A plumber is protecting the public water supply where a commercial boiler with chemical treatment connects to city water (a high-hazard, health-hazard cross-connection). Which backflow assembly is appropriate?

Giải thích

For high-hazard (health-hazard) cross-connections such as a chemically treated boiler, a reduced-pressure principle assembly is required, because it provides the highest level of mechanical protection against both backpressure and backsiphonage of toxic substances. A single check valve or hose bibb offers far less protection. RP assemblies must be tested at least annually by a certified tester.