Product Item: Dual Plate Check Valve, Thru Drilled, Double Flanged
Design Standard: API 594
Type: Double Flanged Dual Plate Check Valve
Body: ASTM A216 WCB
Size: 30 Inch, DN750
Pressure: Class 900 LB, PN150
Disc: ASTM A216 WCB + SS 316
Pin Seat: ASTM A276 316
Hinge Pin: ASTM A182 F316
Spring: Inconel X750
Backseat: Stellite Faced
Connection End: RTJ Flanged


Source: https://www.landeevalve.com/dual-plate-check-valves-api-594-wcb-30-inch-900-lb-rtj.html