... .working principle: a. low pressure difference condition, gate main through stem external force andguide pad/, its seal face and seat close ... / 304L/ SS316/ 316L /WCB / LCB / WC9 and so on.3. Stem: 304/ 316/ Cr13% and so on4. Sealing face: soft seal ... such as API ,ANSI,DIN BS,AND JIS . non rising stem flange knife gate valve