A、 Working principle of manual directional valve

Manual directional valve is an important fluid control device, and its working principle mainly relies on manual operating force to drive the valve core to move inside the valve body, thereby achieving the on/off and directional changes of the oil circuit. It is mainly composed of valve body, sealing components, cam, valve stem, handle and other components.

 

When external force pushes the handle, it drives the valve stem and cam to rotate, and the cam has the function of positioning, driving, and locking the sealing component to open and close. According to the direction of rotation of the handle, the sealing components inside the valve body will correspondingly close or open different channels, allowing fluid to flow along the predetermined path. This reversing method has the characteristics of accurate action, high degree of automation, stable and reliable operation, and has therefore been widely used in industries such as petroleum, chemical, mining, and metallurgy.

 

B、 Maintenance of manual directional valve malfunction

Although manual directional valves have many advantages, some malfunctions may also occur during use. Here are some common faults and their repair methods:

 

1. Leakage: Leakage is a common malfunction of manual directional valves, which may be caused by loose connecting screws, missing or failed sealing rings, high oil pressure, or rough installation surfaces. For these reasons, measures such as tightening the connecting screws, replacing the sealing ring, adjusting the oil pressure, and grinding the installation surface can be taken to solve the problem.

 

2. The valve core cannot move: The inability of the valve core to move may be due to improper clearance between the valve core and the inner hole of the valve body, deformation of the valve core, wear or failure of the manual connecting rod, and blockage caused by oil contamination. To solve this problem, methods such as reconfiguring the valve core, calibrating or replacing the valve core, replacing or repairing the manual connecting rod, and cleaning the valve core can be attempted.

 

3. No action or slow action of the actuator: The absence or slow action of the actuator may be caused by loose connection pins between the handle and the valve core, severe wear of the valve core leading to increased internal leakage, or oil contamination blocking the oil port. For these faults, measures such as reinstalling the connecting pin, replacing the valve core, and cleaning the valve and pipeline can be taken to restore the normal operation of the executing components.

 

Overall, although manual directional valves may encounter some malfunctions during use, their stable operation can be ensured with proper maintenance and handling. By understanding the working principle and common troubleshooting methods of manual directional valves, users can better apply and maintain this important fluid control equipment.

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