Cast Steel Non-Return Valves Design Features MANUFACTURING STANDARD – API – 594FLANGED ENDS AS PER ANSI B1.65 OR CUSTOMER REQUIRMENTSSTELLIED SEAT CAN ALSO BE PROVIDED AT EXTRA COSTNITRILE RUBBER SEAT FOR BODY / DISCS ARE ALSO AVAILABLEBY-PASS ARRANGEMENT ALSO AVAILABLETESTING STANDARD API – 598 Part Specifications