PTFE energized seals have found a multitude of applications in the aerospace industry.
There are many reasons for the use of PTFE in aerospace. It offers excellent strength, extremely low friction, toughness, dimensional stability, and abrasion resistance. When combined with a spring-energizer, it provides a combination of properties and characteristics that work very well in the aerospace industry.
PTFE Seals and Aerospace
PTFE seals can be found in flight controls, jet engines, airframes, air management systems, and fuels systems. This includes commercial, military, and space applications. PTFE energized seals can be used in engine cooling lines, auxiliary power units, cabin pressure systems, compressor seals, turbine seals, pumps, fuel injectors, hydraulic controls, and more.
1. Low Friction
One of PTFE’s most outstanding characteristics is extremely low friction. It is self-lubricating and can be used in dry-running applications without a problem. PTFE also does not exhibit problematic stick-slip behavior. These features also reduce power and torque requirements, while increasing overall efficiency.
2. Extreme Temperature Performance
Aerospace applications often involve extreme temperatures, and PTFE is made for extreme temperatures. It can handle a wide range of temperatures, with a maximum continuous operating temperature of 550°F down to cryogenic temperatures like -450°F. In addition, it remains extremely stable even at high temperature while retaining its flexibility at low temperatures. PTFE is also nonflammable and has a UL 94 Flame Rating of 94 V-0.
3. Extreme Chemical Inertness
PTFE is one of the most chemically compatible polymers on the market today. It will not contaminate any sensitive media it comes into contact with, and is non-soluble. This makes it ideal for the aggressive chemicals encountered in aerospace applications, including jet fuels, degreasers, and hydraulic fluids. Its primary weakness is alkali metals.
4. Wide Pressure Range
Aerospace seals typically need to operate under extreme pressures, often ranging from 20 ksi to vacuum pressures. Note that there are blends of PTFE specifically for high PV applications such as those encountered in aerospace applications. It is also known for its excellent compressive strength.
Other Excellent Qualities
Another key aspect of PTFE spring energized seals is the incredible wear properties that PTFE possesses. It also exhibits very, very low water absorption due to its hydrophobic nature, which also makes it easy to clean. PTFE is compatible with a variety of fillers that can improve its various properties so that it can be better tailored to meet design needs. It also offers excellent stiffness and outstanding dimensional stability.
Power of Spring-Energized PTFE Seals
PTFE has excellent characteristics for aerospace applications, from its wide range of both operating pressures and temperatures to its chemical resistivity and dimensional stability. When such properties are combined with its ease of manufacture and its performance in extreme environments, it’s easy to see why PTFE energized seals are a first choice for many aerospace engineers.