1. Product introduction: 

XF rubber slowly-closing check valve is a new water supply and drainage valve with full rubber structure, duck-mouthed appearance and functions of positive flow-in and reserve cut-off. According to thrust analysis and calculation as well as different operation conditions, it is manufactured with different design mechanism and different rubber products by special processing, At positive operation the water flow inform entrance and the valve will be open at weak hydraulic pressure. The hydraulic pressure is higher. The valve gate will open more greatly and the water flow is greater, At reserve operation, the valve gate closes naturally and seals tightly cut-off valve, the back pressure is higher, the valve gate closes more tightly and the seal effect is better. It is used widely in various drainage exits to prevent from pouring backwards and flowing backwards in city planning, water conservancy and sewage disposal etc, it is the ideal product to replace flap valve. 

2. Product characteristics: 

The advantages are specially marked in comparison with traditional flap valve: 

A) Open and close automatically in security and reliability according to hydraulic difference without noise and in no need of operator and maintenance. 

B) Positive start has little water resistance and start-up pressure and the flow can be adjusted naturally according to hydraulic pressure. 

C) Reserve cut-off has good seal without leakage to prevent from flowing backwards. The back pressure is higher and the effect is barrier. 

D) Anticorrosion, aging resistance, deformation resistance, strong adaptability and long use life

E) Wide size scope, nominal diameter of DN50-DN3000. 

3. Installation structure type: 

1) Belled XF-T---installed at the exit of drainage pipe
2) Flanged XF-T---installed at the exit end with flange of drainage pipe
3) Mounting plate XF-F---installed on the building at the water exit end. 
4) Build-in XF-F---installed at the exit end of rain and sewage system in cities. 
5) Grout or cement pipe XF-T---installed at the end of grout or cement pipe. 

4. Notice for order: 

1) Users should provide filed operation conditions explain and technical requirements. 
2) User should provide necessary technical parameter including nominal diameter of pipe, joint external diameter, installation type and the valves of positive star pressure and reserve cut-off back pressure. 
3) Our technicians will select type and design for users according to the request of users. 

Manufacturer of Rubber Check Valves, Duckbill valves, check valves and rubber duckbill valves!