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PQR coupon for dissimilar thickness

PQR coupon for dissimilar thickness

Postby laurudolphy » Wed Nov 19, 2014 12:49 pm

Dear Friends,

Client specification is as it follows:
Regarding WPS, where 3/8" < T < 1", then the qualified range will be from 0,5T to 1,5T. All other AWS D1.1 requirements apply.

I have a production weld, 24" pipe with thickness 12,7 mm to a 24" pipe with thickness 25 mm. There is a transition taper of 1:4 at this joint. The internal diameter shall be flush and the weld type is butt joint single V groove, partial penetration. So, I need to develop a WPS for this joint.

I am thinking as it follows:

Using a single pWPS, I shall weld,
Coupon No. 1 - 12 mm thickness to 12 mm thickness,
Coupon No. 2 - 25 mm thickness to 25 mm thickness.
Both test coupons will be tested with NDT, mechanical tests and CVN and I will prepare two PQR.
PQR No. 1 will qualify from 12 mm to 18 mm with CVN.
PQR No. 2 will qualify from 16 mm to 47.5 mm with CVN.

Then I will write a new WPS based on the above two PQR and use this for the production joint that is mentioned above (12.7 mm to
25 mm).

Could you please let me know if you think that my proposal would be acceptable by the client.
Any other opinion about that?

Thanks in advance
laurudolphy
 
Posts: 51
Joined: Wed Aug 14, 2013 1:19 pm

Re: PQR coupon for dissimilar thickness

Postby art » Fri Nov 21, 2014 12:48 am

You are qualifying the thickness of the weld which is 12 mm on a 24" diameter pipe.
AWS D1.1 Table 4.2 gives you the range of qualification for a 12 mm pipe wall thickness.

Regards,
Art
art
 
Posts: 1
Joined: Fri Nov 21, 2014 12:41 am

Re: PQR coupon for dissimilar thickness

Postby laurudolphy » Fri Nov 21, 2014 1:53 pm

Hi Art,
Thanks for your reply.
Unfortunately, the client specs are more stringent than the AWS D1.1.
I have mentioned the thickness limitation in my first post.
Besides the thickness limitation, the essential variable quoted by the client is "delivery condition".

In actual construction the joint/material is as follows:
24" quenched pipe API 5L X52 with 12.7 mm thickness - welded to - 24" pipe formed from 25 mm EH36 plate TMCP (Thermo-Mechanically Controlled Processed).

Alternatively I was thinking if I can get a 14" pipe API 5L X52 with 12.7 mm thickness and also roll a EH36 TMCP plate with 13 mm thickness to 14" pipe so as to join them using 6G position.

In such a case I will avoid to weld 2 coupons as mentioned in my initial query.

Appreciate your feedback.
laurudolphy
 
Posts: 51
Joined: Wed Aug 14, 2013 1:19 pm

Re: PQR coupon for dissimilar thickness

Postby Ballbearing » Sat Nov 22, 2014 5:37 am

As Art stated you are only qualifying the weld thickness (12.7 mm).
Go with your 14" proposal or just use some of your production pipe / rolled plate.
Whichever is quicker and easier,
Cheers,
BB
Ballbearing
 
Posts: 76
Joined: Wed Jun 12, 2013 10:11 pm


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