Post Weld Heat Treating ASME B31.3 Help
Post Weld Heat Treating ASME B31.3 Help
(OP)
My company has provided two vessels that required PWHT. Unfortunatly the vessel manufacturer only stress relieved for 15 minutes and it appears that it should have been done for a minimum of 1 hour. The vessels have already placed in service on hydrocarbon gas.
Can the existing vessels be stress relieved after cleaning or is it necessary/easier to replace the vessels?
Thanks
Can the existing vessels be stress relieved after cleaning or is it necessary/easier to replace the vessels?
Thanks





RE: Post Weld Heat Treating ASME B31.3 Help
Please note that B31.3 is not applicable to pressure vessels.
RE: Post Weld Heat Treating ASME B31.3 Help
I do know that the vessels were to be rated to 200 psig with .125 corosion allowence. The material is carbon steel of some type, made from plate, rolled and welded. I find your comment regarding pressure vessels interesting.
Inspection is catching it now. Installation occured a year ago for one, and 6 months for another. As for our QA, it may have been that the requirement was not passed along through purchasing. PWHT was performed by an outside vendor who did so to a code they may have selected. Everything probably appeared correct to our QA. We'll figure out where the fault lies later so we can prevent furture mistakes.
We obviously have some additional research to do. I'll let you know how it turns out.
Thanks again
kaf
RE: Post Weld Heat Treating ASME B31.3 Help
Are these stamped ASME Code Pressure Vessels ? Section VIII ?
Is there a U-1 data report to which you can refer ?
MJC
RE: Post Weld Heat Treating ASME B31.3 Help
The application is draining liquids from a fuel gas compressor line. We are using nitrogen as a motive gas to "pump" the liquid away since P2 is greater than P1. The unit functions as a blowcase pump.
RE: Post Weld Heat Treating ASME B31.3 Help
we can take suitable result.
RE: Post Weld Heat Treating ASME B31.3 Help
If the material is carbon steel there fore the Pno. is 1 and you can attention to table UCS-56 from ASME sec VIII Div.1 and solve your problems.
RE: Post Weld Heat Treating ASME B31.3 Help
Material is carbon steel. From here and other sources, referenced spec should have been ASME Section VIII, Div. 1 Table UCS-56. I am discussing with the client tomorrow.
Thanks for the help