KnaT
Mechanical
- Jan 18, 2012
- 38
We have a Casing Spool Body of Material AISI 4130 on which we are to conduct welding repairs followed by PWHT.
Our Client just restricted our Welding Procedure for carrying out the repair because it was approved for only 1 cycle PWHT.
The PQR coupon was Post weld heat treated at 630 deg. C for 4 hours and 45 Minutes.
For pressure vessels we used to decide the PWHT Soak times based on ASME Section VIII Div. 1 or 2 (e.g. 1 hour for upto 25mm thk. and additional time as the thickness increased.) For Soak time mentioned on the PQR we referred to QW 407 and made sure that our soak time of the coupon covered 80% of intended soak time of production welding.
The part under discussion is being governed by API 6A which is just mentioning that the PWHT variables shall be governed by the WPS.
Q: If I am using a WPS with 6 hours of PWHT soak time then am I supposed to PWHT that part for 6 hours regardless of its thickness?
or
Is there a way similar to ASME Sec. VIII Div. 1 for calculating PWHT time required of a specific thickness of API 6A components?
Any guidance in this regard will be more than appreciated.
Our Client just restricted our Welding Procedure for carrying out the repair because it was approved for only 1 cycle PWHT.
The PQR coupon was Post weld heat treated at 630 deg. C for 4 hours and 45 Minutes.
For pressure vessels we used to decide the PWHT Soak times based on ASME Section VIII Div. 1 or 2 (e.g. 1 hour for upto 25mm thk. and additional time as the thickness increased.) For Soak time mentioned on the PQR we referred to QW 407 and made sure that our soak time of the coupon covered 80% of intended soak time of production welding.
The part under discussion is being governed by API 6A which is just mentioning that the PWHT variables shall be governed by the WPS.
Q: If I am using a WPS with 6 hours of PWHT soak time then am I supposed to PWHT that part for 6 hours regardless of its thickness?
or
Is there a way similar to ASME Sec. VIII Div. 1 for calculating PWHT time required of a specific thickness of API 6A components?
Any guidance in this regard will be more than appreciated.
