Why NACE required for SS 316L Material ?

[Venkatachalam Ponnusamy]

Understand that SS 316L is already a corrosion resistance material but still our client asking us to Procure SS 316L material certified with NACE requirements.
If i approach vendor for NACE requirement for SS 316L, they don't carry out any additional test under NACE standard, but their TPI certify the procured material i.e SS 316L will comply NACE requirement, they charge some additional 3% for certification purpose only.
Also understands that the NACE is applicable depends on H2S Partial pressure mainly(should be equal to or exceeds 0.05 PSIA on wet gas) as per NACE MR 0175 for Upstream Equipment's and piping's.

Can anyone explain why NACE certification is required for SS 316L ? and Your experience in NACE for SS 316L MOC. Even most of the clients asking to comply NACE for SS Materials. Your Thoughts and experience please..

Regards,
Venkat

 

[Vikko]

it is all useless pieces of paper that some burocrats want in order to keep themselves sure that in the worst case, whenever anything happen wrong, they have no responsibilities for their wrongdoing and their ignorance of everything, but they own a huge amount stock of paper, for the purpose of defending themselves against legal cases. The material manufacturer will give you all the additional paper you ask (usually they will never do any additional test, because usually the metal manufacturers do not even bother to do the normal tensile tests and chemical analysis that they certified on their EN 10204 or mill certificate under the supervision of "indipendent" inspectors and authority), for the exact same piece of metal, made with the exact same manufacturing technology, but of course, at an increased cost. This is how it has always worked and as it will always work.

 

[EdStainless]

The only real implication is that there is an upper hardness limit.
But annealed material has to meet this level anyway.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[SJones]

Regarding "certification" see these search results Link

Your client doesn't yet understand that only the end user can "certify".

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

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

 

[GD2]

Venkatachalam,
First let's get the fundamentals clear.

1. SS316L is an CRA alloy. It resists corrosion against many process and environments.
2. NACE MR0175 -specifies materials to be used under H2S service (sour) to protect against SCC damage.

Once these two definitions are understood, it gets easy to follow the rest.

So even if your material is SS316L but is used in a sour service (as defined in your process), it usually required compliance to NACE MR0175. SS316L is susceptible to SCC.

Why MR0175 is used even if it is meant for refinery service?
The answer is: NACE MR0175 was the first published document by NACE, predominantly for offshore use where the process conditions are usually harsh.

Later, NACE had developed another publication MR0103 for refinery use where most of the harsh conditions of the H2s environment had been removed by then. But, most of the industry practice had stayed to MR0175.

So bottom line: you will still need a compliance to NACE MR0175 even if it is SS316L. Part 3 in NACE MR0175 defines the requirement. It usually to protect the material from cold working after after forming and treatment.


GDD
Canada