Flange type rubber check valve’s diameter gradually reduce along flow direction, and gradually forming a duckbill shape sealing parts, so it is also called flange type rubber duckbill valve. Please note that the nominal diameter is larger than DN800, the body weight will be very large, when operation, a lot of remain water will be left in the abdominal cavity body and water impact effect, a supporting rod shall be increased. It can prevent flood and waste water to flow backward to sewer and basement, and avoid heavy loss; it can prevent flood to flow backward to waste water plant and drainage pump station; prevent waste water or peculiar smell fluid spread and can drain away water at any time; In rainy season, rubber check valve can prevent the flood of inland river from sewer to street; The quality is better than flap valve, and overcome the uptight close disadvantage of flap valve. Rubber material usually is Natural rubber and Neoprene rubber. Natural rubber is fit for waste water which includes alkali and acid; Neoprene rubber can wear UV,and fit for outdoor environments. Flange material is carbon steel or stainless steel. Drilling can be according to .DIN,BS EN, ASME, JIS and other standards.

Working principle

It is a full rubber structure, with "positive inflows reverse backstop" new drainage valve product features. It is calculated based on stress analysis and stress for different conditions, different design mechanisms, use of different rubber formulations, make according to a special process . When forward, the water floods from the inlet and tiny water pressure, will be able to open the valve. The greater of the pressure, the valve opens larger, the greater of the water flow. Reverse work, valve port close naturally, sealed backstop, the larger back pressure, the more tightly of the valve port, sealing the better, maximum back pressure which can be made to withstand varying degrees by an elastic material and the rubber compound.

Product Features

1. Automatically open and close according to pressure differential pressure, safe and reliable, no noise, no need of personnel to operate, no maintenance;
2. Forward turn-resistance, a small start-up pressure and flow naturally adjusted according to the water pressure;
3. Reverse backstop sealed, no leaks, it prevents backflow, the greater the back pressure, the better the results;
4. Anti-corrosion, anti-aging, deformation, adaptability, long service life;
5. A wide range of sizes, nominal diameter DN50 ~ DN3000.