According to open and close the role of the valve is different, valve classification methods are many, here to introduce the following several.

1, According to the role and use classification (1) shut off valve: shut off valve is also known as closed circuit valve, its role is to put through or cut off the medium in the pipeline.Block valves include gate valves, globe valves, plug valves, ball valves, butterfly valves and diaphragm valves.(2) Check valve: check valve is also known as check valve or check valve, its role is to prevent the media in the pipeline backflow.The bottom valve of water pump suction pipe is also a check valve.(3) Safety valve: The role of the safety valve is to prevent the pressure of the medium in the pipeline or device from exceeding the specified value, so as to achieve the purpose of safety protection.(4) control valve: control valve class includes control valve, throttle valve and pressure reducing valve, its role is to regulate the pressure of the medium, flow and other parameters.(5) Flow valve: The flow valve category includes a variety of distribution valves and traps, etc., its role is to distribute, separate or mix the medium in the pipeline

2, According to nominal pressure classification (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 valve with nominal pressure PN ≤.(3) Medium pressure valve: refers to the valve whose nominal pressure PN is,, and.(4) High-pressure valve: refers to the valve with nominal pressure PN of 10 ~ 80Mpa.(5) Ultra-high pressure valve: refers to the valve with nominal pressure PN≥100Mpa.