When you watch the concrete pump work, it is easy to notice that when much of the mortar has been pumped into the cylinder, there is still a considerable amount of aggregates left in the hopper. At this point, you should remove some of the aggregates from the hopper and add some mortar into it for repeated mixing.
As the pressure increases during pumping, the impact force that acts on the pipe may associatively grow, which causes the pipe to move back and forth. Impact force is not only the cause of pumping pressure loss, but it also strains the pipe joint from time to time. This would lead to the early failure of pipe clamp and rubber ring, resulting in pipe leakage. Hence, it is necessary to clamp the pump into position.
When the S-tube valve assembly is connected with the pumping cylinder, users should first conduct an overall inspection on the pump parts according to the concrete pump user manual before the pump is started for idle running. Upon filling the concrete into the hopper, users should make sure that surface level of the concrete mixture should be above the axis of the mixer shaft.
Please do not pile up the concrete on the screen of the hopper. Concrete flow rate should be properly controlled. Remove any oversize aggregates or other foreign matters. Without permission, please do not move the screen in the hopper.
After the concrete is poured into the hopper, the aggregates might separate from the cement mortar. At this point, you should shut off the pump and re-mix the concrete to ensure a uniform distribution of concrete particles. After the mixing, start the pump for idle running for 10 minutes to see whether all the pump parts function properly. The inner wall of transportation pipes should be thick enough to withstand the pumping pressure. Pipes installed near the pump should be of high quality to withstand vibration, impact, and wear. Inspect the pipe joints, seal rings, and pipe bends for any damages.
Users also need to prepare a set of pump cleaning devices. Before starting the pump, users should ensure there is no one around the piping system except the operators. Leave the pipe idle running for a few minutes and observe the data shown the in the gauge. Check the operating condition of the pump and mixer. If everything goes well, then users can start the pump for pumping. Remember to fill 10L of clean water and 0.3 m3 of cement mortar to lubricate the pump and pipes.