The purpose of this NACE standard is to present the recommended practices for providing impressed current cathodic protection to the normally submerged steel surfaces inside water storage tanks. It contains recommendations for the design and installation of these cathodic protection systems and methods for determining the effectiveness of these systems. Recommendations for the operation and maintenance of both automatic and manual systems are also provided. This standard is applicable to relatively large water storage tanks used in municipal water supply and fire protection, including elevated as well as flat-bottom tanks at ground level.

Although the general principles outlined in this standard are applicable to all such tanks, the impressed current cathodic protection system described in this standard may not be practical for smaller tanks.

This standard was originally prepared in 1988 by Task Group T-7L-1, a component of Unit Committee T-7L on Cathodic Protection. The task group was composed of corrosion engineers and others experienced in the design, installation, and maintenance of impressed current cathodic protection systems for water storage tanks. It was reaffirmed by T-7L in 1990 and again in 1995, and is issued by NACE International under the auspices of Group Committee T-7 on Corrosion by

 1.1 This standard presents recommended practices for applying impressed current cathodic protection to the internal submerged surfaces of steel tanks used for the storage of natural waters.

1.2 It is recognized that galvanic anode systems are used successfully for cathodic protection of the internal surfaces of water storage tanks; however, this standard addresses only impressed current systems.

Historical Document 1995