Pressure control valve types

Pressure control valve types

In the pneumatic transmission system, all pressure control valves work by using the principle of balance between air pressure and spring force, which can be divided into the following three categories:

(1) pressure reducing valve. Also known as pressure regulating valve, constant value device (precision pressure reducing valve), etc., play a role in decompression, pressure regulation;

In a hydraulic system, often use a hydraulic pump, but the need to supply oil actuator is generally more than one, and each actuator working liquid pressure is not the same. Under normal circumstances, the pressure of hydraulic pump are executed according to the system components in need the components of the pressure of peak pressure to choose, in this way, because the other components of the working pressure of hydraulic pump than the oil pressure is low, can be in each branch circuit on a pressure reducing valve series, by adjusting the pressure reducing valve to make various actuators to obtain appropriate work pressure.

Pressure relief valve according to the structure and working principle, can also be divided into two categories: direct and pilot.

The pressure reducing valve is a pressure control valve that USES liquid to flow through narrow gaps and produce pressure loss, so that its outlet pressure is lower than the inlet pressure. According to the different pressure regulation requirements, the constant value pressure valve, the constant difference pressure valve and the constant ratio pressure valve.

(2) overflow valve. Also known as safety valve, pressure cut-off valve, etc., play the role of pressure limit safety protection;

The overflow valve is used to overflow the corresponding liquid of the hydraulic system through the valve port, adjust the working pressure of the system or limit its maximum working pressure, and prevent the system working pressure overload.

The main requirement of overflow valve is good static and dynamic characteristics. Static characteristic means that the pressure-flow characteristic is good. Dynamic characteristics refer to stable operation, small overshoot of pressure and quick overflow response after sudden external interference.

(3) sequence valve and balance valve. Some kind of control is carried out according to the air pressure.

In the hydraulic system, some actions are regular. Sequence valve is to take different or the same pressure as the control signal, automatically open or cut off a certain oil line, control the actuator in a certain order to carry out the action of the pressure valve.

According to the different control mode, the sequence valve is generally divided into internal control type and external control type. The so-called internal control is directly using the valve inlet hydraulic pressure to control the valve opening and closing; External control is the use of external control oil pressure to control the valve opening and closing, so, this form of sequence valve is also known as liquid control. Generally used sequence valves are internal control. From the structure, the sequence valve also has the direct movement type and the pilot type two kinds. Because of its simple structure and reliable action, the direct-moving sequential valve can meet the requirements of most cases.

The above: Gear pump also needs maintenance