WPS AND PQR IMPACT TESTING

[dygorane]

MDMT for vessel is -50°F for design pressure. There one more condition other than design pressure (pressure less than design pressure) which needs MDMT of -58°F.

Using reduction ratio UCS-66 base metal needs to be impact tested at -50°F and not at -58°F.

Can we take reduction for impact testing of WPS and PQR? Can we impact test WPS and PQR at -50°F OR we have to impact WPS and PQR at -58°F?

Thanks
Dinesh

 

[AravindSujay]

Hi, MDMT not only depends on temperature, but also on thickness of the base material. The fig.UCS-66 of ASME depends on the material too. pls be specific.

 

[gr2vessels]

Dinesh,
You PQR is qualified for a specific impact test requirement, say -50F. That means your fabricated component must be impact tested at least -50F. How do you arrive to the -50F impact test temperature, that is driven by the thickness and the applicability of UCS-66 and has nothing to do with your PQR. Again, if the impact test requirements for your pressure component requires test at -75F, then your PQR qualified for only -50F is not acceptable and you have to produce a PQR qualified at -75F.
cheers,
gr2vessels

 

[weldtek]

See UG 84(g)(4) paraphrasing, 'test temp for welds and HAZ's shall not be higher than req'd for base metals'