Advantages and Disadvantages of using Pneumatic Systems
Compared to other drive technologies (electro)pneumatic systems demonstrate a series of advantages as well as some disadvantages:
Availability: air is available for compression almost anywhere in a practically unlimited supply. |
Transport: compressed air can be easily transported in pipes over long distances. No return pipe is needed. |
Storage: compressed air can be stored in a container. Even transport in bottles is possible. |
Temperature: compressed air is insensitive to temperature fluctuations. Thus its use can be guaranteed in even under the most extreme conditions. |
Explosion-proof: compressed air can also be used in areas where there is a risk of explosion . |
Cleanliness: leaking pipes, hoses or pneumatic elements do not cause any contamination due to the escaping air. An important plus in such areas as the food or textile industry. |
Speed: with compressed air relatively high operating speeds of up to 2 m/s can be achieved in pneumatic cylinders. |
Controllability: the forces exerted by pneumatic actuators and their speed can be continuously adjusted. |
Very good load capacity: compressed air tools and actuators can be loaded up to standstill and are thus extremely capable of handling heavy loads. |
Preparation: compressed air requires good preparation. Dirt and damp must be kept out of the systems as otherwise this subjects the pneumatic elements to undue depreciation. |
Compressibility: it is impossible to attain uniform and constant piston speeds using compressed air. |
Forces: compressed air is only economically viable up to a certain expenditure of force. The traditional operating pressure is normally around approx. 7 bars. |
Air exhaust: the air exhaust that is generated causes relatively loud noise. This problem can be mitigated to a large extent using sound insulation. |
Costs: compressed air is a relatively expensive energy source. However, these costs can be somewhat offset by the relatively low cost of the pneumatic components and their high performance (timing rates). |
Differences between Pneumatic and Electropneumatic controls
Pneumatic and electropneumatic controls both feature a pneumatic power component which is comprised of the following components
Actuators (directional control valves, which are electrically actuated in the case of electropneumatic controls) |
Working elements (cylinders, pneumatic motors, optical displays) |
The signal control component (consisting of signal inputs and processing elements) is designed differently:
In a pneumatic control system, control is achieved by pneumatic components such as various types of valve, air-distribution routers, sequencers etc. |
In an electropneumatic control system, the signal control element is designed with electrical components like electrical pushbuttons and switches, proximity switches or programmable logic controls (PLC), for example. |
In both cases the directional control valves constitute the link between the power control and the signalling control elements.