Pneumatic Anchor Cable Tensioning: Core Functions And Operating Points

1. Pressure Testing and Pressure Holding Performance
Before leaving the factory, the pressure holding performance of the gear pump must be tested. At a rated pressure of 60MPa, the pressure gauge must remain stable for 2-3 minutes.
The pressure regulating valve must be calibrated to the target pressure, and the pushing/retracting action is controlled by the directional control valve.
2. Key Selection Parameters
The tensioning and anchoring jacks must match the diameter of the steel strand (e.g., 17.8mm corresponds to 200 kN tensioning, and 400 kN for anchoring).
It is recommended to use 32# hydraulic oil for the pneumatic hydraulic pump, avoiding high-viscosity oil which may cause slow oil output or excessive load.
3. Directional Control Valve Operation and Pressure Holding
The directional control valve has three positions (pushing/pressure release/retracting) to control the oil circuit. When holding pressure, the position must be fixed and the air source must be cut off.
4. Common Troubleshooting
No pressure gauge fluctuation: Check the pressure holding valve, directional control valve, and oil circuit for blockages.
Oil leakage: Check the sealing of the oil inlet and outlet at the bottom of the jack.
5. Safety and Maintenance Standards
Must comply with the requirements for equipment and hydraulic systems in explosive environments as specified in the "Coal Industry Standard Compilation".