If you are also stuck to decide whether to choose a hydraulic system or a pneumatic actuators for factory automation. Here are some differences between hydraulic system and pneumatic actuators, which will make your decision easy:
Hydraulic systems use liquids and oil is the most common liquid medium for hydraulic systems. Also, mostly hydraulic fluids are not compressible. As they do not compress that’s the reason hydraulics are capable of operating at extremely higher forces ranging from 1,500 PSI to 2,500 PSI.
Hydraulic systems use incompressible oil and hence they are able to afford more control and accuracy in movement. Hydraulic fluid remains under pressure in the circuit at all times due to which the operating costs are comparatively lower. As, Hydraulic uses liquids which are non-compressible, they become suitable for industrial uses where there is a need of high degrees of precision positioning. Due to minimal variability in the expected force provided through the actuator, these systems are capable of holding static loads for extended periods. These systems are best for mobile applications like trucks and heavy equipment.
However, besides having many pluses hydraulic systems do have some drawbacks too, such as hydraulic systems are complex in nature due to which the necessary materials used for installation hydraulic systems are costlier than the pneumatic systems. Hydraulic systems is the most expensive option to opt for.
Also, because of the oil which is used as the medium of transmission, a system leakage are prominent, thereby resulting safety and environmental hazards. Also, leakages can be very costly if not detected and dealt with immediately. As hydraulic circuits operate at higher pressure which increases the risk of fire potential. Not only this, even hydraulic systems are dirty and messy to operate. All the materials required in hydraulic systems such as filters, lines, pumps and oil require frequent checks, changes, cleaning and replacements on timely basis. Therefore, it requires more maintenance which in turn increases the downtime and costs.
Unlike Hydraulic systems, gas is the main medium used to move poser from one location to another in Pneumatic fluid circuits. It is because gases can be compressed and require more space. As, pneumatic fluids are compressible so they operate at lower pressures, typically at 100 pounds per square inch (PSI) or less. And the movements are faster-average 2 m/s. Because pneumatic systems operate at low pressure, hence it is mandatory that they are constructed from lighter-weight materials compared to their hydraulic counterparts.
As, pneumatic systems are constructed with the lighter materials and have relatively fewer operating parts, thereby resulting in a lower initial cost. However, depending on usage, operating costs can be higher. More often than not, using Pneumatic systems in industrial applications are considered unwise, as it requires very fine, precision positioning and gas rapidly expands when decompressed, thereby resulting in an expected variability in force transmitted. However, because of the clean operations these systems are best for food applications.
Pneumatic systems are more suitable in manufacturing settings, which requires accuracy and a more gentle operating force. Operating pneumatic systems are often quieter as the gas compression system is typically installed separately from the pneumatic circuit and actuator. Also, pneumatic systems require low maintenance and cleaning.
Because of use of gas, chances of industrial incidents are less and doesn’t require specialized labor skillsets.
However, there are many drawbacks which includes compressor, air filters, and condensate lines may require maintenance. To maintain variable speed and slow movement, along with high accuracy is difficult to maintain and is expensive. Also, with time actuator wear out therefore require replacements, thereby resulting to expenses.
When it is about choosing fluid power systems there is no one-size-fits-all. Each system, whether a hydraulic or pneumatic, has some pluses and minuses. You can choose actuators as per your usage.