Table of Contents
Abstract
Specifies requirements for the cathodic protection of internal surfaces of pipes and structures including but not limited to heat exchanges, hot water systems, clarifiers, ballast and water storage tanks, cooling conduits and process plants.
Scope
This Standard specifies requirements for the cathodic protection of internal surfaces of pipes and structures including but not limited to heat exchangers, hot water systems, clarifiers, ballast and water storage tanks, cooling conduits and process plants. The internal surfaces of these vessels/structures may contain waters, seawaters, drinking water, brackish waters, sewage and brines. These applications will be termed electrolytes throughout the Standard.
The Standard specifically covers the following subjects which relate to cathodic protection:
(a) The design of structures requiring cathodic protection.
(b) Coatings for use on internal surfaces.
(c) Criteria for the choice of cathodic protection potential.
(d) The design of cathodic protection systems.
(e) The installation of cathodic protection systems.
(f) The operation and maintenance of cathodic protection systems.
NOTES:
1 Guidance on the general use and design of cathodic protection systems and factors affecting the corrosion of internal surfaces are given in Appendix A.
2 This Standard employs conventional (positive) current flow, for consistency with accepted practice, and uses the potential sign conventions specified in AS 1852. In order to understand the various electrochemical reactions which occur at electrodes during cathodic protection, it should be recognized that electron flow occurs in the opposite direction to conventional current flow.
3 For guidance on the use of coatings on the internal surfaces of structures which are to be cathodically protected, refer to Appendix E.
4 For guidance on the environmental factors which should be considered when designing a cathodic protection system, refer to Appendix F.
5 For an example of a form that may be used with designing a cathodic protection system of internal surfaces, refer to Appendix G.
6 For guidance on the graphical symbols relating to cathodic protection refer to Appendix H.
7 For guidance on the calibration and maintenance of reference electrodes, refer to Appendix K.
History
First published as AS 2832.4-1994.
Originated as AS 2832.4-1994.
Second edition 2006.