Common Installation Misconceptions of Vertical Multi-stage Centrifugal Pumps
A slight oversight during the installation of a vertical multistage centrifugal pump can lead to improper installation, affecting the pump's operational performance in the future. Below is an analysis of common installation pitfalls for vertical multistage centrifugal pumps and related solutions.
There are numerous elbows in the suction pipeline of the vertical multistage centrifugal pump
If multiple elbows are used in the inlet pipeline, it will increase local water flow resistance. Additionally, elbows should bend vertically and must not bend horizontally to prevent air accumulation.
2. When installing the inlet pipeline of the device, ensure the horizontal section is level or slightly upward
This practice will cause air to accumulate in the suction pipe, reducing the vacuum level of the pipe and Pump, thereby decreasing the Pump's water lifting capacity and reducing water output. The correct approach is: the horizontal section should be slightly inclined toward the water source, not kept level, and must not be raised upward.
3. The suction port of the multi-stage centrifugal pump is directly connected to the elbow
This will cause uneven water flow distribution when the water passes through the elbow and enters the impeller. When the diameter of the inlet pipe is larger than the Pump's inlet, an eccentric reducer should be installed. The flat section of the eccentric reducer must be placed on top, while the curved section should be positioned below. Otherwise, air accumulation may occur, leading to reduced water output or failure to draw water, along with impact noises. If the inlet pipe has the same diameter as the Pump's inlet and outlet, a straight pipe should be added between the Pump inlet and the elbow. The length of the straight pipe must not be less than 2 to 3 times the diameter of the water pipe.
The outlet pipe of the multistage centrifugal pump is located above the normal water level in the discharge pool
If the outlet is above the normal water level of the discharge pool, although the pump head is increased, the flow rate will be reduced. If the terrain conditions require the outlet to be higher than the water level of the discharge pool, elbows and short pipes should be installed at the pipe outlet to convert the water pipe into a siphon type, thereby lowering the outlet height.
The inlet position of the feed pipe is incorrect
The distance between the inlet of the water inlet pipe and the bottom or wall of the water pool should be less than the diameter of the inlet. If there are mud, sand, or other debris at the bottom of the pool, when the distance between the inlet and the bottom is less than 1.5 times the diameter, it can cause poor water intake during pumping or the suction of mud, sand, and debris, leading to clogging of the inlet.
② When the water intake depth of the inlet pipe is insufficient, it can cause whirlpools around the pipe, affecting water intake and reducing output flow.
When installing the foot valve, the lowest section of the inlet pipe is not vertical
For such devices, the valve cannot close automatically, leading to water leakage. The correct installation method is: the inlet pipe equipped with a foot valve should ideally have its lowest section installed vertically. If vertical installation is constrained by terrain conditions, the angle between the pipe axis and the horizontal plane should exceed 60°. When installing a pump, numerous factors must be considered, with pipeline installation being particularly critical. Pumps and pipes are often used together, requiring mutual consideration and coordination to achieve optimal performance.
