1. Pipeline centrifugal pumps are matched with some pipeline
centrifugal pumps. Users believe that this can increase the actual head, but in
fact, the actual head of the water pump is equal to the total head to the loss
head. After the water pump model is determined, the total head is fixed; The
loss of head mainly comes from pipeline resistance. The smaller the pipe
diameter, the greater the resistance, and therefore the greater the loss of
head. Therefore, reducing the pipe diameter not only does not increase the
actual head of the water pump, but also reduces it, leading to a decrease in
pump efficiency. Similarly, when a small diameter water pump uses a large water
pipe for pumping, the actual head of the pump will not be reduced. Instead, the
loss head will be reduced due to the decrease in pipeline resistance, resulting
in an increase in actual head.
2. High head water pumps are used for low head
pumping. Some pipeline centrifugal pumps users believe that the lower the
pumping head, the smaller the motor load. Under the misleading misconception,
when choosing a water pump, the head of the pump is often chosen too high. In
fact, for centrifugal pumps, when the pump model is determined, the power
consumption is directly proportional to the actual flow rate of the pump. The
flow rate of the water pump will decrease with the increase of the head, so the
higher the head, the smaller the flow rate, and the smaller the power
consumption. On the contrary, the lower the head, the greater the flow, and the
greater the power consumed.
3. If there are too many elbows on the inlet
pipeline of the centrifugal pump in the pipeline, it will increase local water
flow resistance. And the elbow should turn in the vertical direction, and it is
not allowed to turn in the horizontal direction to avoid gathering air.
4.
When installing the water inlet pipeline, the horizontal section should be
horizontal or upward. This will cause air to accumulate in the water inlet
pipeline, reduce the vacuum degree of the water pipe and water pump, and reduce
the suction head and water output of the water pump. The correct approach is to
tilt the horizontal section slightly towards the direction of the water source,
not horizontally, and not upward.
5. The inlet of the pipeline centrifugal
pump is directly connected to the elbow, which will cause uneven distribution of
water flow when passing through the elbow and entering the impeller. When the
diameter of the inlet pipe is greater than that of the water pump inlet, an
eccentric reducing pipe should be installed. The flat part of the eccentric
reducer should be installed above, and the inclined part should be installed
below. Otherwise, air will accumulate, water output will decrease or water
cannot be pumped, and there will be a sound of impact. If the diameter of the
inlet pipe is equal to that of the water pump inlet, a straight pipe should be
added between the water pump inlet and the elbow, and the length of the straight
pipe should not be less than 2-3 times the diameter of the water pipe.
6. If
the outlet of the pipeline centrifugal pump is above the normal water level of
the outlet pool, although the pump head is increased, the flow rate is reduced.
If the water outlet must be higher than the water level of the water tank due to
terrain conditions, elbows and short pipes should be installed at the pipe mouth
to make the water pipe a siphon type and reduce the height of the water
outlet.
7. When installing the bottom valve, the lower section of the inlet
pipe is not vertical. If installed in this way, the valve cannot close on its
own, causing water leakage. The correct installation method is to install the
inlet pipe with a bottom valve, and ensure that the next section is vertical. If
vertical installation is not possible due to terrain conditions, the angle
between the water pipe axis and the horizontal plane should be above 60 °.
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