HS41X-16T-A Safe Backflow Preventer (Contaminant Barrier Valve) is a safety device designed to prevent backflow contamination in drinking water or fire pipelines, consisting of two in-series check valves and a drain. Its core structure includes:

Core Structure

‌Double-sealed system: Primarily prevents backflow through two in-series check valves, with an additional drain valve installed in the middle to enhance protection.‌

‌Drain Valve: Equipped with a diaphragm design, connected to the first check valve via a high-pressure hose, it automatically closes when the pressure difference reaches 0.035MPa, preventing backflow of water.‌

Operating Principle

Normal Water Supply: Clean water enters the drainage unit through a primary check valve and flows to the user via a secondary check valve. When the pipeline is empty, a high-pressure hose maintains the membrane pressure difference, keeping the valve in a closed state.

Seal Failure Protection: In the event of a primary or secondary check valve seal failure, the drain valve can still maintain a seal through pressure relief, preventing backflow contamination.

Applicable Scenarios

Suited for scenarios requiring high safety protection such as water supply for high-rise buildings, fire protection systems, and municipal pipelines. The nominal pressure ranges from 1.0 to 2.5 MPa, with bore sizes from 50 to 600 mm. Materials include cast iron, stainless steel, and comply with national standards such as GB/T 13927.