P4 to P5A PWHT : Varying thicknesses

[JIPMKWA]

We have a 1.813" M.W bottle header ( Existing ) P4A

Welding to a 1.75" M.W new bottle header spool piece ( New ) P5A


My question is - Obviously we go with the higher material grade for the PWHT procedure ( P5A ) , but should I also use the bigger thickness ( 1.813" instead of 1.750" ) for my soak time ? ( 1:45 mins as opposed to 2 hours ) I know this is a negligable amount of time but I was wondering for future reference should it involve thicker sections.



Thank you very much in advance

 

[racookpe1978]

Almost always, you must use the thicker section when two sections are being welded and then PWHT'ed.

I'm hedging my answer there, but I can think of no exceptions to that rule.

 

[metengr]

First and foremost, READ the code of construction for what defines nominal thickness for PWHT.

 

[JIPMKWA]

The term "nominal thickness" as used in Tables PW-39-1 through PW39-14 is defined as follows :

(A) For full penetration butt welds , the nominal thickness is the thinner of the parts being joined.




It was looking me right in the face under the P1 PWHT table. Thanks for the direction metengr

 

[racookpe1978]

Good find. Thank you metengr.

 

[metengr]

Sure, since I belong to Section I standards committee. I need to assist others.

 

[srk127]

we want to weld pipes P1+P5B, P1+P5A, P4+P5A, P4+P15E, P5A+P15E what electrodes to be used for TIG welding and SMAW and PWHT requirements.
P1=SA106-B or C, P4= SA335P11, P5A=SA335P22, A182F22, P5B A217C5, P15E=A182F91, A335P91,A217C12A. Can anybody help
Thank you

 

[c8829]

What is nominal thickness if both the full penetration butt welded parts(thickness 1.5") are of same thickness according to UW-40(f)(1).??
Does it need PWHT if its P.NO-1????

 

[c8829]

Sorry the thickness is 1.25"