Effect of Heat treatment on pressure vessel with seal welded trays
Effect of Heat treatment on pressure vessel with seal welded trays
(OP)
We have a pressure vessel which will be post weld heat treated. The vessel materials is SA516-70. Trays materials is 410S stainless steel. The trays are seal welded to the support ring (Carbon Steel).
We plan to perform the whole vessel PWHT after the seal weld of tray to support ring. But we worry about the distortion and warping of trays during PWHT due to the thin thickness of tray and different thermal coefficient of carbon steel and 410S.
Does anybody has the experience before? please advise. Thanks.
We plan to perform the whole vessel PWHT after the seal weld of tray to support ring. But we worry about the distortion and warping of trays during PWHT due to the thin thickness of tray and different thermal coefficient of carbon steel and 410S.
Does anybody has the experience before? please advise. Thanks.





RE: Effect of Heat treatment on pressure vessel with seal welded trays
RE: Effect of Heat treatment on pressure vessel with seal welded trays
Do you means that the warping and distortion will not occur during the PWHT?
The vessel diameter is 4200mm. Tray thickness:3 mm.
RE: Effect of Heat treatment on pressure vessel with seal welded trays
No. It can occur because of exposure to elevated temperature during PWHT. Why did you install the tray structure before PWHT? Normally, carbon steel pads are used during fabrication and PWHT to allow structural welding to these pads after PWHT of the main vessel.
If you already have welded the tray structures before PWHT, I would suggest you install some temporary supports for PWHT.
RE: Effect of Heat treatment on pressure vessel with seal welded trays
RE: Effect of Heat treatment on pressure vessel with seal welded trays
RE: Effect of Heat treatment on pressure vessel with seal welded trays