Pumps are selected for a particular application in a hydraulic system based on a number of factors some of which are:
• Flow rate requirement
• Operating speed
• Pressure rating
• Cost and
The selection of a pump typically entails the following sequence of operations:
• Selection of the appropriate actuator (cylinder or motor) based on the load encountered.
• Determining the flow-rate requirements: This involves a calculation to determine the flow rate required to drive the actuator through a specified distance, within a given time limit.
• Determination of the pump speed and selection of the prime mover: This together with the flow rate calculations helps determine the pump size. (volumetric displacement).
• Selection of the pump-type based on the application.
• Selection of system pressure requirements: This also involves determination of the total power to be delivered by the pump.
• Selecting the reservoir capacity along with the associated piping and other related components.
• Computation of the overall system costs.
Normally the above sequence is repeated several times over, for different sizes and types of components. Once this is done, the best overall system is selected for a given application. This process is known as optimization.