Comments with Richard's affirmative vote

Comments to TG 360 Committee – Ballot August 2010

Definitions:

Coating: (1) A liquid, liquefiable, or mastic composition that, after application to a surface, is converted into a solid protective, decorative, or functional adherent film; (2) (in a more general sense) a thin layer of solid material on a surface that provides improved protective, decorative, or functional properties. For the purposes of this standard, “Coating” is defined as an electrically insulating material applied to the surface of a metallic structure that provides an adherent film which protects a metallic structure from the surrounding electrolyte.

Reason for change: Not all coatings are “thin”. Not sure how you would define “thin”.

6.2.1.4.9 When operating pressure and conditions are conducive to high pH stress corrosion cracking, the use of polarized potentials in the cracking range relative to the temperature indicated in Figure 1 is not advised.56

This table concerns me since many times the SCC happens under disbonded coatings and that is not affected by the polarized potential measurements outside of the coating. Could there be precautionary statement to cover these situations?

6.4.3 In situations in which the temperature of the reference electrode is below 15 °C (59 °F) and above 35 °C (95 °F), refer to Table 2.

This table is very confusing to most folks and will cause many problems. Why is there not a difference when the temperature is between 15º C and 35º C? Now when you are out of these ranges we have to calculate these differences. We have already thoroughly confused the industry with reference cell conversions that change continually according to which course they are taking at the time. Is this really a serious problem? If so, why has it not been in the document before? Do we really need this?

Thanks for all the hard work and effort!

Richard Norsworthy
Polyguard Products, Inc.
214-912-9072