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Re: [MW:10329] RE: 10320] PWHT of tank shell plates as per API 650

By Materials & Welding
Hi
 
If i am not wrong the below clause is for the flush type cleanout fittings rather than the shell butt welded plates
 
Thanks & Regards,
 
K. Babu

----- Original Message -----
From: pgoswami
Sent: Monday, March 14, 2011 10:23 AM
Subject: [MW:10323] RE: 10320] PWHT of tank shell plates as per API 650

Mr Malhotra,
 
Please refer the following clause of API 650 regarding PWHT, for Gr I,II,III,IIIA steel,Table 4-4a illustrates the grouping, which mostly applies to Carbon Steel.
 
If the steel used falls in any one of the above group and the weld exceeds 25 mm (1 inch) in thickness ,PWHT would be required as per clause 5.7.4., 5.7.4.3
 
Thanks.
 
 
Pradip Goswami,P.Eng.IWE
Welding & Metallurgical Specialist & Consultant
Ontario,Canada.
Email-pgoswami@sympatico.ca,

5.7.4 Thermal Stress Relief: When the shell material is Group I, II, III, or IIIA, all opening connections NPS 12 or larger in nominal diameter in a shell plate or thickened insert plate more than 25 mm (1 in.) thick shall be prefabricated into the shell plate or thickened insert plate, and the prefabricated assembly shall be thermally stress-relieved within a temperature range of 600°C – 650°C (1100°F – 1200°F) for 1 hour per 25 mm (1 in.) of thickness prior to installation. The stress-relieving  requirements need not include the flange-to-neck welds or other nozzle-neck and manhole-neck attachments, provided the following conditions are fulfilled:


From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of Manav Malhotra
Sent: Sunday, March 13, 2011 1:08 PM
To: materials-welding@googlegroups.com
Subject: [MW:10320] PWHT of tank shell plates as per API 650

Dear Members,
 
We have crude and petroleum tanks in which shell plates thickness vary from 8 mm to 45 mm and the tanks are constructed by our contarctors. We just want to be sure whether PWHT has to be carried out or not. Our contrcator says as per API 650 there will be no PWHT of shell plates. I also refered API 650 but couldnt find any thing about pwht of shell plates. Cab any one help me out on this issues, in case pwht is to be carried out for shell plates, kindly provide the reference clause no from API 650.
 
Regards,
 

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