PWHT requirement
PWHT requirement
(OP)
Hi all!
I am currently calculating an equipment with 30 mm C.S. shell thickness which is not required to be PWHT, but on the I/O nozzles we have to use C.S. reinforcement pads with 40 mm thickness because of design /space requirements. Shall we have to PWHT the entire equipment only because of these pads? Is it enough to local PWHT? Or do you know if there is any exception on the Code to avoid this PWHT?.
Thanks in advance for your support!
I am currently calculating an equipment with 30 mm C.S. shell thickness which is not required to be PWHT, but on the I/O nozzles we have to use C.S. reinforcement pads with 40 mm thickness because of design /space requirements. Shall we have to PWHT the entire equipment only because of these pads? Is it enough to local PWHT? Or do you know if there is any exception on the Code to avoid this PWHT?.
Thanks in advance for your support!





RE: PWHT requirement
The code talks about PWHT based upon thickness of welds, it does not say every weld must be PWHT.
Now, I would look at a thickened neck for reinforcement instead of pad. Use of forgings is an effective way to do away with reinforcing pads, especially when it forces you to do a local pwht.
RE: PWHT requirement
RE: PWHT requirement
RE: PWHT requirement
if you don't , you can go forging with a smaller pad.
anything is better than local PWHT.
RE: PWHT requirement
Not sure of the required and available reinforcement areas , however you can check if projecting nozzle neck on inside of vessel wall and reducing RF pad thickness to say 36 mm meets reinforcement calculations.
Be sure to check with yout process people , if projecting nozzle neck inside of vessel is acceptable to them , as this creates some liquid hold up when nozzle is located on bottom of vessel.
RE: PWHT requirement
Anyway i will post the final solution we decide.
Thanks again!