What component distinguishes a hydraulic system from a pneumatic system?

The distinguishing component between a hydraulic system and a pneumatic system primarily lies in the medium that each system uses for power transmission. In hydraulic systems, the medium is a liquid, typically oil, that is incompressible and allows for the efficient transfer of force. Conversely, pneumatic systems use compressed air or gas, which is compressible, to achieve similar tasks.

In terms of the components listed, while the return line is an essential part of both hydraulic and pneumatic systems, it does not specifically distinguish one from the other. A return line functions to allow fluid or gas to return to the reservoir or source for both systems. Therefore, this component is common across both hydraulic and pneumatic systems rather than serving as a distinguishing factor.

On the other hand, a pressure regulator is used in both systems to control the pressure of the fluid or gas, and an accumulator, while more prominent in hydraulic systems as a pressure storage mechanism, is also not exclusive to them. A compressor, which is necessary for pneumatic systems to compress air, does not apply to hydraulic systems where a pump is used instead.

Ultimately, the defining feature that distinguishes hydraulic systems from pneumatic systems is the type of fluid used (liquid vs. gas) and the implications that has for the system's operation