(1) Install a filter screen on the hopper to prevent large stones from entering the hopper.
(2) The proportion of concrete shall be strictly controlled to ensure that the slump of concrete does not change greatly.
(3) During the pump operation, the operator must pay close attention to the pump pressure change. If it is found that the pressure rises and the pumping is difficult, the concrete shall be pumped back to the hopper for mixing and then sent out. If the reverse pump still does not work for many times, the pumping shall be stopped, the blocked square tube shall be removed, and the pumping shall be started after cleaning.
