PWHT for Clad Pipe

[xuanthien]

I have Pipe CS A106 thickness 25mm + 3mm Overlay 316L designed follow ASME B31.3. I know that when we design ASME B31.3 all Carbon Steel material have thickness above 19mm shall be performed PWHT. But i don't know Carbon Steel + Overlay need to perform PWHT or not. What range temp PWHT? What problem for Corrosion overlay when we perform PWHT?

 

[sk10009]

No need to PWHT because the thickness of C.S is below 19mm.

 

[xuanthien]

In case thickness CS above 19mm, we need to perform PWHT or not. (CS A106 thickness 25mm)

 

[metengr]

The requirement for PWHT for P-No 1 base material in Table 3.3.1 in B31.3 is 20mm or less in thickness (before cladding). Your base metal thickness is below 20mm, so PWHT is not required.

 

[weldstan]

Under the 2014 edition of B31.3, PWHT would no be required. Under the previous edition it would be.

 

[weldstan]

Please also note that the designer/Owner may elect not to PWHT when such PWHT would prove detrimental to the service.