In order to ensure the safety and reliability of lifting operations, cranes should be equipped with comprehensive safety devices to protect the components or remind operators to pay attention in case of accidents, thus playing a role in safety protection.

1. Each relief valve in the hydraulic system can suppress abnormal high pressure in the circuit, prevent damage to the hydraulic oil pump and motor, and prevent overload.

2. Crane arm slewing safety device: When an unexpected accident occurs and the high-pressure hose or oil pipe in the crane arm slewing oil cylinder circuit bursts or cuts off, the balance valve in the hydraulic circuit will take effect, locking the working oil from the lower chamber of the oil cylinder to prevent the crane arm from falling, thereby ensuring the safety of the operation.

3. Crane arm telescopic safety device: When an unexpected accident occurs and the high-pressure hose or oil pipe in the crane arm telescopic oil cylinder circuit bursts or cuts off, the balance valve in the hydraulic circuit will take effect, locking the working oil from the lower chamber of the oil cylinder, allowing the crane to retract on its own, thereby ensuring the safety of the operation.

4. Height limit device: After the hook is lifted to the specified height, it touches the limit weight, opens the travel switch, and the "over winding" indicator light will turn on. At the same time, it cuts off the operation of lifting the hook, extending the boom, and lowering the boom to ensure safety.

5. Leg locking device: In the event of an accident, if the high-pressure hose or oil pipe leading to the vertical cylinder of the leg breaks or cuts, the bidirectional hydraulic lock in the hydraulic system can block the pressure oil in both chambers of the leg locking cylinder, preventing the leg from retracting or swinging out, thereby ensuring the safety of the lifting operation.