Directional valve troubleshooting


In the process of using the directional valve, there may be a variety of problems, so how should we troubleshoot? Let's take a look!

1. During the operation of the hydraulic system, when the stop depresses the stroke directional valve, P is connected with the A cavity, but now it is not connected or the class is connected.


(1) The return spring at the lower end of the stroke valve is installed incorrectly, and after complete compression, the spring height jacks up the valve core, so that the width of the open valve of P-A is not large enough or there is no opening.

(2) Due to poor heat treatment and other reasons, the stroke valve roller is strictly worn.

(3) The stroke causes the size of the stop to be wrong or the installation is not good.


(1) Replace the springs that meet professional standards.

(2) Replace the rollers with new ones that meet the standards.

(3) Correctly replace the block that meets the size and install it according to the requirements.

2. P and A cavity should not be connected, but they are still connected when the stop does not depress the stroke directional valve.


There is dirt blocking between the spool and the valve hole and getting stuck, and the return spring force at the lower end of the spool is not enough to overcome its clamping force, so that the function of the spool rises.

Troubleshooting: Carefully inspect the spool and orifice to remove dirt.

3. The O-ring sealing ring on the valve cover holds the spool handle too much.


(1) The return spring is missing or wrongly installed, so that the return spring force is insufficient.

(2) The burr spring is stuck at the acute angle of the valve hole sinking groove, and the valve core cannot rise and reset.


(1) You can loosen the valve cover first, and then align it, and then tighten the screw evenly diagonally, so that the valve core can move up and down flexibly.

(2) Disassemble, clean and change oil.

(3) The size of the installation groove should be replaced with an appropriate O-ring or an appropriate widened O-ring seal.

(4) The missing installation should be made up, and the wrong installation should be corrected to increase the return force of the spring.

(5) The burr can be removed, so that the valve core can move flexibly in the valve body hole.

4. Oil leakage failure of directional valve


(1) The seal is worn, and in the case of long-term use or high frequency of use, the directional valve seal is easy to wear, resulting in oil leakage.

(2) The oil in the hydraulic system contains tiny impurities, which will be deposited on the surface of the seal of the directional valve in long-term use, resulting in seal failure.


(1) Replace the sealing layer, by replacing the worn seals, you can solve the problem of oil leakage of the directional valve, before replacing the seals, you need to completely empty the oil in the hydraulic system, and thoroughly clean the working surface of the directional valve.

(2) Clean the directional valve, and regularly clean the directional valve can effectively prevent the deposition of dirt. When cleaning, you can soak the directional valve for a while with a suitable cleaning agent, and then clean the surface of the directional valve with a clean brush or cotton cloth.

The above is the troubleshooting method of the directional valve, I hope these can help you.


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