Why for SA 387 GR 11, Pvelite is making PWHT mandatory, even thickness less than 16 mm ?

[inammanj123]

I am designing exchanger of 1.25Cr (SA-387 Gr 11). As per UCS 56, for P NO. 4 PWHT is not mandatory is thickness is less than 16 mm, but Pvelite is making PVELITE mandatory PWHT even if thickness is 12 mm. Kindly clarify.

 

[david339933]

The exemption is only for circ seams in pipe/tube.

 

[inammanj123]

david339933, thankyou for clarifying. So it means table UCS-56 thickness requirement is not just for plate, further detail should be taken from UCS 56-3, Where it gives detail that 16 mm thickness exemption is only when made from pipe of less than 16 mm, for plate material, all thickness required PWHT ucs-56-3 (a), (1)

 

[r6155]

@ inammanj123
Didn't you think that PWHT is required?
Heat exchanger Design includes calculations and Inspection Plan and tests.
What is the level of RT you are thinking of for PWHT?

Regards