PWHT for vessel constructed of 304SS clad

[engineermat]

ASME VIII Div.1 UCL-34(b)states that vessels or parts of vessels constructed of chromium stainless steel integral or weld metal overlay cladding and those lined with chromium stainless steel applied linings shall be postweld heat treated in all thicknesses.

Is this requirement applied to 304 austentic stainless steel?

Thanks.

 

[metengr]

engineermat;
Is the vessel being fabricated under UCL or UCS? The reason for my asking is that different rules apply for carbon steel substrate construction and weld overlay versus an integrally clad vessel construction, as is discussed in UCL. Read the scopes of each section carefully.

If the vessel is being built to UCL, review UCL-34 (a) and (b). To summarize, for UCL-34 (a) PWHT is only required if the base material requires PWHT, and if so, you can use the exemption notes in Table UCS-56 for weld overlay.

(b) the chromium stainless steel in this section for PWHT refers to either ferritic or martensitic stainless steels, and not austenitic stainless steels because these are not air hardening.

 

[engineermat]

met,

Thanks.

Vessel will be fabricated under UCS.