PWHT as per UCS-56
PWHT as per UCS-56
(OP)
Per UCS-56 for P-No. 1 state for thickness up to 38 mm pwht is not mandatory if preheat applied during welding at min temp. 200 deg F.
I was ordered 38 mm thk used for shell. Since material under tolerance for SA516-70 (refer to SA20) the actual thk is more than 38.0 mm. The min actual thk is 38.4 mm. There are no actual thk under 38.0 mm. Shall I perform pwht for this case?
I was ordered 38 mm thk used for shell. Since material under tolerance for SA516-70 (refer to SA20) the actual thk is more than 38.0 mm. The min actual thk is 38.4 mm. There are no actual thk under 38.0 mm. Shall I perform pwht for this case?





RE: PWHT as per UCS-56
Regards,
Mike
RE: PWHT as per UCS-56
RE: PWHT as per UCS-56
My opinion is that generally speaking, material is not going to come under the ordered thickness except by that amount allowed by SA 20 which is 0.010". In most cases it will run slightly over the ordered thickness as you have found. Keeping in mind that Code requirements are minimum, Metengr is giving you good advice to err on the side of safety.
However, by Code rules, you are under no obligation to mic each plate for an exact thickness and PWHT because it exceeds the nominal 38 mm (1.5") by 0.4 mm or 0.015".
RE: PWHT as per UCS-56
Joe Tank