NACE has recently updated the guidance for use of 316L stainless steel in sour service environments. More info available at

[link Point to another website Only the registered members can access]
I have a few questions for everyone:

1. Do you all have any comments on your experiences and practices for selection in sour service?
2. Specifically, do you follow or exceed MR0175, and if so, what changes do you usually make?
3. Do you have many issues with titanium use in sour service? What issues have arisen?


The full text of the link above also quoted here (text only unfortunately):

"We are still coming across questions about the updated 316L limits in NACE MR0175, so I decided to prepare a short blog about these updated limits.

Technical corrigenda and technical circulars are documents that amend an existing standard. Some of these amendments can be editorial, like in the figure 1 shown below where the symbol “W” in the pH column should be replaced by the symbol “≥”; some other amendments are derived from ballots that make technical changes. We will cover the ballots on a different article in this blog.

Technical circular #2 of NACE MR0175 / ISO 15156 – 2009 was issued on the 27th of August, 2013. This circular addresses, among other changes, the updated limits for 316L (UNS S31603). These changes were based on experimental data such as Ref 1.

The changes mean that the limits at 149⁰C (1.5psi ppH2S, 1000mg/l Chlorides and a pH ≥ 4 remain; in addition to this limit, the experimental data has been included to define new limits at 60⁰C, 90⁰C, 93⁰C and 120⁰C. At 60⁰C the ppH2S is increased to a maximum of 145psi and chloride content of 50,000mg/l at a pH of 4.5 or above. This is a considerable change that will have an impact on the materials selection of new equipment. It will also impact the life extension of existing assets.

During the material selection when considering 316L, is very important to review the operating (and design) conditions against the limits stated in the Technical Corrigenda #2. Similar values were included in Norsok M001, however, with the inclusion on NACE MR0175 / ISO 15156, we expect to see significant effects around the world.

Are these changes affecting your selection? Does it have an impact on existing equipment? Let’s have a conversation
Table A-2 ISO 15156 2009

Table A-2 ISO 15156 2009

Figure 1 Table A.2 of ISO 15156-3 2009
Table A-2 of ISO 15156 2009 as per Technical Circular 2

Table A-2 of ISO 15156 2009 as per Technical Circular 2

Figure 2 Table A.2 of ISO 15156-3 2009 as per the Technical Circular 2

Ref 1: Briony K Holmes and Stuart Bond , “Sour service limits of dual-certified 316/316L austenitic stainless steel and weldments” Paper 10308 presented at Corrosion 2010. San Antonio, Texas, USA, 14-18 March 2010."