Cast Iron Wafer Handle Single Stem Butterfly Valve DN40-600,PN10/16;Body:CI ... : Monel, ductile iron, stainless steel, ductile iron with nylon coatedSeat: EPDM or NBR or PTFEStem: SS416 or SS316Pin: SS316Operated: Handle or wormgear, pneumatic ... .If the valve leakage after two years service, just remove handle then add a bushing to prevent leakage , need not disassemble ...