1. High head pumps for low-head water sucking
Many people believe that the lower the pumping head, the lower the motor load. Under this kind of wrong understanding misguide, when buying the water pump, some people often chooses high head water pump.
In fact, for centrifugal pumps, the size of its power consumption is proportional to the actual flow of the pump in terms of certain pump model. And the pump flow will be reduced with the increase in the head, so the higher the head, the smaller the flow, the lower the power consumption. Conversely, the lower the head, the greater the flow, the greater the power consumption.
Therefore, in order to prevent motor overload, the general requirements of the actual pump pumping head must not be less than 60% of the nominal head. So when the high-lift pump for too low-lift, the motor easy to overload and heat, serious motor can be burned.
2. Large diameter pumps with small pipes for pumping
Many people believe that this can improve the actual head, in fact, the actual head of the pump total head-loss head. When the type of the pump is determined, the total head is certain; the loss head mainly comes from the resistance of the pipeline, the smaller the diameter of the pipeline, obviously the greater the resistance, and therefore the loss head is larger, so the actual head of the pump can not be increased after reducing the diameter of the pipeline, it reduces the efficiency of the pump. In the same way, when the small diameter pump is pumped with the big pipe, the actual head of the pump will not be reduced, but the loss head will be reduced because the resistance of the pipe will be reduced, and the actual head will be increased. As long as the lift is certain, the pump impeller size unchanged, no matter how much pipe diameter, the pressure on the impeller is certain. However, with the increase of pipe diameter, the flow resistance will decrease, the flow rate will increase, and the power consumption will also increase. But as long as the rated head range, no matter how to increase the diameter of the pump can be normal work, but also can reduce the loss of the pipeline, improve pump efficiency.
3. When installing the water inlet pipe, the horizontal section should be horizontal or upward
This will make the intake pipe to collect air, reduce the vacuum of the pipe and pump, so that the pump suction head is reduced, water output is reduced. The correct approach is: its Horizontal Section should be slightly inclined to the direction of the water source, should not be horizontal, not to tilt up.
4. Centrifugal pump intake pipe with more elbow
If more elbows are used in the re-entry pipe, the local flow resistance will be increased. And the elbow should turn in the vertical direction, not allowed to turn in the horizontal direction, so as not to collect air.
5. The inlet of the Centrifugal pump is directly connected to the elbow
This will cause the water flow through the elbow into the impeller uneven distribution. When the diameter of the inlet pipe is larger than the inlet of the pump, the eccentric variable diameter pipe should be installed. The plane part of the eccentric diameter-changing pipe should be installed on the top, and the inclined part on the bottom. Otherwise the accumulation of air, water reduction or pumping water, and there are impact sound, etc. . If the inlet pipe is the same as the pump inlet diameter, a straight pipe should be added between the pump inlet and the elbow. The straight pipe length should not be less than 2 ~ 3 times of the pipe diameter.
6. The bottom section of the inlet pipe with the bottom valve is not vertical
Such as this installation, the valve can not close by itself, resulting in leakage. The correct installation method is: installed at the bottom of the inlet valve, the next section is best vertical, such as due to topographical constraints can not be installed vertically, the water pipe axis and horizontal angle should be above 60.
7. The inlet of the water pipe is not in the right position
The distance between the water inlet of the water inlet pipe and the bottom of the water inlet pool and the wall of the pool is less than the diameter of the water inlet. If there is sediment at the bottom of the pool, the distance between the water inlet and the bottom of the pool is less than 1.5 times of the diameter, the water intake will be blocked or the intake of sediment debris.
When the inlet water depth of the intake pipe is not enough, it will cause the water surface around the intake pipe to produce whirlpool, affect the water intake and reduce the water output. The correct installation method is: small and medium-sized pumps water depth should not be less than 300 ~ 600 mm, large pumps should not be less than 600 ~ 1000 mm.
8. The outlet pipe is above the normal water level of the outlet pool
If the outlet is above the normal water level of the SUMP, the pump head is increased, but the flow rate is reduced. If the outlet must be higher than the water level of the sump due to the limitation of the terrain, the elbow and short pipe should be installed at the pipe mouth to make the pipe become Siphon type and reduce the height of the outlet.
