Hydrogen, Helium, and Nitrogen in Aerospace
The term, “aerospace” is used to generally reference the atmosphere and outer space. However, aerospace activities are diverse and include a myriad of commercial, industrial, and military applications. These activities and applications rely heavily on atmospheric gases and in particular, hydrogen, helium, and nitrogen. These gases are used for rocket propellant, pressure testing, purging, cooling, and mitigating fire hazard.
Hydrogen for Rocket Propellant
Hydrogen is the lightest, simplest element (only one proton and one electron), in the periodic table and has always played an important role in aerospace activity as rocket fuel. Hydrogen is used as rocket propellant over other gases because it has the lowest molecular weight, highest caloric value, and it burns with extreme intensity. As the lightest element, hydrogen normally exists as a gas. Gases, especially lightweight hydrogen, are low-density which means they can take up a lot of valuable space on aircraft. To save space and ensure adequate supply, hydrogen is utilized in its liquid state. To liquefy hydrogen gas, it must be cooled to ‑423 degrees Fahrenheit.
Helium for Pressure Testing, Purging, and Cooling
Helium, an inert, odorless, tasteless, and colorless gas, is used in aerospace for purging hydrogen systems, as a pressurizing agent for ground and flight fluid systems, and as a cryogenic cooling agent. Helium gas plays a vital role in the production of rocket components and supporting launch activities. Aerospace manufacturers use helium for pressure testing to detect leaks in critical equipment such as rocket engines. Helium is an effective leak detector because of its low viscosity and ability to diffuse over very large areas. Helium leak detectors were developed during World War II and can detect and measure leaks that are thousands of times smaller than leaks detected with other methods.
Helium is also used in aerospace for purging and heat transfer. Helium can be used for purging since it is inert, has the lowest melting and boiling point of any gas, and has a low freezing temperature. It’s the only element that liquifies at a lower temperature than hydrogen. This makes it ideal for purging, as it displaces very cold liquids such as liquid oxygen or hydrogen without risk of freezing. Helium’s high thermal conductivity makes it a superior heat transfer medium for many applications.
Nitrogen for Mitigating Fire Hazard
Nitrogen is the most common element in our atmosphere at 78%. It’s a component of all living matter, including water, soil, plants, and the human body. Nitrogen is unique in that it can be used to prevent fires, but is also used to make explosives. It’s used in aerospace to mitigate the risk of fire and explosion. Since jet fuel is highly flammable, aircraft run the risk of both. As an inert gas, nitrogen optimizes aerospace applications by preventing combustion and fires by purging oxygen. It not only reduces fire risk, but also prevents fuel tank oxidation, degradation, and corrosion. Nitrogen’s inert nature makes it an excellent choice for aircraft tire inflation and for safely inflating emergency escape rafts, if needed.
Aerospace Gases in the Rocky Mountain Region
For each of these activities, high purity gases or gas mixtures are critical, as contamination could be harmful. Purchasers should ensure that the hydrogen, helium, and/or nitrogen supplied for their application is certified, high purity gas. Finding a supplier that partners with specialty gas experts like PurityPlus will guarantee you are receiving a safe and reliable supply.
Rocky Mountain Air provides helium, hydrogen, and nitrogen in high-pressure gas or liquid cylinders. Our PurityPlus partnership certifies that we are selling the highest-grade product, and that products will be delivered whenever you need them. This partnership aligns directly with Rocky Mountain Air’s promise to deliver flawless dependability to our customers. Contact your local branch to learn more about PurityPlus specialty gases, or to order today. We look forward to serving you!
