Inconsistency between Table A.18 and A.23

This page addresses an inconsistency between Table A.18 and A.23 in NACE MR0175/ISO 15156-3, specifically relating to the use of martensitic stainless steels in different types of equipment and components.

Clarification on the Meaning of “”Any Equipment or Component””

The question asks for clarification on the meaning of “”any equipment or component”” in Table A.18 and whether this excludes casing and tubing hangers and valve stems.

Martensitic Stainless Steels Allowed for Various Equipment and Components

The answer explains that Table A.18 allows the use of martensitic stainless steels under a specific set of environmental limits for “”any equipment or component,”” which includes wellhead and tree components, valve and choke components, and casing and tubing hangers and valve stems.

Exclusions for Casing and Tubing Hangers and Valve Stems

Meanwhile, Table A.23 allows the use of the same selection of materials for wellhead and tree components and valve and choke components under a less restrictive set of environmental conditions, but excludes casing and tubing hangers and valve stems under these less restrictive conditions.

References

The answer also refers to Table 1 of NACE MR0175/ISO15156-3 for the list of equipment covered by the standard and “”General Remarks”” under ISO 15156-3, A.1.6 of this “”Inquiries and interpretations”” document.

Related Inquiry

This question pertains to NACE MR0175/ISO 15156-3 A.6.2, specifically Table A.18 and Table A.23, and the reference cited is ISO 15156 Maintenance Panel Inquiry 2004-23 Q2.