PWHT?
PWHT?
(OP)
A heat treated vertical pressure vessel needs replacement of top dished head. After welding the new head, does the vessel require to be heat treated fully or a partial heat treatment of top half would be sufficient? What are the general conditions to adhere for stress relief?
Thanks, SBlowers
Thanks, SBlowers





RE: PWHT?
how thick is the weld joint to shell?
was the pwht for service and is the vessel still in the same service?
RE: PWHT?
RE: PWHT?
RE: PWHT?
If it has undergone PWHT already I would think only the new weld would be needing PWHT.
Same thing when making a vessel in two parts, pwht-ing them.
Then welding a closure seam and local pwht on the closure seam only.
grtz
RE: PWHT?
The same also holds true for NDT, unless other options are evaluated by the Inspector and, if necessary, from the Jurisdiction.
RE: PWHT?
If openings are in the new head, the head and nozzles can be independently post weld heat treated prior to welding the head to the shell. After making the head to shell weld it is then subject to PWHT.