Is PWHT required for A333 Gr.6 Piping Weld joints?
Is PWHT required for A333 Gr.6 Piping Weld joints?
(OP)
We need to weld A333 Gr-6 pipes for a modification.
Should we go for the PWHT of these weld joints. The Pipe wall thickness is 12.5 mm.
As per B31.3 Table 331.3.1, PWHT requirment does not specify separately for LTCS PWHT...it talks about chemical composition and thickness as the criteria.
Please opine......!
Should we go for the PWHT of these weld joints. The Pipe wall thickness is 12.5 mm.
As per B31.3 Table 331.3.1, PWHT requirment does not specify separately for LTCS PWHT...it talks about chemical composition and thickness as the criteria.
Please opine......!





RE: Is PWHT required for A333 Gr.6 Piping Weld joints?
If your WPS / PQR demonstrate hardness in the as-welded condition on the order of 215 BHN or lower (or around 225-230 Hv for microhardness) throughout the weldment and HAZ, and if you are not sour or are at least less than 70 kPa partial pressure H2S, I am inclined to not do PWHT.
Regards,
SNORGY.
RE: Is PWHT required for A333 Gr.6 Piping Weld joints?
RE: Is PWHT required for A333 Gr.6 Piping Weld joints?
RE: Is PWHT required for A333 Gr.6 Piping Weld joints?
Clause 4.2 of standard SA333/SA333M for HEAT TREATMENT states:-
"All seamless and welded pipes, other than grades 8 and 11, shall be treated to control their microstructure in accordance with one of the following methods".
In fact this clause prompted me to think about PWHT in A333 GR. 6 to have a impact strnght at low temperautres.
RE: Is PWHT required for A333 Gr.6 Piping Weld joints?
if you are a standard nom thickness less than 3/4"
I would not pwht at all
and you should not have to worry about hardess or impacts if you are using a weld procedure that is already qualified to these.
this material is normally no problem to get hardess below 200 bhn an impacts at -45*F