Table A.6 in NACE MR0175/ISO 15156-3: What Instruments Are Included?

This page features an inquiry about Table A.6 in NACE MR0175/ISO 15156-3, which defines material and environmental limits for instrumentation and control devices.

The Question

The question pertains to whether certain instruments, including pressure gauges, diaphragm seals, electronic pressure transmitters, electric and mechanical temperature measuring devices, and various accessories, fall under the category described in Table A.6.

The Answer

The answer provided states that Table A.6 encompasses instrumentation and control devices that have been used in sour service without any known failures. Thus, it is the responsibility of the manufacturer to assess whether austenitic stainless steel instrumentation and control devices used for compressors are included in Table A.6. The Maintenance Panel cannot provide advice on specific design issues, and the applicability of Table A.6 to specific components should be determined through an agreement between the user and manufacturer.

Additionally, the answer encourages the submission of a ballot to revise/clarify Table A.6, which should include field history in accordance with ISO 15156-1 clause 8.2.

Conclusion

This question pertains to NACE MR0175/ISO 15156-3 Table A.6, and the reference cited is ISO 15156 Maintenance Panel Inquiry #2011-02.

By following the guidelines set forth in Table A.6, manufacturers and users of instrumentation and control devices can ensure their safe and effective use in sour service environments.