test coupons

[metboss]

Hi all,
(Applicable standard: API 6A (latest ed) and our equipment is Wellhead PSL-3)


As per our internal standard, test coupons shall be either sacrificial production part or prolongation method to qualify production parts having identical size and shape.
But our vendor proposed a seperate QTC method and as per their justification, it is acceptable as per API 6A.
Can anybody advise me "what is the differences among sacrificial production part, prolongation method & a seperate QTC if equipment falls under PSL-3 ??
What is their impact on qualification ?

Regards

 

[redpicker]

You really need to get a copy of the standard and read it for yourself to answer these questions.

It has been a while since I dealt with 6A, and I am sure I have not read the latest edition. However, I do believe that for PSL-3 products, the test specimens may come from either a prolongation, a sacrificial production part, or a separate QTC. There are specific size limits on the QTC, based on PSL and product size (I believe) as well as processing limitations.

As far as the "impact" on qualification, I am not sure I understand what you mean. It sounds as if your internal standard does not allow the use of the QTC. Either you can follow your internal standard or not. Is your vendor refusing to follow your standard? Is he the only vendor available?

rp