scope:

This standard provides performance standards and compliancetesting procedures for atmospheric type vacuum breakers that are singlepipe-applied, flushometer-applied, or integrally-applied. Atmospheric typevacuum breakers provide protection of the potable water supply againstpollutants or contaminants that enter the water system due to backsiphonagethrough the outlet. This standard does not apply to water closet tank ballcocksor similar devices that depend on float-operated valves to control flow.