HYDROLICS

Hydraulics are similar to pneumatic systems in function. Both systems use fluids but, unlike pneumatics, hydraulics use liquids rather than gasses. Hydraulics systems are capable of greater pressures: up to 10000 pounds per square inch (psi) vs about 100 psi in pneumatics systems. This pressure is due to the incompressibility of liquids which enables greater power transfer with increased efficiency as energy is not lost to compression, except in the case where air gets into hydraulic lines. Fluids used in hydraulics may lubricate, cool and transmit power as well. Pneumatics, being less multifaceted, require oil lubrication separately, which can be messy with air pressure. Pneumatics are simpler in design and to control, safer (with less risk of fire) and more reliable, partially as the compressibility of the gas-absorbing shock can protect the mechanism.