CV300 by Dixon Valve | Spring-Loaded Check Valve | 3" Female NPT x 3" Female NPT | BrassFeatures: Soft seat for bubble tight shutoff, spring loaded for fast seating action. Flow profile designed to minimize head loss. Materials: NBR seat. Specifications: Pressure rating : 1 2" 2" 400 PSI WOG; 3" 4" 175 PSI WOG Temperature range: 10F to 210F ( 10C to 100C) Cracking pressure: 0. 50 PSI Part Number Female NPT x Female NPT CV050 1 2" x 1 2" CV075 3 4" x 3 4" CV100 1" x 1" CV125 1 1 4" x 1 1 4" CV150 1 1 2" x 1 1 2" CV200 2" x 2" CV300 3" x