... Standard:DIN,BS,API,JIS,MSS etc Electric actuator butterfly valve Feature:1) Standard for face to face: ... steel, Al bronze or other materials you require. c) Seat: EPDM, NBR, PTFE, VITON d) Stem: Carbon steel ... (centerline double flanged butterfly valve), D343(double eccentric flanged butterfly valve), Grooved end type, Double disc wafer check valve, Flapper check valve, Eccentric plug valve, Half-lug ...