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Re: [MW:14373] Acceptance criteria for welding of Cupro-Nickel pipe

By Materials & Welding
Dear Mr. Anil,
 
We could not come up even after all possible attempts like extensive cleaning, enclosure for the welding, purging with Argon etc. Most of the defects (especially porosity) exist wherever start/stops of welding are there.
 
Regards,
A Megnath
----- Original Message -----
From: Anil Hegde
Sent: Monday, May 28, 2012 10:11 AM
Subject: Re: [MW:14369] Acceptance criteria for welding of Cupro-Nickel pipe

Mr Megnath ,
 
Kindly clean the joint surface by buffing wheel  & then take RT .
 
It will get cleared
 
Regards
Anil Hegde
 
 
On Sat, May 26, 2012 at 11:57 AM, Megnath <megnath@gmail.com> wrote:
Dear friends,
We are doing welding (GTAW using 99.99% Argon & 70-30 cnsumable) of
CuNi - 90-10 pipe and all of them fall under class 1 pipe and forced
to examine the weld by Radiograpy. On review of radiograph, none of
the joint gets cleared. The only problem with welding is "POROSITY".
As pe our contract, the size of permissible porosity is 0.2t
(thickness of pipe is 3,4mm) and even 1mm porosity calls for repair.
Could any one share your knowledge on the following.
1. Acceptance criteria for RT of CuNi pipe weld
2. How to overcome from the porosity

Best Regards,
Megnath

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