The purpose of this standard recommended practice is to present the procedures and practices used in providing galvanic anode cathodic protection to the normally submerged steel surfaces inside water storage tanks. This standard provides owners, engineers, and contractors with specific guidelines for the design and installation of these cathodic protection systems; methods for determining the effectiveness of these systems; and recommendations for the operation and maintenance of these systems. This standard is applicable to water storage tanks of various sizes used in municipal water supply and fire protection, including elevated tanks as well as flat-bottom tanks at ground level. Although the general principles outlined in this standard are applicable to all such tanks, the galvanic anode cathodic protection system described in this standard may not be practical for relatively large tanks.

This standard was prepared by NACE International Task Group T-7L-1, a component of Unit

Committee T-7L on Cathodic Protection, and is issued under the auspices of Group Committee T-

7 on Corrosion by Waters. The task group was composed of corrosion engineers and others experienced in the design, installation, and maintenance of galvanic anode cathodic protection systems for water storage tanks. ·

1.1 This standard presents recommended procedures for using galvanic anodes to apply cathodic protection to the internal submerged surfaces of steel tanks used for the storage of natural waters.

1.2 It is recognized that impressed current systems are used extensively for cathodic protection of the internal surfaces of water storage tanks; however, this standard addresses only galvanic anode systems. For a description of impressed current systems, refer to NACE Standard RP0388.

1.3 Natural waters, as used in this standard, include both potable and nonpotable fresh waters associated with water supply systems and fire protection.

1.4 The ground level and elevated storage tanks considered in this standard are of welded, bolted, or riveted steel construction and include many shapes and sizes:…

Historical Document 1996