Hydraulic and pneumatic equipment both function on the same principle of fluid power, using fluids to generate and control power. The basic difference between hydraulic and pneumatic is based on the material used to generate energy. While hydraulic equipment uses liquids such as mineral oil or water, pneumatic equipment use gases such as air or nitrogen.
Fluid power systems are based on the concept of converting mechanical energy to fluid energy by using a pump that is driven by a prime mover. Pressurized fluids are directed into actuator devices such as hydraulic or pneumatic cylinders by valves to provide motion and generate energy. In comparison to electrically-driven systems, fluid power systems can produce higher power with more safety.
Here are the key differences between hydraulic and pneumatic equipment:
Power Produced
Hydraulic systems use fluids that are not compressible and maintain their consistency, as a result of which more power is generated in comparison to pneumatic systems which use atmospheric air or inert gases either in dry form or with lubrication that are easily compressible. Pneumatic systems generate power from gases, enabling higher control in the production of power, more precision in use and easier maneuverability.
Power, the fluids in hydraulic systems can be used in an as-is condition while the gases for pneumatic systems have to be compressed to a certain degree before they can be used for power generation.
Costs
The overall hydraulic and pneumatic equipment market is expected to reach $55.89 billion by 2024, growing at a CAGR of 5.43 percent. North America currently accounts for nearly half of the total market share, while the Middle East and Africa and APAC regions are expected to have the fastest growth.
A hydraulic system setup has a higher one-time setup expense and takes up more space as compared to a pneumatic system, however, the operational costs are less. The fluid used in the equipment can be reused so there is less recurring expense. The life of the hydraulic system is shorter than that of a pneumatic system as there is more wear and tear from the use of non-compressible fluids.
A pneumatic system can be established at a lesser price with simple designs that take up less space, but the operating costs are high. As the gas used in the pneumatic equipment needs to be compressed before use, there is a steady running cost which is not needed in hydraulic systems. The overall life of a pneumatic system is longer with less wear and tear because of the use of compressible gases.
Applications
Due to the large amounts of power produced by hydraulic systems, they are used in large machinery and in major industries such as automotive, machine tools, turbines, elevators, and dams. Pneumatic equipment is used in robotics, mining, dentistry, and construction.
In contrast to hydraulic equipment, pneumatic equipment can be used in the food industry, pharmaceuticals and biotechnology as there is less risk of contamination from gases as compared to the liquids used in hydraulics.
Based on the same principles of fluid power systems, hydraulic and pneumatic equipment have similar terminology, components, and execution, but there are many differences based on the core substance used. Fluids used in hydraulic equipment make it stronger while the gases used in pneumatic equipment make it more precise. Both can produce high power in small volumes and have a longer life than electrically driven systems.