Fluid power is energy transmitted and controlled by means of a pressurized fluid, either liquid or gas. The term fluid power applies to both hydraulics and pneumatics. Hydraulics uses pressurized liquid, for example, oil or water;pneumatics uses compressed air or other neutral gases. Fluid power can be effectively combined with other technologies through the use of sensors, transducers and microprocessors.

How It Works

Pascal’s Law expresses the central concept of fluid power: “Pressure exerted by a confined fluid acts undiminished equally in all directions.”

An input force of 10 pounds (44.8 N) on a 1-square-inch (6.45 cm2) piston develops a pressure of 10 pounds per square inch (psi) (68.95 kN/m2 or 68.95 KPa) throughout the container. This pressure will allow a 10-square-inch piston to support a 100-pound (444.8 N) weight. The forces are proportional to the piston areas.