These are the times when fluid power applications are endless. We have pneumatic and hydraulic power systems that are quite similar to each other in a number of ways. You get similar power circuits, vales and festo fittings that are really essential to their system. However, there are some certain significant differences that you should be considering as you choose one of the systems for yourself according to your needs.
The main difference in their working is that of the medium that is utilized by their systems in order to transmit power. With pneumatic systems, you have gases that are highly compressible such as pure gas or air. On the other hand, you have hydraulics that utilizes incompressible liquids such as water, mineral oil, ethylene glycol, high temperature fire resistant liquids to make the power transmission possible.
Because of this primary difference, you also see a difference in their power output. With pneumatic, you get 80 to 100 pounds per square-inch while with hydraulics you have 1000-1500 psi generally. However, with some specialized applications, this power can be increased up to 10000 psi as well.
On one hand, you need to establish a tank or container that the hydraulic system can use in order to store and use the oil essential to its working. While on the other hand, there is no such requirement for a pneumatic system. As you get the air from the atmosphere that can be easily filtered by the in-built air filter.
With pneumatic systems, you get simple designs along with minimal initial cost. This is because the material used in these air operated system is quite inexpensive. While with the hydraulic system you can expect high machinery costs and along with high and regular maintenance. However, in the long run, the hydraulic system is 4 to 5 times cheaper than the pneumatic system because of its low operating cost. This is because you need a lot of energy and horsepower to compress the atmospheric pressure to working pressure. This is why the air motor components that you have in the system are quite expensive to operate.
With the hydraulic system, it is often recommended that you also install central power units to improve the advantages that you get from it. Installing a central power unit will help you with the reduction of noise levels as well as you get a backup if the working pump breaks down. On the downside, the uptime for all the machines is also increased as well.
In terms of management, pneumatic systems are really easy to manage and maintain as the air operated circuits that you have in these systems are much cleaner and any leaks in them are not that dangerous as well. However, as mentioned earlier this will be quite expensive as you have to install about 5 compressors to get the desired result.
This is not the case with hydraulic systems, you need to take proper measures and hire professionals for the maintenance. There is some safety measure that needs to be implemented before you set up the system.
In the end, we have:
- Pneumatic systems that utilized moving air or atmospheric pressure as they work. As these gases are compressible you get a delay in the output, the movement, and the power that you get. You also need a compressor for the functioning. We see pneumatic systems in precision drills that are used by dentists, air brakes used in trucks, cars, and buses, nail guns, lungs, dentist chairs, etc.
- While hydraulic systems have confined systems that use moving liquids. Since these liquids are not compressible there is no delay in the output. Common machines where this system is used are garbage trucks, lifts, cars, etc.