The hydraulic machines which convert the mechanical energy into hydraulic energy are called pumps. If the mechanical energy is converted into pressure energy by means of the centrifugal force acting on the fluid, the hydraulic machine is called a centrifugal pump. Centrifugal pumps Reciprocating pumps The discharge is continuous and smooth The discharge is fluctuating and pulsating It can handle a large quantity of liquid It handles a small quantity of liquid only It can be used for lifting highly viscous liquids It is used only for lifting pure or less viscous liquids It is used for large discharge through smaller heads It is meant for a small discharge and high heads Cost of a centrifugal pump is less as compared to reciprocating pump Cost of a reciprocating pump is approximately four times the cost of a centrifugal pump Centrifugal pump runs at high speed. They can be coupled to an electric motor It runs at low speed. Speed is limited due to consideration of separation and cavitation The operation of a centrifugal pump is smooth and without much noise. The maintenance cost is low The operation of a reciprocating pump is complicated and with much noise. The maintenance cost is high. It requires a smaller floor area and installation cost is low It requires a larger floor area and installation cost is high Efficiency is high Efficiency is low