PWHT due to wet sour service

[ALA445]

Dear experts, A vessel is subjected to PWHT due to wet sour service. Is it mandatory that PQR needs to be qualified with PWHT cycle complying with NACE MR 0175 or compliance with UCS-56 would be sufficient? All material conform to the requirements of NACE MR 0175 / ISO 15156. Thanks for your kind input.

 

[cap1a79]

PWHT is not mandatory based on ISO-15156 although it is one of the best ways to comply with the hardness requirement.

But in case PWHT is possibly applied due to any reasons(ex., fails to comply with hardness), PQR shall cover the property on the expected number of cycles by PWHT.

Sihyoung Lee,

 

[0707]

If the vessel is subjected to PWHT due to wet sour service. IMO Is it mandatory that PQR needs to be qualified with PWHT cycle complying with NACE MR 017.

luis

 

[cap1a79]

Yes, it is. You can also confirm QW-407 of ASME Sec IX as per the welding method that PWHT is "essential" factor. Hence, PWHT on actual WPS shall be aligned with simulation test of the PQR.

Lee SiHyoung,