What are the differences in performance between different types of directional control valves?

Different types of directional control valves do have significant differences in performance. These differences are mainly reflected in the following aspects:

1. Differences in control methods
Solenoid valve:
Controls the movement of the valve core through electromagnetic force, thereby realizing the on-off and direction switching of the oil circuit.
It has the advantages of fast response speed and high control accuracy.
It can be divided into single solenoid valve and double solenoid valve. The valve core of the single solenoid valve will return to the initial position when the power is off, while the double solenoid valve needs to be powered on to maintain the position of the valve core.
Mechanical valve:
Operate the movement of the valve core by manual, foot or mechanical force.
The structure is simple and easy to maintain.
But the response speed is relatively slow and the control accuracy is low.
Air-controlled valve:
Use air pressure to control the movement of the valve core.
Suitable for occasions requiring remote control.
It also has the characteristics of fast response speed, but may require an additional air pressure source compared to solenoid valves.
Man-controlled valve:
Like a manual valve, it is directly operated by manpower.
The control method is intuitive, but it is not suitable for occasions that require frequent or remote control.

2. Differences in working principles
Direct-acting valve:
Directly relies on human power, electromagnetic force or pneumatic force to achieve reversing.
Simple structure, but limited reversing force.
Pilot valve:
Consists of two parts, the pilot head and the valve body. The pilot head piston drives the valve stem in the valve body to achieve reversing.
Applicable to occasions that require a large reversing force.

3. Differences in reversing stability and reliability
Different types of directional control valves also differ in reversing stability and reliability. For example, the sliding valve reversing valve changes the on-off and direction of the oil circuit by moving the valve core in the valve body. Its reversing stability and reliability depend on factors such as the processing accuracy and matching clearance of the valve core. Some specially designed directional control valves, such as hydraulically controlled check valves, have better anti-sealing and pressure-maintaining performance, and are suitable for occasions where pressure stability needs to be maintained for a long time.

4. Differences in applicable scenarios
Different types of directional control valves are also suitable for different scenarios due to their characteristics. For example:
Solenoid valves are widely used in automation systems that require precise control because of their fast response speed and high control accuracy.
Mechanical valves are often used in some manual control or low-requirement automation systems due to their simple structure and easy maintenance.
Pneumatic valves are suitable for situations that require remote control, such as pneumatic systems.