Flow rate , Q The flow rate of a pump is defined by the amount of liquid that is being discharged by the pump per unit time. Some commonly used units of flow rate are l/s, l/min, m3/h, and gal/min. Th...

Vibration When the motor of a pump is connected to the power supply, the motor rotates to drive the pump impeller, generating vibration. Table 1 in ISO 15783 provides the maximum allowable vibration l...

Pump Total Head, H The pump total head is defined as follows: Where, = density of the liquid = acceleration due to gravity = suction height at p1 = discharge height at p2 = suction pressure = discharg...

Viscosity Viscosity is an indication of how easily a fluid flows. When a fluid flows, the interaction between the molecules within the fluid creates resistance, which is shear stress. The relationship...

Net Positive Suction Head, NPSH Net positive suction head is the head above the vapor pressure of the liquid. From a pressure point of view, it is the amount of absolute pressure to overcome the liqui...

Specific speed, Specific speed is the relation between the impeller’s rotation speed and the rated flow rate and head. It is the most important factor to consider in the design of the impeller. The un...

Axial force, Axial force is the pressure exerted by the pumped liquid on the impeller in the axial direction during operation. The impeller on the seal-less pump is not fixed in the axial direction. T...

Hydraulic Power, Hydraulic power is the power delivered by the pump in the form of flow rate and head. Hydraulic power is defined by Where, = density of the liquid = acceleration due to gravity = pump...