Automatic rising bollards can work with two different systems: Hydraulic and pneumatic.
Hydraulic and pneumatic bollards are both power circuits using an operating media. For hydraulic bollards, hydraulic fluid is used, while pneumatic bollards use compressed air.
How pneumatic automatic rising bollards work
Pneumatic automatic rising bollards use compressed air. A pneumatic ram is mounted within the bollard. The ram is pushed up and down with positive air pressure from a nearby compressor.
Atmospheric air is often used as operating medium, but pneumatic circuits can also use other systems. Dry nitrogen may for example be used on outdoor appliances to prevent freezing problems.
Pneumatic rising bollards are usually have a low initial cost but can require more energy to run than a hydraulic bollard. It takes one horsepower to compress 4 cfm of atmospheric air to 100 psi.
Air motors tend to more quiet than hydraulic bollards, however, because the compressor tends to be installed far away from the bollard itself.
Advantages of Hydraulic bollards by Australian Automation Systems
A hydraulic bollard circulates the same fluid repeatedly in the system. The fluid is stored in a fixed reservoir that is part of the bollard, and most types have a dedicated power unit for each machine.
Different kinds of liquid can be used, as long as it’s an almost non-compressible type. This allows the movement to be very accurate. Most hydraulic systems use mineral oil, water or synthetic liquids.
One of the advantages of hydraulic bollards is that they operate at higher pressure, around 1500 to 2500 psi. A higher pressure needs smaller actuators for the same outcome, so it will take up less space and clutter less.
The initial cost is a little higher than a pneumatic bollard, but the energy efficiency could be worth the initial cost in the long run.
Hydraulic bollards by Australian Automation Systems offer many advantages, such as reliable performance in intense temperatures and weather conditions. This is because of the hydraulic pump which is built-in to the bollard. This is also useful in cases when the installation requires a distance up to 80 meters between the bollard and the control unit.