CRA Cladding NACE: Applicability to Carbon Steel HAZ of Clad Pipe’s CRA Girth Weld

Overview

The inquiry seeks to clarify if NACE MR0175/ISO 15156-2 section A.2.1.5 and Table A.1, as well as section A.13.1 in NACE MR0175/ISO 15156-3, are applicable to the carbon steel HAZ of a clad pipe’s CRA girth weld, except for the portion crossing the carbon steel HAZ of the overlay. These sections pertain to the cladding, lining, and overlay of a carbon steel component’s overall internal surface in contact with fluids. A figure is included to illustrate the inquiry.

Response

The response states that NACE MR0175/ISO 15156-2 section A.2.1.5 allows for waiving the maximum hardness requirements through NACE MR0175/ISO 15156-3 section A.13.1. The latter defines the conditions and requirements for waiving the limit, with the user required to demonstrate and document the cladding or overlay’s long-term integrity. The cladding’s long-term integrity can be affected by heat and stress-relief treatments, environmental cracking under operating conditions, other corrosion mechanisms, mechanical damage, and the overlay’s dilution. This inquiry pertains to NACE MR0175/ISO 15156-2 sections A.2.1.4 and A.2.1.5. ISO 15156 Maintenance Panel Inquiry #2016-07 constitutes the reference.

Conclusion

In conclusion, the applicability of NACE MR0175/ISO 15156-2 section A.2.1.5 and Table A.1, as well as section A.13.1 in NACE MR0175/ISO 15156-3, to the carbon steel HAZ of a clad pipe’s CRA girth weld, except for the portion crossing the carbon steel HAZ of the overlay, depends on the demonstration and documentation of the cladding or overlay’s long-term integrity. The user must comply with the conditions and requirements specified in NACE MR0175/ISO 15156-3 section A.13.1 to waive the maximum hardness requirements.