FAQ's

What are the chloride limits for UNS S31600 and UNS 31603?

Chloride con column is “see remark”- which is any combination of chloride concentration and in situ pH occurring in production is acceptable.
E.G. TABLE A.2, S31600 can resist 5000 mg/h Chloride concentration??
How to understand these figures? or they are same service, means
5000 mg/l is only valid for temp less than 93 oc, PH2S less than 10.2 kPa???

Q1: Regarding 15156-2 Table A.2 for UNS S31600, the remarks section defines acceptance for any chloride and in situ pH. Can UNS S31600 be acceptable with a chloride content of 5000 mg/L?

A1: Table A.2 permits any level of chloride for austenitic stainless steels defined in Clause A.2 with the following restrictions: temperature shall be no higher than 60°C, the partial pressure of H2S shall be no higher than 100 kPa and no elemental sulfur. Note that the material restrictions defined in note a in Table A.2 also apply.

Q2: How do I understand these figures in Table A.2?

A2: We cannot provide consulting services. You may need to employ a consultant to help your understanding of these material and application limits.

Reference MP Inquiry 2017-06 (NACE MR0175 Part 3 A.2)

Our team of metallurgists and corrosion specialists can help you with the interpretation and implementation of the NACE MR0175 requirements. We have experience dealing with chlorides, pH and ppH2S requirements. Contact us today to find the answers you are urgently requiring.

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