There are many factors to consider when installing a water pump, and the most important one is the installation of pipelines. D-type horizontal multi-stage centrifugal pumps and pipelines are often used together. The two need to be considered and cooperate with each other to achieve better results. What are the matters needing attention in the pipeline installation of D type horizontal multistage centrifugal pump?
1. Each multi-stage centrifugal pump should be equipped with an independent suction pipe to directly suck water from the suction pool. When several water pumps share suction pipes, the number of suction pipes should not be less than two, and necessary valves should be installed. When one suction pipe is overhauled, the other suction pipe can meet the design flow requirements of the pump room. The length of the suction pipe should be as short as possible, pipe fittings should be few, and pressure loss should be small. The suction pipe is generally made of steel pipe, and its horizontal section should have an upward slope (≥0.005) along the direction of the water flow to prevent the air in the pipe from gathering and forming an air bag.
2. A valve should be installed on the water pressure pipe. When the pipe diameter is greater than or equal to DN300, an electric or hydraulic valve should be used. There is no need to install a check valve on the water pressure pipe, but a check valve must be installed in the following situations. However, check valves must be set in the following situations: pump rooms with pumps working in parallel; pump rooms with vacuum diversion, it is difficult to vacuum after the water in the pipeline is emptied; if there is no check valve after the pump is stopped, negative pressure may appear in the water supply system .
What should I pay attention to when installing D-type horizontal multistage centrifugal pump pipeline?
All pipes that are matched with the water pump should be strictly sealed to prevent leakage of water and air.
1. When installing the water inlet pipe, the horizontal section is horizontal or upturned. This will cause air to accumulate in the water inlet pipe, reduce the vacuum of the water pipe and the water pump, reduce the suction lift of the water pump, and reduce the water output. The correct approach is: its horizontal section should be slightly inclined towards the direction of the water source, it should not be level, let alone tilt upward.
2. There are many elbows used on the inlet pipe
If more elbows are used in the inlet pipe, it will increase the 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.
3, the water pump inlet is directly connected to the elbow
This will make the water flow unevenly distributed when entering the impeller through the elbow. When the diameter of the inlet pipe is larger than the water inlet of the pump, an eccentric reducing pipe should be installed. The flat part of the eccentric reducer should be installed on the top, and the inclined part should be installed below. Otherwise, the air will gather, the water output will be reduced or the water will not be able to be pumped, and there will be impact noises. If the diameter of the water inlet pipe and the water inlet of the pump are the same, a straight pipe should be added between the water inlet of the pump and the elbow. The length of the straight pipe shall not be less than 2 to 3 times the diameter of the water pipe.
4. The next section of the inlet pipe equipped with a bottom valve is not vertical
If installed like this, the valve cannot close by itself, causing water leakage. The correct installation method is: the inlet pipe with the bottom valve, the next section is vertical. If it cannot be installed vertically due to topographical conditions, the angle between the axis of the water pipe and the horizontal plane should be above 60.
5. The position of the inlet of the water inlet pipe is wrong
(1) The distance between the water inlet of the water inlet pipe and the bottom and wall of the water inlet is less than the diameter of the water inlet. If there is dirt such as mud and sand at the bottom of the pool, and the distance between the water inlet and the bottom of the pool is less than 1.5 times the diameter, it will cause poor water intake or suction of mud and debris during pumping, which will block the water inlet.
(2) When the water inlet depth of the water inlet pipe is not enough, this will cause vortexes on the water surface around the water inlet pipe, which will affect the water intake and reduce the water output. The correct installation method is: the depth of the medium and small pumps should not be less than 300~600mm, and the large pumps should not be less than 600~1000mm
6 The outlet of the water outlet is above the normal water level of the outlet pool
If the water outlet is above the normal water level of the outlet pool, although the pump lift is increased, the flow rate is reduced. If the water outlet must be higher than the water level of the pool due to terrain conditions, elbows and short pipes should be installed at the nozzle to make the water pipe a siphon type and reduce the height of the water outlet.
