The manometric efficiency in a pump is the ratio of:

Explanation:

Manometric Efficiency:

• The manometric efficiency of a centrifugal pump is defined as the ratio of the manometric head to the head imparted by the impeller.
• Manometric head is the actual head against which a centrifugal pump works.

To understand this better, let's break down the terms:

Manometric Head:

• It is the total head developed by the pump minus the losses in the pump.
• It is essentially the head that is effectively used to lift the fluid.

Head Imparted by the Impeller:

• This is the theoretical head that the impeller would impart to the fluid if there were no losses.

The formula for manometric efficiency (ηm) is given by:

ηm = (Manometric Head) / (Head Imparted by the Impeller)

Important Points

• The manometric efficiency is always less than 100% due to losses in the pump.
• Higher manometric efficiency indicates a more effective pump with fewer losses.

Additional Information

Other efficiencies related to centrifugal pumps include:

(1) Volumetric Efficiency:

• It is the ratio of the actual discharge to the theoretical discharge.
• It accounts for the leakage losses within the pump.

(2) Mechanical Efficiency:

• It is the ratio of the power available at the impeller to the power at the shaft.
• It accounts for the mechanical losses in the pump.

(3) Overall Efficiency:

• It is the product of volumetric efficiency, mechanical efficiency, and manometric efficiency.