O-rings are used extensively in the aerospace manufacturing industry. Also known as toric joints, they are mechanical seals with a round cross-section. O-rings are placed around shafts and other cylindrical components where they protect against leaks. How are O-rings used in the aerospace manufacturing industry exactly?
#1) Fuel Components
The fuel components of a typical airplane feature several O-rings. Most airplanes have a fuel pump, for instance. It lives up to its namesake by “pumping” fuel out of the tank so that it can be transferred to the airplane’s engine or engines. Because it carries fuel, the fuel pump must be properly sealed, which is why it contains an O-ring.
#2) Landing Gear
O-rings are commonly used in landing gear systems. Landing gear systems are typically hydraulic. When preparing to land, airplanes will lower their landing gear via pressurized air or gas. Like with fuel systems, landing gear systems must be properly sealed. There are many different types of seals available for these hydraulic systems, but O-rings are among the most common.
#3) Oil Lines
Another common application for O-rings in aerospace manufacturing is oil lines. Aircraft engines require oil just like automotive engines. Oil is designed to lubricate the moving parts of an engine while subsequently protecting the engine from excessive friction and heat. Because the oil operates in a pressurized environment, it must be sealed. O-rings are used to seal the oil-carrying hoses and lines so that oil doesn’t leak out.
#4) Flight Instruments
Even the flight instruments may feature one or more O-rings. Flight instruments consist of sensors that relay information to pilots in the cockpit. For accurate readings, they must be properly sealed. O-rings can provide this necessary sealing to ensure accurate and reliable readings.
#5) Pressure Relief Valve
O-rings are commonly used in pressure relief valves. Pressure relief valves, as the name suggests, are designed to relieve excess pressure. Airplane cabins, for instance, may feature a pressure relief valve. Some airplanes use an O-ring as part of their pressure relief valve.
Auxillary Power Units (APUs) may feature one or more O-rings. What are APUs exactly? In aerospace manufacturing, an APU is a small engine that provides backup or supplementary power. When an airplane initially turns on, it will typically draw power from the APU. It will also draw power from the APU for climate control purposes. Regardless, APUs often feature one or more O-rings.