Journal of Aeronautics & Aerospace Engineering
Open Access

Pneumatic Systems for Aircraft

Sushree Sunena^{* *}Correspondence: Sushree Sunena, Department of Biotechnology, Utkal University, Bhubaneshwar, Odisha, India, Email:

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Perspective

In the past, several aircraft manufacturers installed a high-pressure pneumatic system (3,000 psi) on their planes. The Fokker F27 was the final airplane to use this sort of technology. These systems work similarly to hydraulic systems, except instead of using a liquid to convey power, they use air. Both pneumatic and hydraulic systems employ restricted fluids and are comparable devices. The phrase confined refers to a situation in which you are imprisoned or totally contained. The term “fluid” refers to liquids such as water, oil, or anything else that flows. Liquids and gases are both called fluids because they flow; yet, the properties of the two are vastly different. Liquids are nearly incompressible; no matter how hard you compress a quart of water, it still takes up roughly a quart of space.

Gases, on the other hand, are extremely compressible; a quart of air may be squeezed into a thimbleful of space. Gases and liquids, despite their differences, are both fluids that may be contained and used to transport electricity. The air pressure needs of pneumatic systems define the type of unit used to supply pressured air. Air is generally kept in metal bottles for high-pressure systems at pressures ranging from 1,000 to 3,000 psi, depending on the system. [Graphic 12-70] One of the valves on this sort of air bottle is a charging valve. To add air to the bottle, a ground-operated compressor can be attached to this valve. The control valve is the other valve. It serves as a cut-off valve, trapping air in the bottle until the system is turned on. Despite its low weight, the high-pressure storage cylinder has a significant drawback. The tiny quantity of bottled air limits operation because the apparatus cannot be replenished during flight.

Components of a pneumatic system

Pneumatic and hydraulic systems are frequently contrasted, although such comparisons may only be made in broad terms. For typical pressure buildup, pneumatic systems do not use reservoirs, hand pumps, accumulators, regulators, or engine-powered or electrically driven power pumps. However, there are some commonalities in some of the components:

Air compressors: Permanently fitted air compressors have been installed on certain aeroplanes to recharge air bottles whenever pressure is required to operate a unit. Compressors of many sortsare employed for this purpose. Depending on the maximum required operating pressure, some have two stages of compression, while others have three.

Relief valves: In pneumatic systems, relief valves are employed to avoid harm. They function as pressure limiting units, preventing lines from bursting and seals from blowing out.

Control valves: In a typical pneumatic system, control valves are also required. Three-port housing, two poppet valves, and a control lever with two lobes make up the control valve.

Check valves: Hydraulic and pneumatic systems both employ check valves. Air enters the check valve’s left port, compressing a light spring and pushing it open, enabling air to flow out the right port. When air comes from the right, however, the valve shuts, preventing air from exiting via the left port. As a result, a pneumatic check valve is a flow control valve with just one direction of flow.

Restrictors: In pneumatic systems, restrictors are a form of control valve a restrictor with a big input port and a small output port, such as an orifice. The actuating unit’s airflow and operating speed are slowed by the tiny outlet port.

Variable restrictor: The variable restrictor is another sort of speed- regulating device. It has a needle valve with threads around the top and a point on the bottom end that can be adjusted. The needle valve pushes the sharp point into or out of a small aperture depending on which way it is twisted to reduce or expand the size of the opening. Because air entering the inlet port must pass through this opening before reaching the outlet port, the rate of airflow via the restrictor is likewise determined by this adjustment.

Filters: Filters of various sorts are used to protect pneumatic systems from dirt. A micronic filter consists of two-port housing, a cartridge that can be replaced, and a relief valve. Air normally enters from the inlet, circulates around the cellulose cartridge, and then exits through the outlet port. When the cartridge becomes blocked with debris, the relief valve is forced open, allowing unfiltered air to escape through the outlet port.

Desiccant/Moisture separator: In a pneumatic system, the moisture separator is always positioned downstream of the compressor. Its job is to get rid of any moisture left behind from the compressor. A reservoir, a pressure switch, a dump valve, and a check valve make up a full moisture separator. A regulator and a relief valve may also be included. The pressure switch energizes and de-energizes the dump valve. It thoroughly purges the separator reservoir and connects to the compressor when de-energized.

Both pneumatic and hydraulic systems employ restricted fluids and are comparable devices. The phrase confined refers to a situation in which you are imprisoned or totally contained. The term “fluid” refers to liquids such as water, oil, or anything else that flows. Liquids and gases are both called fluids because they flow; yet, the properties of the two are vastly different.

Liquids are nearly incompressible; no matter how hard you compress a quart of water, it still takes up roughly a quart of space. Gases, on the other hand, are extremely compressible; a quart of air may be squeezed into a thimbleful of space. Gases and liquids, despite their differences, are both fluids that may be contained and used to transport electricity.