... system, such as water heater. It can start working at zero differential pressure. This type of valve can change ... flange mounting.1)port size: 1/8 " ~2 "2) Working Medium: air, water, oil, gas3) Action Type: direct action4 ... :2.5,4,,16,20,25,35,40,507) Working Pressure: 0~0.7MPa8) Max. Proof Pressure: 1MPa ... for NO9) Seal Material: NBR or VITON or EPDM10) Working Temperature: NBR for -5~80°C; VITON for - ...