Valve is a control component in the fluid delivery system, with functions such as shut-off, regulation, flow guidance, prevention of backflow, pressure stabilization, diversion or overflow pressure relief. Valves used in fluid control systems, from the simplest ball valve to the most complex automatic control system used in a variety of valves, its varieties and specifications are quite large.

Valve is in the fluid system, used to control the direction of the fluid, pressure, flow of the device, is to make the pipeline and equipment in the medium (liquid, gas, powder) flow or stop and can control its flow of devices.
Valve is a control part of the pipeline fluid delivery system, used to change the cross section of the pathway and the direction of media flow, with the function of inflow, cut-off, throttling, check, diversion or overflow pressure relief.

According to the classification of materials, there are metal and plastic materials, etc.
According to its function, it can be divided into ball valves, check valves, control valves, gate valves, etc.