... ,steel 4,12 years OEM manufacturer experience Duckbill Check Valve,adjustable check valve,duckbill valve1:Compared with traditional flat valves,it owns ... -1500-F900150015251150ZXF1000-1600-F1000160017251325ZXF1200-1840-F1200184019501485 Certificates obtained: Duckbill Check Valve,adjustable check valve,duckbill valve