Cranes equipped with safety devices which

To ensure safe and reliable lifting operations,  hoist and trolley  equipped with a better safety devices in order to unexpected circumstances, play a protective parts or alert the operator, and thus play a security role.
  A hydraulic system, the pressure relief valve: inhibit loop abnormally high pressure in order to prevent damage to the hydraulic pumps and motors, and to prevent is overloaded.
  2 luffing jib safety device: When the unexpected accident, boom luffing cylinder loop pressure hose or pipe burst or cut off, the hydraulic circuit balancing valves on the work, lock cylinder lower chamber from work oil, the boom will not fall, thereby ensuring the safety of operation.
  3 telescopic crane safety device: When unexpected accidents, telescopic boom cylinder circuit of the high-pressure hose or pipe burst or cut off, the hydraulic circuit balancing valves on the work, lock cylinder lower chamber from the working oil, the suspension will retract themselves, thus ensuring the safety of operation.
  4 height limit device: hook up the required height to rise after touching limit hammer, turn the trip switch, "over round" indicator light that is bright, while cutting off the hook lifting, boom stretched out, hanging Arm volts to the operation of such action to ensure safety. Then just manipulate the hook down, boom boom retracted or looked up (to the Security side operation), etc. handle, lift the weight limit constraint, the operation returns to normal. For special occasions, such as still need to make a small amount of over-winding operation, press the release button on the meter box, this time limit will be lifted role, but this time the operation must be very careful to prevent accidents.
  5 leg locking device: When unexpected accident occurred, leading to the leg vertical cylinder hoses or tubing rupture or cutting, the hydraulic system can be disabled with a two-way hydraulic lock cylinder two leg  Manual block  pressure oil chamber, the branch Notations or throw the legs, thereby ensuring the safety of the lifting operation.
  6 from the weight indicator: Starting weight indicator is set in the basic arm together side (ie, the right side of the cab), the operator sitting in the control room can be clearly observed, can accurately indicate the boom elevation and the corresponding conditions allow  hoist equipment  rated capacity.
  7 Lifting Characteristics Table: Set in the control room on the front side of the lower wall, the table lists the various arm lengths and a variety of work rate and the nominal weight lifting height for operation inspection. Lifting operation, must not exceed the values  specified in the table.