To ensure safe and reliable operation of lifting cranes should be equipped with perfect safety devices, so that in case of an accident, mechanical or protect Calls attention, and thus play a security role.
1. Each hydraulic system relief valve: Can cause abnormally high pressure loop to prevent damage to the hydraulic pumps and motors, and to prevent the overload condition.
2. Luffing crane safety device: When unexpected accident, boom luffing cylinder loop high-pressure hose or pipe burst or cut off, the hydraulic circuit balancing valves to work, locking the working oil from the fuel tank under the chamber, so that the arm will not fall, so as to ensure the safety of operations.
3. Telescopic crane safety device: When unexpected accident, telescoping boom cylinder circuit of high-pressure hose or pipe burst or cut off, the hydraulic circuit balancing valves on the work, the lower chamber of the cylinder lock from the working oil to make hanging retract on their own, so as to ensure the safety of operations.
4. Height limit device: hook raised from a predetermined height, the touch weight limit, open limit switch, "over round" indicator light that is bright, and cut off the hook lifting, arm extended, arm V and other actions to ensure the safety of operations.
5. Leg locking device: When unexpected accident, leading to the legs vertical cylinder high-pressure hose or pipeline rupture or cut, the hydraulic system can be blocked leg bidirectional hydraulic lock cylinder block two pressure oil chamber, so that the legs do not reduced or thrown, to ensure the safety of lifting operations.
6. From the weight of indicator: Starting weight indicator is provided in the closing side of the basic arm, the operator sitting in the control room will be able to be clearly observed, it can accurately indicate the boom crane elevation and the corresponding conditions allowed the rated capacity .
7. amplitude limit device; for luffing crane shall be installed minimum amplitude limiter and prevent the boom dipping rebound device. Trolley for the more heavy machinery, to be fitted with trolley limit switch and the terminal buffer means.
8. The rail clamp and walking stopper: tower crane track rail clamp must be installed. Travel limit device should be installed at the same time.
9. anemometer: the roots of the boom hinge point height of more than 50m crane anemometer must be installed at the top.
10. Lightning and anti-electromagnetic sensing devices: the height of the boom hinge point of the root of more than 50m crane shall be installed lightning protection devices and measures taken to prevent electromagnetic induction according to the actual situation Phi.
11. In order to prevent the rotary tower crane shall be equipped with limit torque overload coupling.