This document provides instructions for operating, assembling, and disassembling a centrifugal pump. It describes the main components of a centrifugal pump, including the electric motor, impeller, shaft, casing, and bearings. The objectives are to understand the working principle of the pump, calculate its efficiency, recognize its parts, and learn how to identify and fix common defects. The steps provided include shutting off power, removing plumbing, taking the pump housing apart, removing the impeller and shaft seal, and disassembling the motor armature. Reassembly follows the reverse order. Problem solving tips are given for abnormal noise or reduced output.

1. SWAMI KESHVANAND INSTITUTE OF TECHNOLOGY MANAGEMENT
& GRAMOTHAN, JAIPUR.
3ME8-Basic Mechanical Engineering Lab.
EXPERIMENT No. 3
Object:- Operation, Assembling and disassembling of Centrifugal Pump.
Objectives :- After doing the experiment, student will be able to
i) Know the principle and working of a pump.
ii) Calculate the efficiency
iii) Know the mechanisms of the pump
iv) Recognize the different parts of the pump
v) Know the different defects developed in the pump and to rectify the same
Apparatus- Electric motor, Centrifugal Pump, Tools Needed- Allen Keys, Wrenches, Open
End/Adjustable Wrench/Ratchet & Socket, Wire Cutters, Screwdriver, Grease.
Principle
1. Electric energy is given to the motor. It is the primary energy available.
2. This electric energy rotates rotor of the motor. This motor rotor is coupled with the
impeller shaft of the pump. Therefore the impeller shaft rotates.
3. The water / fluid coming in the suction is forced by the impeller to rise to the required
height.
4. Therefore there is conversion of electric energy to kinetic energy and ultimately to
potential energy.
Centrifugal Force adding potential energy to the water.The process liquid enters the suction
nozzle and then into center of a revolving device known as an impeller. When the impeller
rotates, it spins the liquid sitting in the cavities between the vanes outward and provides
centrifugal acceleration.
As liquid leaves the impeller, a low-pressure area is created causing more liquid to flow toward
the inlet. Because the impeller blades are curved, the fluid is pushed in a tangential and radial
direction by the centrifugal force to reach to the required height. As such the water gains
potential energy.
Mathematically we can write:

2. A handy formula for peripheral velocity is:
Figure below depicts a side cross-section of a centrifugal pump indicating the movement of the
liquid.

3. A centrifugal pump and motor has three main components:
1. An electric motor acting as prime mover.
2. A rotating componentcomprised of an impeller and a shaft
3. A stationary component comprised of a casing, casing cover, and bearings.
The general components, both stationary and rotary, are depicted in Figure The main
components are discussed in brief below. Figure shows these parts on a photograph of a pump
in the field.

4. Disassembling
Centrifugal pumps move the bodies of water used in swimming pools and wells. A centrifugal
pump operates using a quickly spinning impeller to create a suction that moves water through a
plumbing system. Centrifugal pumps consist of a number of moving parts that require regular
maintenance. Disassembling a centrifugal pump involves separating the motor from the wet
section of the pump, removing the impeller and seal from the shaft, and removing the motor
armature and bearing from the motor casing.
1. Shut down the centrifugal pump and turn off the electricity flowing to the pump at the
breaker. Remove any plumbing pipes or hoses attached to the pump. Cut the plumbing
with a PVC hacksaw if PVC plumbing exists.
2. Unscrew the bolts placed evenly around the pump housing with a wrench. Pull apart the
two pieces of the centrifugal pump and set aside the wet portion.
3. Set a wrench onto the motor's shaft and hold it to keep it from moving. Rotate the pump
impeller counterclockwise until it comes off of the shaft.
4. Pull the ceramic shaft seal carefully off the shaft. Pull the spring portion of the seal out of
the back of the impeller.
5. Unscrew the screws holding the motor armature to the electrical portion of the motor.
Pull the entire motor armature out of the motor. Pull the motor bearing off the back of the
motor armature.
Assembling
1. While assembling the pump, we have to fit the parts in the reverse order, i.e. last part
opened is to be fitted first.
2. We have to tighten the nuts and bolts properly.
3. After assembling the pump, it has to be tested for the proper working.
Problem Solving
1. Abnormal noise coming out from pump-
Check-coupling, bearing. Impeller profile, Nuts- Bolts
Find fault and how it is to be repaired?
2. Output of pump-Pressureand discharge has been reduced. –
Check-Impeller profile, Seals / glands.
How it is to be corrected?
Experiment Outcome
1. We have learnt the principle of centrifugal pump.
2. After dissembling the pump, we have recognized the various parts of the pump and their
functions.