'NACE compliance' can only be confirmed after review of the purchase order and the inspection documents of the valve.

Steve Jones
Materials & Corrosion Engineer

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

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

There is nothing called sure fire way, even if you see the Purchase order or check the material certificates of the valve especially When you are dealing with valve without identification.

Even if you have identification and are able to trace to certificate and the certificate say it is NACE compliant, the extent of your sure fire based on the certificate. The level of assurance you have now depends on the reliability of the valve certificate issued by valve manufacturer.

I have come across many occasions (At least once in one project) where the top valve manufacturer (Although they have all fancy ISO 9000 and API 6A certification) fails after start up and when one digs we find the stem material which is supposed to be 316 is 718 or when the stem is supposed to be 410S it is XM-19 etc. Right now i am dealing with top DBB manufacturer from Italy and France (Shell Approved, Exxon Approved, Supplies regularly to Total, BP, Oxy), fails (No China material) all the material had traceability (Good stamp, good West European certificate for material and valve), yet in PMI (Which was done after failure of over 50 valves), we had problems.

So there is nothing called sure fire. It depends on what is going to give you assurance and how much you would like to see. In any case, it is my firm view that valve NACE compliance is non issue (So long as the valves are bolted/ flanged and not welded to piping), since if it fails, you can always replace it with relative ease.

The focus for NACE compliance is to be given on welded item and welded valves, because, if it fails after start up, we have many operational issues (as compared to flanged valves). I am not saying flanges valves can fail and it is OK, i am saying, at the time of final walk through, one can focus more on gross issues. If one wants to increase the level of assurance then there are methods that works reasonably well and those give adequate assurance. Despite this, as i told you earlier i deal with failed valves.

This is what i feel about walk through. It is my view that one can identify gross error, during walk thorough, if one goes into finer details, it is no longer walk through. It is dig up.

If you want less than sure fire method with reasonable assurance, i can share. First step is to identify the lines that you consider critical and do the exercise only on those critical.

Conduct N2 + He leak test at operating pressures, it will take care of the leak from gland of valves. Even of the internal non metallic seals and parts are not OK and valve leaks, it does not leak to atmosphere, so much you have assurance when you check the for leak from gland area.

Have a PMI machine and some emery paper and WD 40 and some thinner, chalk, wire brush and magnet and Ferrite meter, small grinding machine (File) You need 2/ 3 person team to walk with you.

Take 2 walks, one focusing only on valves and another general.

By the time you walk through you would have gotten familiar (From the shapes of the valves and the hand wheel color or other unique feature, who is the manufacturer of the valve).

On the lines that are considered critical, select one valve per manufacturer in the line and spend some time to check for punch mark or embossing on the body. If the material has identification, and if is listed in NACE/ISO 15156-3 (For high alloy) and NACE/ISO 15156-2 (A 105, A 106, A 333, A 234, A 420 CS and LTCS general valve material) need no further verification as these do not need any special blessing to be called as NACE compliant, they are automatically compliant.

If there are no marking, then perform PMI and verify as above. Here your assurance reduces since NACE gives specific heat treatment recommendation for some of the alloys, if you do not have punch mark, a material chemistry may be OK, but may not be OK from the heat treatment point of view especially for high alloy material. Hence you should know there a reduction in assurance.

If you are in the beginning of the project, there is much easier way, if you are not tired and want hear about that, then there is a simple way which is very close to sure fire.

bmoorthy ,

Thanks for the response. Joining the project toward the end , it becomes very cumbersome.

Sure, I would like to hear the "close to sure fire " way as well

" There is no Shortcut to anyplace worth going "

Generally the piping class for sour service and non sour service will be different.

This is becuase, for Sour service the gasketing and sealing and leakage class from seat may be different, the extent of NDE on the casting for sour might be stringent and there could be minor difference in the inernal spring material etc.


If EPC contractor procures say 50 nos 6" 300 rating valve (in total for a given project) you need to insist that there has to be separate data sheet for sour valvs and non sour valves and you need to ask the EPC contractor to order it as a separate line item in PO and ask the EPC contractor to insist there has to be separate cross section drawing for NACE and non NACE valve.

That is manual valves are ordered in bulk and are generally ordered based on piping class. So a 6" 300 rating CS valve in sour service and 6" 300 rating CS valve in Non Sour service (although may have the same material of construction) are generally ordered under diffferent PO line item and may have different corss section drawing.


It is my guess you represent end user. if so in the project specificaiton you need to include a statement such as this

"Valve Manufacturer shall ensure that all valves in sour service shall have Red color (Or some other unique color coding of your liking) painted on the handle or gear box or on the actuator) marking or strip or word "sour" or "NACE" or the valve tag or valve piping class etc in such unique color"

By implementing such objective veificaiton mechanism, during the final walk through you need to have the uncomfortable feeling of having missed a Non Sour valve in Sour line.

On many occsaions by incorporating such color coding, we were able to identify even to the level of bolt and nuts and got it replaced.

If your company is not too particular on the color of piping and color of the valve be the same, then you may even ask the whole valve in sour be painted in different color.

Some of the EPC contractor for standardization procures all valves as sour, when the valves involved as CS and SS as the cost differntial bewteen Sour valve and non sour valve is very less when considering the over all cost involved / spent in this kind of verificaiton and identification issues.

Quote (bmoorthy)

and if is listed in NACE/ISO 15156-3 (For high alloy) and NACE/ISO 15156-2 (A 105, A 106, A 333, A 234, A 420 CS and LTCS general valve material) need no further verification as these do not need any special blessing to be called as NACE compliant, they are automatically compliant

The certificates still have to be checked to confirm that the material is in the correct heat treatment condition, the correct heat treatment temperatures have been used, and the correct hardness has been achieved, and, for certain materials, that the process conditions will be within the prescribed limits. 'Surefire?' Doesn't seem to be.

Steve Jones
Materials & Corrosion Engineer

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

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

Yes i agree, that is why there is nothing called sure fire in the absence of identificaiton (Which is the original issue).

For CS & LTCS there is no issue with heat treatment.

For SS 316, SS 304 and austenitic SS material to A 403 or A 182 or A 479 also no issue since the requirement for heat treatment 9Solution Anneal) by default in these ASTM, are in full compliance to NACE heat treatment requirements.

Whereas for material like 410 and 8825 and other exotic alloys, ASTM provides various heat treatment options and NACE restricts the heat treatment to some extent.

In any case, whatever we do and howmuch ever we verify the traceability, identification and certificates, the assurance level is limited to the trust worthiness and trueness of the certificates issued by valve manufactuer and most failures that happen in valve is not due to wrong instatement of wrong valve by EPC contractor, it occurs at manufacturer's facility.


Recently we are faced with a situation where in the Valve certificate issued by one of the top valve manufacturer in the world and procured under world reputed third party inspection (3.2 certification for body and bonnet), failed with in one year of service. the failure was not in body or bonnet, but due to the failure of gland flange (Non pressure part) and failure of stem and stem seals (3 failures) when many valves of the same configuartion were dismounted and checked (Stripped and check for each component) in the presence of valve manufacturer, it became clear that there were mix up in material in non pressure part. This could never have been identified by walk through.

Precisely

Steve Jones
Materials & Corrosion Engineer

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

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