Api spec 6dss 2017 (american petroleum institute)

Specification for Subsea Pipel ine Valves

AP I SPEC IF ICATION 6DSS

TH IRD ED ITION , AUGUST 201 7

EFFECTIVE DATE : AUGUST 1 , 201 8

Special Notes

AP I pub l ications necessari ly add ress prob lems of a genera l natu re . Wi th respect to particu lar ci rcumstances, loca l ,

state, and federa l laws and regu lations shou ld be reviewed .

Ne i ther AP I nor any of AP I 's emp loyees, subcon tractors , consu l tan ts , comm i ttees, or other ass ignees make any

warran ty or represen tation , e i ther express or imp l ied , wi th respect to the accu racy, comp leteness, or usefu lness of the

in formation con ta ined here in , or assume any l iab i l i ty or respons ib i l i ty for any use , or the resu l ts of such use , of any

in formation or process d isclosed in th is pub l ication . Ne i ther AP I nor any of AP I 's emp loyees, subcon tractors ,

consu l tan ts, or other ass ignees represen t that use of th is pub l ication wou ld not in fringe upon private ly owned righ ts .

AP I pub l ications may be used by anyone des iring to do so. Every effort has been made by the I nsti tu te to assu re the

accu racy and re l iab i l i ty of the data con ta ined in them ; however, the I nsti tu te makes no represen tation , warran ty, or

guaran tee in connection wi th th is pub l ication and hereby express ly d iscla ims any l iab i l i ty or respons ib i l i ty for loss or

damage resu l ting from i ts use or for the vio lation of any au thori ties having ju risd iction wi th wh ich th is pub l ication may

con fl ict.

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practices . These pub l ications are not in tended to obviate the need for app lying sound eng ineering judgmen t

regard ing when and where these pub l ications shou ld be u ti l ized . The formu lation and pub l ication of AP I pub l ications

is not in tended in any way to inh ib i t anyone from us ing any other practices .

Any manu factu rer marking equ ipmen t or materia ls in con formance wi th the marking requ iremen ts of an AP I standard

is so le ly respons ib le for comp lying wi th a l l the app l icab le requ iremen ts of that standard . AP I does not represen t,

warran t, or guaran tee that such products do in fact con form to the app l icab le AP I standard .

Al l righ ts reserved . No part of th is work may be reproduced , trans lated , stored in a retrieval system , or transm i tted by any means,

e lectron ic, mechan ica l , photocopying , record ing , or otherwise, wi thou t prior wri tten perm iss ion from the pub l isher. Con tact the

Publ isher, AP I Pub l ish ing Services , 1 220 L Street, NW, Wash ing ton , DC 20005.

Copyright © 2017 American Petroleum Institute

Foreword

Noth ing con ta ined in any AP I pub l ication is to be construed as g ran ting any righ t, by imp l ication or otherwise, for the

manu factu re , sa le, or use of any method , apparatus, or product covered by letters paten t. Ne i ther shou ld anyth ing

con ta ined in the pub l ication be construed as insu ring anyone aga inst l iab i l i ty for in fringemen t of letters paten t.

Sha l l : As used in a standard , “sha l l ” denotes a m in imum requ i remen t in order to con form to the speci fication .

Shou ld : As used in a standard , “shou ld ” denotes a recommendation or that wh ich is advised bu t not requ ired in order

to con form to the speci fication .

Th is documen t was produced under AP I standard ization procedu res that ensu re appropriate noti fication and

participation in the deve lopmen ta l process and is des ignated as an AP I standard . Questions concern ing the

in terpretation of the con ten t of th is pub l ication or commen ts and questions concern ing the procedu res under wh ich

th is pub l ication was deve loped shou ld be d irected in wri ting to the D i rector of S tandards , American Petro leum

Insti tu te , 1 220 L S treet, NW, Wash ing ton , DC 20005. Requests for perm iss ion to reproduce or trans late a l l or any part

of the materia l pub l ished here in shou ld a lso be add ressed to the d i rector.

Genera l ly, AP I standards are reviewed and revised , reaffirmed , or wi thd rawn at least every five years. A one-time

extens ion of up to two years may be added to th is review cycle. S tatus of the pub l ication can be ascerta ined from the

AP I Standards Departmen t, te lephone (202) 682-8000 . A cata log of AP I pub l ications and materia ls is pub l ished

annua l ly by AP I , 1 220 L Street, NW, Wash ing ton , DC 20005.

Suggested revis ions are invi ted and shou ld be subm i tted to the Standards Departmen t, AP I , 1 220 L S treet, NW,

Wash ing ton , DC 20005, standards@ap i .org .

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1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

2 Normative References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

3 Terms , Defin i tions , Acronyms , Abbreviations , Symbols , and Un i ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

3.1 Terms and Defin i tions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

3.2 Acronyms , Abbreviations , Symbols , and Un i ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 0

4 Valve Types and Con figurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2

4.1 Valve Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2

4.2 Valve Con figurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 3

5 Des ign . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 5

5.1 Des ign Standards and Calcu lations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 5

5.2 Pressure and Temperature Rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 5

5.3 S izes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 6

5.4 Face-to-face and End -to-end D imens ions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 6

5.5 Valve Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 6

5.6 Operator In formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 7

5.7 P igg ing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 9

5.8 Valve Ends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 9

5.9 Valve Cavi ty Pressure Rel ief . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

5.1 0 Drains , Ven ts , Body Test Ports , Seal Test Port, and Body Connections . . . . . . . . . . . . . . . . . . . . . . . . . . 21

5.1 1 Stem /Seat and Cavi ty In jection Poin ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

5.1 2 Drain , Sealan t, and Ven t Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

5.1 3 Hand -wheels and Wrenches—Levers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

5.1 4 Pos i tion of the Obturator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

5.1 5 Pos i tion Ind icators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

5.1 6 Travel Stops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

5.1 7 Valve Operator In terface Requ iremen ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

5.1 8 ROT System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

5.1 9 Li fting Poin ts and Supports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

5.20 Drive Trains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

5.21 Stem Reten tion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

5.22 Body and Stem Seals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

5.23 Valve Stem Seal In tegri ty Verification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

5.24 Overpressure Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

5.25 Pressure Cap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

5.26 Stem /Shaft Protector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

5.27 Hydrau l ic Lock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

5.28 Corros ion /Eros ion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

5.29 Des ign Val idation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

5.30 Hyperbaric Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

6 Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

6.1 Material Speci fication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

6.2 Tens i le Test Requ iremen ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

6.3 Service Compatibi l ity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

6.4 Cast Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

6.5 Forged Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

6.6 Compos i tion Lim i ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

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6.7 Impact Test Requ iremen ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

6.8 Bol ting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

6.9 Cathod ic Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

6.1 0 Sour Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

6.1 1 Hydrogen -induced Cracking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

6.1 2 Drain Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

6.1 3 Heat Treating Equ ipmen t Qual ification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

7 Weld ing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

7.1 Weld ing Consumables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

7.2 Weld ing Procedure and Welder/Weld ing Operator Qual i fications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

7.3 Impact Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

7.4 Hardness Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

7.5 Repairs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

8 Qual i ty Con trol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

8.1 Qual i ty Con trol Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

8.2 NDE Requ iremen ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

8.3 Measuring and Test Equ ipmen t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

8.4 Qual i fication of Personnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

8.5 Weld ing Inspectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

8.6 NDE of Repairs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

8.7 Production Material Hardness Testing on Cri tical Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

8.8 Marking , Age Con trol , and Storage for Nonmetal l ic Seals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

9 Valve Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

1 0 Factory Acceptance Testing (FAT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

1 0 .1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

1 0 .2 Stem Backseat Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

1 0 .3 Hydrostatic Shel l Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

1 0 .4 Operational /Functional Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

1 0 .5 Hydrostatic Seat Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

1 0 .6 Cavi ty Rel ief Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

1 0 .7 Drain ing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

1 0 .8 Low-pressure Gas Seat Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

1 0 .9 H igh -pressure Gas Shel l Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

1 0 .1 0 H igh -pressure Stem Seal In tegri ty Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

1 0 .1 1 H igh -pressure Gas Seat Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

1 0 .1 2 Check Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

1 0 .1 3 Instal lation of Body Connections After Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

1 0 .1 4 Testing of Body Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

1 0 .1 5 CP Con tinu ity Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

1 0 .1 6 Post-testing Corros ion Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

1 1 Coating /Pain ting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

1 2 Marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

1 3 Preparation for Sh ipmen t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

1 4 Documen tation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

1 4.1 M in imum Documen tation and Reten tion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

vi

Con ten ts

Page

1 4.2 Documen tation Provided wi th the Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

1 4.3 Supplemen tary Documen tation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

1 5 Faci l i ty Requ iremen ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

1 5.1 M in imum Faci l i ty Requ iremen ts for the Assembler/manu facturer Category of Manu facturing . . . . . . . 55

1 5.2 Con formance wi th Speci fication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

1 5.3 Processes Requ iring Val idation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

1 6 Purchas ing Gu idel ines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Annex A (in formative) Use of AP I Monogram by Licensees . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Annex B (informative) Valve Con figurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Annex C (normative) Valve End-to-End and Face-to-Face D imens ions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

Annex D (informative) Actuator—Gearbox Requ iremen ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

Annex E (informative) Gu idance for Travel Stops by Valve Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

Annex F (in formative) Des ign Val idation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

Annex G (informative) Hyperbaric Val idation Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 02

Annex H (normative) Pressure Boundary Bol ting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 06

Annex I (informative) Pressure-con tain ing Castings and Forg ings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 07

Annex J (normative) Qual ification of Heat Treating Equ ipmen t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 08

Annex K (normative) Requ iremen ts for Nondestructive Exam ination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 0

Annex L (in formative) Supplemen tary Test Requ iremen ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 5

Annex M (informative) Isolation Valve Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 7

Annex N (normative) External Coating for End Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 20

Annex O (in formative) Marking Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 22

Annex P (informative) Supplemen tary Documen tation Requ iremen ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 24

B ibl iography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 28

F igures

1 Typical F lange D imens ions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

2 Bol t Hole M isal ignmen t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

3 Charpy V-notch WM Specimen Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

4 Charpy V-notch HAZ Specimen Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

B .1 Expand ing Gate/Ris ing Stem Gate Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

B .2 S lab Gate/Through -condu i t Ris ing Stem Gate Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

B .3 Plug Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

B .4 Top En try Trunn ion -moun ted Bal l Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

B .5 Two-p iece Bol ted Bal l Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

B .6 Two-p iece Welded Bal l Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

B .7 Fu l l -open ing Cast Swing Check Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

B .8 Fu l l -open ing Forged Swing Check Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

B .9 Axial -flow Check Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

Con ten ts

Page

B .1 0 Axial On -off Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

F.1 Test Procedure for Pressure Temperature Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 00

J .1 Thermocouple Location—Rectangu lar Furnace (Working Zone) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 09

J .2 Thermocouple Location—Cyl indrical Furnace (Working Zone) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 09

M .1 B lock and B leed—Type A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 8

M .2 B lock and B leed—Type B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 8

M .3 Double B lock and B leed—Type A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 8

M .4 Double B lock and B leed—Type B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 9

M .5 Double Isolation and B leed—Type A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 9

M .6 Double Isolation and B leed—Type B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 9

N .1 Raised Face . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 20

N .2 Ring Type Join t or Raised Face Ring Type Join t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 20

N .3 Weld Face . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 21

N .4 Pipe Pup Weld Ends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 21

Tables

1 M in imum Bore for Fu l l -open ing Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 4

2 M in imum V-notch Impact Requ iremen ts for Carbon and Low-al loy Steels (Fu l l -s ize Specimen ) . . . . . . 31

3 M in imum V-notch Impact Requ iremen ts for Duplex and Super Duplex Stain less Steel

(Fu l l -s ize Specimen ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

4 Chem ical Compos i tion of N ickel -based Al loy UNS N06625 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

5 M in imum Duration of Stem Backseat Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

6 Valve Marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

7 M in imum Faci l i ty Requ iremen ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

C .1 Gate Valves—Face-to-face (A) and End -to-end (B and C) D imensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

C .2 Plug Valves—Face-to-face (A) and End -to-end (B and C) D imens ions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

C .3 Bal l Valves—Face-to-face (A) and End-to-end (B and C) D imens ions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

C .4 Check Valves—Face-to-face (A) and End-to-end (B and C) D imens ions . . . . . . . . . . . . . . . . . . . . . . . . . . 84

C .5 Axial On -off Valves—Face-to-face (A) and End -to-end (B and C) D imens ions . . . . . . . . . . . . . . . . . . . . . 87

E .1 Valve Travel Stops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

F.1 Des ign Val idation for Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

F.2 Room Temperature Gas Leakage Acceptance Cri teria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

G .1 Hyperbaric Qual ification Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 02

K.1 NDE Requ iremen ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 1

K.2 Exten t, Method , and Acceptance Cri teria of NDE/i tem Exam ination Code . . . . . . . . . . . . . . . . . . . . . . . 1 1 2

Q.1 Valve Datasheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 26

In troduction

Th is speci fication is the resu l t of updating the requ i remen ts from AP I Speci fication 6DSS , Second Ed i tion , includ ing

Errata1 .

The revis ion of AP I 6DSS , Th i rd Ed i tion , is deve loped based on inpu t from the AP I 6DSS Task Group techn ica l

experts. The techn ica l revis ions have been made in order to accommodate the needs of industry and to move th is

speci fication to a h igher leve l of service to the petro leum and natu ra l gas industry.

In th is speci fication , data are expressed in both U .S . customary (USC) and metric (S I ) un i ts.

Except as otherwise requ ired by th is specification , to determ ine con formance wi th the specified requ iremen ts, observed

or calcu lated values are to be rounded to the nearest un i t in the last righ t-hand place of figures used in expressing the

l im i ting va lue, in accordance wi th the round ing method of ASTM E29 or ISO 80000-1 , Annex B , Ru le A.

Th is speci fication is not in tended to inh ib i t a manu factu rer from offering , or the pu rchaser from accepting , a l ternative

equ ipmen t or eng ineering so lu tions for the ind ividua l app l ication . Th is may be particu larly app l icable where there is

innovative or deve lop ing techno logy.

Speci fication for Subsea P ipe l ine Valves

1 Scope

Th is speci fication defines the requ i remen ts for the des ign , manu factu ring , qual i ty con tro l , assembly, testing , and

documen tation o f bal l , check, gate , p lug , and axial on–off valves for appl ication in subsea pipe l ine systems for the

petro leum and natu ral gas industries .

Th is speci fication is not app l icable to valves for pressu re ratings exceed ing C lass 2500 .

I f product is suppl ied bearing the AP I Monog ram and manu factu red at a faci l i ty l icensed by AP I , the requ i remen ts

of Annex A apply.

2 Normative References

The fo l lowing referenced documen ts are ind ispensable for the appl ication of th is documen t. For dated

references, on ly the ed i tion ci ted appl ies.

For undated references, the latest ed i tion of the referenced documen t ( includ ing any amendmen ts) app l ies,

except that new ed i tions may be used on issue and shal l become mandatory upon the effective date speci fied by

the pub l isher or 6 mon ths from the date of the revis ion (where no effective date is speci fied ) .

AP I Techn ical Report 1 7TR1 1 , Pressure Effects on Subsea Hardware During Flowline Pressure Testing in Deep

Water

AP I Speci fication 20E , Alloy and Carbon Steel Bolting for Use in the Petroleum and Natural Gas Industries

AP I Speci fication 20F, Corrosion Resistant Bolting for Use in the Petroleum and Natural Gas Industries

ASME B1 6 .5 1

, Pipe Flanges and Flanged Fittings: NPS 1/2 Through 24 Metric/Inch Standard

ASME B1 6 . 1 0 , Face-to-Face and End-to-End Dimensions of Valves

ASME B1 6 .25 , Buttwelding Ends

ASME B1 6 .34, Valves—Flanged, Threaded, and Welding End

ASME B1 6 .47, Large Diameter Steel Flanges: NPS 26 Through NPS 60 Metric/Inch Standard

ASME B31 .4, Pipeline Transportation Systems for Liquids and Slurries

ASME B31 .8 , Gas Transmission and Distribution Piping Systems

ASME Boiler and Pressure Vessel Code (BPVC), Section II: Materials, Part D: Properties

ASME Boiler and Pressure Vessel Code (BPVC), Section V: Nondestructive Examination

ASME Boiler and Pressure Vessel Code (BPVC), Section VIII: Pressure Vessels; Division 1: Rules for

Construction of Pressure Vessels

ASME Boiler and Pressure Vessel Code (BPVC), Section VIII: Pressure Vessels; Division 2: Alternative Rules

ASME Boiler and Pressure Vessel Code (BPVC), Section IX: Welding and Brazing Qualifications

1

ASME I n ternationa l , 2 Park Avenue , New York, New York 1 001 6-5990 , www. asme . org .

1

2 AP I SPEC IF ICATION 6DSS

ASNT SNT-TC-1 A 2

, Personnel Qualification and Certification in Nondestructive Testing

ASTM A320/A320M 3

, Standard Specification for Alloy-Steel and Stainless Steel Bolting for Low-Temperature

Service

ASTM A370 , Standard Test Methods and Definitions for Mechanical Testing of Steel Products

ASTM A578/A578M , Standard Specification for Straight-Beam Ultrasonic Examination of Rolled Steel Plates for

Special Applications

ASTM A609/A609M , Standard Practice for Castings, Carbon, Low-Alloy, and Martensitic Stainless Steel,

Ultrasonic Examination Thereof

ASTM E8/E8M , Standard Test Methods for Tension Testing of Metallic Materials

ASTM E1 0 , Standard Test Method for Brinell Hardness of Metallic Materials

ASTM E1 8 , Standard Test Methods for Rockwell Hardness of Metallic Materials

ASTM E29 , Standard Practice for Using Significant Digits in Test Data to Determine Conformance with

Specifications

ASTM E1 1 0 , Standard Test Method for Rockwell and Brinell Hardness of Metallic Materials by Portable

Hardness Testers

ASTM E562 , Standard Test Method for Determining Volume Fraction by Systematic Manual Point Count

ASTM E1 245 , Standard Practice for Determining the Inclusion or Second-Phase Constituent Content of Metals

by Automatic Image Analysis

ASTM G48 , Standard Test Methods for Pitting and Crevice Corrosion Resistance of Stainless Steels and Related

Alloys by Use of Ferric Chloride Solution

AWS QC1 4

, Specification for AWS Certification of Welding Inspectors

EN 287-1 5

, Qualification test of welders—Fusion welding—Part 1: Steels

EN 1 0204 , Metallic products—Type of inspection documents

ISO 1 48-1 6

, Metallic materials—Charpy pendulum impact test—Part 1: Test method

ISO 5208:201 5 , Industrial valves—Pressure testing of valves

ISO 581 7, Welding—Fusion-welded joints in steel, nickel, titanium and their alloys (beam welding

excluded)—Quality levels for imperfections

ISO 6506-1 , Metallic materials—Brinell hardness test—Part 1: Test method

ISO 6508-1 , Metallic materials—Rockwell hardness test—Part 1: Test method

2

American Socie ty for Nondestruct ive Testing , 1 71 1 Arl ingate Lane , P .O . Box 2851 8 , Co lumbus , Oh io 43228 ,

www. asn t. org .

3

ASTM I n ternat iona l , 1 00 Barr Harbor Drive , West Conshohocken , Pennsylvan ia 1 9428 , www. astm . org .

4

American We ld ing Soc ie ty, 8669 NW 36 S treet, #1 30 , M iam i , F lorida 331 66-6672 , www. aws . org .

5

Eu ropean Comm i ttee for Standard ization , Avenue Marn ix 1 7, B-1 000 Brusse ls, Be lg ium , www. cen .eu .

6

I n ternat iona l Organ ization for S tandard izat ion , 1 , ch . de la Vo ie-Creuse , Case posta le 56 , CH -1 21 1 Geneva 20 ,

Swi tzerland , www. i so . org .

SPEC IFICATION FOR SUBSEA PIPELINE VALVES 3

ISO 6892-1 , Metallic materials—Tensile testing—Part 1: Method of test at room temperature

ISO 9606-1 , Qualification testing of welders—Fusion welding—Part 1: Steels

ISO 971 2 , Non-destructive testing—Qualification and certification of NDT personnel

ISO 1 0474, Steel and steel products—Inspection documents

ISO 1 51 56 (al l parts) , Petroleum and natural gas industries—Materials for use in H2S-containing environments in

oil and gas production

ISO 1 5607, Specification and qualification of welding procedures for metallic materials—General rules

ISO TR 1 5608:201 3 , Welding—Guidelines for a metallic materials grouping system

ISO 1 5609 (al l parts) , Specification and qualification of welding procedures for metallic materials—Welding

procedure specification

ISO 1 561 4-1 , Specification and qualification of welding procedures for metallic materials—Welding procedure

test—Part 1: Arc and gas welding of steels and arc welding of nickel and nickel alloys

ISO 1 561 4-7 , Specification and qualification of welding procedures for metallic materials—Welding procedure

test—Part 7: Overlay welding

ISO 1 7636-1 , Non-destructive testing of welds—Radiographic testing—Part 1: X- and gamma-ray techniques

with film

ISO 1 7637, Non-destructive testing of welds —Visual testing of fusion-welded joints

ISO 80000-1 :2009 , Quantities and units: Part 1—General principles

MSS SP-55 7

, Quality Standard for Steel Castings for Valves, Flanges and Fittings and Other Piping

Components—Visual Method for Evaluation of Surface Irregularities

NACE MR01 75 8

(al l parts) , Petroleum, petrochemical, and natural gas industries—Materials for use in

H2S-containing environments in oil and gas production

NACE TM0284, Evaluation of Pipeline and Pressure Vessel Steels for Resistance to Hydrogen-Induced

Cracking

SAE AMS 2750 9

, Pyrometry

3 Terms, Defin i tions, Acronyms, Abbreviations, Symbols, and Un i ts

3.1 Terms and Defin i tions

For the pu rposes of th is documen t, the fo l lowing defin i tions app ly.

3.1 .1

actuator

E lectric or hydrau l ic device bo l ted or otherwise attached to the valve for powered open ing and clos ing of the

valve .

7 Manu factu rers S tandard izat ion Socie ty of the Valve and F i ttings I ndus try, 1 27 Park S treet, NE , Vienna, Vi rg in ia

221 80 -4602 , www.mss-hq . com .

8

NACE I n ternationa l , 1 5835 Park Ten P lace , Houston , Texas 77084 , www. nace . org .

9

SAE I n ternational , 400 Commonweal th Drive , Warrendale , Pennsylvan ia 1 5096-0001 , www. sae . org .

4 AP I SPEC IF ICATION 6DSS

3.1 .2

assembler

manu facturer

Organ ization that performs assembly (see 3 . 1 .3) and con forms to the requ i remen ts of Section 1 5 .

NOTE The terms “assemb ler” and “manu factu rer” are used in terchangeab ly th roughou t th is documen t and are

cons idered to be equ ivalen t .

3.1 .3

assembly

Association of mu l tip le parts/componen ts in to a fin ished product, includ ing , as a m in imum , instal lation o f al l

pressu re-con tain ing parts and pressu re-con tro l l ing parts needed to ensu re con formance to app l icable pressu re

testing requ i remen ts.

3.1 .4

bid irectional seat

Valve seat des igned to seal against pressu re sou rce in e i ther d i rection .

3.1 .5

bid irectional valve

Valve des igned for blocking the flu id in e i ther d i rection .

3.1 .6

bleed (verb)

To drain or ven t.

3.1 .7

block and bleed valve

BB

Sing le valve wi th at least one seating su rface that, in the closed pos i tion , provides a seal against pressu re from

one end of the valve wi th the body ven ted .

3.1 .8

block valve

Gate , plug , or bal l valve that b locks flow in to the downstream condu i t when in the closed pos i tion .

NOTE Valves are both s ing le seated or double seated and e i ther b id i rectional or un id i rectional .

3.1 .9

body connection

Connection provided for in -service pu rposes such as leak detection , flu id in jection , flush ing , and /or hydrate

remed iation and as speci fied by the pu rchaser.

3.1 .1 0

body test port

Connection provided to perm i t mon i toring of seat leakage du ring test.

NOTE S ing le seated valves and downstream seating valves have no requ i remen t for a body test port.

3.1 .1 1

breakaway thrust

breakaway torque

Maximum th rust or torque requ i red to operate a valve at maximum pressu re d i fferen tial (MPD ) .

3.1 .1 2

by ag reemen t

Ag reed between manu factu rer and pu rchaser.