The multi-stage centrifugal pump is composed of multiple impellers (two or more) connected in series on the same slender shaft. During operation, it is pressurized step by step to meet the user's requirements. Since the pumps of the slender shaft system are supported at two points, during operation, since the force of each impeller is in the same direction, the shaft will have winding properties. Therefore, the installation requirements are relatively high.
Purpose: In order to make the multi-stage centrifugal pump operate normally for a long time, reduce the vibration and noise caused by the shaft winding. Extend the service life of the water pump.
Multi-stage centrifugal pump installation requirements:
First, pour the reinforced concrete foundation according to the correct installation drawing. And reserve the anchor bolt embedded hole according to the installation size. (Requirements: Under normal circumstances, the total weight of the base is 5-7 times the weight of the pump, including the pump, motor, base, etc. According to the local geology, the geology is relatively loose, and it needs to be enlarged or heavier). The surface of the foundation is required to be flat.
After the concrete foundation curing period is up, the concrete is solidified (usually 10-15 days in summer and 20-30 days in winter). Begin to assemble water pumps and motors.
Hoist the assembled water pump and the motor on the foundation, put on the anchor bolts, pad the adjustment horns, and perform the first calibration of the water pump (when the water pump is a self-balancing 6-foot plate, apply the four front and back plates Correct and fasten the feet. After calibration, check the gap between the middle foot and the bottom plate with a feeler gauge, and use horns for cushioning. The horns are not allowed to be larger than the maximum gap between the feet. Corrected coaxiality error Within ±05mm, the angle error between the end faces of the two couplings is within ±0.05mm, and the gap between the end faces of the two couplings is between 4-6mm. Prepare for the second calibration)
After the first correction is completed, the second watering can be carried out. Fill the embedded hole with concrete.
The maintenance period for the second watering is up. After the concrete is fully solidified and firm, tighten the anchor bolts. At the same time, the water pump is corrected twice (the corrected coaxiality error is within ±05mm, the end face angle error between the two couplings is within ±0.05mm, and the gap between the end faces of the two couplings is between 4-6mm. .Be prepared for the third calibration)
After the second calibration is completed, fill the cavity in the pump base with concrete (purpose: to better reduce vibration. Concrete has good vibration absorption)
After the above is completed, the inlet and outlet pipes of the water pump can be connected (both the suction pipe and the discharge pipe of the pump should be supported, so that the pump flange cannot be subjected to any external force). And plumbing accessories.
Before connecting the pipeline, all impurities (wood, rust, welding slag, rags, gloves, plastic cloth, etc.) in the pipeline must be removed. Do not allow any debris to enter the pump port.
After the pipes are connected, the water pump must be calibrated for the third time (the corrected coaxiality error is within ±05mm, the end face angle error between the two couplings is within ±0.05mm, and the difference between the end faces of the two couplings is within ±0.05mm. The gap is between 4-6mm.) Tighten all connecting bolts at the same time.
After the above work is fully completed, clean up the materials used on site (tools, redundant installation materials and debris, etc.). Ensure that the site is clean.
After the above work is completed, the water pump can be refueled and cranked. Ready to debug and run.
Preparatory work before installation of multistage centrifugal pump
1. Prepare installation tools and lifting equipment; 2. Check whether the components of the pump unit are loose or damaged during transportation; 3. Check whether the foundation is level. Installation diagram of multi-stage centrifugal pump:
Multistage centrifugal pump installation sequence
1. When the unit is transported to the site, the person with the base has already calibrated the water pump and motor. When leveling the base, it is not necessary to remove the pump and motor, so the installation is very convenient;
2. Put the base on the foundation, and put a wedge-shaped iron near the anchor bolts, and pad the base by 20~40 mm high for filling with grout after leveling;
3. Check the levelness of the base with a spirit level, fill the base with cement slurry after leveling, and check the level again after the cement dries;
4. When the power of the unit is large, the pump, motor and base may be packaged separately for the convenience of transportation. At this time, users need to install and calibrate the pump unit by themselves. The method is as follows:
a. Remove the dirt on the supporting plane of the base, the feet of the water pump and the feet of the motor, and place the water pump and the motor on the base;
b. Adjust the level of the pump shaft, and fix the pump on the base with bolts after leveling to prevent it from moving;
c. Lift the motor, make the pump coupling and the motor coupling match, and lower the motor to the corresponding position on the base;
d. Adjust the gap between the two couplings to about 5mm, and correct whether the axis lines of the motor shaft and the pump shaft coincide. The method is to put a flat ruler on the coupling, and the outer circle of the two couplings should be in line with the flat ruler. If they are not coincident, the relative position of the motor or pump should be adjusted, or the pad should be adjusted with a thin iron sheet;
e. In order to check the installation accuracy, the gap between the two coupling planes should be measured with a feeler gauge at several different positions on the circumference of the coupling. The difference between the maximum and minimum gaps on the coupling plane should not exceed 0.3mm. , The difference between the top and bottom or left and right of the center line at both ends shall not exceed 0.1mm.
5. When the unit does not have a base, it needs to be installed directly on the foundation. The method is similar to that of 4., but more attention should be paid to calibration.
Precautions for installation of multistage centrifugal pumps
1. The pipeline should not be put on the pump during installation, otherwise the pump will be easily damaged;
2. The anchor bolts must be tightened during installation, and the unit should be inspected every certain period of time to prevent it from loosening, so as to avoid severe vibration when the pump starts running and affect the performance of the pump;
3. Before installing the pump, carefully check whether there are hard objects (such as rocks, iron sand, etc.) in the pump flow path that affect the operation of the pump to avoid damage to the flow components during the operation of the pump;
4. For easy maintenance and safe use, a regulating valve should be installed on the inlet and outlet pipes of the pump and a pressure gauge should be installed on the inlet and outlet flanges of the pump. For high-lift pumps, in order to prevent water hammer, Install a check valve in front of the outlet gate valve to cope with power loss accidents such as sudden power failure, so as to ensure that the pump runs under the best conditions and prolong the service life of the pump;
5. When the pump is used in occasions with suction, it should be equipped with a bottom valve, and the inlet pipeline should not have too many bends, and there should be no water or air leakage, so as not to affect the suction performance of the pump;
6. To prevent impurities from entering the pump. Blocking the flow channel affects performance, so a filter should be installed in front of the pump inlet;
7. Rotate the rotor parts of the water pump before installing the pipeline. There should be no friction or jamming. Otherwise, the pump should be disassembled to check the cause.
