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PWHT of welded overlay pressure vessel

PWHT of welded overlay pressure vessel

Postby zirsald » Fri Dec 06, 2013 4:55 pm

Dear forum members,
For a pressure vessel that is being constructed as per ASME VIII-1 by material SA-516 Gr 60 with thickness 40 mm I have to perform 3 mm inconel 625 welding overlay. Due to the fact that the wall thickness of the vessel is higher than 38 mm (ASME VIII-1, UCS-56) PWHT is required. Could you please let me know whether the PWHT shall be performed before or after welding overlay?
thanks,
Zirsald
zirsald
 
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Re: PWHT of welded overlay pressure vessel

Postby mohd » Sat Dec 07, 2013 5:13 pm

dear zirsald,

As per UCL-34, PWHT in range of carbide precipitation as well as within the range where a sigma phase may form could result in failure of the vessel.

PWHT could be performed on base metal before applying welding overlay provided UCS-56-Note (2)(c)(5) minimum preheating requirement is met.

Interpretation: VIII-1-98-108

Subject: Section VIII, Division 1 (1998 Edition, 1999 Addenda); UCL-51 and Table UCS-56

Date Issued: March 22, 2000

File: BC00-080


Question (1): A pressure vessel is constructed of P-No. 1 and P-No. 8 materials, and is intended for lethal service. The vessel is PWHT. After PWHT, but before performing the hydrotest, the interior of the vessel has a stainless steel lining applied using plug welds. Does Note (2)(c)(5) of Table UCS-56 in Section VIII, Division 1 permit the liner to be applied after the vessel has been PWHT without the need to perform any additional heat treatment?


Reply (1): Yes, provided that the preheat requirements are met.

You can simulate PQR accordingly.

Hope this help,

regards,
mohd
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Re: PWHT of welded overlay pressure vessel

Postby zirsald » Mon Dec 09, 2013 6:27 pm

Thanks a lot Mohd
zirsald
 
Posts: 14
Joined: Mon Sep 30, 2013 1:51 pm

Re: PWHT of welded overlay pressure vessel

Postby sirajsharmapunj » Tue Sep 05, 2017 6:08 am

hey guys,

I have a similar problem. i have a 78 mm thk Boiler Plate (A516-70) that is needed to be weld to a 10 mm thk SS304L lining. This is to be used as a flange at a boiler. Since the boiler plate is 78 mm i understand there is a need for PWHT. However, this is a combination of 2 disimmilar materials. Can i perform PWHT on this? If yes, how do i do it?

Regards,
Siraj
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