(1) truncation class: such as gate valve, globe valve, plug valve, ball valve, butterfly valve, needle valve, diaphragm valve, etc. Cut-off valve, also known as closed-circuit valve, cut-off valve, its role is to connect or cut off the medium in the pipeline.

(2) Check class: such as check valve, check valve is also known as check valve or check valve, check valve is an automatic valve, its role is to prevent the media in the pipeline to reverse flow, to prevent the pump and drive motor reversal, as well as the leakage of container media. The bottom valve of the water pump suction close also belongs to the class of check valve.

(3) Safety class: such as safety valves, explosion-proof valves, accident valves, etc. The role of the safety valve is to prevent the medium pressure in the pipeline or device from exceeding the specified value, so as to achieve the purpose of safety protection.

(4) Regulation class: such as regulating valves, throttle valves and pressure reducing valves, its role is to adjust the pressure, flow and other parameters of the medium.

(5) Shunt class: such as distribution valves, three-way valves, steam traps. Its role is to distribute, separate or mix the medium in the pipeline.

(6) Special purpose class: such as pigging valve, blowdown valve, exhaust valve, filter, etc. The exhaust valve is an essential auxiliary component in the pipeline system, which is widely used in boilers, air conditioners, oil and gas, water supply and drainage pipelines. It is often installed at commanding heights or elbows to eliminate excess gas in the pipeline, improve the efficiency of pipeline road use and reduce energy consumption.