Hot forming heads, PFHT necessary?
thread292-447220
ElCidCampeador (Mechanical)(OP)11 Dec 18 07:53
Hi,
I have an ellipsoidal head (Mat. SA 516 GR.70, D.I.1000 Thk.60mm) that has to be welded to a pressure vessel designed acc.to ASME VIII Div.1.
The vessel is impact tested acc. to UCS 66.
The supplier of head will hot press @ 920°C the head without PFHT of normalization.
Acc. to ASME I need to d ...
Hot forming heads, PFHT necessary?
thread292-447220
ElCidCampeador (Mechanical)(OP)11 Dec 18 07:53
Hi,
I have an ellipsoidal head (Mat. SA 516 GR.70, D.I.1000 Thk.60mm) that has to be welded to a pressure vessel designed acc.to ASME VIII Div.1.
The vessel is impact tested acc. to UCS 66.
The supplier of head will hot press @ 920°C the head without PFHT of normalization.
Acc. to ASME I need to do a welding test coupon and have PQR with impact test.
Do you think it's necessary a PFHT of normalization for the head? (N.B: Vessel will take PWHT per ASME later, but I know that PWHT and PFHT are not the same)
Vessel is impact tested, the fact that normalization could change curves in figure UCS-66 doesn't change the mandatory request of a test coupon (which is required in any case), so why doing a PFHT which will increase costs?
This is my idea, I wait your opinions. Thanks.
david339933 (Industrial)11 Dec 18 16:57
PFHT is required when heads are cold formed...your head is hot formed. PFHT is not required.
PWHT and PFHT are essentially the same thing, if the governing thickness is considered to be the full thickness of the plate.