The most cost-effective Rubber Duckbill Valve:
1.highly flexibility
2.full rubber structure 
3.low cracking pressure

Product introduction:

 Rubber duckbill valve is a new water supply and drainage valve with full rubber structure.duck-mouthed appearance and functions or postive flow-in and reserve cut-off.according to thrust analysisi and calculation as well as different operation conditions,it is manufactured with different design mechansim and different rubber products by special processing. all positive operation .the water flow in ffrom 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 valva gate closes more tightly and the seal effect is better.it is used widely in various drainage exit 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.