By using different compensation techniques, the variable displacement type of these pumps can continuously alter fluid discharge per revolution and system pressure based on load requirements, maximum pressure cut-off settings, horsepower/ratio control, and even fully electro proportional systems, requiring no other input than electrical signals. This makes them potentially hugely power saving compared to other constant flow pumps in systems where prime mover/diesel/electric motor rotational speed is constant and required fluid flow is non-constant. Radial piston pumps A radial piston pump is a form of hydraulic pump. The working pistons extend in a radial direction symmetrically around the drive shaft, in contrast to the axial piston pump. Hydraulic pumps, calculation formulas Flow where , flow (m/s) , stroke frequency (Hz) , stroked volume (m) , volumetric efficiency Power where , power (W) , stroke frequency (Hz) , stroked volume (m) , pressure difference over pump (Pa) , mechanical/hydraulic efficiency Mechanical efficiency where , mechanical pump efficiency percent , theoretical torque to drive , actual torque to drive Hydraulic efficiency where , hydraulic pump efficiency , theoretical flow rate output , actual flow rate output References External links External gear pump description Internal gear pump description Mechanical efficiency description Hydraulic efficiency description Pumps Pump, Hydraulic