Centrifugal Pumps

Centrifugal pumps are the sub class of the turbo machinery of dynamic axisymmetric type that is work absorbing. These pumps are used to transport the fluids by a rotational kinetic energy process of conversion into the hydrodynamic energy of the fluid flow.

The energy of rotational is typically from an electric motor or an engine.  These are most preferred hydraulic pumps used in domestic and industrial world.



  • Pump Main Housing: It is the part where whole pumping system is arranged and it acts as a protection to the apparatus.
  • Impeller: this is the major rotating part that provides centrifugal acceleration to the fluid. Radial flow impeller, axial flow impeller and mixed flow impeller are the types of impellers used in centrifugal pumps.


  • Impeller Seal: It is used to grip the impeller without being separated in the process of pump action.
  • Impeller Bearings: Impeller Seal supports Impeller Seal.
  • Motor: It is the part that is responsible for the pump working.
  • Coupling: Couplings are used to compensate the axial growth of the shaft along with transmit torque to the impeller. Rigid and flexible shaft couplings are used in most of the shaft couplings to the impeller.
  • Shaft-drive: Shaft drive is used to guide the shaft movement.
  • Shaft seal: It acts as a grip to the shaft seal to avoid dispositioning of shaft while working.
  • Diffuser: A diffuser is a set of stationary vanes that is completely surrounded by the impeller. It supports in the increment of the centrifugal pump efficiency.
  • Inlet and Outlet Flange: These flanges acts as a support to the part as protecting rim, collar or an object that serves in strengthening and maintenance on a rail.
  • Volute:


It is a casing that receives the fluid which is to be pumped by an impeller. It is a spiral curve that recedes from a center point.

  • Wearing Rings: Wearing Rings acts as a leakage joint in between impeller and casing. It ensures leakage from high to low pressure.
  • Stuffing Boxes: Stuffing boxes are used for the sealing purpose. All the leakages and adequate cooling facility are controlled by these boxes.
  • Packing: These are intended in restriction of strict leakage around a shaft.
  • Lantern Rings: These are used for easy movement of the lubricant and these rings are inserted between the packing rings.


Centrifugal pumps are employed in many hydraulic systems for the movement of fluids through piping system. Centrifugal force is the main basic principle employed in the working of centrifugal pump. These forces influence the materials and objects that move in a circular pattern. This force regulates the motion along with pressure of the pumping unit. These are an integral part of the hydraulic machinery. The casing fluid generally used is water. A fast rotary force is exerted by a special unit that spins water and spins it to generate the centrifugal force and let them to the discharge channels. This discharged water creates vacuum for the atmospheric pressure into force that allows more water out of the casing. This process is continuous and is dependent on the rotary motion and the supply of water constantly. The impellers and vanes to provide the rotary motion though the design and their implementations depend on the project and capacity requirements.

Pumping procedure:

A shaft is attached to the pair of rotary vanes in the interior portion with a rotary can. A pulley is provided that is responsible for the rotary movements. After the filling of can the pulley begins to rotate the shaft at high speed that causes a spin in its movement. Due to the rotatory movement the centrifugal force pushes the water towards the walls of the can, which in turn is pressed against the edges of the container. As the water cannot move outward they climb upward in an even manner when the water is drawn downwards at its center. Over flow of water mean the production of kinetic energy and the caught water is supplied more to the pump. The spilling of water is caught in the receiver tank and a surplus tank is attached in order to maintain the continuous supply. This centrifugal effect is achieved by the vanes or impeller within a can.

Vanes and Impeller:

The vanes is radial within a water casing, because the spin of water while rotating where these actions make the centrifugal pumps a crucial part of any pumping system. Straight vane and curved vane are most common types of vanes. Similarly these impellers form an integral unit of the pumping system that provides the rotational force that moves the vanes.

Working of centrifugal pump:


This pump converts the mechanical energy from a motor into the energy of a moving fluid. A part of energy is converted into kinetic energy of the fluid. The fluid enters the casing through the eye. This fluid is caught by the impeller blades that are whirled tangentially in and leaves radially outward with the help of the circumferential parts that diffuse through the casing. The moving fluid gains both pressure as well as velocity after its passage through the impeller. The further increase of pressure takes place after its decrement in the dough nut shaped diffuse or the scroll section.

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