The product structure with filter backflow preventer is reasonable, easy to use, strong sealing performance, durable and beautiful appearance. It is widely used in electric power, metallurgy, petroleum, chemical industry, gas, urban construction, papermaking, textile, medicine, food, shipping, water supply and drainage, energy, drilling and other departments.

(HS41X-A)The antifouling block valve with filter consists of two separated check valves and a hydraulic transmission to the drain valve. The Diyi check valve body is equipped with a filter screen. Due to the local head loss of the check valve, the pressure in the middle chamber is always lower than that in the water inlet. This pressure difference drives the drain valve to close and the pipeline supplies water normally. When the pressure is abnormal (i.e. the pressure at the outlet is higher than that in the central cavity), even if both check valves cannot be sealed in reverse, the safety relief valve can automatically open to drain the backwater and form an air partition to ensure the sanitation and safety of upstream water supply.

1. Ordinary type can be installed vertically and horizontally
2. For safe horizontal installation, the site environment should be clean and there should be enough maintenance space. The height of the outlet of the safety drainer or (air isolator) should be greater than 300mm from the ground, and should not be submerged by water or debris
3. Drainage facilities should be set in the installation area
4. The gate valve (butterfly valve) and rubber like soft joint (or expansion joint) should be installed in front of the valve, and the gate valve (butterfly valve) should be installed behind the valve. When the water quality is poor, the filter should be installed in front of the valve