Centrifugal pumps are amongst the most common pump types used in Australia. The application for centrifugal pumps across Australia varies from the liquid being pumped to temperature, system, pressure and other such factors. The HVAC, civil and mining markets predominantly use centrifugal pumps in Australia.
This group of pumps consist of a shaft mounted impeller(s) rotating unidirectionally within a casing. The liquid enters the impeller eye and acquires energy in the form of velocity as it passes through the impeller passages. The velocity head is converted into pressure head by the volute or spiral shaped outer casing of the pump which directs the liquid from the out perimeter of the impeller to the pump discharge. A less common method of developing pressure head is to surround the impeller with concentric diffusing passages.
Centrifugal pumps can be divided into two main groups depending on the type of impeller.
Centrifugal pumps are selected primarily on the basis of flow capacity and the total head against which the pumped fluid is to be delivered through the transfer system.
Centrifugal Pump Performance is usually expressed in terms of the following of its characteristics:
- Capacity (Q) – expressed in volumetric units in a given time i.e.; litres per second
- Head (H) – measured in kilopascals (kPa) or metres (m)
- Power (P) – kW
- Speed (N) – revolutions per minute (RPM) or revolutions per second (RPS)
- Efficiency (תּ) – as a ratio of useful work performed against power input
The graphical relationship between head, capacity, power, speed and NPSH is best shown in the form of a pump performance curve.
For more details on centrifugal pumps in Australia and New Zealand, contact our friendly staff at Masterflow. The online Masterflow Pump Selection software also provides a useful method of selecting the correct pump for your application.