Flange Flapper Check Valve * brass valve *useful flappe *Size: 1-1/2"~4" *DN: DN40, DN50, DN65, DN80, DN100 HHSN Spring Check Valve 1. Nominal pressure: 1.6 MPa2. Actuating Medium: Water, non-corrosive liquid, gas3. Working pressure: 0.01-1.6MPa for water or oil; max working pressure for gas: 0.8MPa4. Operating temperature: -20° C ≤ t ≤ 120 ° C