Difference Between Hydraulics and Pneumatics

Is there any industry in your knowledge that doesn’t require any movement or force? I think that almost every industry requires motion or force to hold, shape, or compress products. This means that you can find applications of fluid power in many industries.

          Fluid power is a technology that generates, transmits, and controls the system using pressurized fluids. Hydraulics, pneumatics, and electric are the three important power-transmitting technologies currently used. Among these, hydraulics and pneumatics come under fluid power. A fluid power system will transfer fluids from one part of the system to another part for generating force. In this article, we can discuss the hydraulics and pneumatics differences.

        Both work using the same technology for generating power or force. But, the medium it uses for converting mechanical energy will differ. The hydraulic system uses pressurized fluids like petroleum oils, synthetic oils, and water. In the case of a pneumatic system, it uses compressed gases or air. This is the key difference between hydraulic and pneumatic systems.

          You can find examples of pneumatic and hydraulic systems in your daily life. Working of the lungs is an example of the pneumatic system and blood flow is an example of a hydraulic system. Hydraulics have other applications in dams, car brakes and steering, amusement parks, machine tools, lifts, and a lot more. Dentistry, mining, air brakes, nail guns, and robotics are some of the applications of the pneumatic system.

Pneumatic vs Hydraulic

• Hydraulic systems are designed as closed systems and pneumatic systems are open systems.
• Operating pressure of the pneumatic system is 100psi and that of a hydraulic system is 500 to 5000psi
• Hydraulic systems are self-lubricating(because they use different varieties of oils) whereas the pneumatic system requires separate arrangements for lubricating the system.
• The reservoir, pumps, and valves, used in the hydraulic system for storing and pumping fluids make the system more large and complex. So, the larger components require more pressure and this makes the hydraulic system more expensive. The maintenance and repair of hydraulic systems are more complicated than pneumatics. Pneumatic systems are simple, cheap, and economical.
• It is possible for a hydraulic system motor to start the motor under a high load. Also, hydraulic systems are very slow, accurate, and provide linear movement. For a pneumatic system, too-slow operations will create jerking.
• Leakage of the hydraulic system will make the operating environment messy. Also, leakage of pressurized fluids is dangerous for both workers and machinery. For the hydraulic system, the leakage will slow down the system's performance. However, the pneumatic system is affected by leakage.
• Some hydraulic oils are petroleum-based. In hydraulic systems, there is a risk of fire. However, the pneumatic systems are free from fire hazards.
• Valve operations of pneumatic systems are easier than hydraulics systems.
• An air compressor is a basic component of a pneumatic system.