256HC Mast SectionSafety technology of tower crane lifting operation: hydraulic system inspection, lifting operation
1. Hydraulic system of tower crane
256HC Mast Section：
http://www.towercranesupply.com/product/256hc-mast-section-liebherr-tower-crane
(1) the hydraulic oil must conform to the variety and grade specified in the original manufacturer's instructions. For example, when substituting, its performance must be the same or similar to the original variety and label, and it is not allowed to substitute at will, nor to mix two different kinds of hydraulic oil.
(2) the hydraulic oil and hydraulic system must be kept clean and free of dust, moisture, metal chips, rust and other impurities. The amount of oil in the tank should be kept at the normal oil level. When changing oil, the hydraulic system should be thoroughly cleaned and the new oil must be filtered. The container containing hydraulic oil must be kept clean, and the inner wall of the container shall not be painted.
(3) the hydraulic oil pipe joint shall be firm and shock proof, the hose shall be free from sharp bend or twist, and shall not collide and rub with other pipes or objects.
(4) the inlet and outlet and rotation direction of the hydraulic pump shall be consistent with the label. Do not knock when disassembling the coupling.
(5) the hose connection of the hydraulic cylinder shall not be loosened, the inlet and outlet of each valve shall not be installed reversely, and the flange screws shall be tightened according to the specified pre tightening force.
(6) when the hydraulic pump starts and stops, the relief valve shall be unloaded, and the regulating pressure of the relief valve shall not exceed the maximum pressure of the hydraulic system.
(7) all parts of the hydraulic system must be connected and sealed reliably without leakage, and the interlocking device must be calibrated.
(8) when opening the vent valve or checking the leakage of the high-pressure system, do not face the direction of the injection port.
(9) in case of small or partial spray leakage of high-pressure system, it shall be unloaded for maintenance, and it is not allowed to check or block the spray leakage by hand.
(10) in case of failure or accident of the hydraulic system, the inspection and adjustment can only be carried out after unloading.
2. Tower crane lifting operation
(1) before jacking, it is necessary to check the connection of all parts of the hydraulic jacking system, adjust the gap between the guide roller of the jacking jacket and the tower body, and then loosen the cable, whose length is slightly greater than the jacking height, and fasten the cable drum.
(2) the jacking operation must be conducted under the command of a specially assigned person. Non operators are not allowed to board the operation platform of the jacking jacket. Only one person is allowed to operate in the operation room and strictly obey the signal command.
(3) jacking shall be carried out in the daytime, and sufficient lighting shall be provided when it is necessary to work at night under special circumstances.
(4) when the wind force is above level 4, lifting operation is not allowed. If the wind force suddenly increases during the operation, the operation must be stopped immediately and the upper and lower tower bodies shall be connected firmly.
256HC Mast Section：
http://www.towercranesupply.com/product/256hc-mast-section-liebherr-tower-crane
(5) when jacking, the boom and balance arm must be in a balanced state, and the rotating part must be braked. It is forbidden to rotate the boom and other operations. If any fault is found during jacking, the jacking must be stopped immediately for inspection, and the jacking can be continued after troubleshooting. If the fault cannot be eliminated in a short time, the jack up sleeve frame shall be lowered to its original position and all connecting bolts shall be fastened in time.
(6) when removing the connecting bolt (PIN) between the rotary table and the standard section of the tower body, if the last bolt is difficult to be disassembled, the bolt (PIN) in the diagonal direction shall be reinserted and other measures shall be taken. Do not loosen the bolts (pins) by rotating the boom.
(7) when jacking, it is necessary to confirm that the jacking support foot is firmly in place before continuing the next action.
(8) pay attention to the pressure change of the hydraulic system at any time during the jacking work, and check and adjust in time in case of any abnormality. A special person shall be assigned to measure the verticality change of the tower body with a theodolite and make records.
(9) after jacking to the specified height, the tower body must be attached to the building before continuing to be jacked.
(10) the precautions for jacking during disassembly are the same as above. However, the anchorage device shall not be disassembled in advance, only when it is lowered to the attachment joint.
(11) after the jacking of the installation and disassembly work is completed, the connecting bolt pin shafts shall be tightened according to the specified pre tightening force, the guide roller of the jacking sleeve frame shall be in good agreement with the tower body, the left and right control levers of the hydraulic system shall be in the middle position, and the power supply of the hydraulic jacking mechanism shall be cut off.
256HC Mast Section：
http://www.towercranesupply.com/product/256hc-mast-section-liebherr-tower-crane
