ASME IX requirement for WPS PWHT Temperature range Vs PQR PWHT Temperature

[marcolino21576]

Hello,

I have one question related to a WPS for A351 CF8M (basically a cast 316SS version).

The PQR was performed with a PWHT (solution annealing and water quenching) to 1075°C (1967°F), with impact test.

Given that QW 407.2 refers to QW 407.1, and the P no. of the base metal being 8, the applicable clause of 407.1 shall be
407.1 (b) (2) which states "PWHT within a specified temperature range", my question is: what is the "specified temperature range" within I could change the PWHT temperature of my WPS without needing to qualify a new PQR?

Thank you very much to everybody for your kind assistance

Marco

 

[david339933]

Standard Designation: BPV Section IX
Edition/Addenda:
Para./Fig./Table No:
Subject Description: Section IX, QW-407.1, PWHT of Weld Procedure
Date Issued: 12/15/1978
Record Number: BC-78-488
Interpretation Number : IX-78-102
Question(s) and Reply(ies):
Question (1): What is meant by the term "range" as it appears in the wording for PWHT in QW-407.1?

Reply (1): The Code does not address itself to specifying a postweld heat treatment temperature range. It would be the responsibility of the manufacturer or fabricator to develop a temperature range suitable for the material used and designated in the Welding Procedure Specification. It is hoped that a postweld heat treatment temperature would be selected to fall midway in the range developed.

Question (2): How much may the temperature of PWHT of WPS qualification coupons differ from the PWHT temperature of the vessel?

Reply (2): There is no connection between the PWHT of welded test coupons and the PWHT requirements of a vessel. The values may be similar, but are not required to be so by Code requirements.

ATTENTION

The foregoing interpretation has been further considered and the following corrected interpretation to Question (2) sent to the inquirer.

Corrected Issued: September 25, 1979

Question (2): How much may the temperature of PWHT of WPS qualification coupons differ from the PWHT temperature of the vessel?

Reply (2): The PWHT of the welded test coupons and the PWHT of the vessel must be of the same type of PWHT as designated for the various conditions outlined in QW-407.1

 

[marcolino21576]

Thanks David,

much appreciated!

Kind Regards

Marco