1.1 This emergency guideline presents procedures for the selection of protective coatings for carbon steel and austenitic stainless steel under insulation systems. Protective coatings have been recognized and accepted as a highly effective method of protecting insulated metallic substrates from corrosion. Attempts to prevent water from entering insulated systems have not been successful, and corrosion protection techniques such as inhibitors and cathodic protection have been less effective than protective coatings in mitigating corrosion under insulation. 1 .2 Coating systems considered in this emergency guideline are: thin film liquid-applied coatings, fusionbonded coatings, metallizing, and wax-tape coatings. These systems have a history of successful use. Other systems may also be satisfactory. 1.3 Insulation covering is not addressed in this emergency guideline. 1.4 Failures with inorganic zinc coatings under wet insulation are not discussed in this document; the subject has been addressed in NACE Publication 6H189. 1.5 Coating manufacturers or project specifications should be consulted regarding suitability of specific products for carbon and austenitic stainless steels under insulation systems.

1997