1. Reasonably determine the pipe diameter of horizontal multistage centrifugal pump. The pipe diameter will affect the pump station efficiency. It is proved in practice that too large or too small pipe diameter is uneconomical. When the pipe length and flow are fixed and the pipe diameter is large, the flow rate is small, the head loss is small, and the power consumption is small, but the pipeline investment is high; If the pipe diameter is small, the situation is opposite to the above. In order to reduce pipeline loss, the diameter of inlet and outlet pipes of horizontal multistage centrifugal pumps should be reasonably determined. If the pipe diameter that has been put into operation is too small, the water head loss of the pipeline will increase. In order to improve the pipeline efficiency, the pipeline can be replaced according to the economic pipe diameter.

2. Shorten the pipeline length of horizontal multistage centrifugal pump. The length of inlet and outlet pipes shall be shortened as much as possible. However, when the terrain between the water source and the outlet pool is flat, shortening the pipeline will inevitably increase the excavation volume of the approach channel, the inlet pool and the pump house, or increase the filling works of the outlet pool and the main channel. The small pump station is installed horizontally instead of obliquely, or the pump is installed in the well or half of the well, and the pipeline is arranged in a straight line instead of a broken line, which can shorten the length of the pipeline in the pump room, save elbows, and reduce the head loss. The resistance loss of the pipeline can be reduced by improving the smoothness of the inner wall of the pipeline according to the conditions. Generally, the pumping device of high lift centrifugal pump should mainly reduce the frictional resistance.

3 Reduce the local resistance coefficient of pipeline accessories is very large, which causes large head loss and must consume a lot of energy during operation. Therefore, unnecessary inner pipe accessories shall be minimized.

The bottom valve has the largest resistance coefficient in the pipeline accessories, which should be replaced by other water filling equipment and cut-off facilities. According to relevant data, the energy loss of the bottom valve accounts for 50%~70% of the total energy loss of the water pipe and 10%~50% of the total energy loss of the inlet and outlet pipes. (Welcome to pay attention to the official account: pump steward) The lower the pump station head, the greater the proportion of energy loss of the bottom valve. In addition, the existence of the bottom valve also brings a lot of trouble to the operation management. Therefore, it was proposed to cancel the bottom valve very early. At present, some pump stations have cancelled the bottom valve and replaced it with vacuum pump for water filling, which has achieved good energy-saving effect. But in small pumping units, the bottom valve is still widespread, which is one of the reasons for its low efficiency. In order to reduce the head loss at the inlet and outlet of the pipeline, a bell mouth can be added at the inlet of the pipeline. For the inclined pipeline, the flat cut pipe or special horn pipe can be installed at the inlet, and the diffusion pipe is used at the outlet of the pipeline, which has significant energy saving effect.

4 Eliminate the "anti-aircraft gun" type outflow The so-called "anti-aircraft gun" type outflow is the free (jet) outflow from the outlet pipe of the horizontal multi-stage centrifugal pump above the water surface of the outlet pool. This outflow mode artificially raises the actual lift of the pump station, the working point of the pump moves to the upper left, the flow of the pump decreases, and the efficiency decreases. At the same time, due to the turbulence of the flow in the outflow pool, the head loss in the pool (plant) and the length of the outflow building (or structure) increase. In order to increase the water output, improve the pump efficiency and reduce the unit energy consumption, the outlet of the water pump should be installed below the water surface of the outlet building (or structure).

The built "anti-aircraft gun" type pump station can be converted into a siphon outlet. In order to prevent backflow of water in the outlet pool during shutdown, facilities are provided to destroy siphon vacuum. The small pump station can install a vent pipe at the rising section of the siphon corresponding to the design water level elevation of the outlet pool. When the pump is shut down, because the water rapidly discharges under the action of gravity, a vacuum is formed here, and the air is sucked in by this pipe, and the siphon is damaged. The sectional area of the vent pipe is generally 5-8% of the sectional area of the outlet pipe.