Why is centrifugal pump delivery valve closed?

When the pump builds up its pressure, it is opened and can be used to control or vary the discharge. The delivery valve is closed again before the pump is switched off so that the delivery pressure is not transmitted to the suction pipe (otherwise there may be some backflow from the reservoir).

Why is it necessary to close the discharge stop valve on centrifugal pumps before starting the pump?

By closing the discharge valve, the starting current can be reduced. When we start the pump with an open discharge valve, the discharge head will act on the pump, i.e. more resistance, so that the motor has to give more starting torque to the pump, which means more current is drawn by the motor.

What is working principle of centrifugal pump?

A centrifugal pump operates through the transfer of rotational energy from one or more driven rotors, called impellers. The action of the impeller increases the fluid’s velocity and pressure and directs it towards the pump outlet.

What happens if discharge valve of positive displacement pump is closed?

A positive displacement pump operating against a closed discharge valve will continue to produce flow until the pressure in the discharge line has increased until the line bursts or the pump is severely damaged – or both. …

What are the advantages and disadvantages of centrifugal pump?

Centrifugal Pump – Advantage & Disadvantage

• Small in size, space saving & less capital costs.
• Easy for maintenance.
• No danger creates if discharge v/v is closed while starting.
• Deal with large volume.
• Able to work medium to low head.
• Able to work medium to low viscous fluid.

Where the centrifugal pumps are used?

Common Industrial Centrifugal Pump Applications Water supply for residential areas. Fire protection systems. Sewage/slurry disposal. Food and beverage manufacturing.