AWWA C550

Abstract

This standard describes protective interior coatings for valves used for water supply, wastewater collection and treatment, and reclaimed water service having a pH range from 4 to 9; and for hydrants used for water supply service. The standard describes the material, application, and performance requirements for these interior coatings. The coating shall not contain coal tar. These coatings are applied for protection of ferrous surfaces of valves and hydrants. <br><em>Special coating conditions.</em> <br>Exterior coatings. It is normal commercial practice for the coating applicator to apply this coating to the exterior surface of resilient seat gate valves and hydrant components. It should be recognized that the performance requirements for exterior service may vary from those specified for interior use because of differences in exposure conditions. <br>Internal hydrant coatings. This standard covers interior hydrant coatings in areas designed for constant contact with water supply. It does not cover internal coatings of dry-barrel hydrants on areas downstream of the main valve. <br>Special service conditions. The purchaser and the manufacturer shall agree on special coating requirements prior to manufacturing of product if special service conditions exist. Special service conditions may include salt water, acid, high temperature, wastewater, or reclaimed water. Coatings for these special service conditions may or may not conform to this standard. <br>The purpose of this standard is to provide the minimum requirements for protective interior coatings for valves and hydrants, including materials, coating process, testubg, and rpair.