... .Stem: SS (One Piece with Pin) 5.Seat: NBR EPDM Double Flange Butterfly Valve (Center Line) 1.Size: DN50 to DN12002 ... Worm Gear Penumatic Electric 9.Flange drilling standard: BS4504 BS10 TABLE D/E ANSI B16.5 JIS 5K 10K 20K DIN2501 ... , air, vapor, food, medicine, acids, alkalis, salts, paper making etc. Double Flange Butterfly Valve