DOUBLE FLANGE BUTTERFLY VALVE,BIG SIZE API609/BS5155 1.DOUBLE FLANGE WITH BONDED RUBBER SEAT 2. ... WITH ISO 5211 MOUNTING FLANGE DOUBLE FLANGE BUTTERFLY VALVE,BIG SIZEAPI609/BS5155DN50-DN1200Double flange type with bonded rubber seatFace to ... :bonded rubber seat,EPDM/NBROperation:handle lever/gear box/acutuators big size butterfly valve