Neither. MR0103 was created after MR0175 to better meet the needs of the refining industry. MR0175 is basically for upstream oil and gas production while MR0103 is the down stream refining. There are many differences, such as environmental restrictions on materials and guidelines on determining sour environments.

I believe there is a NACE paper outlining and comparing the two standards. Could be searched on NACE site.

Thank you so much for the answer, however i saw this article http://www.valvemagazine.com/magazine/sections/mat... and it basically says if the casting didn't have weld repair then it's dual certified? because material and heat treatments requirements are the same on both, and MR0175 has a better hardness requirement. the only difference is the weld spec if there any?

There are similarities, such as heat treatment condition of carbon steels, but they are not automatically dual certified. That being said, they certainly can be dual. I have a feeling you haven't actually looked in either standard.

Both standards have moved on significantly since 2002, so which version of MR0103 does the client think that they can gain parity with? Use of the word "certified" is also pushing things a little since there is no such thing as certification for NACE.

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.

The current version of NACE that the valve is compliant with is MR0175 (2002). the customer didn't specify what version of MR0103 he is interested in but i am assuming it would be the latest since it's a new refinery under construction.

i end up providing the answer to the customer as per david339933 first message above, because there are multiple materials in this valve including CS and SS and duplex and i don't know the specific heat treatment of each and whether if there was weld repair involved ( weld repair for casting porosity for example) in addition if i would have said yes then i would have to provide an official letter stating the valve is dual certified (complaint). i didn't want to do that unless im 100% confidant which would required alot of digging.

so i guess the short answer is always no unless the same material (Ni content requirement for example), same heat treat, same or better hardness.

Mous1747, there is no such thing as "NACE certified". The NACE MR0175 specification states that it is the end user's responsibility to determine the specific service environment (pressure, temp, and partial pressure of H2s, CO2, pH, amount of chlorides, and is liquid water present?) and use the guidelines provided in NACE MR0175 to determine what processes the fabricator must use to mitigate risk of cracking in that particular service environment.