Subsubsection By Delivery Characteristics
All shaft driven pumps will deliver liquids at different volume rates if they are run at different speeds. Most pump designs require a change in speed to change their capacity (constant delivery). However, some rotary type pumps, and some radial or axial piston pumps are designed to vary the quantity of liquid delivered while maintaining the prime mover at a single speed. Pumps with these characteristics are known as variable delivery pumps.
Variable delivery pumps are most commonly found in hydraulic systems, where the delivery rate can be adjusted to control the rate of motion of hydraulic cylinders and actuators.
