How to install a centrifugal split case pump?

Five-step centrifugal split case pump installation, easy to remember

The centrifugal pump installation process includes basic inspection → water pump installation in place → detection and adjustment → lubrication and refueling → trial operation. Today I will take you to understand the detailed process of this.

Basic inspection process

View split case double suction pump construction drawings


Construction Conditions

  1. The pump installation layer has passed the structural acceptance.
  2. The relevant axes and elevation lines of the building have been drawn.
  3. The concrete strength of the pump foundation has reached more than 70%.

Basic inspection

The base coordinates, elevations, dimensions, and reserved holes should meet the design requirements. The surface of the foundation is flat and the strength of the concrete meets the requirements for equipment installation.

1) The plane size of the pump foundation should be 100 ~ 150mm wider than the periphery of the pump unit base when installed without vibration isolation; 150mm wider than the periphery of the pump base when vibration isolation is installed. The elevation of the top of the foundation should be more than 100mm above the floor completion surface of the pump room when vibration isolation is installed, and more than 50mm above the floor completion surface of the pump room when vibration isolation is installed, and no standing water should be formed. Drainage facilities are provided around the periphery of the foundation to facilitate drainage or prevent accidental leakage during maintenance.

2) The oil dirt, gravel, soil, and water in the foundation holes of the pump and the reserved holes of the anchor bolts should be removed; the threads and nuts of the embedded anchor bolts should be protected intact; the surface of the place where the gasket is placed should be plain.

split-case-pump (18)

Water pump installed in place

Place the pump on the foundation and use the gasket to make the pump in level. After the pump is installed, the same set of horns should be spot welded together to prevent loosening when the force is applied.

1) The pump is installed without vibration isolation.

After the pump is aligned and leveled, install the anchor bolts. The screw should be vertical. The exposed length of the screw should be 1/2 of the screw diameter. During the secondary grouting of the anchor bolts, the strength of the concrete should be 1 to 2 grades higher than the foundation, and not lower than C25; it should be tamped during grouting, and the anchor bolts should not be tilted and the installation accuracy of the pump unit should not be affected.

2) Water pump vibration isolation installation.

① Horizontal pump isolation installation

The horizontal water pump unit’s vibration isolation measures are to install rubber shock absorbers (pads) or spring shock absorbers under the reinforced concrete base or section steel base.

② Vertical water pump vibration isolation installation

The vibration isolation measures of the vertical pump unit are to install rubber shock absorbers (pads) under the pump unit base or steel backing plate.

③ A rigid connection is used between the pump unit base and the vibration damping base or steel backing plate.

④ The model specifications and installation position of the vibration damping pad or vibration damper should meet the design requirements. The shock absorbers (pads) under the same base should use the same model of the same manufacturer.

⑤ The pump unit must take measures to prevent the pump unit from tilting during the installation of the shock absorber (pad). After the pump unit shock absorber (pad) is installed, when installing the water inlet and outlet pipes, fittings and accessories of the pump unit, measures to prevent the pump unit from tilting must also be taken to ensure safe construction.

3) On-site assembly of large water pumps

When the large pump is separated from the motor, the precautions are as follows:

① On the concrete foundation, make a profiled steel support according to the design drawing, and fix it on the foundation with anchor bolts for rough leveling.

② The water pump and motor are in place.


If the motor needs to be inspected before it is in place, it should be ensured that it does not touch the enameled wire of the motor rotor and stator windings. Check the stator slots for foreign objects; test whether the gap between the rotor and the stator is uniform; whether the motor bearings are intact.

Change the lubricant.

If the pump needs cleaning, it needs to be disassembled. When the bearing bush is used, it is necessary to check the bearing bush clearance to avoid over-looseness or shaft holding.

The coupling of the pump and the motor is fixed to the shaft with a key, and the installation is required to be level. Can be measured with a square or spirit level. Everything is ready to go.

Detection and adjustment

Measure and adjust the pump inlet and outlet flanges and the processing surface of the base with a spirit level and a wire drop, and perform precise installation of the pump. The level of the horizontal pump body should not be greater than 0.1 / 1000, and the vertical pump body The verticality should not be greater than 0.1 / 1000.

When the pump is connected to the motor with a coupling, use a dial indicator, feeler gauge, etc. to measure and adjust the coupling in the axial and radial directions. The axial tilt of the coupling should not be greater than 0.8 / 1000, and the radial displacement is not Should be greater than 0.1mm.

When adjusting the concentricity between the pump and the motor, loosen the bolts on the coupling, the bolts connecting the pump with the motor and the base, and use different thicknesses of steel plates or copper sheets to adjust the angular displacement and radial displacement. Pry up a corner of the motor or pump slightly to be adjusted, and cut the steel sheet or copper sheet cut into the shape shown below on the bolt.

When the test is qualified, tighten the bolts that were loosened.

Lubrication and refueling

Check the oil cup of the water pump and refuel, and turn the coupling. The water pump turner should be flexible and free from abnormal phenomena.


Trial run

Open the water inlet valve and the pump exhaust valve to fill the pump with water and close the valve on the pump outlet pipe. Jog the water pump first to check whether there is any abnormality and whether the steering of the motor meets the steering requirements of the pump. Then start the water pump, slowly open the valve on the outlet pipe, check the operation of the water pump, the temperature rise of the motor and bearings, the pointer values ​​of the pressure gauge and vacuum gauge, and the pipeline connection. They should be normal and meet the design requirements.

2020-03-25T17:05:37+08:00March 25th, 2020|