NACE hardness survey for a WPS
NACE hardness survey for a WPS
(OP)
Good morning all,
I have a company that developed a Welding procedure for joining 4130 weldneck flange to A106 B line pipe, the PQR and resulting WPS is fine, but the number in the NACE hardness survey was not properly converted to vickers hardness, so they used the WPS and welded a new coupon this month and PWHTed it and re-tested the hardness testing and the numbers came out well. The problem is, they did not use the same wall thickness as the that was used in the original WPS in 1999, the original coupon was 4.5"x0.674" and the new coupon is 3"x0.625".
Questions:
1. Can we accept it like that and just limit the thickness range qualified by the NACE to 2 X 0.625?
2. Or can we accept it for the original range of 2 X 0.674"
3. Or Is it even acceptable for the coupon for NACE and PQR to be different provided they were welded with the same WPS (processes, and variables).
I appreciate any input.
Thanks.
I have a company that developed a Welding procedure for joining 4130 weldneck flange to A106 B line pipe, the PQR and resulting WPS is fine, but the number in the NACE hardness survey was not properly converted to vickers hardness, so they used the WPS and welded a new coupon this month and PWHTed it and re-tested the hardness testing and the numbers came out well. The problem is, they did not use the same wall thickness as the that was used in the original WPS in 1999, the original coupon was 4.5"x0.674" and the new coupon is 3"x0.625".
Questions:
1. Can we accept it like that and just limit the thickness range qualified by the NACE to 2 X 0.625?
2. Or can we accept it for the original range of 2 X 0.674"
3. Or Is it even acceptable for the coupon for NACE and PQR to be different provided they were welded with the same WPS (processes, and variables).
I appreciate any input.
Thanks.





RE: NACE hardness survey for a WPS
Yes, this is the correct approach.
RE: NACE hardness survey for a WPS
RE: NACE hardness survey for a WPS
1. for normal service, the WPS is qualified upto 1.340"
2. But for NACE/sour service, the WPS is qualified upto 1.250"
right?
RE: NACE hardness survey for a WPS
RE: NACE hardness survey for a WPS
Yes, provided impact testing was not required per B31.3.
RE: NACE hardness survey for a WPS
RE: NACE hardness survey for a WPS
Why? because the company made a mistake in coverting the hardness reading on the original test and it was a long time ago, since they could find the records to verify the actual hardness scale they used, they used the PQR to weld another coupon and re-tested it for hardness, but the original thickness range qualified still holds for the WPS and the NACE service is qualified only to 2 times the thickness of the new pipe coupon welded...
RE: NACE hardness survey for a WPS
RE: NACE hardness survey for a WPS
what do you think?
RE: NACE hardness survey for a WPS
RE: NACE hardness survey for a WPS
NACE MR0175, Vickers' hardness test
RE: NACE hardness survey for a WPS
To my knowledge, while MR0175 provides details as to hardness testing requirements such as those found in par 7.3.3.2 & 7.3.3.3,
I don't see specific comments that would make me think your situation would require limiting qualified thickness to 2x the plate thickness of the test plate that received hardness tests only, especially considering that we're only talking the difference between 0.674" and 0.625".
When I add supplementary hardness tests to an existing PQR I try to reasonably match plate thickness and chemistry, but, I'm more concerned about matching or going over on the CE than I'd be concerned with being within 1/16" of plate thickness.
Of course, this is just my opinion and others may be able to offer some enlightenment.
RE: NACE hardness survey for a WPS
Any other thoughs??
RE: NACE hardness survey for a WPS
RE: NACE hardness survey for a WPS
Using the logic above, if I used a WPS that allowed me to go above the thickness bounded by hardness testing, why bother with hardness testing?
RE: NACE hardness survey for a WPS
Steve Jones
Materials & Corrosion Engineer
http://www.linkedin.com/pub/8/83b/b04