ASSE 1053 establishes design and performance requirements for Freeze Resistant Dual Check Backflow Preventer Wall Hydrants, which protect the potable water supply against backsiphonage and backpressure without damage to the device due to freezing. To verify protection under the high hazard conditions present at threaded hose outlets, these devices must be field-testable. ASSE 1053 devices are classified as Type A or Type B. Type A devices automatically drain water when the hydrant valve is closed and the hose is removed to prevent damage from freezing, and Type B devices automatically drain water with a hose removed or attached, end nozzle closed, and the hydrant valve closed.