1,Double Disc Check Valve 2,ISO9001and CE Certificate 3,double disc 4,do OEM Double Disc Check Valve Technical Date:Nominal Diameter:DN50-DN700Nominal Pressure ... °CSuitable Medium:Water,Sewage,Seawater,Gas,Food,Oils,etc.Double Disc Check Valve Standard:Design Standard:JB/T8527-97Structural Length:GB/T12221 ...