Provides the minimum requirements for inflow preventer assemblies, including material design, inspection testing, marking, handling, and packaging for shipment. This standard can be referenced in documents for inflow preventer assemblies.

The American Water Works Association had this guide written to assist those who will choose, locate and/or install air valves for water use (it doesn't contain the AWWA standard, which is a separate publication). The use and principles of air valves are discussed in an introduction, the remainder of

This standard describes the double check-valve backflow prevention assembly for potable water applications. The assembly shall be capable of withstanding a working water pressure of at least 150 psi (1,034 kPa) without damage to working parts or impairment of function and for operation on hot or cold potable water lines.

This standard describes the reduced-pressure principle backflow prevention assembly for potable water applications. The assembly shall be capable of withstanding a working water pressure of at least 150 psi (1,034 kPa) without damage to working parts or impairment of function and for operation on hot- or cold-water lines.

Operators, technicians, and engineers will find the information in this manual useful for gaining a basic understanding of the use and application of air valves. A valuable guide for selecting, sizing, locating, and installing air valves in water applications, M51 provides information on air valve types listed in AWWA Standard C512, latest edition, including the following: air-release valve; air/vacuum valve; and combination air valve.