Thursday, January 7, 2010

RE: [MW:3989] Need confirmation as per code

Hi,

 

To the best of my knowledge fabrication codes for new components, such as B31.3 or 31.1 would discourage any welding with the system in full pressurized condition. As a bare minimum the system has to be depressurized and partly or fully emptied, due to the fact that any uncontrolled heat input during welding may create sudden water pressure and may damage components.

 

Welding on piping containing water is followed for wall/thickness restoration (in-service repair) in power plants , with the system being depressurized. ASME Sec-XI (repair code for Nuclear Components) permits it on a case by case basis, subject to satisfactory, design calculations, welding procedure/ mockup qualifications. As a bare minimum a mock-up to establish the welding parameters with controlled heat input should be established.   

 

This in-service repair has been approved for P1 and Austenitic S.S in the electric utilities.

 

Thanks.

 

Pradip Goswami, P.Eng

88,Garth Trails Crescent

Hamilton,Ontario, L9B2X1,Canada

Email-pgoswami@sympatico.ca

Email-pgoswami@quickclic.net

Tel-905-679-9677


From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of nawab ali bhatti
Sent: Wednesday, January 06, 2010 6:12 AM
To: materials-welding@googlegroups.com
Subject: [Norton AntiSpam] [MW:3979] Need confirmation as per code

 

 

Dear Members / Friends

 

I need code reference regarding following

                Q.1: Client wants to weld pads without releasing water?

                Q.2:  Can weld without releasing water, if yes what problems will appear in future?

                Q.3:  If we can weld, what is the code / standard acceptance criteria?   

                      subcontractor filled water for Hydrotest without completing the welding of some pads(plate 9mm) & shoe supports      

Materials as following

1.       Pipe Thickness is 23.83 mm

2.       Dia 18”

3.       Service : high pressure steam

4.       Design pressure/temperature is 53.4 bar/427C

5.       Test pressure is 148.2 Bar as per B31.3

 

 

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