Distribution and Maintenance Guide for Hydraulic System Valves (Below 200 Tons)

1. Valve Distribution

In hydraulic systems below 200 tons, the main valves include:

• Valve 1

• Valve 2

• Valve 3

• Valve 4

• Valve 5

2. Functional Description of Key Valves

1. Main Pressure Valve: Used to adjust the system pressure, serving as the core pressure control component of the hydraulic system.

2. Slow Descent Speed Regulating Valve: Controls the slow descending speed of actuators .

3. Safety Valve: Opens automatically when the system pressure exceeds the set value to protect system safety.

4. Fast Descent Speed Regulating Valve: Adjusts the fast descending speed of actuators.

3. Common Problems and Solutions

1. Automatic Slide Down

When the slide slides down automatically at a certain position, solve it by adjusting the pressure settings of the main pressure valve or safety valve. Specific steps:

1. Turn off the power supply of the hydraulic system to ensure safe operation.

2. Locate the adjusting screws of the main pressure valve or safety valve.

3. Rotate the adjusting screws slowly to adjust the pressure gradually until the slide stops sliding down.

4. Test the slide operation after adjustment to confirm the problem is resolved.

2. No System Pressure

When the system has no pressure, check whether the spool piston of relevant valves works normally. Specific steps:

1. Turn off the system power and release the system pressure.

2. Dismantle relevant valves (e.g., main pressure valve).

3. Check if the spool piston under the valve can move freely; clean or replace the spool if it is stuck.

4. Reinstall the valves and ensure good sealing.

5. Start the system and test if the pressure returns to normal.

3. Valve Reinstallation

Pay attention to the following points when reinstalling valves after disassembly:

• Ensure the valves are installed in the correct position and aligned with the interfaces.

• Check the integrity of seals and replace them if necessary.

• Conduct a pressure test after installation to confirm no leakage.

4. Maintenance Precautions

1. Regularly check the working status of valves to ensure no jamming of the spool piston.

2. Keep the hydraulic oil clean, replace the filter element regularly, and prevent impurities from entering the valves.

3. Avoid excessive pressure adjustment during operation to prevent valve damage.

4. For complex problems, contact JUGAO professional technicians for maintenance.