ISO 15156 & Stainless Steel 2

[Cokino]

On the base of the new edition of NACE MR 0175 (now ISO 15156) austenitic stainless steel to be used for any equipment is not allowed for service temperature > 60°C! Can you confirm this?? Is it correct??

In my opinion, when chloride are absent and for low or moderate H2S partial pressure, stainless steel as 316 are suitable (i.e. outlet piping on the amine regen overhead, acid gas lines, etc.), despite of temperature limits.

I hope I'm wrong, on the contrary I think we are in front of an incoming revolution in the material selection for sour environments.

Thanks

 

[gvn]

Hi Cokino,

We have reviewed similar problem based on current NACE MR0175/ISO 15156 (Dec 2003)!

Yes, Table A.2 limits Austenitic Stainless Steel (which includes SS316/316L) 60 deg C. If NACE is specified, SS316L is not acceptable to the current standard, if the operating temperature is greater than 60 deg C. This is going to haunt all the Operators/Consultants, as we can’t specify SS316L any more if temp > 60 deg C! Please also see Tables A.4 and A.6 where SS316 is an acceptable material for instrument tubing, compression fitting and compressors! I think this will be queried to NACE and let’s see what happens!

Earlier NACE editions were purely concentrating on SSC. Current NACE also addresses CSCC, HIC, SOHIC, GHIC etc. Current NACE also doesn’t mention the basis for 60 deg C limit i.e. internal or external – should be external and why not allow coating to address CSCC?

Regards,
GVN

 

[grampi1]

Be aware that under NACE/ISO 15156 Operators can use 316 if they can document successful use in existing applications in similar services.

 

[gvn]

Hi Grampi1,

Can you please tell me in which section of NACE/ISO 15156 states that Operators can use 316 if they can document successful use in existing applications in similar services?

Regards,
GVN

 

[grampi1]

NACE/ISO 15156 Part 3, 6.1 5th paragraph, and Part 1 para 8.2

 

[Cokino]

Thanks for your contribution!

I’ve just discovered that all relevant queries and responses from maintenance panel have been collected in the following document:

http://www.nace.org/nace/content/technical/MR0175/MR0175InquiriesandResponses.pdf

As you can read, the 60°C temperature limit has been widely discussed and it has led to an amendment proposal (see pag. 14) which is being considered but not yet approved.

Let’s wait for the final decision...


Regards