is usuall$ not necessar$ to re)o%e the) for inspection of the piping s$ste). #he effecti%eness of corrosion-resistant linings is greatl$ reduced due to !rea's or holes in the lining. #he linings should !e inspected for separation !rea's holes and !listers. If an$ of these conditions are noted it )a$ !e necessar$ to re)o%e portions of the internal lining to in%estigate the effecti%eness of the lining and the condition of the )etal piping !eneath the lining. Alternati%el$ ultrasonic inspection fro)
the eternal surface can !e used to )easure :all thic'ness and detect separation holes and !listers. efractor$ linings )a$ spill or crac' in-ser%ice :ith or :ithout causing an$ significant pro!le)s. Corrosion !eneath refractor$ linings can result in separation and !ulging of the refractor$. If !ulging or separation of the refractor$ lining is detected portions of the refractor$ )a$ !e re)o%ed to per)it inspection of the piping !eneath the refractor$. Hther:ise ultrasonic thic'ness )easure)ents )a$ !e )ade fro) the eternal )etal surface. here operating deposits such as co'e are present on a pipe surface it is particularl$ i)portant to deter)ine :hether such deposits ha%e acti%e corrosion !eneath the). #his )a$ re8uire a thorough inspection in selected areas. *arger lines should ha%e the deposits re)o%ed in selected critical areas for spot ea)ination. S)aller lines )a$ re8uire that selected spools !e re)o%ed or that B )ethods such as radiograph$ !e perfor)ed in selected areas. 51#1
9atigueCrac0ing
7atigue crac'ing of piping s$ste)s )a$ result fro) ecessi%e c$clic stresses that are often :ell !elo: the static $ield strength of the )aterial. #he c$clic stresses )a$ !e i)posed !$ pressure )echanical or ther)al )eans and )a$ result in lo:-c$cle or high-c$cle fatigue. #he onset of lo:-c$cle fatigue crac'ing is often directl$ related to the nu)!er of heat-up and cool-do:n c$cles eperienced. cessi%e piping s$ste) %i!ration ?such as )achine or flo:-induced %i!rations also can cause high-c$cle fatigue da)age. ?See ".4.4 for %i!rating piping sur%eillance re8uire)ents and +." for design re8uire)ents associated :ith %i!rating piping. 7atigue crac'ing can t$picall$ !e first detected at points of high-stress intensification such as !ranch connections. *ocations :here )etals ha%ing different coefficients of ther)al epansion are =oined !$ :elding )a$ !e suscepti!le to ther)al fatigue. ?See &.&.3 for fatigue considerations relati%e to threaded connections. Preferred B )ethods of detecting fatigue crac'ing include li8uid-penetrant testing ?P# or )agnetic-particle testing ?(#. Acoustic e)ission also )a$ !e used to detect the presence of crac's that are acti%ated !$ test pressures or stresses generated during the test. It is i)portant that the o:ner@user and the inspector understand that fatigue crac'ing is li'el$ to cause piping failure !efore it is detected :ith an$ B )ethods. Hf the total nu)!er of fatigue c$cles re8uired to produce a failure the %ast )a=orit$ are re8uired to initiate a crac' and relati%el$ fe:er c$cles are re8uired to propagate the crac' to failure. #herefore proper design and installation in order to pre%ent
the initiation of fatigue crac'ing are i)portant. 51#1!%
Creep Crac0ing
Creep is dependent on ti)e te)perature and stress. Creep crac'ing )a$ e%entuall$ occur at design conditions since so)e piping code allo:a!le stresses are in the creep range. Crac'ing is accelerated !$ creep and fatigue interaction :hen operating conditions in the creep range are c$clic. #he inspector should pa$ particular attention to areas of high stress concentration. If ecessi%e te)peratures are encountered )echanical propert$ and )icrostructural changes in )etals also )a$ ta'e place :hich )a$ per)anentl$ :ea'en e8uip)ent. Since creep is dependent on ti)e te)perature and stress the actual or esti)ated le%els of these para)eters shall !e used in an$ e%aluations. An ea)ple of :here creep crac'ing has !een eperienced in the industr$ is in 11@4 Cr steels a!o%e 699N7 ?4,9NC. B )ethods of detecting creep crac'ing include li8uid penetrant testing )agnetic-particle testing ultrasonic testing radiographic testing and in-situ )etallograph$. Acoustic e)ission testing also )a$ !e used to detect the presence of crac's that are acti%ated !$ test pressures or stresses generated during the test. 51#1!!
8rittle 9racture
Car!on lo:-allo$ and other ferritic steels )a$ !e suscepti!le to !rittle failure at or !elo: a)!ient te)peratures. rittle fracture usuall$ is not a concern :ith relati%el$ thin-:all piping. (ost !rittle fractures ha%e occurred on the first application of a particular stress le%el ?that is the first h$drotest or o%erload unless critical defects are introduced during ser%ice. #he potential for a !rittle failure shall !e considered :hen reh$drotesting or )ore carefull$ e%aluated :hen testing e8uip)ent pneu)aticall$ or :hen adding an$ other additional loads. Special attention should !e gi%en to lo:-allo$ steels ?especiall$ 2 R Cr-1 (o )aterial !ecause the$ )a$ !e prone to te)per e)!rittle)ent and to ferritic stainless steels. API P "+6 Section 3 pro%ides procedures for the assess)ent of e8uip)ent for resistance to !rittle fracture. #3 Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
"-& API "+9 51#1!"
9ree6e .amage
At su!freezing te)peratures :ater and a8ueous solutions in piping s$ste)s )a$ freeze and cause failure !ecause of the epansion of these )aterials. After unepectedl$ se%ere freezing :eather it is i)portant to chec' for freeze da)age to eposed piping co)ponents !efore the s$ste) tha:s. If rupture has occurred lea'age )a$ !e te)poraril$ pre%ented !$ the frozen fluid. *o: points driplegs and deadlegs of piping s$ste)s containing :ater should !e carefull$ ea)ined for da)age. ".4 #PS H7 IBSPC#IHB AB S0/I**ABC ifferent t$pes of inspection and sur%eillance are appropriate depending on the circu)stances and the piping s$ste) ?see note. #hese include the follo:ing< a. Internal %isual inspection. !. #hic'ness )easure)ent inspection. c. ternal %isual inspection. d. /i!rating piping inspection. e. Supple)ental inspection. Bote< See Section & for fre8uenc$ and etent of inspection.
'4" Interna( isua( Inspection Internal %isual inspections are not nor)all$ perfor)ed on piping. hen possi!le and practical internal %isual inspections )a$ !e scheduled for s$ste)s such as large-dia)eter transfer lines ducts catal$st lines or other large-dia)eter piping s$ste)s. Such inspections are si)ilar in nature to pressure %essel inspections and should !e conducted :ith )ethods and procedures si)ilar to those outlined in API "19. e)ote %isual inspection techni8ues can !e helpful :hen inspecting piping too s)all to enter. An additional opportunit$ for internal inspection is pro%ided :hen piping flanges are disconnected allo:ing %isual inspection of internal surfaces :ith or :ithout the use of B. e)o%ing a section of piping and splitting it along its centerline also per)its access to internal surfaces :here there is need for such inspection. '4% Thic-ness .easure/ent Inspection A thic'ness )easure)ent inspection is perfor)ed to deter)ine the internal condition and re)aining thic'ness of the piping co)ponents. #hic'ness )easure)ents )a$ !e o!tained :hen the piping s$ste) is in or out of operation and shall !e perfor)ed !$ the inspector or ea)iner. '4! E0terna( isua( Inspection An eternal %isual inspection is perfor)ed to deter)ine the condition of the outside of the piping insulation s$ste) painting and coating s$ste)s and associated hard:are; and to chec' for signs of )isalign)ent %i!ration and lea'age. hen corrosion product !uildup is noted at pipe support contact
areas lifting off such supports )a$ !e re8uired for inspection. hen doing this care should !e eercised if the piping is in-ser%ice. ternal piping inspections )a$ !e )ade :hen the piping s$ste) is in-ser%ice. efer to API P "+4 for infor)ation helpful in conducting eternal inspections. A chec'list to assist in conducting eternal piping inspections is pro%ided in Appendi . ternal inspections shall include sur%e$s for the condition of piping hangers and supports. Instances of crac'ed or !ro'en hangers J!otto)ing outK of spring supports support shoes displaced fro) support )e)!ers or other i)proper restraint conditions shall !e reported and corrected. /ertical support du))$ legs also shall !e chec'ed to confir) that the$ ha%e not filled :ith :ater that is causing eternal corrosion of the pressure piping or internal corrosion of the support leg. 5orizontal support du))$ legs also shall !e chec'ed to deter)ine that slight displace)ents fro) horizontal are not causing )oisture traps against the eternal surface of acti%e piping co)ponents. ello:s epansion =oints should !e inspected %isuall$ for unusual defor)ations )isalign)ent or displace)ents that )a$ eceed design. #he inspector should ea)ine the piping s$ste) for the presence of an$ field )odifications or te)porar$ repairs not pre%iousl$ recorded on the piping dra:ings and@or records. #he inspector also should !e alert to the presence of an$ co)ponents in the ser%ice that )a$ !e unsuita!le for longter) operation such as i)proper flanges te)porar$ repairs ?cla)ps )odifications ?flei!le hoses or %al%es of i)proper specification. #hreaded co)ponents that )a$ !e )ore easil$ re)o%ed and installed deser%e particular attention !ecause of their higher potential for installation of i)proper co)ponents. #he periodic eternal inspection called for in &.4 should nor)all$ !e conducted !$ the inspector :ho also shall !e responsi!le for record 'eeping and repair inspection. Qualified operating or )aintenance personnel also )a$ conduct eternal inspections :hen accepta!le to the inspector. In such cases the persons conducting eternal piping inspections in accordance :ith API "+9 shall !e 8ualified through an appropriate a)ount of training. In addition to these scheduled eternal inspections that are docu)ented in inspection records it is !eneficial for personnel :ho fre8uent the area to report deterioration or changes to the inspector. ?See Appendi and Section &.3 of API P "+4 for ea)ples of such deterioration.
'44
i1rating Piping and Line .o2e/ent
Surveillance
Hperating personnel should report %i!rating or s:a$ing piping to engineering or inspection personnel for assess)ent. Hther significant line )o%e)ents should !e reported that )a$ ha%e resulted fro) li8uid ha))er li8uid slugging in %apor Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
PIPIBG IBSPC#IHB CHFIBSPC#IHB PAI A*#A#IHB AB A#IBG
H7 IB-S/IC PIPIBG SS#(S "-+ lines or a!nor)al ther)al epansion. At =unctions :here %i!rating piping s$ste)s are restrained periodic )agneticparticle testing or li8uid-penetrant testing should !e considered to chec' for the onset of fatigue crac'ing. ranch connections should recei%e special attention.
'4' )upp(e/enta(I nspection Hther inspections )a$ !e scheduled as appropriate or necessar$. a)ples of such inspections include periodic use of radiograph$ and@or ther)ograph$ to chec' for fouling or internal plugging ther)ograph$ to chec' for hot spots in refractor$ lined s$ste)s or inspection for en%iron)ental crac'ing. Acoustic e)ission acoustic lea' detection and ther)ograph$ can !e used for re)ote lea' detection and sur%eillance. 0ltrasonics and@or radiograph$ can !e used for detecting localized corrosion. "."
#5ICEBSS (AS0(B# *HCA#IHBS
''" +enera( #hic'ness )easure)ent locations ?#(*s are specific areas along the piping circuit :here inspections are to !e )ade. #he nature of the #(* %aries according to its location in the piping s$ste). #he selection of #(*s shall consider the potential for localized corrosion and ser%ice-specific corrosion as descri!ed in ".3. ''% T.L.onitoring ach piping s$ste) shall !e )onitored !$ ta'ing thic'ness )easure)ents at #(*s. Piping circuits :ith high potential conse8uences if failure should occur and those su!=ect to higher corrosion rates or localized corrosion :ill nor)all$ ha%e )ore #(*s and !e )onitored )ore fre8uentl$ ?see &.3.
#(*s should !e distri!uted appropriatel$ throughout each piping circuit. #(*s )a$ !e eli)inated or the nu)!er reduced under certain circu)stances such as olefin plant cold side piping anh$drous a))onia piping clean noncorrosi%e h$drocar!on product or highallo$ piping for product purit$. In circu)stances :here #(*s :ill !e su!stantiall$ reduced or eli)inated persons 'no:ledgea!le in corrosion should !e consulted. #he )ini)u) thic'ness at each #(* can !e located !$ ultrasonic scanning or radiograph$. lectro)agnetic techni8ues also can !e used to identif$ thin areas that )a$ then !e )easured !$ ultrasonics or radiograph$. hen acco)plished :ith ultrasonics scanning consists of ta'ing se%eral thic'ness )easure)ents at the #(* searching for localized thinning. #he thinnest reading or an a%erage of se%eral )easure)ent readings ta'en :ithin the area of a test point shall !e recorded and used to calculate corrosion rates re)aining life and the net inspection date in accordance :ith Section +. here appropriate thic'ness )easure)ents should include )easure)ents at each of the four 8uadrants on pipe and fittings :ith special attention to the inside and outside radius of el!o:s and tees :here corrosion@erosion could increase corrosion rates. As a )ini)u) the thinnest reading and its location shall !e recorded. #(*s should !e esta!lished for areas :ith continuing C0I corrosion at S@A interfaces or other locations of potential localized corrosion as :ell as for general unifor) corrosion. #(*s should !e )ar'ed on inspection dra:ings and on the piping s$ste) to allo: repetiti%e )easure)ents at the sa)e #(*s. #his recording procedure pro%ides data for )ore accurate corrosion rate deter)ination.
''! T.L)e(ection In selecting or ad=usting the nu)!er and locations of #(*s the inspector should ta'e into account the patterns of corrosion that :ould !e epected and ha%e !een eperienced in the process unit. A nu)!er of corrosion processes co))on to refining and petroche)ical units are relati%el$ unifor) in nature resulting in a fairl$ constant rate of pipe :all reduction independent of location :ithin the piping circuit either aiall$ or circu)ferentiall$. a)ples of such corrosion pheno)ena include high-te)perature sulfur corrosion and sour :ater corrosion ?pro%ided %elocities are not so ecessi%e as to cause local corrosion@erosion of el!o:s tees and other si)ilar ite)s. In these situations the nu)!er of #(*s re8uired to )onitor a circuit :ill !e fe:er than those re8uired to )onitor
circuits su!=ect to )ore localized )etal loss. In theor$ a circuit su!=ect to perfectl$ unifor) corrosion could !e ade8uatel$ )onitored :ith a single #(*. In realit$ corrosion is ne%er trul$ unifor) so additional #(*s )a$ !e re8uired. Inspectors )ust use their 'no:ledge ?and that of others of the process unit to opti)ize the #(* selection for each circuit !alancing the effort of collecting the data :ith the !enefits pro%ided !$ the data. (ore #(*s should !e selected for piping s$ste)s :ith an$ of the follo:ing characteristics< a. 5igher potential for creating a safet$ or en%iron)ental e)ergenc$ in the e%ent of a lea'. !. 5igher epected or eperienced corrosion rates. c. 5igher potential for localized corrosion. d. (ore co)pleit$ in ter)s of fittings !ranches deadlegs in=ection points and other si)ilar ite)s. e. 5igher potential for C0I. 7e:er #(*s can !e selected for piping s$ste)s :ith an$ of the follo:ing three characteristics< a. *o: lea'. potential for creating a safet$ or en%iron)ental e)ergenc$ in the e%ent of a !. elati%el$ noncorrosi%e piping s$ste)s. c. *ong straight-run piping s$ste)s. Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
"-, API "+9 #(*s can !e eli)inated for piping s$ste)s :ith either of the follo:ing t:o characteristics< a. tre)el$ lo: potential for creating a safet$ or en%iron)ental e)ergenc$ in the e%ent of a lea'. !. Boncorrosi%e s$ste)s as de)onstrated !$ histor$ or si)ilar ser%ice and s$ste)s not su!=ect to changes that could cause corrosion. ".&
#5ICEBSS (AS0(B# (#5HS
0ltrasonic thic'ness )easuring instru)ents usuall$ are the )ost accurate )eans for o!taining thic'ness )easure)ents on installed pipe larger than BPS 1. adiographic profile techni8ues are preferred for pipe dia)eters of BPS 1 and s)aller. adiographic profile techni8ues )a$ !e used for locating areas to !e )easured particularl$ in insulated s$ste)s or :here nonunifor) or localized corrosion is suspected. here practical ultrasonics can then !e used to o!tain the actual thic'ness of the areas to !e recorded. 7ollo:ing
ultrasonic readings at #(*s proper repair of insulation and insulation :eather coating is reco))ended to reduce the potential for C0I. adiographic profile techni8ues :hich do not re8uire re)o%ing insulation )a$ !e considered as an alternati%e. hen corrosion in a piping s$ste) is nonunifor) or the re)aining thic'ness is approaching the )ini)u) re8uired thic'ness additional thic'ness )easuring )a$ !e re8uired. adiograph$ or ultrasonic scanning are the preferred )ethods in such cases. dd$ current de%ices also )a$ !e used. hen ultrasonic )easure)ents are ta'en a!o%e 1"9N7 ?&"NC instru)ents couplants and procedures should !e used that :ill result in accurate )easure)ents at the higher te)peratures. (easure)ents should !e ad=usted !$ the appropriate te)perature correction factor. Inspectors should !e a:are of possi!le sources of )easure)ent inaccuracies and )a'e e%er$ effort to eli)inate their occurrence. As a general rule each of the B techni8ues :ill ha%e practical li)its :ith respect to accurac$. 7actors that can contri!ute to reduced accurac$ of ultrasonic )easure)ents include the follo:ing< a. !. c. d. e. f.
I)proper instru)ent cali!ration. ternal coatings or scale. cessi%e surface roughness. cessi%e Jroc'ingK of the pro!e ?on the cur%ed surface. Su!surface )aterial fla:s such as la )inations. #e)perature effects Mat te)peratures a!o%e 1"9N7 ?&"NC.
g. S)all fla: detector screens. h. #hic'nesses of less than 1@, inch ?3.2 )) for t$pical digital thic'ness gauges. In addition it )ust !e 'ept in )ind that the pattern of corrosion can !e nonunifor). 7or corrosion rate deter)inations to !e %alid it is i)portant that )easure)ents on the thinnest point !e repeated as closel$ as possi!le to the sa)e location. Alternati%el$ the )ini)u) reading or an a%erage of se%eral readings at a test point )a$ !e considered. hen piping s$ste)s are out of ser%ice thic'ness )easure)ents )a$ !e ta'en through openings using calipers. Calipers are useful in deter)ining approi)ate thic'nesses of castings forgings and %al%e !odies as :ell as pit depth approi)ations fro) C0I on pipe. Pit depth )easuring de%ices also )a$ !e used to deter)ine the depth of localized )etal loss. ".+
PSS0 #S#IBG H7 PIPIBG SS#(S
Pressure tests are not nor)all$ conducted as part of a routine inspection. ?See ,.2.& for pressure testing re8uire)ents for repairs alterations and rerating. ceptions to this include re8uire)ents of the 0nited States Coast Guard for o%er:ater piping and re8uire)ents of local =urisdictions after :elded alterations or :hen specified !$ the inspector or piping engineer. hen the$ are conducted pressure tests shall !e perfor)ed in accordance :ith the re8uire)ents of AS( 31.3. Additional considerations are pro%ided in API P "+4 and API P "+6. *o:er pressure tests :hich are used onl$ for tightness of piping s$ste)s )a$ !e conducted at pressures designated !$ the o:ner@user. #he test fluid should !e :ater unless there is the possi!ilit$ of da)age due to freezing or other ad%erse effects of :ater on the piping s$ste) or the process or unless the test :ater :ill !eco)e conta)inated and its disposal :ill present en%iron)ental pro!le)s. In either case another suita!le nontoic li8uid )a$ !e used. If the li8uid is fla))a!le its flash point shall !e at least 129N7 ?46NC or greater and consideration shall !e gi%en to the effect of the test en%iron)ent on the test fluid. Piping fa!ricated of or ha%ing co)ponents of 399 series stainless steel should !e h$drotested :ith a solution )ade up of pota!le :ater ?see note or stea) condensate. After testing is co)pleted the piping should !e thoroughl$ drained ?all high-point %ents should !e open during draining air !lo:n or other:ise dried. If pota!le :ater is not a%aila!le or if i))ediate draining and dr$ing is not possi!le :ater ha%ing a %er$ lo: chloride le%el higher p5 ?19 and inhi!itor addition )a$ !e considered to reduce the ris' of pitting and )icro!iologicall$ induced corrosion. Bote< Pota!le :ater in this contet follo:s 0.S. practice :ith 2"9 parts per )illion )ai)u) chloride sanitized :ith chlorine or ozone. 7or sensitized austenitic stainless steel piping su!=ect to pol$thionic stress corrosion crac'ing consideration should !e gi%en to using an al'aline-:ater solution for pressure testing ?see BAC P91+9. If a pressure test is to !e )aintained for a period of ti)e and the test fluid in the s$ste) is su!=ect to ther)al epansion precautions shall !e ta'en to a%oid ecessi%e pressure. hen a pressure test is re8uired it shall !e conducted after an$ heat treat)ent. 91 Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199
Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
PIPIBG IBSPC#IHB CHFIBSPC#IHB PAI A*#A#IHB AB A#IBG
H7 IB-S/IC PIPIBG SS#(S "-6 efore appl$ing a h$drostatic test to piping s$ste)s consideration should !e gi%en to the supporting structure design. A pneu)atic pressure test )a$ !e used :hen it is i)practica!le to h$drostaticall$ test due to te)perature structural or process li)itations. 5o:e%er the potential ris's to personnel and propert$ of pneu)atic testing shall !e considered :hen carr$ing out such a test. As a )ini)u) the inspection precautions contained in AS( 31.3 shall !e applied in an$ pneu)atic testing. uring a pressure test :here the test pressure :ill eceed the set pressure of the safet$ %al%e on a piping s$ste) the safet$ relief %al%e or %al%es should !e re)o%ed or !lan'ed for the duration of the test. As an alternati%e each %al%e dis' )ust !e held do:n !$ a suita!l$ designed test cla)p. #he application an additional load to the %al%e spring !$ turning the ad=ustingofscre: is not reco))ended. Hther appurtenances that are incapa!le of :ithstanding the test pressure such as gage glasses pressure gages epansion =oints and rupture dis's should !e re)o%ed or !lan'ed. *ines containing epansion =oints that cannot !e re)o%ed or isolated )a$ !e tested at a reduced pressure in accordance :ith the principles of AS( 31.3. If !loc' %al%es are used to isolate a piping s$ste) for a pressure test caution should !e used to not eceed the per)issi!le seat pressure as descri!ed in AS( 1&.34 or applica!le %al%e )anufacturer data. 0pon co)pletion of the pressure test pressure relief de%ices of the proper settings and other appurtenances re)o%ed inopera!le during the pressure test shall !e reinstalledoror)ade reacti%ated. ".,
(A#IA* /I7ICA#IHB AB
TRACEA3ILIT uring repairs or alterations allo$ )aterial piping s$ste)s 5 #5 A**H (A#IA* IS Q0I #H (AIB#AIB PSS0 CHB#AIB(B# the inspector shall %erif$ that the installation of ne: )aterials is consistent :ith the selected or specified construction )aterials. #his )aterial %erification progra) should !e consistent :ith API P "+,. 0sing ris' assess)ent procedures the o:ner@user can )a'e this assess)ent !$ 199-percent %erification P(I
testing in certain critical situations or !$ sa)pling a percentage of the )aterials. P(I testing can !e acco)plished !$ the inspector or the ea)iner :ith the use of suita!le )ethods as descri!ed in API P "+,. If a piping s$ste) co)ponent should fail !ecause an incorrect )aterial :as inad%ertentl$ su!stituted for the proper piping )aterial the inspector shall consider the need for further %erification of eisting piping )aterials. #he etent of further %erification :ill depend upon circu)stances such as the conse8uences of failure and the li'elihood of further )aterial errors. #he o:ner@user shall assess the need and etent regarding application of the practices consistent :ith API P "+, addressing inad%ertent )aterial su!stitution in eisting allo$ piping s$ste)s. A )aterial %erification progra) consistent :ith API P "+, )a$ include procedures for prioritization and ris' ran'ing piping circuits. #hat assess)ent )a$ lead to retroacti%e P(I testing as descri!ed in API P "+, to confir) that the installed )aterials are consistent :ith the intended ser%ice. Co)ponents identified during this %erification that do not )eet acceptance criteria of the P(I testing progra) ?such as in API P "+, Section & :ould !e targeted for replace)ent. #he o:ner@user and authorized piping inspector in consultation :ith a corrosion specialist shall esta!lish a schedule for replace)ent of those co)ponents. #he authorized inspector shall use periodic B as necessar$ on the identified co)ponents until the replace)ent. ".6
IBSPC#IHB H7 /A*/S
Bor)all$ thic'ness )easure)ents are not routinel$ ta'en on %al%es in piping circuits. #he !od$ of a %al%e is nor)all$ thic'er than other piping co)ponents for design reasons. 5o:e%er :hen %al%es are dis)antled for ser%icing and repair the shop should !e attenti%e to an$ unusual corrosion patterns or thinning and :hen noted report that infor)ation to the inspector. odies of %al%es that are eposed to steep te)perature c$cling ?for ea)ple catal$tic refor)ing unit regeneration and stea) cleaning should !e ea)ined periodicall$ for ther)al fatigue crac'ing. If gate %al%es are 'no:n to !e or are suspected of !eing eposed to corrosion@erosion thic'ness readings should !e ta'en !et:een the seats since this is an area of high tur!ulence and high stress. Control %al%es or other throttling %al%es particularl$ in high-pressure drop-and-slurr$ ser%ices can !e suscepti!le to localized corrosion@erosion of the !od$ do:nstrea) of the orifice. If such )etal loss is suspected the %al%e should !e
re)o%ed fro) the line for internal inspection. #he inside of the do:nstrea) )ating flange and piping also should !e inspected for local )etal loss. hen %al%e !od$ and@or closure pressure tests are perfor)ed after ser%icing the$ should !e conducted in accordance :ith API Std "6,. Critical chec' %al%es should !e %isuall$ and internall$ inspected to ensure that the$ :ill stop flo: re%ersals. An ea)ple of a critical chec' %al%e )a$ !e the chec' %al%e located on the outlet of a )ultistage high head h$droprocessing charge pu)p. 7ailure of such a chec' %al%e to operate correctl$ could result in o%erpressuring the piping during a flo: re%ersal. #he nor)al %isual inspection )ethod should include< a. Chec'ing to insure that the flapper is free to )o%e as re8uired :ithout ecessi%e looseness fro) :ear. !. #he flapper stop should not ha%e ecessi%e :ear. #his :ill )ini)ize the li'elihood that the flapper :ill )o%e past the top dead central position and re)ain in an open position :hen the chec' %al%e is )ounted in a %ertical position. 99 99 99 Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
"-19 API "+9 c. #he flapper nut should !e secured to the flapper !olt to a%oid !ac'ing off in ser%ice. *ea' chec's of critical chec' %al%es are nor)all$ not re8uired. ".19
IBSPC#IHB H7 *S IB-S/IC
Inspection for piping :eld 8ualit$ is nor)all$ acco)plished as a part of the re8uire)ents for ne: construction repairs or alterations. 5o:e%er :elds are often inspected for corrosion as part of a radiographic profile inspection or as part of internal inspection. hen preferential :eld corrosion is noted additional :elds in the sa)e circuit or s$ste) should !e ea)ined for corrosion. Hn occasion radiographic profile ea)inations )a$ re%eal :hat appears to !e i)perfections in the :eld. If crac' li'e i)perfections are detected :hile the piping s$ste) is in operation further inspection :ith :eld 8ualit$ radiograph$ and@or ultrasonics )a$ !e used to assess the )agnitude of the i)perfection.
Additionall$ an effort should !e )ade to deter)ine :hether the crac'-li'e i)perfections are fro) srcinal :eld fa!rication or )a$ !e fro) an en%iron)ental crac'ing )echanis). n%iron)ental crac'ing shall !e assessed !$ the piping engineer. If the noted i)perfections are a result of srcinal :eld fa!rication inspection and@or engineering anal$sis is re8uired to assess the i)pact of the :eld 8ualit$ on piping integrit$. #his anal$sis )a$ !e one or )ore of the follo:ing< a. Inspector =udg)ent. !. Certified :elding inspector =udg)ent. c. Piping engineer =udg)ent. d. ngineering fitness-for-ser%ice anal$sis. Issues to consider :hen assessing the 8ualit$ of eisting :elds include the follo:ing< a. Hriginal fa!rication inspection acceptance criteria. !. tent )agnitude and orientation of i)perfections. c. *ength of ti)e in-ser%ice. d. Hperating %ersus design conditions. e. Presence of secondar$ piping stresses ?residual and ther)al. f. Potential for fatigue loads ? )echanical and th er)al. g. Pri)ar$ or secondar$ piping s$ste). h. Potential for i)pact or transient loads. i. Potential for en%iron)ental crac'ing. =. eld hardness. In )an$ cases for in-ser%ice :eld)ents it )a$ not !e appropriate to use the srcinal construction code radiograph$ acceptance criteria for :eld 8ualit$ in AS( 31.3. #hese acceptance criteria are intended to appl$ to ne: construction on a sa)pling of :elds not =ust the :elds ea)ined in order to assess the pro!a!le 8ualit$ of all :elds ?or :elders in the s$ste). So)e :elds )a$ eist that :ill not )eet these criteria !ut :ill still perfor) satisfactoril$ in-ser%ice after !eing h$drotested. #his is especiall$ true on s)all !ranch connections that are nor)all$ not ea)ined during ne: construction. #he o:ner@user shall specif$ industr$-8ualified 0# shear :a%e ea)iners :hen the o:ner@user re8uires the follo:ing< a detection of interior surface ?I !rea'ing planar fla:s :hen inspecting fro) the eternal surface ?H; or ! :here detection characterization and@or through-:all sizing is re8uired of planar defects. Application ea)ples for the use of such industr$-8ualified 0# shear :a%e ea)iners include fitness-for-ser%ice and )onitoring of 'no:n fla:s. #he re8uire)ent for use of industr$-8ualified 0# shear :a%e ea)iners !eco)es effecti%e t:o $ears after pu!lication in this code or addendu).
".11
IBSPC#IHB H7 7*ABG LHIB#S
#he )ar'ings on a representati%e sa)ple of ne:l$ installed fasteners and gas'ets should !e ea)ined to deter)ine :hether the$ )eet the )aterial specification. #he )ar'ings are identified in the applica!le AS( and AS#( standards. Questiona!le fasteners should !e %erified or rene:ed. 7asteners should etend co)pletel$ through their nuts. An$ fastener failing to do so is considered accepta!l$ engaged if the lac' of co)plete engage)ent is not )ore than one thread. If installed flanges are ecessi%el$ !ent their )ar'ings and thic'nesses should !e chec'ed against engineering re8uire)ents !efore ta'ing correcti%e action. 7lange and %al%e !onnet fasteners should !e ea)ined %isuall$ for corrosion. 7langed and %al%e !onnet =oints should !e ea)ined for e%idence of lea'age such as stains deposits or drips. Process lea's onto flange and !onnet fasteners )a$ result in corrosion or en%iron)ental crac'ing. #his ea)ination should include those flanges enclosed :ith flange or splash-and-spra$ guards. 7langed =oints that ha%e !een cla)ped and pu)ped :ith sealant should !e chec'ed for lea'age at the !olts. 7asteners su!=ected to such lea'age )a$ corrode or crac' ?caustic crac'ing for ea)ple. If repu)ping is conte)plated affected fasteners should !e rene:ed first. 7asteners on instru)entation that are su!=ect to process pressure and@or te)perature should !e included in the scope of these ea)inations. See API P "+4 for reco))ended practices :hen flanged =oints are opened. 91 9& Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
&-1 SECIO! -"F#E(E!C/ *!$ E0E! OF I!SPECIO!
&.1
GBA*
#he fre8uenc$ and etent of inspection on piping circuits depend on the for)s of degradation that can affect the piping and conse8uence of a piping failure. #he %arious for)s of
degradation that can affect refiner$ piping circuits are descri!ed in ".3 :hile a si)plified classification of piping !ased on the conse8uence of failure is defined in &.2. As descri!ed in ".1 inspection strateg$ !ased on li'elihood and conse8uence of failure is referred to as ris'-!ased inspection. #he si)plified piping classification sche)e in Section &.2 is !ased on the conse8uence of a failure. #he classification is used to esta!lish fre8uenc$ and etent of inspection. #he o:ner@user )a$ de%ise a )ore etensi%e classification sche)e that )ore accuratel$ assesses conse8uence for certain piping circuits. #he conse8uence assess)ent :ould consider the potential for eplosion fire toicit$ en%iron)ental i)pact and other potential effects associated :ith a failure. After an effecti%e assess)ent is conducted the results can !e used to esta!lish a piping circuit inspection strateg$ and )ore specificall$ !etter define the follo:ing< a. #he )ost appropriate inspection )ethods scope tools and techni8ues to !e utilized !ased on the epected for)s of degradation; !. #he appropriate inspection fre8uenc$; c. #he need for pressure testing after da)age has !een incurred or after repairs or )odifications ha%e !een co)pleted; and d. #he pre%ention and )itigation steps to reduce the li'elihood and conse8uence of a piping failure. A I assess)ent )a$ !e used to increase or decrease the inspection li)its descri!ed in #a!le &-1. Si)ilarl$ the etent of inspection )a$ !e increased or decreased !e$ond the targets in #a!le &-2 !$ a I assess)ent. hen used to increase inspection inter%al li)its or the etent of inspection I assess)ents shall !e conducted at inter%als not to eceed the respecti%e li)its in #a!le &-1 or )ore often if :arranted !$ process e8uip)ent or conse8uence changes. #hese I assess)ents shall !e re%ie:ed and appro%ed !$ a piping engineer and authorizedli)its pipingininspector ator inter%als not to the respecti%e #a!le &-1 )ore often if eceed :arranted !$ process e8uip)ent or conse8uence changes. &.2
PIPIBG S/IC C*ASSS
All process piping s$ste)s shall !e categorized into different classes. Such a classification s$ste) allo:s etra inspection efforts to !e focused on piping s$ste)s that )a$ ha%e the highest potential conse8uences if failure or loss of contain)ent should occur. In general the higher classified s$ste)s re8uire )ore etensi%e inspection at shorter inter%als in order to affir) their integrit$ for continued safe operation.
Classifications should !e !ased on potential safet$ and en%iron)ental effects should a lea' occur. H:ner@users shall )aintain a record of process piping fluids handled including their classifications. API P +"9 and B7PA +94 pro%ide infor)ation that )a$ !e helpful in classif$ing piping s$ste)s according to the potential hazards of the process fluids the$ contain. #he three classes listed !elo: in &.2.1 through &.2.3 are reco))ended.
5%" C(ass" Ser%ices :ith the highest potential of resulting in an i))ediate e)ergenc$ if a lea' :ere to occur are in Class 1. Such an e)ergenc$ )a$ !e safet$ or en%iron)ental in nature. a)ples of Class 1 piping include !ut are not necessaril$ li)ited to those containing the follo:ing< a. 7la))a!le ser%ices that )a$ auto-refrigerate and lead to !rittle fracture. !. Pressurized ser%ices that )a$ rapidl$ %aporize during release creating %apors that )a$ collect and for) an eplosi%e )iture such as C2 C3 and C4 strea)s. 7luids that :ill rapidl$ %aporize are those :ith at)ospheric !oiling te)perature !elo: "9N7 ?19NC. c. 5$drogen sulfide ?greater than 3 percent :eight in a gaseous strea). d. Anh$drous h$drogen chloride. e. 5$drofluoric acid. f. Piping o%er or ad=acent to :ater and piping o%er pu!lic through:a$s. ?efer to epart)ent of #ransportation and 0.S. Coast Guard regulations for inspection of o%er:ater piping.
5%% C(ass% Ser%ices not included in other classes are in Class 2. #his classification includes the )a=orit$ of unit process piping and selected off-site piping. #$pical ea)ples of these ser%ices include those containing the follo:ing< a. Hn-site h$drocar!ons that :ill slo:l$ %aporize during release such as those operating !elo: the fash point. !. 5$drogen fuel gas and natural gas. c. Hn-site strong acids and caustics.
5%! C(ass! Ser%ices that are fla))a!le !ut do not significantl$ %aporize :hen the$ lea' and are not located in high-acti%it$ areas are in Class 3. Ser%ices that are potentiall$ har)ful to 93
93 Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
&-2 API "+9 hu)an tissue !ut are located in re)ote areas )a$ !e included in this class. a)ples of Class 3 ser%ice are as follo:s< a. Hn-site h$drocar!ons that :ill not significantl$ %aporize during release such as those operating !elo: the flash point. !. istillate and product lines to and fro) storage and loading. c. Hff-site acids and c austics. &.3
IBSPC#IHB IB#/A*S
#he inter%al !et:een piping inspections shall !e esta!lished and )aintained using the follo:ing criteria< a. Corrosion rate and re)aining life cal culations. !. Piping ser%ice classification. c. Applica!le =urisdictional re8uire)ents. d. Ludg)ent of the inspector the piping engineer the piping engineer super%isor or a corrosion specialist !ased on operating conditions pre%ious inspection histor$ current inspection results and conditions that )a$ :arrant supple)ental inspections co%ered in ".4.". #he o:ner@user or the inspector shall esta!lish inspection inter%als for thic'ness )easure)ents and eternal %isual inspections and :here applica!le for internal and supple)ental inspections. #hic'ness )easure)ents should !e scheduled !ased on the calculation of not )ore than half the re)aining life deter)ined fro) corrosion rates indicated in +.1.1 or at the )ai)u) inter%als suggested in #a!le &-1 :hiche%er is shorter. Shorter inter%als )a$ !e appropriate under certain circu)stances. Prior to using #a!le &-1 corrosion rates should !e calculated in accordance :ith +.1.3. #a!le &-1 contains reco))ended )ai)u) inspection inter%als for the three categories of piping ser%ices descri!ed in &.2 as :ell as reco))ended inter%als for in=ection points and S@A interfaces. #he inspection inter%al )ust !e re%ie:ed and ad=usted as necessar$ after each inspection or significant change in operating conditions. General corrosion localized corrosion pitting en%iron)ental crac'ing and other for)s of deterioration )ust !e considered :hen esta!lishing the %arious inspection inter%als.
&.4
#B# H7 /IS0A* #BA* AB C0I
IN)PECTION) ternal %isual inspections including inspections for corrosion under insulation ?C0I should !e conducted at )ai)u) inter%als listed in #a!le &-1 to e%aluate ite)s such as those in Appendi . Alternati%el$ eternal %isual inspection inter%als can !e esta!lished !$ using a %alid I assess)ent conducted in accordance :ith API P ",9. #he eternal %isual inspection on a !are pipe is to assess the condition of paint and coating s$ste)s to chec' for eternal corrosions and to chec' for other for)s of deterioration. #his eternal %isual inspection for potential C0I is also to assess insulation condition and shall !e conducted on all piping s$ste)s suscepti!le to C0I listed in ".3.3.1. #he results of the %isual inspection should !e docu)ented to facilitate follo:-up inspections. 7ollo:ing the eternal %isual inspection of suscepti!le s$ste)s additional ea)ination is re8uired for the inspection of C0I. #he etent and t$pe of the additional C0I inspection are listed in #a!le &-2. a)aged insulation at higher ele%ations )a$ result in C0I in lo:er areas re)ote fro) the da)age. B inspection for C0I should also !e conducted as listed in #a!le &-2 at suspect locations of ".3.3.2 ?ecluding c )eeting the te)perature criteria for ".3.3.1 ?e f h. adiographic ea)ination or insulation re)o%al and %isual inspection is nor)all$ re8uired for this inspection at da)aged or suspect locations. Hther B assess)ent )ethods )a$ !e used :here applica!le. If the inspection of the da)aged or suspect areas has located significant C0I additional areas should !e inspected and :here :arranted up to 199 percent of the circuit should !e inspected. #he etent of the C0I progra) descri!ed in #a!le &-2 should !e considered as target le%els for piping s$ste)s and locations :ith no C0I inspection eperience. It is recognized that se%eral factors )a$ affect the li'elihood of C0I to include< a. *ocal cli)atic conditions ?see ".3.3. !. Insulation design. c. Coating 8ualit$. d. Ser%ice conditions. 7acilities :ith C0I inspection eperience )a$ increase or reduce the C0I inspection targets of #a!le &-2. An eact accounting of the C0I inspection targets is not re8uired. #he o:ner@user )a$ confir) inspection targets :ith operational histor$ or other docu)entation. Piping s$ste)s that are 'no:n to ha%e a re)aining life of o%er 19 $ears or that are ade8uatel$ protected against eternal corrosion need not !e included for the B
inspection reco))ended in #a!le &-2. 5o:e%er the condition of the insulating s$ste) or the outer =ac'eting such as a cold-!o shell should !e o!ser%ed periodicall$ !$ operating or other personnel. If deterioration is noted it should !e reported to the inspector. #he follo:ing are ea)ples of these s$ste)s< a. Piping s$ste)s insulated effecti%el$ to preclude the entrance of )oisture. !. Lac'eted cr$ogenic piping s$ste)s. c. Piping s$ste)s installed in a cold !o in :hich the at)osphere is purged :ith an inert gas. d. Piping s$ste)s in :hich the te)perature !eing )aintained is sufficientl$ lo: or sufficientl$ high to preclude the presence of :ater. 93 93 93 Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
P
IPIBG I BSPC#IHB C H I • BSPC#IHB PAI A *#A#IHB ,
AB
R A#IBG H7 I B S /IC P IPIBG •
S S#(S &-3 &."
#B# H7 #5ICEBSS (AS0(B#
IN)PECTION #o satisf$ inspection inter%al re8uire)ents each readings thic'nesson )easure)ent inspection should o!tain thic'ness a representati%e sa)pling of #(*s on each circuit ?see ".". #his representati%e sa)pling should include data for all the %arious t$pes of co)ponents and orientations ?horizontal and %ertical found in each circuit. #his sa)pling also )ust include #(*s :ith the earliest rene:al date as of the pre%ious inspection. #he )ore #(*s )easured for each circuit the )ore accuratel$ the net inspection date :ill !e pro=ected. #herefore scheduled inspection of circuits should o!tain as )an$ )easure)ents as necessar$. #he etent of inspection for in=ection points is co%ered in ".3.1. &.&
#B# H7 S(A**-H A0I*IA
PIPIN+, AND T6READED7CONNECTION) IN)PECTION) *1*1!
Small8ore Piping Inspection
S)all-!ore piping ?SP that is pri)ar$ process piping should !e inspected in accordance :ith all the re8uire)ents of this docu)ent. SP that is secondar$ process piping has different )ini)u) re8uire)ents depending upon ser%ice classification. Class 1 secondar$ SP shall !e inspected to the sa)e re8uire)ents as pri)ar$ process piping. Inspection of Class 2 and Class 3 secondar$ SP is optional. SP deadlegs ?such as le%el !ridles in Class 2 and Class 3 s$ste)s should !e inspected :here corrosion has !een eperienced or is anticipated. *1*1"
Au:iliary Piping Inspection
Inspection of secondar$ auiliar$ SP associated :ith instru)ents and )achiner$ is optional. Criteria to consider in deter)ining :hether auiliar$ SP :ill need so)e for) of inspection include the follo:ing< a. Classification. !. Potential for en%iron)ental or fatigue crac'ing. c. Potential for corrosion !ased on eperience :ith ad=acent pri)ar$ s$ste)s.
d. Potential for C0I. *1*1#
hreadedConnections Inspection
Inspection of threaded connections :ill !e according to the re8uire)ents listed a!o%e for s)all-!ore and auiliar$ piping. hen selecting #(*s on threaded connections include onl$ those that can !e radiographed during scheduled inspections. #hreaded connections associated :ith )achiner$ and su!=ect to fatigue da)age should !e periodicall$ assessed and considered for possi!le rene:al :ith a thic'er :all or upgrading to :elded co)ponents. #he schedule for such rene:al :ill depend on se%eral issues including the follo:ing< a. Classification of piping. !. (agnitude and fre8uenc$ of %i!ration. c. A)ount of u nsupported :eight. d. Current piping :all thic'ness. e. hether or not the s$ste) can !e )aintained on-strea). f. Corrosion rate. g. Inter)ittent ser%ice. Bote< #hic'ness )easure)ents appl$ to s$ste)s for :hich #(*s ha%e !een esta!lished in accordance :ith ".". a See ".3.1. Inspection inter%als for potentiall$ corrosi%e in=ection@ )i points can also !e esta!lished !$ a %alid ris'-!ased inspection anal$sis in accordance :ith API P ",9. ! See ".3.4. #a!le &-1Feco))ended (ai)u) Inspection Inter%als #$pe of Circuit #hic'ness (easure)ents /isual ternal Class 1 " $ears " $ears Class 2 19 $ears " $ears Class 3 19 $ears 19 $ears In=ection points a 3 $ears $ Class Soil-to-air interfaces ! $ Class • #a!le &-2Feco))ended tent of C0I Inspection 7ollo:ing /isual Inspection Approi)ate A)ount of 7ollo:up
a)ination :ith B or Insulation e)o%al at Areas :ith a)aged Insulation Approi)ate A)ount of C0I Inspection !$ B at Suspect Areas ?".3.3.2 on Piping S$ste)s :ithin Suscepti!le #e)perature anges ?".3.3.2efh Pipe Class 1 +"T "9T 2 "9T 33T 3 2"T 19T 93 Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S
--‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
+-1 SECIO! "I!SPECIO! $** E*L(*IO! *!*L/SIS *!$ #ECO#$I!) ,1!
C;((;SI;& (A7 .77(-I&AI;&
,1!1!
(emaining Li'e Calculations
#he re)aining life of the piping s$ste) shall !e calculated fro) the follo:ing for)ula< :here tactua( D the actual thic'ness in inches ?)illi)eters )easured the ti)e ofas inspection a gi%en location oratco)ponent specifiedfor in ".&. tre8uired D the re8uired thic'ness in inches ?)illi)eters at the sa)e location or co)ponent as the tactua( )easure)ent co)puted !$ the design for)ulas ?e.g. pressure and structural !efore corrosion allo:ance and )anufacturer>s tolerance are added. #he long-ter) ?*# corrosion rate of piping circuits shall !e calculated fro) the follo:ing for)ula< tinitia( and tactua( #he short ter) ?S# corrosion rate of piping circuits shall !e calculated fro) the follo:ing for)ula<
tpre2ious and tactua(
:here tinitia( D the thic'ness in inches ?)illi)eters at the sa)e location as tactua( )easured at initial installation or at the co))ence)ent of a ne: corrosion rate en%iron)ent tpre2ious D the thic'ness in inches ?)illi)eters at the sa)e location as tactua( )easured during one or )ore pre%ious inspections. #he preceding for)ulas )a$ !e applied in a statistical approach to assess corrosion rates and re)aining life calculations for the piping s$ste). Care )ust !e ta'en to ensure that the statistical treat)ent of data results reflects the actual condition of the %arious pipe co)ponents. Statistical anal$sis e)plo$ing point )easure)ents is not applica!le to piping s$ste)s :ith significant localized unpredicta!le corrosion )echanis)s. *ong-ter) and short-ter) corrosion rates should !e co)pared to see :hich results in the shortest re)aining life as part of the data assess)ent. #he authorized inspector in consultation :ith a corrosion specialist shall select the corrosion rate that !est reflects the current process. ?See &.3 for inspection inter%al deter)ination. ,1!1"
&ewly Installed Piping Systems or Changes
in Ser%ice 7or ne: piping s$ste)s and piping s$ste)s for :hich ser%ice conditions are !eing changed one of the follo:ing )ethods shall !e e)plo$ed to deter)ine the pro!a!le rate of corrosion fro) :hich the re)aining :all thic'ness at the ti)e of the net inspection can !e esti)ated< a. A corrosion rate for a piping circuit )a$ !e calculated fro) data collected !$ the o:ner@user on piping s$ste)s of si)ilar )aterial in co)para!le ser%ice. !. If data for the sa)e or si)ilar ser%ice are not a%aila!le a corrosion rate for a piping circuit )a$ !e esti)ated fro) the o:ner@user>s eperience or fro) pu!lished data on piping s$ste)s in co)para!le ser%ice. c. If the pro!a!le corrosion rate cannot !e deter)ined !$ either )ethod listed in ite) a or ite) ! the initial thic'ness )easure)ent deter)inations shall !e )ade after no )ore than 3 )onths of ser%ice !$ using nondestructi%e thic'ness )easure)ents of the piping s$ste). Corrosion )onitoring de%ices such as corrosion coupons or corrosion pro!es )a$ !e useful in esta!lishing the ti)ing of these thic'ness )easure)ents. Su!se8uent )easure)ents shall !e )ade after appropriate inter%als until the corrosion rate is esta!lished. ,1!1#
7:isting Piping Systems
Corrosion rates shall !e calculated on either a short-ter) or a long-ter) !asis. If calculations indicate that an inaccurate rate of corrosion has !een assu)ed the rate to !e used for the net period shall !e ad=usted to agree :ith the actual rate found. ,1"
-AI&?
PRE))URE DETER.INATION #he )ai)u) allo:a!le :or'ing pressure ?(AP for the continued use of piping s$ste)s shall !e esta!lished using the applica!le code. Co)putations )a$ !e )ade for 'no:n e)aining *ife ?$ears tactua( tre8uired O corrosion rate Minches ?)) per $ear ------------------------------------------------------------------------------- D
Corrosion rate ?*# tinitia( tactua( O ti)e ?$ears !et:een -------------------------------------------------- D
Corrosion rate ?S# tpre2ious tactua( O ti)e ?$ears !et:een -------------------------------------------------- D
91 91 91 Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
+-2 API "+9 )aterials if all the follo:ing essential details are 'no:n to co)pl$ :ith the principles of the applica!le code< a. 0pper and@or lo:er te)perature li)its for specific )aterials. !. Qualit$ of )aterials and :or')anship. c. Inspection re8uire)ents. d. einforce)ent of openings. e. An$ c$clical ser%ice re8uire)ents. 7or un'no:n )aterials co)putations )a$ !e )ade assu)ing the lo:est grade )aterial and =oint efficienc$ in the applica!le code. hen the (AP is recalculated the :all thic'ness used in these co)putations shall !e the actual thic'ness as deter)ined !$ inspection ?see ".& for definition )inus t:ice the esti)ated corrosion loss !efore the date of the net inspection ?see &.3. Allo:ance shall !e )ade for the other loadings in accordance :ith the applica!le code. #he
applica!le code allo:ances for pressure and te)perature %ariations fro) the (AP are per)itted pro%ided all of the associated code criteria are satisfied. #a!le +-1 contains t:o ea)ples of calculations of (AP illustrating the use of the corrosion half-life concept. ,1#
(7@3I(7. HIC>&7SS .77(-I&AI;&
#he re8uired thic'ness of a pipe shall !e the greater of the pressure design thic'ness or the structural )ini)u) thic'ness. 7or ser%ices :ith high ris' the piping engineer should consider increasing the re8uired thic'ness to pro%ide for unanticipated or un'no:n loadings or undisco%erd )etal loss. ,14
ASS7SS-7& ;9 I&SP7CI;& 9I&.I&?S
Pressure containing co)ponents found to ha%e degradation that could affect their load carr$ing capa!ilit$ ?pressure loads and other applica!le loads e.g. :eight :ind etc. per API P "+6 shall !e e%aluated for continued ser%ice. 7itness-forser%ice techni8ues such as those docu)ented in API P "+6 )a$ !e used for this e%aluation. #he fitness-forser%ice techni8ues used )ust !e applica!le to the specific degradation o!ser%ed. #he follo:ing techni8ues )a$ !e used as applica!le< a. #o e%aluate )etal loss in ecess of the corrosion allo:ance a fitness-for-ser%ice assess)ent )a$ !e perfor)ed in accordance :ith one of the follo:ing sections of API P "+6. #his assess)ent re8uires the use of a future corrosion allo:ance :hich shall !e esta!lished !ased on Section +.1 of this inspection code. 1. Assess)ent of Gener al (etal *ossFAPI P "+6 Section 4. 2. Assess)ent of *ocal (etal *ossFAPI P "+6 Section ". 3. Assess)ent of Pitting CorrosionFAPI P "+6 Section &. !. #o e%aluate !listers and la)inations a fitness-for-ser%ice assess)ent should !e perfor)ed in accordance :ith API P "+6 Section +. In so)e cases this e%aluation :ill re8uire the use of a future corrosion allo:ance :hich shall !e esta!lished !ased on Section +.1 of this inspection code. c. #o e%aluate :eld )isalign)ent and shell distortions a fitness for ser%ice assess)ent should !e perfor)ed in accordance :ith API P "+6 Section ,. d. #o e%aluate crac'-li'e fla:s a fitness for ser%ice assess)ent should !e perfor)ed in accordance :ith API P "+6 Section 6. e. #o e%aluate the effects of fire da)age a fitness for ser%ice assess)ent should !e perfor)ed in accordance :ith API P "+6 Section 11. +." PIPIBG S#SS ABA*SIS Piping )ust !e supported and guided so that ?a its :eight is carried safel$ ?! it has sufficient flei!ilit$ for ther)al
epansion or contraction and U it does not %i!rate ecessi%el$. Piping flei!ilit$ is of increasing concern the larger the dia)eter of the piping and the greater the difference !et:een a)!ient and operating te)perature conditions. Piping stress anal$sis to assess s$ste) flei!ilit$ and support ade8uac$ is not nor)all$ perfor)ed as part of a piping inspection. 5o:e%er )an$ eisting piping s$ste)s :ere anal$zed as part of their srcinal design or as part of a rerating or )odification and the results of these anal$ses can !e useful in de%eloping inspection plans. hen unepected )o%e)ent of a piping s$ste) is o!ser%ed such as during an eternal %isual inspection ?see ".4.3 the inspector should discuss these o!ser%ations :ith the piping engineer and e%aluate the need for conducting a piping stress anal$sis. Piping stress anal$sis can identif$ the )ost highl$ stressed co)ponents in a piping s$ste) and predict the ther)al )o%e)ent of the s$ste) :hen it is placed in operation. #his infor)ation can !e used to concentrate inspection efforts at the locations )ost prone to fatigue da)age fro) ther)al epansion ?heat-up and cool-do:n c$cles and@or creep da)age in high-te)perature piping. Co)paring predicted ther)al )o%e)ents :ith o!ser%ed )o%e)ents can help identif$ the occurrence of unepected operating conditions and deterioration of guides and supports. Consultation :ith the piping engineer )a$ !e necessar$ to eplain o!ser%ed de%iations fro) the anal$sis predictions particularl$ for co)plicated s$ste)s in%ol%ing )ultiple supports and guides !et:een end points. Piping stress anal$sis also can !e e)plo$ed to help sol%e o!ser%ed piping %i!ration pro!le)s. #he natural fre8uencies in :hich a piping s$ste) :ill %i!rate can !e predicted !$ anal$sis. #he effects of additional guiding can !e e%aluated to assess its a!ilit$ to control %i!ration !$ increasing the s$s9& 91 91 Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
PIPIBG IBSPC#IHB CHFIBSPC#IHB PAI A*#A#IHB AB A#IBG
H7 IB-S/IC PIPIBG SS#(S +-3 #a!le +-1F#:o a)ples of the Calculation of (ai)u) Allo:a!le or'ing Pressure ?(AP Illustrating the 0se of the Corrosion 5alf-*ife Concept
a)ple 1< esign pressure@te)perature "99 psig@ 499N7 ?344+ 'Pa@294NC Pipe description BPS 1& standard :eight A 19&- Hutside dia)eter of pipe 1& in. ?49& )) Allo:a!le stress 29999 psi ?13+699 'Pa *ongitudinal :eld efficienc$ 1.9 #hic'ness deter)ined fro) inspection 9.32 in. ?,.13 )) H!ser%ed corrosion rate ?see +.1.1 9.91 in.@$r. ?9.2"4 ))@$r. Bet planned inspection " $rs. sti)ated corrosion loss !$ date of inspection D " : 9.91 D 9.9" in. ?" : 9.2"4 D 1.2+ )) (AP D 2St@ In 0.S. units In S.I. units Conclustion< HE a)ple 2< Bet planned inspection + $rs. sti)ated corrosion loss !$ date of net inspection D + : 9.91 D 9.9+ in. ?+ : 9.2"4 D 1.+, )) (AP D 2St@ In 0.S. units In S.I units Conclusion< (ust reduce inspection inter%al or deter)ine that nor)al operating pressure :ill not eceed this ne: (AP during the se%eth $ear or rene: the piping !efore the se%enth $ear. Bote< 1. psig D pounds per s8uare inch gauge; psi D pounds per s8uare inch 2. #he for)ula for (AP is fro) AS( 31.3 8uation 3! :here t D corroded thic'ness 2 29999 ? 1.9 ? V V 9.32 2 9.9" V ? O ? V 1& ----------------------------------------------------------------------------------------------------- ""9psig D 2 13+ 699 ? V 1.9 ? V ,.13 ? V 2 1.2+ V ? O M 49& ----------------------------------------------------------------------------------------------------------- 3+4+'Pa D 2 29999 ? 1.9 ? V V 9.32 2 9.9+ V ? O ? V 1&
----------------------------------------------------------------------------------------------------- 4"9psig D 2 13+ 699 ? V 1.9 ? V ,.13 ? V 2 1.+, V ? O M 49& ----------------------------------------------------------------------------------------------------------- 3194'Pa D #1 Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
+-4 API "+9 te)>s natural fre8uencies !e$ond the fre8uenc$ of eciting forces such as )achine rotational speed. It is i)portant to deter)ine that guides added to control %i!ration do not ad%ersel$ restrict ther)al epansion. +.& PH#IBG AB CHS 7H PIPIBG
))TE. IN)PECTION An$ significant increase in corrosion rates shall !e reported to the o:ner@user for appropriate action. #he o:ner@user shall )aintain appropriate per)anent and progressi%e records of each piping s$ste) co%ered !$ API "+9. #hese records shall contain pertinent data such as piping s$ste) ser%ice; classification; identification nu)!ers; inspection inter%als; and docu)ents necessar$ to record the na)e of the indi%idual perfor)ing the testing the date the t$pes of testing the results of thic'ness )easure)ents and other tests inspections repairs ?te)porar$ and per)anent alterations or rerating. esign infor)ation and piping dra:ings )a$ !e included. Infor)ation on )aintenance acti%ities and e%ents affecting piping s$ste) integrit$ also should !e included. #he date and results of re8uired eternal inspections shall !e recorded. ?See API P "+4 for guidance on piping inspection records. #he use of a co)puter-!ased s$ste) for storing calculating and anal$zing data should !e considered in %ie: of the %olu)e of data that :ill !e generated as part of a piping testpoint progra). Co)puter progra)s are particularl$ useful for the follo:ing< a. Storing the actual thic'ness readings. !. Calculating short- and long-ter) corrosion rates retire)ent dates (AP and reinspection inter%als on a test-point !$ test-point !asis. c. 5ighlighting areas of high corrosion rates circuits o%erdue for inspection circuits close to retire)ent thic'ness and other infor)ation. d. 7itness-for-ser%ice assess)ent docu)entation re8uire)ents are descri!ed in API P "+6 Section 2.,. Specific docu)entation re8uire)ents for the t$pe of fla: !eing assessed are pro%ided in the appropriate section of API P
"+6. Algorith)s for the anal$sis of data fro) entire circuits also )a$ !e included in the progra). Care should !e ta'en to ensure that the statistical treat)ent of circuit data results in predictions that accuratel$ reflect the actual condition of the piping circuit. 91 Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
,-1 SECIO! 4"#EP*I#S *LE#*IO!S *!$ #E#*I!) OF PIPI!) S/SE5S
,.1 PAIS AB A*#A#IHBS #he principles of AS( 31.3 or the code to :hich the piping s$ste) :as !uilt shall !e follo:ed. ,.1.1 Authorization All repair and alteration :or' )ust !e done !$ a repair organization as defined in Section 3 and )ust !e authorized !$ the inspector prior to its co))ence)ent. Authorization for alteration :or' to a piping s$ste) )a$ not !e gi%en :ithout prior consultation :ith and appro%al !$ the piping engineer. #he inspector :ill designate an$ inspection hold points re8uired during the repair or alteration se8uence. #he inspector )a$ gi%e prior general authorization for li)ited or routine repairs and procedures pro%ided the inspector is satisfied :ith the co)petenc$ of the repair organization. ,.1.2 Appro%al All proposed )ethods of design eecution )aterials :elding procedures ea)ination and testing )ust !e appro%ed !$ the inspector or !$ the piping engineer as appropriate. H:ner@user appro%al of on-strea) :elding is re8uired. elding repairs of crac's that occurred in-ser%ice should not !e atte)pted :ithout prior consultation :ith the piping engineer in order to identif$ and correct the cause of the crac'ing. a)ples are crac's suspected of !eing caused !$ %i!ration ther)al c$cling ther)al epansion pro!le)s and en%iron)ental crac'ing. #he inspector shall appro%e all repair and alteration :or' at designated hold points and after the repairs and alterations ha%e !een satisfactoril$ co)pleted in accordance :ith the re8uire)ents of API "+9. ,.1.3 elding epairs ?Including Hn-Strea) ,.1.3.1 #e)porar$ epairs
7or te)porar$ repairs including on-strea) a full encircle)ent :elded split slee%e or !o-t$pe enclosure designed !$ the piping engineer )a$ !e applied o%er the da)aged or corroded area. *ongitudinal crac's shall not !e repaired in this )anner unless the piping engineer has deter)ined that crac's :ould not !e epected to propagate fro) under the slee%e. In so)e cases the piping engineer :ill need to consult :ith a fracture anal$st. If the repair area is localized ?for ea)ple pitting or pinholes and the specified )ini)u) $ield strength ?S(S of the pipe is not )ore than 49999 psi ?2+",99 'Pa and a fitnessfor-ser%ice anal$sis sho:s it>s accepta!le a te)porar$ repair )a$ !e )ade !$ fillet :elding a properl$ designed split coupling or plate patch o%er the pitted or locall$ thinned area. ?See ,.2.3 for deisng consideration and Appendi C for an ea)ple. #he )aterial for the repair shall )atch the !ase )etal unless appro%ed !$ the piping engineer. A fillet-:elded patch shall not !e installed on top of an eisting fillet-:elded patch. hen installing a fillet-:elded patch ad=acent to an eisting fillet-:elded patch the )ini)u) distance !et:een the toe of the fillet-:elded shall not !e less than< :here d D the )ini)u) distance !et:een the toes of fillet :elds of ad=acent fillet :eld attach)ents in in. ?)) D the inside radius in in. ?)). t D the )ini)u) re8uired thic'ness of the fillet:elded patch in in. ?)). 7or )inor lea's properl$ designed enclosures )a$ !e :elded o%er the lea' :hile the piping s$ste) is in-ser%ice pro%ided the inspector is satisfied that ade8uate thic'ness re)ains in the %icinit$ of the :eld and the piping co)ponent can :ithstand :elding :ithout the li'elihood of further )aterial da)age such as fro) caustic ser%ice. #e)porar$ repairs should !e re)o%ed and replaced :ith a suita!le per)anent repair at the net a%aila!le )aintenance opportunit$. #e)porar$ repairs )a$ re)ain in place for a longer period of ti)e onl$ if appro%ed and docu)ented !$ the piping engineer. ,.1.3.2 Per)anent epairs epairs to defects found in piping co)ponents )a$ !e )ade !$ preparing a :elding groo%e that co)pletel$ re)o%es the defect and then filling the groo%e :ith :eld )etal deposited in accordance :ith ,.2. Corroded areas )a$ !e restored :ith :eld )etal deposited in accordance :ith ,.2. Surface irregularities and conta)ination shall !e re)o%ed !efore :elding. Appropriate B
)ethods shall !e applied after co)pletion of the :eld. If it is feasi!le to ta'e the piping s$ste) out of ser%ice the defecti%e area )a$ !e re)o%ed !$ cutting out a c$lindrical section and replacing it :ith a piping co)ponent that )eets the applica!le code. Insert patches ?flush patches )a$ !e used to repair da)aged or corroded areas if the follo:ing re8uire)ents are )et< a. 7ull-penetration groo%e :elds are pro%ided. !. 7or Class 1 and Class 2 piping s$ste)s the :elds shall !e 199 percent radiographed or ultrasonicall$ tested using B procedures that are appro%ed !$ the inspector. c. Patches )a$ !e an$ sh ape !ut shall ha%e rounded corners M1 inch ?2" )) )ini)u) radius. ,.1.4 Bon:elding epairs ?Hn-Strea) #e)porar$ repairs of locall$ thinned sections or circu)ferential linear defects )a$ !e )ade on-strea) !$ installing a properl$ designed and applied enclosure ?e.g. !olted cla)p d 4 t D 9& 9& 9& Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
,-2 API "+9 non)etalic co)posite :rap )etallic and epo$ :raps or other non-:elded applied te)porar$ repair. #he design shall include control of aial thrust loads if the piping co)ponent !eing cla)ped is ?or )a$ !eco)e insufficient to control pressure thrust. #he effect of cla)ping ?crushing forces on the co)ponent also shall !e considered. uring turnarounds or other appropriate opportunities te)porar$ lea' sealing and lea' dissipating de%ices including %al%es shall !e re)o%ed and appropriate actions ta'en to restore the srcinal integrit$ of the piping s$ste). #he inspector and@or piping engineer shall !e in%ol%ed in deter)ining repair )ethods and procedures. Procedures that include lea' sealing fluids ?Jpu)pingK for process piping should !e re%ie:ed for acceptance !$ the inspector or piping engineer. #he re%ie: should ta'e into consideration the co)pati!ilit$ of the sealant :ith the lea'ing )aterial; the pu)ping pressure on the cla)p ?especiall$ :hen repu)ping; and an$ resulting crushing forces; and the ris' of sealant affecting do:nstrea) flo: )eters relief %al%es or )achiner$; the ris' of su!se8uent lea'age at
!olt threads causing corrosion or stress corrosion crac'ing of !olts; and the nu)!er of ti)es the seal area is repu)ped. ,.2 *IBG AB 5H# #APPIBG All repair and alteration :elding shall !e done in accordance :ith the principles of AS( 31.3 or the code to :hich the piping s$ste) :as !uilt. An$ :elding conducted on piping co)ponents in operation )ust !e done in accordance :ith API Pu!l 2291. #he inspector shall use as a )ini)u) the JSuggested 5ot #ap Chec'listK contained in API Pu!lication 2291 for hot tapping perfor)ed on piping co)ponents. ,.2.1 Procedures Qualifications an d ecords #he repair organization shall use :elders and :elding procedures 8ualified in accordance :ith AS( 31.3 or the code to :hich the piping :as !uilt. #he repair organization shall )aintain records of :elding procedures and :elder perfor)ance 8ualifications. #hese records shall !e a%aila!le to the inspector prior to the start of :elding. ,.2.2 ,.2.2.1 Preheating Preheating and Post:eld 5eat #reat)ent Preheat te)perature used in )a'ing :elding repairs shall !e in accordance :ith the applica!le code and 8ualified :elding procedure. ceptions for te)porar$ repairs )ust !e appro%ed !$ the piping engineer. Preheating to not less than 399N7 ?1"9NC )a$ !e considered as an alternati%e to post:eld heat treat)ent ?P5# for alterations or repairs of piping s$ste)s initiall$ post:eld heat treated as a code re8uire)ent ?see note. #his applies to piping constructed of the P-1 steels listed in AS( 31.3. P-3 steels :ith the eception of (n-(o steels also )a$ recei%e the 399N7 ?1"9NC )ini)u) preheat alternati%e :hen the piping s$ste) operating te)perature is high enough to pro%ide reasona!le toughness and :hen there is no identifia!le hazard associated :ith pressure testing shutdo:n and startup. #he inspector should deter)ine that the )ini)u) preheat te)perature is )easured and )aintained. After :elding the =oint should i))ediatel$ !e co%ered :ith insulation to slo: the cooling rate. Bote< Preheating )a$ not !e considered as an alternati%e to en%iron)ental crac'ing pre%ention. Piping s$ste)s constructed of other steels initiall$ re8uiring P5# nor)all$ are post:eld heat treated if alterations or repairs in%ol%ing pressure retaining :elding are perfor)ed.
#he use of the preheat alternati%e re8uires consultation :ith the piping engineer :ho should consider the potential for en%iron)ental crac'ing and :hether the :elding procedure :ill pro%ide ade8uate toughness. a)ples of situations :here this alternati%e could !e considered include seal :elds :eld )etal !uildup of thin areas and :elding support clips. ,.2.2.2 Post:eld 5eat #reat)ent P5# of piping s$ste) repairs or alterations should !e )ade using the applica!le re8uire)ents of AS( 31.3 or the code to :hich the piping :as !uilt. See ,.2.2.1 for an alternati%e preheat procedure for so)e P5# re8uire)ents. ceptions for te)porar$ repairs )ust !e appro%ed !$ the piping engineer. *ocal P5# )a$ !e su!stituted for 3&9-degree !anding on local repairs on all )aterials pro%ided the follo:ing precautions and re8uire)ents are applied< a. #he application is re%ie:ed and a procedure is de%eloped !$ the piping engineer. !. In e%aluating the suita!ilit$ of a procedure consideration shall !e gi%en to applica!le factors such as !ase )etal thic'ness ther)al gradients )aterial properties changes resulting fro) P5# the need for full-penetration :elds and surface and %olu)etric ea)inations after P5#. Additionall$ the o%erall and local strains and distortions resulting fro) the heating of a local restrained area of the piping :all shall !e considered in de%eloping and e%aluating P5# procedures. c. A preheat of 399N7 ?1"9NC or higher as specified !$ specific :elding procedures is )aintained :hile :elding. d. #he re8uired P5# te)perature shall !e )aintained for a distance of not less than t:o ti)es the !ase )etal thic'ness )easured fro) the :eld. #he P5# te)perature shall !e )onitored !$ a suita!le nu)!er of ther)ocouples ?a )ini)u) of t:o !ased on the size and shape of the area !eing heat treated. e. Controlled heat also shall !e applied to an$ !ranch connection or other attach)ent :ithin the P5# area. 9& 9& Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
PIPIBG IBSPC#IHB CHFIBSPC#IHB PAI A*#A#IHB AB A#IBG
H7 IB-S/IC PIPIBG SS#(S ,-3
f. #he P5# is perfor)ed for code co)pliance and not for en%iron)ental crac'ing resistance. ,.2.3 esign utt =oints shall !e full-penetration groo%e :elds. Piping co)ponents shall !e replaced :hen repair is li'el$ to !e inade8uate. Be: connections and replace)ents shall !e designed and fa!ricated according to the principles of the applica!le code. #he design of te)porar$ enclosures and repairs shall !e appro%ed !$ the piping engineer. Be: connections )a$ !e installed on piping s$ste)s pro%ided the design location and )ethod of attach)ent confor) to the principles of the applica!le code. 7illet-:elded patches re8uire special design considerations especiall$ relating to :eld-=oint efficienc$ and cre%ice corrosion. 7illet-:elded patches shall !e designed !$ the piping engineer. A patch )a$ !e applied to the eternal surfaces of piping pro%ided it is in accordance :ith ,.1.3 and )eets either of the follo:ing re8uire)ents< a. #he proposed patch pro%ides design strength e8ui%alent to a reinforced opening designed according to the applica!le code. !. #he proposed patch is designed to a!sor! the )e)!rane strain of the part in a )anner that is in accordance :ith the principles of the applica!le code if the follo:ing criteria are )et<
" The a((o#a1(e /e/1rane stress is not e0ceeded in the piping part or the patch. % The strain in the patch does not resu(t in 9i((et #e(d stresses eceeding allo:a!le stresses for such :elds. ! An o2er(a: patch sha(( ha2e rounded corners ;see Appendi C. ,.2.4 (aterials #he )aterials used in )a'ing repairs or alterations shall !e of 'no:n :elda!le 8ualit$ shall confor) to the applica!le code and shall !e co)pati!le :ith the srcinal )aterial. 7or )aterial %erification re8uire)ents see ".,. ,.2." Bondestructi%e a)ination Acceptance of a :elded repair or alteration shall include B in accordance :ith the applica!le code and the o:ner@ user>s specification unless other:ise specified in API "+9. ,.2.& Pressure #esting After :elding is co)pleted a pressure test in accordance :ith ".+ shall !e perfor)ed if practical and dee)ed necessar$
!$ the inspector. Pressure tests are nor)all$ re8uired after alterations and )a=or repairs. hen a pressure test is not necessar$ or practical B shall !e utilized in lieu of a pressure test. Su!stituting appropriate B procedures for a pressure test after an alteration rerating or repair )a$ !e done onl$ after consultation :ith the inspector and the piping engineer. 7or eisting insultated lines that are !eing pressure tested after repairs rerating or alteration it is not necessar$ to strip insulation on all eisting :elds. Pressure test :ith longer hold ti)es and o!ers%ations of pressure gauges can !e su!stituted for insulation stripping :hen the ris's associted :ith lea's under the insulation are accepta!le. hen it is not practical to perfor) a pressure test of a final closure :eld that =oins a ne: or replace)ent section of piping to an eisting s$ste) all of the follo:ing re8uire)ents shall !e satisfied< a. #he ne: or replace)ent piping is pressure tested and ea)ined in accordance :ith the applica!le code go%erning the design of the piping s$ste) or if not practical :elds are ea)ined :ith appropriate B as specified !$ the authorized piping inspector. !. #he closure :eld is a full-penetration !utt-:eld !et:een an$ pipe or standard piping co)ponent or straight sections of pipe of e8ual dia)eter and thic'ness aiall$ aligned ?not )iter cut and of e8ui%alent )aterials. Accepta!le alternati%es are< ?1 slip-on flanges for design cases up to Class 1"9 and "99N7 ?2&9NC and ?2 soc'et :elded flanges or soc'et :elded unions for sizes BPS 2 or less and design cases up to Class 1"9 and "99N7 ?2&9NC. A spacer designed for soc'et :elding or so)e other )eans shall !e used to esta!lish a )ini)u) 1@1& inch ?1.& )) gap. Soc'et :elds shall !e per AS( 31.3 and shall !e a )ini)u) of t:o passes. c. An$ final closure !utt-:eld shall !e of 199-percent radiographic 8ualit$; angle-!ea) ultrasonic fla: detection )a$ ha%e !e used or pro%ided the appropriate acceptance criteria !een esta!lished. d. (# or P# shall !e perfor)ed on the root pass and the co)pleted :eld for !utt-:elds and on the co)pleted :eld for fillet-:elds. #he o:ner@user shall specif$ industr$-8ualified 0# shear :a%e ea)iners for closure :elds that ha%e not !een pressure tested and for :eld repairs identified !$ the piping engineer or authorized piping inspector. #he re8uire)ent for use of industr$-8ualified 0# shear :a%e ea)iners !eco)es effecti%e t:o $ears after pu!lication in this code or addendu). ,.3 A#IBG erating piping s$ste)s !$ changing the te)perature rating
or the (AP )a$ !e done onl$ after all of the follo:ing re8uire)ents ha%e !een )et< a. Calculations are perfor)ed !$ the piping engineer or the inspector. !. All reratings shall !e esta!lished in accordance :ith the re8uire)ents of the code to :hich the piping s$ste) :as !uilt or !$ co)putation using the appropriate )ethods in the latest edition of the applica!le code. c. Current inspection records %erif$ that the piping s$ste) is satisfactor$ for the proposed ser%ice conditions and that the appropriate corrosion allo:ance is pro%ided. 91 9& 93 9& 9& 93 93 Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S9,@93@299& under license :ith API *icenseeDChe%ron Bot for esale 96<"+<"2 (# Bo reproduction Corp@"6123,,199 or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
,-4 API "+9 d. erated piping s$ste)s shall !e lea' tested in accordance :ith the code to :hich the piping s$ste) :as !uilt or the latest edition of the applica!le code for the ne: ser%ice conditions unless docu)ented records indicate a pre%ious lea' test :as perfor)ed at greater than or e8ual to the test pressure for the ne: condition. An increase in the rating te)perature that does not affect allo:a!le tensile stress does not re8uire a lea' test. e. #he piping s$ste) is chec'ed to affir) that the re8uired pressure relie%ing de%ices are present are set at the appropriate pressure and ha%e the appropriate capacit$ at set pressure. f. #he piping s$ste) rerating is accepta!le to the inspector or piping engineer. g. All piping co)ponents in the s$ste) ?such as %al%es flanges !olts gas'ets pac'ing and epansion =oints are ade8uate for the ne: co)!ination of pressure and te)perature. h. Piping flei!ilit$ is ade8uate for design te)perature changes. i. =.
Appropriate engineering records are updated. A decrease in )ini)u) operating te)perature is =ustified
!$ i)pact test results if re8uired !$ the applica!le code. Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
6-1 SECIO! 6"I!SPECIO! OF 7(#IE$ PIPI!)
Inspection of !uried process piping ?not regulated !$ the epart)ent of #ransportation is different fro) other process piping inspection !ecause significant eternal deterioration can !e caused !$ corrosi%e soil conditions. Since the inspection is hindered !$ the inaccessi!ilit$ of the affected areas of the piping the inspection of !uried piping is treated in a separate section of API "+9. I)portant non)andator$ references for underground piping inspection are the follo:ing BAC docu)ents< P91&6 P92+4 and P92+"; and Section 11 of API P &"1. 6.1 #PS AB (#5HS H7 IBSPC#IHB 6.1.1
A!o%e-Grade /isual Sur%eillance
Indications of lea's in !uried piping )a$ include a change in the surface contour of the ground discoloration of the soil softening of pa%ing asphalt pool for)ation !u!!ling :ater puddles or noticea!le odor. Sur%e$ing the route of !uried piping is one )ethod of identif$ing pro!le) areas. 6.1.2 Close-Inter%al Potential Sur%e$ #he close-inter%al potential sur%e$ perfor)ed at ground le%el o%er the !uried pipe can !e used to locate acti%e corrosion points on the pipe>s surface. Corrosion cells can for) on !oth !are and coated pipe :here the !are steel contacts the soil. Since the potential at the area of corrosion :ill !e )easura!l$ different fro) an ad=acent area on the pipe the location of the corrosion acti%it$ can !e deter)ined !$ this sur%e$ techni8ue. 6.1.3
Pipe Coating 5olida$ Sur%e$
#he pipe coating holida$ sur%e$ can !e used to locate coating defects on !uried coated pipes and it can !e used on ne:l$ constructed pipe s$ste)s to ensure that the coating is intact and holida$-free. (ore often it is used to e%aluate coating ser%icea!ilit$ for !uried piping that has !een in-ser%ice for an etended period of ti)e. 7ro) sur%e$ data the coating effecti%eness and rate of coating deterioration can !e deter)ined. #his infor)ation is used !oth for predicting corrosion acti%it$ in a specific area and for forecasting replace)ent of the coating for corrosion control.
6.1.4 Soil esisti%it$ Corrosion of !are or poorl$ coated piping is often caused !$ a )iture of different soils in contact :ith the pipe surface. #he corrosi%eness of the soils can !e deter)ined !$ a )easure)ent of the soil resisti%it$. *o:er le%els of resisti%it$ are relati%el$ )ore corrosi%e than higher le%els especiall$ in areas :here the pipe is eposed to significant changes in soil resisti%it$. (easure)ents of soil resisti%it$ should !e perfor)ed using the enner 7our-Pin (ethod in accordance :ith AS#( G"+. In cases of parallel pipes or in areas of intersecting pipelines it )a$ !e necessar$ to use the Single-Pin (ethod to accuratel$ )easure the soil resisti%it$. 7or )easuring resisti%it$ of soil sa)ples fro) auger holes or eca%ations a soil !o ser%es as a con%enient )eans for o!taining accurate results. #he depth of the piping shall !e considered in selecting the )ethod to !e used and the location of sa)ples. #he testing and e%aluation of results should !e perfor)ed !$ personnel trained and eperienced in soil resisti%it$ testing.
<"'
Cathodic Protection .onitoring Cathodicall$ protected !uried piping should !e )onitored regularl$ to assure ade8uate le%els of protection. (onitoring should include periodic )easure)ent and anal$sis of pipe-tosoil potentials !$ personnel trained and eperienced in cathodic protection s$ste) operation. (ore fre8uent )onitoring of critical cathodic protection co)ponents such as i)pressed current rectifiers is re8uired to ensure relia!le s$ste) operation. efer to BAC P91&6 and Section 11 of API P &"1 for guidance applica!le to inspecting and )aintaining cathodic protection s$ste)s for !uried piping. 6.1.& Inspection (ethods Se%eral inspection )ethods are a%aila!le. So)e )ethods can indicate the eternal or :all condition of the piping :hereas other )ethods indicate onl$ the internal condition. a)ples are as follo:s< a. Intelligent pigging. #his )ethod in%ol%es the )o%e)ent of a de%ice ?pig through the piping either :hile it is in-ser%ice or after it has !een re)o%ed fro) ser%ice. Se%eral t$pes of de%ices are a%aila!le e)plo$ing different )ethods of inspection. #he line to !e e%aluated )ust !e free fro) restrictions that :ould cause the de%ice to stic' :ithin the line. 7i%e dia)eter !ends are usuall$ re8uired since standard 69-degree pipe ells )a$ not pass a pig. #he line )ust also ha%e facilities for launching and reco%ering the pigs.
!. /ideo ca)eras. #ele%ision ca)eras are a%aila!le that can !e inserted into the piping. #hese ca)eras )a$ pro%ide %isual inspection infor)ation on the internal condition of the line. c. ca%ation. In )an$ cases the onl$ a%aila!le inspection )ethod that can !e perfor)ed is unearthing the piping in order to %isuall$ inspect the eternal condition of the piping and to e%aluate its thic'ness and internal condition using the )ethods discussed in ".4.2. Care should !e eercised in re)o%ing soil fro) a!o%e and around the piping to pre%ent da)aging the line or line coating. #he last fe: inches ?)) of soil should !e re)o%ed )anuall$ to a%oid this possi!ilit$. If the eca%ation is sufficientl$ deep the sides of the trench should !e properl$ Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
6-2 API "+9 shored to pre%ent their collapse in accordance :ith HS5A regulations :here applica!le. If the coating or :rapping is deteriorated or da)aged it should !e re)o%ed in that area to inspect the condition of the underl$ing )etal.
9.2 FRE!E"#$ %"& E'TE"T (F I"S)E#TI(" 6.2.1 A!o%e-Grade /isual Sur%eillance #he o:ner@user should at approi)atel$ &-)onth inter%als sur%e$ the surface conditions on and ad=acent to each pipeline path ?see 6.1.1. 6.2.2
Pipe-to-Soil Potential Sur%e$
A close-inter%al potential sur%e$ on a cathodicall$ protected line )a$ !e used to %erif$ that the !uried piping has a protecti%e potential throughout its length. 7or poorl$ coated pipes :here cathodic protection potentials are inconsistent the sur%e$ )a$ !e conducted at "-$ear inter%als for %erification of continuous corrosion control. 7or piping :ith no cathodic protection or in areas :here lea's ha%e occurred due to eternal corrosion a pipe-to-soil potential sur%e$ )a$ !e conducted along the pipe route. #he pipe should !e eca%ated at sites :here acti%e corrosion cells ha%e !een located to deter)ine the etent of corrosion da)age. A continuous potential profile or a close-inter%al sur%e$ )a$ !e re8uired to locate acti%e corrosion cells. 6.2.3 Pipe Coating 5olida$ Sur%e$ #he fre8uenc$ of pipe coating holida$ sur%e$s is usuall$ !ased on indications that other for)s of corrosion control are
ineffecti%e. 7or ea)ple on a coated pipe :here there is gradual loss of cathodic protection potentials or an eternal corrosion lea' occurs at a coating defect a pipe coating holida$ sur%e$ )a$ !e used to e%aluate the coating. 6.2.4
Soil Corrosi%it$
7or piping !uried in lengths greater than 199 feet ?39 ) and not cathodicall$ protected e%aluations of soil corrosi%it$ should !e perfor)ed at "-$ear inter%als. Soil resisti%it$ )easure)ents )a$ !e used for relati%e classification of the soil corrosi%it$ ?see 6.1.4. Additional factors that )a$ :arrant consideration are changes in soil che)istr$ and anal$ses of the polarization resistance of the soil and piping interface. 6.2." Cathodic Protection If the piping is cathodicall$ protected the s$ste) should !e )onitored at inter%als in accordance :ith Section 19 of BAC P91&6 or Section 11 of API P &"1.
<%5 E0terna( and Interna( Inspection Inter2a(s If internal corrosion of !uried piping is epected as a result of inspection on the a!o%e-grade portion of the line inspection inter%als and )ethods for the !uried portion should !e ad=usted accordingl$. #he inspector should !e a:are of and consider the possi!ilit$ of accelerated internal corrosion in deadlegs. #he eternal condition of !uried piping that is not cathodicall$ protected should !e deter)ined !$ either pigging :hich can )easure :all thic'ness or !$ eca%ating according to the fre8uenc$ gi%en in #a!le 6-1. Significant eternal corrosion detected !$ pigging or !$ other )eans )a$ re8uire eca%ation and e%aluation e%en if the piping is cathodicall$ protected. Piping inspected periodicall$ !$ eca%ation shall !e inspected in lengths of & feetO, feet ?2.9 )O2." ) at one or )ore locations =udged to !e )ost suscepti!le to corrosion. ca%ated piping should !e inspected full circu)ference for the t$pe and etent of corrosion ?pitting or general and the condition of the coating. If inspection re%eals da)aged coating or corroded piping additional piping shall !e eca%ated until the etent of the condition is identified. If the a%erage :all thic'ness is at or !elo: retire)ent thic'ness it shall !e repaired or replaced. If the piping is contained inside a casing pipe the condition of the casing should !e inspected to deter)ine if :ater and@or soil has entered the casing. #he inspector should %erif$ the follo:ing< ?a !oth ends of the casing etend !e$ond the ground line; ?! the ends of the casing are sealed if
the casing is not self-draining; and U the pressure-carr$ing pipe is properl$ coated and :rapped. 6.2.+ *ea' #esting Inter%als An alternati%e or supple)ent to inspection is lea' testing :ith li8uid at a pressure at least 19 percent greater than )ai)u) operating pressure at inter%als one-half the length of those sho:n in #a!le 6-1 for piping not cathodicall$ protected and at the sa)e inter%als as sho:n in #a!le 6-1 for cathodicall$ protected piping. #he lea' test should !e )aintained for a period of , hours. 7our hours after the initial pressurization of the piping s$ste) the pressure should !e noted and if necessar$ the line repressurized to srcinal test pressure and isolated fro) the pressure source. If during the re)ainder of the test period the pressure decreases )ore than " percent the piping should !e %isuall$ inspected eternall$ and@or inspected internall$ to find the lea' and assess the etent of corrosion. Sonic )easure)ents )a$ !e helpful in locating lea's during lea' testing. uried piping also )a$ !e sur%e$ed for integrit$ !$ using te)perature-corrected %olu)etric or pressure test )ethods. #a!le 6-1F7re8uenc$ of Inspection for uried Piping ithout ffecti%e Cathodic Protection Soil esisti%it$ ?oh)-c) Inspection Inter%al ?$ears W 2999 " 2999 to 19999 19 19999 1" • Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
PIPIBG IBSPC#IHB CHFIBSPC#IHB PAI A*#A#IHB AB A#IBG
H7 IB-S/IC PIPIBG SS#(S 6-3 Hther alternati%e lea' test )ethods in%ol%e acoustic e)ission ea)ination and the addition of a tracer fluid to the pressurized line ?such as heliu) or sulfur heafloride. If the tracer is added to the ser%ice fluid the o:ner@user shall confir) suita!ilit$ for process and product.
9.3 RE)%IRS T( B!RIE& )I)I"* S$STEMS !.3.1 Repairs to Coatings An$ coating re)o%ed for inspection shall !e rene:ed and inspected appropriatel$. 7or coating repairs the inspector should !e assured that the coating )eets the follo:ing criteria<
a. It has sufficient adhesion to the pipe to pre%ent underfil) )igration of )oisture. !. It is sufficientl$ ductile to resist crac'ing. c. It is free of %oids and gaps in the coating ?holida$s. d. It has sufficient strength to resist da)age due to handling and soil stress. e. It can support an$ supple)ental cathodic protection. In addition coating repairs )a$ !e tested using a high%oltage holida$ detector. #he detector %oltage shall !e ad=usted to the appropriate %alue for the coating )aterial and thic'ness. An$ holida$s found shall !e repaired and retested.
!.3. Clap Repairs If piping lea's are cla)ped and re!uried the location of the cla)p shall !e logged in the inspection record and )a$ !e surface )ar'ed. oth the )ar'er and the record shall note the date of installation and the location of the cla)p. All cla)ps shall !e considered te)porar$. #he piping should !e per)anentl$ repaired at the first opportunit$. 6.3.3 elded epairs elded repairs shall !e )ade in accordance in ,.2.
9 . + RE #( R &S ecord s$ste)s for !uried piping should !e )aintained in accordance :ith +.&. In addition a record of the location and date of installation of te)porar$ cla)ps shall !e )aintained Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
A! *PPE!$I0 *"I!SPECO# CE#IFIC*IO!
A.1
a)ination
A :ritten ea)ination to certif$ inspectors :ithin the scope of API "+9 shall !e !ased on the current API "+9 Inspector Certification od$ of Eno:ledge as pu!lished !$ API. A.2
Certification
An API "+9 authorized piping inspector certification :ill
!e issued :hen an applicant has successfull$ passed the API "+9 certification ea) and satisfies the criteria for eperience and education. 5is@her education and eperience :hen co)!ined shall !e e8ual to at least one of the follo:ing< a. A achelor of Science degree in engineering or technolog$ plus one $ear of eperience in super%ision of inspection acti%ities or perfor)ance of inspection acti%ities as descri!ed in API "+9. !. A t:o $ear degree or certificate in engineering or technolog$ plus t:o $ears of eperience in the design construction repair inspection or operation of piping s$ste)s of :hich on $ear )ust !e in super%ision of inspection acti%ities or perfor)ance of inspection acti%ities as descri!ed in API "+9. c. A high school diplo)a or e8ui%alent plus three $ears of eperience in the design construction repair inspection or operation of piping s$ste)s of :hich one $ear )ust !e in super%ision of inspection acti%ities or perfor)ance of inspection acti%ities as descri!ed in API "+9. d. A )ini)u) of fi%e $ears of eperience in the design construction repair inspection or operation of piping s$ste)s of :hich on $ear )ust !e in super%ision of inspection acti%ities or perfor)ance of inspection acti%ities as descri!ed in API "+9. A.3ecertification .3.1 ecertification is re8uired three $ears fro) the date of issuance of the API "+9 authorized piping inspector certificate. ecertification !$ :ritten ea)ination :ill !e re8uired for authorized piping inspectors :ho ha%e not !een acti%el$ engaged as authorized piping inspectors :ithin the )ost recent three-$ear certification period and for authorized piping inspectors :ho ha%e not pre%iousl$ passed the ea). a)s :ill !e in accordance :ith all pro%isions contained in API "+9.
=Acti2e(: engaged as an authori&ed piping inspector> shall !e defined as a )ini)u) of 29T of ti)e spent perfor)ing inspection acti%ities or super%ision of inspection acti%ities or engineering support of inspection acti%ities as descri!ed in the API "+9 o%er the )ost recent three $ear certification period. %.3.2
Bote< Inspection acti%ities co))on to other API inspection docu)ents ?B record'eeping re%ie: of :elding docu)ents etc. )a$ !e considered here.
.3.3 Hnce e%er$ other recertification period ?e%er$ si $ears inspectors acti%el$ engaged as an authorized piping inspector shall de)onstrate 'no:ledge of re%isions to API "+9 that :ere instituted during the pre%ious si $ears. #his re8uire)ent shall !e effecti%e si $ears fro) the inpector>s initial certification date. Inspectors :ho ha%e not !een acti%el$ engaged as an authorized piping inspector :ithin the
)ost recent three-$ear certification period shall recertif$ as re8uired in A.3.1. 9& 9& 9& 99 9& Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
8! *PPE!$I0 7"EC8!IC*L I!(I#IES
3"
Introduction API :ill consider :ritten re8uests for interpretations of API "+9. API staff :ill )a'e such interpretations in :riting after consultation if necessar$ :ith the appropriate co))ittee officers and the co))ittee )e)!ership. #he API co))ittee responsi!le for )aintaining API "+9 )eets regularl$ to consider :ritten re8uests for interpretations and re%isions and to de%elop ne: criteria as dictated !$ technological de%elop)ent. #he co))ittee>s acti%ities in this regard are li)ited strictl$ to interpretations of the latest edition of API "+9 or to the consideration of re%isions to API "+9 !ased on the ne: data or technolog$.
As a )atter of polic$ API does not appro%e certif$ rate or endorse an$ ite) construction proprietar$ de%ice or acti%it$; and accordingl$ in8uiries re8uiring such consideration :ill !e returned. (oreo%er API does not act as a consultant on specific engineering pro!le)s or on the general understanding or application of the rules. If !ased on the in8uir$ infor)ation su!)itted it is the opinion of the co))ittee that the in8uirer should see' engineering or technical assistance the in8uir$ :ill !e returned :ith the reco))endation that such assistance !e o!tained. All in8uiries that do not pro%ide the infor)ation needed for full understanding :ill !e returned. .2
In8uir$7or)at
In8uiries shall !e li)ited strictl$ to re8uests for interpretation of the latest edition of API "+9 or to the consideration of re%isions to API "+9 !ased on ne: data or technolog$. In8uiries shall !e su!)itted in the follo:ing for)at< a. ScopeF#he in8uir$ shall in%ol%e a single su!=ect or closel$ related su!=ects. An in8uir$ letter concerning unrelated su!=ects :ill !e returned. !. ac'groundF#he in8uir$ statean theinterpretation purpose of of API "+9 or to propose the in8uir$ :hich shall !e letter either shall to o!tain consideration of a re%ision to API "+9. #he letter shall pro%ide concisel$ the infor)ation needed for co)plete understanding of the in8uir$ ?:ith s'etches as necessar$ and include references to the applica!le edition re%ision paragraphs figures and ta!les. c. In8uir$F#he in8uir$ shall !e stated in a cond ensed and precise 8uestion for)at o)itting superfluous !ac'ground infor)ation and :here appropriate co)posed in such a :a$ that J$esK or JnoK ?perhaps :ith pro%isos :ould !e a suita!le repl$. #his in8uir$ state)ent should !e technicall$ and editoriall$ correct. #he in8uirer shall state :hat he or she !elie%es API "+9 re8uires. If in the opinion of the in8uirer a re%ision to API "+9 is needed the in8uirer shall pro%ide reco))ended :ording. Su!)it the in8uir$ in t$pe:ritten for); ho:e%er legi!l$ hand:ritten in8uiries :ill !e considered. Include the na)e and the )ailing address of the in8uirer. Su!)it the proposal to the follo:ing address< director of the Standards epart)ent A)erican Petroleu) Institute 1229 * Street B.. ashington .C. 2999" )&%(-%+-)%p#'+.
7.3 ec9nical In:uiry #esponses esponses to pre%ious technical in8uires can !e found on the API :e!site at &&p$'..#&&**)%p#'+)&%(-%+-)&*$ inde.ht)l. 91 9& Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
C!
*PPE!$I0 C"E0*5PLES OF #EP*I#S
C.1
epairs
(anual :elding utilizing the gas )etal-arc or shielded )etal-arc processes )a$ !e used. hen the te)perature is !elo: "9N7 ?19NC lo:-h$drogen electrodes AS -1& or -1, shall !e used :hen :elding )aterials confor)ing to AS#( A-"3 Grades A and ; A-19& Grades A and ; A-333; A-334; API "*; and other si)ilar )aterial. #hese electrodes should also !e used on lo:er grades of )aterial :hen the te)perature of the )aterial is !elo: 32N7 ?9NC. #he piping engineer should !e consulted for cases in%ol%ing different )aterials. hen AS -1& or -1, electrodes are used on :eld nu)!ers 2 and 3 ?see 7igure C-1 !elo: the !eads shall !e deposited !$ starting at the !otto) of the asse)!l$ and :elding up:ard. #he dia)eter of these electrodes should not eceed "@32 inch ?4.9 )). lectrodes larger that "@32 inch ?4.9 )) )a$ !e used on :eld nu)!er 1 ?see 7igure C-1 !ut the dia)eter should not eceed 3@1& inch ?4., )). #he longitudinal :elds ?nu)!er 1 7igure C-1 on the reinforcing slee%e shall !e fitted :ith a suita!le tape or )ild steel !ac'ing strip ?see note to a%oid fusing the :eld to the side :all of the pipe. Bote< If the srcinal pipe along :eld nu)!er 1 has !een chec'ed thoroughl$ !$ ultrasonic )ethods and it is of sufficient thic'ness for :elding a !ac'ing strip is not necessar$. All repair and :elding procedures for on-strea) lines )ust confor) to API Pu!l 2291. C.2
S)all epair Patches
#he dia)eter of electrodes should not eceed "@32 inch ?4.9 )). hen the te)perature of the !ase )aterial is !elo: 32N7 ?9NC lo:-h$drogen electrodes shall !e used. ea%ing of :eld !eads deposited :ith lo:-h$drogen electrodes should !e a%oided. All repair and :elding procedures for on-strea) lines )ust confor) to API Pu!lication 2291. a)ples of s)all repair patches are sho:n !elo: in 7igure C-2. 7igure C-1Fncircle)ent epair Slee%e
Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
C" API 5,% 9igure C"Small (epair Patches
Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot:ithout for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
.!
*PPE!$I0 $"E0E#!*L I!SPECIO! C8EC;LIS FO# P#OCESS PIPI!)
.1 ternal Inspection Chec'list for Process Piping Pu!lication #itle X ate Inspected Ite) Inspected $ Status a. *ea's. 1. Process. 2. Stea) #racing. 3. isting Cla)ps. !. (isalign)ent. 1. Piping )isalign)ent@restricted )o%e)ent. 2. pansion =oint )isalign)ent. c. /i!ration. 1. cessi%e o%erhung :eight. 2. Inade8uate support. 3. #hin s)all-!ore or allo$ piping. 4. #hreaded connections. ". *oose supports causing )etal :ear. d. Supports. 1. Shoes off support. 2. 5anger distortion or !rea'age. 3. otto)ed-out springs. 4. race distortion@!rea'age. ". *oose !rac'ets. &. Slide plates@rollers. +. Counter !alance condition. ,. Support corrosion. e. Corrosion. 1. olting support points under cla)ps. 2. Coating@Painting deterioration. 3. Soil-to-air interface. 4. Insulation interfaces. ". iological gro:th.
f. Insulation. 1. a)age@penetrations. 2. (issing =ac'eting@insulation. 3. Sealing deterioration. 4. ulging. ". anding ?!ro'en@)issing. Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
9&@9& Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S under license :ith API *icenseeDChe%ron Corp@"6123,,199 Bot for esale 9,@93@299& 96<"+<"2 (# Bo reproduction or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
Additional copies are available through IHS
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#) %%#"%!"* '( &* *! %& www(api(org 1229 * Street B ashington C 2999"-49+9 0SA 2026828000 Product Bo. C",99" Cop$right A)erican Petroleu) Institute Pro%ided !$ I5S9,@93@299& under license :ith API *icenseeDChe%ron Bot for esale 96<"+<"2 (# Bo reproduction Corp@"6123,,199 or net:or'ing per)itted :ithout license fro) I5S --‘,‘,‘,,“,,,,,““,,,‘,,‘,‘,‘,-‘-‘,,‘,,‘,‘,,‘---
