Post weld heat treatment with AWS D1.1
Post weld heat treatment with AWS D1.1
(OP)
Hello, I have the following question.
We have welded a trunnion to a pipe with a full penetration single side weld. This weld, because of the thickness of the trunnion (65mm), has required PWHT as specification requires PWHT for thickness over 40mm. After being treated, a modification of the dwg requires a fillet weld with a leg of 45mm. As per specification this fillet weld would require PWHT.
I would like to know if the requirement of PWHT can be avoided, as they have already qualified a CJP WPS without PWHT, that would cover up to 40mm (over 40mm would require PWHT), and this would cover all fillet welds.
We have welded a trunnion to a pipe with a full penetration single side weld. This weld, because of the thickness of the trunnion (65mm), has required PWHT as specification requires PWHT for thickness over 40mm. After being treated, a modification of the dwg requires a fillet weld with a leg of 45mm. As per specification this fillet weld would require PWHT.
I would like to know if the requirement of PWHT can be avoided, as they have already qualified a CJP WPS without PWHT, that would cover up to 40mm (over 40mm would require PWHT), and this would cover all fillet welds.





RE: Post weld heat treatment with AWS D1.1
You are governed by the specification - this overrules the code.
"As per specification this fillet weld would require PWHT. "
If that is the requirement then there is no way to avoid other than by a Concession Request to the Client / Owner
Regards,
BB
RE: Post weld heat treatment with AWS D1.1
RE: Post weld heat treatment with AWS D1.1
"Post weld heat treatment with AWS D1.1" is the title of the post
Cheers,
DD
RE: Post weld heat treatment with AWS D1.1
Best regards - Al
RE: Post weld heat treatment with AWS D1.1
If the 'engineer' for your client persists in demanding D1.1, the essential elements are; width/size of heating band, temperature ramp-up rate [degrees/hour], holding [soak] temperature, soak duration, maximum variation of temperature across the PWHT'd area, ramp-down rate, temperature where the PWHT can be stopped and the weldment allowed to cool naturally. Bet you a farthing that that person cannot spec these items.
RE: Post weld heat treatment with AWS D1.1
It has been my experience in this forum that many of our questioners are confused. Knowing that D1.1 does not require PWHT but B31.3 does and the questioner is from the Petroleum industry, would it not be possible that the trunnion attached to a pipe is governed by B31.3 - not D1.1? Or the requirement was specified in the Contract Engineering Specifications as you also indicated.
It is also noted that 78500902 has not responded to any of the replies made to date.
RE: Post weld heat treatment with AWS D1.1
This is governed by the specification that requires PWHT. As mentioned by gtaw and weldstan AWS D1.1 refers to the specification as itself doesn't contemplate PWHT. I have read the complete specification and it is based in LR rules for offshore structures. The good news is that these rules contemplate PWHT as not mandatory, but recommended, therefore I have submitted a clarification/deviation to the client to accept the complete weld (CJP+fillet) without PWHT with the background of qualified WPS without PWHT. I think this should be enough for them to accept the "deviation".
thank you!
RE: Post weld heat treatment with AWS D1.1