What are the different types of hydraulic valves?

Hydraulic valve is an automation component operated by pressure oil. It is controlled by pressure oil of pressure regulating valve. It is usually used in combination with electromagnetic pressure regulating valve and can be used to remotely control the on-off of oil, gas and water pipeline systems of hydropower stations. Commonly used for clamping, control, lubrication and other oil circuits. There are direct acting type and pilot type. Multi-purpose pilot type is used.

The types of hydraulic valves

1.Direction control

Divided into one-way valve and directional valve according to use. Non-return valve: only allows fluid to be connected in the pipeline in one direction, and shuts off in the reverse direction. Reversing valve: change the on-off relationship between different pipelines. According to the working position of the valve core in the valve body, it is divided into two, three, etc. According to the number of controlled channels, it is divided into two, three, four, five and so on. 

2.Pressure control

It is divided into relief valve, pressure reducing valve and sequence valve according to the purpose.

• Overflow valve: It can control the hydraulic system to maintain a constant state when it reaches the set pressure. The relief valve used for overload protection is called a safety valve. When the system fails and the pressure rises to the limit value that may cause damage, the valve port will open and overflow to ensure the safety of the system.

• Pressure reducing valve: It can control the branch circuit to obtain a stable pressure lower than the main circuit oil pressure. Pressure reducing valve can be divided into constant pressure reducing valve (output pressure is constant value), constant difference pressure reducing valve (input and output pressure difference is constant value) and constant ratio reducing valve according to the pressure function it controls. (Keep a certain ratio between input and output pressure).

• Sequence valve: After one actuator (such as hydraulic cylinder, hydraulic motor, etc.) can be activated, other actuators can be activated in sequence.

3.Flow control

The flow area is adjusted by adjusting the area of the orifice between the valve core and the valve body and the local resistance generated by it, to control the movement speed of the actuator. The flow control valve is divided into 5 types according to the purpose.

1. Throttle valve: After adjusting the area of the throttle port, the movement speed of the actuator which can make the load pressure change little and the movement uniformity requirement not high basically remains stable.

2. Speed regulating valve: When the load pressure changes, the inlet and outlet pressure difference of the throttle valve can be maintained at a fixed value. In this way, after the area of the throttle opening is set, the speed regulating valve can keep the flow rate through the throttle valve constant regardless of the change in load pressure, so that the movement speed of the actuator is stable.

3. Diverter valve: Regardless of the size of the load, the same amount of flow or synchronous valve can be obtained for two actuators of the same oil source to obtain equal flow; proportional flow is obtained by proportional flow.

4. Collector valve: The effect is opposite to that of the diverter valve, so that the flow into the collector valve is distributed in proportion. 

5. Diverting and collecting valve: It has both functions of diverting valve and collecting valve.