Purge Useful for SocketWelds? 3

[Aife]

I'm dealing with a 3rd party inspector who is reading the client specification and following it to the letter.

He is insisting that we have a purge to weld 2 socket welds (duplex material). I Also have 2 senior project engineers telling me that the specification infers that the purge is for butt welds only, it's silly to purge on a socket weld and it's 'common-sense' that purges aren't required on fillet welds. (I read the specification and agree with the 3rd party inspector, but I don't have the experience of my senior engineers. I'm just taking the spec as it's written, and it doesn't specify that butt joints are the welds requiring purge.)

Mt 2 senior project engineers are insisting that I submit a query to avoid this clash for future work, and I've been unable to find anything in my welding texts to support the need for a purge while performing sockweld/fillet welding. Could someone here offer some advise on where to look for further information?

 

[GregLamberson]

Aife

That's the 3rd party inspector's job, if the specification needs to be modified, then it needs to be modified but he has to follow the specification "to the letter" unless a waiver is requested and granted.

Can you offer a little more information, what is the governing code, what environment are you in? Is this hot work?

Greg Lamberson, BS, MBA
Consultant - Upstream Energy
Website:

http://www.oil-gas-consulting.com

 

[metengr]

He is insisting that we have a purge to weld 2 socket welds (duplex material). I Also have 2 senior project engineers telling me that the specification infers that the purge is for butt welds only, it's silly to purge on a socket weld and it's 'common-sense' that purges aren't required on fillet welds.

I totally agree with the senior project engineer statement, purge is not required for socket welds.

PS; I would go back and discuss the above with the client.

 

[Aife]

Greg:

The client specification refers to B31.3 and we are welding Duplex Pipe (UNS S31803) using GTAW.

metengr:

I would like to back up my request to forgo the need for the purge, and am looking for some documentation to back-up my reasoning. I've been unable to find anything to support my request, just the opinions of 2 senior engineers.

 

[stanweld]

Depending on the corrosive environment, purges are sometimes specified by the Engineer or Owner for socket welds. If there is ambiguity in the language of the specification, simply generate an RFI asking if the Specification requirements applied to socket welds.

In all of our projects where purging of socket welds was required, it was clearly defined.

 

[metengr]

Aife;

I would like to back up my request to forgo the need for the purge, and am looking for some documentation to back-up my reasoning. I've been unable to find anything to support my request, just the opinions of 2 senior engineers.

You are probably not going to find any Codes or Standards that will provide specific guidance for using a back purge on socket weld joints. In my opinion, if suitable joint preparation and cleanliness guidelines are followed, back purge should not be required.

 

[deanc]

I have seen a purge required on any number of items for what seemed like some rather strange reasons.

Is the client concerned about inner surface contamination (scale,oxides)during heating? Is this an ultra pure system?