10 Tips for for Concrete Pumps Maintenance

1 . When should the drainage of the bottom of the hydraulic oil tank of the concrete pumps be performed?
As we all know, there is a drain valve at the bottom of the hydraulic oil tank, which can drain the water deposited at the bottom of the oil tank, but if the water is drained at the wrong time, it will affect the waterproof effect.
The hydraulic oil should be drained before the motor vehicle (including driving), or stand still (the hydraulic system is not started, the vehicle does not move) for more than two hours before proceeding. At this time, the water has enough time to settle and the drainage effect is best. If the truck is already running or even pumped, the water at the bottom of the tank will be stirred due to the shaking of the fuel tank or the flow of hydraulic oil, causing it to remix with the hydraulic oil, and then draining the water will greatly reduce the effect.

2. What are the precautions when charging the accumulator of a concrete pump?

1. The liquid should be drained, or the unloading switch should be placed in the open position.
2. It should be inflated slowly. If the inflation speed is too fast, the high-pressure nitrogen will rapidly expand and cause rapid cooling, causing the skin to be cold and brittle or even rupture. In addition, if the inflation is too fast, it may cause the original folded skin to expand unevenly and rupture.
3. After inflating, you should wait a few minutes to stabilize the pressure, and then check the inflation pressure.
4. After inflation, soapy water can be used to check the air tightness of the valve.
5. After inflation, in the initial stage of use, follow-up should be strengthened to facilitate timely detection of insufficient air pressure.

3. Can the PSL connection block used in a fixed pump system be used in a variable pump system?
Yes, but a simple modification is required. Replace the spring in the three-way flow control valve with a suitable size ejector rod, and connect the LS port of the pump to the LS port of the connecting block.

4. How to judge the constant pumping power without water valve loading?
After replacing the main oil pump, the constant power valve needs to be re-adjusted. Since there is no water valve at the general maintenance point, the constant power cannot be loaded and tested. The oil pump displacement is determined by the smaller value of constant power control and gear control. Using this principle, the constant power can be roughly judged without a water valve.
First, put the large cavity U-tube ball valve of the pumping cylinder at the maximum opening position. Increase the speed to the maximum, change the gear from small to large, hold the cylinder, and observe the pumping pressure until the pumping pressure begins to change (the speed is always the maximum during this process), the pumping pressure at this time and the corresponding gear The number of pumping times (under the maximum pumping speed) is the constant power parameter.
In order to adjust accurately, several more points can be measured. At this time, you can hold the cylinder at different speeds to obtain constant power parameters under different pressures, or prepare damping joints with different apertures, connect the damping joints in parallel with the U-shaped tube through the pipeline, hold the cylinders and adjust the gears. The constant power parameters under different pressures can be obtained.

5. In the open concrete pumps system, why sometimes the displacement cannot be controlled by adjusting the gear?
Since the displacement control mechanism of the oil pump needs a certain control pressure to drive, for the main oil pump, the control pressure generally comes from the oil pump pressure. When the pump is empty (especially before the concrete piston is installed), sometimes the pumping pressure is lower than the minimum value. At this time, adjusting the gear position cannot change the displacement.

6. How to maintain the manual grease pump?
First of all, the manual grease pump must be cleaned before each start and after the end of pumping, and then check and keep the manual grease pump oil tank full of grease.
Secondly, pull the handle of the grease pump and observe the agitating bearing and the small and small shaft heads of the S tube. If there is clean grease overflow. In the working process, the handle of the manual grease pump should be pulled 10 times every 1 hour.
Finally, the lubrication system must be kept clean, dust and other impurities must be prevented from entering, and acid and alkali substances must not be contacted, and the system must be cleaned every 500 hours of work.

7. How to keep the oil cup of the concrete pump truck lubricated?
There is a lubricating oil cup on each of the two swing valve cylinder seats of the concrete pump truck. Before the pumping work starts, the operator must fill the oil cup with grease and screw the cap to fill it with oil for lubrication. During the working process, the cap should be lubricated once every 4 hours to keep the spherical friction surface in a good lubrication state.

8. How to extend the service life of the concrete piston of the concrete pump truck?
When the coating of the concrete piston conveying cylinder is not worn away and concrete slurry or sand appears on the back of the concrete piston, that is, the water tank, it indicates that the piston is worn and the concrete sealing body, guide ring, and dust ring must be replaced immediately. Since the piston can be retracted to the pumping system water tank through simple operations on the control panel, it is necessary to always allow the piston to withdraw for inspection. In addition, after the piston retreats to the water tank, the concrete seal and guide ring on the piston should be cleaned, and lithium-based grease should be applied for lubrication at the same time, which can effectively extend the service life of the piston.

9. How to keep the connecting shafts of the pump truck lubricated?
The maintenance of the boom, outriggers and turntable is specially designed with grease nipple at the hinge points of each boom section of the pump truck, the connecting shafts between the four outriggers and the support, and the turntable. Usually, it requires every 60 working hours. Grease the lubrication point (grease nipple). It should be completely lubricated with grease until the oil overflows.

10. What are the maintenance points of the rotary reducer of the concrete pump truck?
Every 500 working hours, replace the gear oil for the rotary reducer; every 3 months, grease the surfaces of all gears in the rotary reducer on a regular basis. If dirt is found on the gear surface, it should be removed immediately to prevent damage to the gear.