Wye Pattern Design Reduced Pressure Zone Assemblies are used to protect against high hazard (toxic) fluids in water services to industrial plants, hospitals, morgues, mortuaries, and chemical plants. They are also used in irrigation systems, boiler feed, water lines and other installations requiring maximum protection. They feature a Lead Free* bronze body and threaded ball valve shutoffs. Maximum Working Pressure: 175psi (12.1 bar).