Hydraulic Directional Valve Symbols


The hydraulic directional valve uses the relative movement of the valve core relative to the valve body to reach a specific working position, so that different oil circuits are connected and closed, thereby changing the direction of hydraulic oil flow and changing the direction of movement of the actuator.


hydraulic directional valve types


Classification Types
According to the structure of the valve

Rotary valve

Slide valve

According to the valve operation mode


hydraulic ,electric-hydraulic 

According to valve position and number of positions

2 positions 2 acting, 2 actions 3 acting,

3 positions  4 acting, 3 positions 5 acting

The rotary valve is the function of operating the spool to change direction by rotating, and the spool valve realizes the function of changing direction by the axial movement of the spool.

Manual valves are generally used in small equipment, and various operations such as excavator walking and digging are passed

Manually controlled, so that the operator's intention can be realized. Of course, it can also be controlled by electromagnetic or electro-hydraulic. The digging valve is to operate the spool to realize the function of reversing by rotating, and the spool valve realizes the reversing function through the axial movement of the spool.

Let's look at the hydraulic directional valve symbols

1. Use a box to indicate the working position of the reversing valve; this box is the square in the symbol element, which represents a position of the reversing valve. A few boxes represent a few locations.

2. The number of interfaces connected to the outside on the upper and lower sides of a box is the number of channels;

3. The arrow in the box indicates the on-off state of the oil circuit at this position, but the direction of the arrow is not necessarily the direction of the actual flow of the oil;

4. Generally, P represents the oil inlet, T or O represents the oil return port, A, B, C, etc. represent the oil port connected to the actuator, and K represents the control oil port;

5. "丅""丄" in the box means that the passage is closed by the valve core, that is, the passage is blocked.


hydraulic directional valve operation

  hydraulic directional valve diagram



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