Used in oil, chemical, pharmaceutical, electric power industry pipelines, preventing the medium driven back. 1) Nominal pressure rating: Class 150--Class 900 2) Nominal diameter: NPS2" --16" 3) Attended mode: Flange ends, Welding 4) Working temperatured590° c 5) Actuator: Automatic 6) Body materials: WCB, LCB, 304, 304L, 316, 316L 7) Sealing material: Alloy steel , Stellite alloy