NACE MR0175 1

[david339933]

Can two separate procedures (processes) with hardness testing to NACE MR0175 be combined to fill a single joint, or does harness testing have to be done on a coupon with both processes in the same coupon.

Ex: GTAW root (procedure 1)
SMAW fill (procedure 2)

Can I combine these two procedures in a single joint and still meet the requirements of NACE MR0175 or do I need a pqr coupon containing both these processes harness tested?

 

[SJones]

Bear in mind that NACE MR0175 is not a welding standard. It may have a welding section, but does it really deal with the fundamentals of welding? For example, it will allow you to use ASME IX, but ASME IX doesn't deal with routine hardness control. So, let's say that you qualify the welding procedures on a certain carbon steel composition and the hardness values are great; you then move on to a totally different, thicker material pumped full of hardening elements and proceed to weld it with the same WPS. Will the hardness still be acceptable? If the end user of the equipment has specified ASME IX, and is happy to see you combine WPSs, then you can feel free to proceed as per ASME IX. It is for the end user to decide.

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/pub/8/83b/b04

All answers are personal opinions only and are in no way connected with any employer.

 

[metengr]

Can I combine these two procedures in a single joint and still meet the requirements of NACE MR0175 or do I need a pqr coupon containing both these processes harness tested?

I would qualify a procedure for the combined processes to meet NACE MR0175 requirements, specifically.

 

[Ishack]

Answer to your question is YES. Two PQR having different process can be combined to make new WPS without any further qualification. as you said in your question both wps meet the hardness requirement, then there is no problem as per NACE. Please refer QW 200.4 for details. Even more than one WPS can be used to fill a single joint as per ASME sec IX. The hardness requirement is not a part of PQR and it is a part of NACE code and the welding qualfication (both procedure and welder) shall be done by ASME Sec IX. However the limit / range of essential variables such as thickness limit, weld deposit etc... are to be established based on QW 200.4 (a-1) and (b) while preparing the new WPS

 

[david339933]

Excellent. Thank you. I am well acquainted with QW-200.4(a)/(b)..so as long as client specs do not restrict this I am allowed to combine as per sec IX. Thank goodness for informational forums like these.....(used wisely of course).

 

[SJones]

It is for the end user of the equipment to decide - check and get confirmation that you can make the combination. MR0175 and ASME IX are two different animals, and the former certainly wasn't put together by welding experts. Getting the answer that you wanted to hear on an internet forum wouldn't stand much ground in litigation. You have been given a couple of reasons above as to why straight combination may not be correct.

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/pub/8/83b/b04

All answers are personal opinions only and are in no way connected with any employer.

 

[pradipgoswami]

Hi David,
This is the quote from MR-0175:-

Welding shall be carried out in compliance with appropriate codes and standards as agreed between the supplier and the purchaser. Welding procedure specifications (WPSs) and procedure qualification records (PQRs) shall be available for inspection by the equipment user.
The qualification of welding procedures for sour service shall include hardness testing in accordance with 7.3.3.2, 7.3.3.3 and 7.3.3.4

*7.3.3.2 Hardness testing methods for welding procedure qualification
*7.3.3.3 Hardness surveys for welding procedure qualification
*7.3.3.4 Hardness acceptance criteria for welds

Your Proposal is to use :-Ex: GTAW root (procedure 1) SMAW fill (procedure 2)

In your case as stated above two separate PQR could be combined to support a WPS for MR -0175 applications. In order to do so, each PQR has to meet the requirements of MR-0175, wrt to base metal, restriction on chemistry of welding consumables (if any for C-Mn ans LAS ) and hardness requirements.
Also requirements of QW-200(b)should be met with respect to thickness of weld coupon and individual weld deposition thickness.

Thanks

.

Pradip Goswami,P.Eng.IWE
Welding & Metallurgical Specialist
Ontario, Canada.
ca.linkedin.com/pub/pradip-goswami/5/985/299