HS41X-A Type Reverse Flow Preventer is a safety device designed to prevent backflow contamination in drinking water pipelines, achieving multiple seal protections by adding a drain valve between two check valves. Its core structure consists of two in-series check valves and a hydraulic-driven drain valve. The primary check valve is equipped with a filter mesh, which effectively intercepts impurities.

Working Principle

When the pipeline is normally supplying water, the drain valve remains closed due to the pressure difference caused by local head loss. In the event of abnormal pressure (such as outlet pressure being higher than the middle chamber), the drain valve automatically opens to release water, forming an air barrier to prevent backflow contamination. Even if both check valves fail simultaneously, the drain valve can still block backflow through the drain valve.

Application Range

Broadly applied in metallurgy, petroleum, chemical, construction, and food industries, ensuring the hygiene and safety of drinking water.

Structural Features

‌Dual Sealing: The standard model features two check valves in series, while the safety model adds a drain valve to enhance anti-backflow reliability.‌

Filter Function: The primary check valve is equipped with an integrated filter screen, capable of trapping impurities.

Pressure Differential Drive: During normal water supply, the pressure differential keeps the drain valve closed.

The device effectively handles sudden pressure anomalies with multiple seals and a rapid drainage mechanism, ensuring safe water supply.