PWHT with impact test
PWHT with impact test
(OP)
Hi all,
we have a filter(OD=508mm, 25thk, 714mmLG)and material is A516 Gr60.based on MDMT=-45c, impact test is required and the service is not lethal, but our client has made a comment that PWHT is mandatory with reference to UCS-79.
please let me know your idea and direct me to find the best solution.
Thank you very much
we have a filter(OD=508mm, 25thk, 714mmLG)and material is A516 Gr60.based on MDMT=-45c, impact test is required and the service is not lethal, but our client has made a comment that PWHT is mandatory with reference to UCS-79.
please let me know your idea and direct me to find the best solution.
Thank you very much





RE: PWHT with impact test
RE: PWHT with impact test
I would be happy to entertain an argument to the contrary though from my PV fabricator or designer - as it might result in savings.
However, hanging on 0.5mm seems like splitting hairs and natural conservativeness might say "Stick with the PWHT". What if the plate thickness came in over tolerance??
Some other considerations: What weld process is planned? What NDE is specified??
A 25mm full thickness pressure welds mean a good chance for undetected defects to lurk and possibily bring the vessel undone should the low temp be reached and combine with detrimental residual stresses...
... I think I just convinced myself to stick with PWHT.
Cheers
Rob
RE: PWHT with impact test
RE: PWHT with impact test
RE: PWHT with impact test
Still, if you're swinging on a 0.5mm / 0.08% argument... doesn't sound like much of an argument.
The practical logisitics of PV manufacture in Australia would drive the vessel to be PWHT'd.
Cheers
Rob
RE: PWHT with impact test
2) Plate SA 516-60 t=25 mm shall be normalized and Charpy test shall be at -51°C (see SA-20), the WPQT impact test shall be at -45°C.
I you think that these test pass the requirements without PWHT ...so no PWHT be performed.
I recommend PWHT
Remember: all weld shall be full penetration
Regards
rhg
RE: PWHT with impact test
regarding ucs79, for fabrication by cold forming, when the fiber elongation is more than 5% and the material requires impact test, PWHT is mandatory,but in my case, the elongation is not more than 5%,and PWHT requirement is not mentioned at my clinet SPEC.but for this case they insist to perform PWHT.