Below are details to maintain hydraulic system of bridge girder launcher:
1. Hydraulic oil for hydraulic system: anti-wear hydraulic oil #46
2. Oil for hydraulic system should be clean, oil quality should be often checked in the use process, replace oil as the oil quality becomes worse. Replace oil according to actual working condition, it is suggested to change oil every half a year.
3. Oil filter must be cleaned one time every one month in order to keep the hydraulic oil clean
4. Often check the height of oil level, when the oil level is < mark shown on the liquidometer, infuse oil to reach the certain place (usually normal oil level should be at the place of 4/5 of full scale). Oil shortage will burn the oil pump to cause the system breakdown.
5. After the hydraulic system under the seal condition is open to check, refill enough hydraulic oil into the system
6. Adjustable speed for lateral moving oil cylinder of auxiliary trolley is adjustable, lateral moving speed set value:200mm/min, flow speed control valve pointer is between 3 and 4, higher value can increase the speed. the value has been set before using the bridge girder launcher, it is not recommended to change the value and change without permission is not allowed.
7. Because of accumulation of all kinds of accuracy error (especially error of oil cylinder), the oil cylinder group stretching out and drawing back speed in the free state without external load has a little error (namely oil cylinders do not move at the same time), it should be considered normal. After oil cylinder group enters into the load-bearing work condition, each oil cylinder has a same load value, namely they are in the condition of moving at the same time.
 
8. Often monitor the pressure meter value. Pressure set value for rear support leg hydraulic system 16MPa, that for rear support leg, auxiliary support leg hydraulic system is 17MPa, that for auxiliary trolley lifting system 16MPa, for lateral moving system 5MPa. If error between pressure meter value and set value of hydraulic system > 1.5 MPa, adjust relief valve to reset the value. Too low pressure will cause the hydraulic system fails to realize its function, too high pressure will damage oil pump, coupler or motor.
 
9. Hydraulic system parameters are in accordance with design parameters provided by the mainframe manufacturer. For the actual use, overload should be forbidden to avoid oil leakage caused by damaging blunt valve or sealing elements and to avoid system paralysis caused by damaging oil pump or motor.