According to the classification of nominal pressure of the valve

The valve is in the fluid system, is used to control the direction of the fluid, pressure, flow of the device. The valve is to make the piping and equipment within the medium ( Liquid, gas, powder) Flow or stop and can control the flow of the device. ( 1) Vacuum valve: refers to the working pressure is lower than the standard atmospheric pressure of the valve. ( 2) Low pressure valve: refers to the nominal pressure PN & le; 1. 6 mpa. ( 3) Medium pressure valve: refers to the nominal pressure PN to 2. 5Mpa、4. 0Mpa、6. 4 mpa. ( 4) High pressure valve: refers to the worker called pressure PN 10. 0Mpa～80. 0 mpa. ( 5) Ultrahigh pressure valve: refers to the nominal pressure PN≥ 100. 0 mpa. ( 6) Filter: refers to the nominal pressure PN is 1. 0 mpa, 1。 6 mpa