In order to ensure the safety and reliability of the lifting operation, the crane should be equipped with a complete safety device, so as to protect the machine parts or remind the operator to pay attention in the event of an accident. So as to play a role in safety protection.

1. Each relief valve in the hydraulic system: it can suppress the abnormal high pressure in the circuit to prevent damage to the hydraulic oil pump and motor, and prevent it from being overloaded.

2. Boom luffing safety device: When an accident occurs and the high-pressure hose or oil pipe in the boom luffing cylinder circuit bursts or is cut off, the balance valve in the hydraulic circuit works to lock the working oil from the lower chamber of the cylinder. So that the boom does not fall, so as to ensure the safety of the operation.

3. Boom telescopic safety device: When an accident occurs and the high-pressure hose or oil pipe in the boom telescopic cylinder circuit bursts or is cut off, the balance valve in the hydraulic circuit will work to lock the working oil from the lower cavity of the cylinder, so that the crane can lift. It retracts on its own, ensuring the safety of the job.

4. Height limit device: After the hook is raised to the specified height, touch the limit hammer, turn on the travel switch, the "overwind" indicator light will be on, and at the same time cut off the lifting of the hook, the extension of the boom, and the fall of the boom. Wait until the operation of the action to ensure safety.

5. Outrigger locking device: When an accident occurs and the high-pressure hose or oil pipe leading to the vertical cylinder of the outrigger is ruptured or cut, the two-way hydraulic lock in the hydraulic system can block the pressure oil in the two chambers of the outrigger and the cylinder, so that the outrigger cannot be blocked. can be retracted or thrown out, thus ensuring the safety of lifting operations.

6. Lifting capacity indicator: The lifting capacity indicator is set on the closed side of the basic arm, and the operator can clearly observe it while sitting in the control room, and can accurately indicate the elevation angle of the boom and the rated lifting capacity allowed by the crane under the corresponding working conditions. .

7. Amplitude limit device; for cranes with boom luffing, a minimum amplitude limiter and a device to prevent the boom from bouncing back should be installed. For the overweight machine with trolley luffing, the trolley travel switch and terminal buffer device must be installed.

8. Rail clamps and travel limit devices: rail-mounted tower cranes must be equipped with rail clamps. At the same time, a travel limit device should be installed.

9. Anemometer: For cranes with a hinge point height of more than 50m at the root of the boom, an anemometer must be installed on the top.

10. Lightning protection and anti-electromagnetic wave induction device: For cranes with a hinge point height of more than 50m at the root of the boom, lightning protection devices and anti-electromagnetic induction measures should be installed according to the actual situation.

11. Tower cranes should be equipped with limit torque couplings to prevent slewing overload.