Neutral gases

From FestoWiki - english
Jump to: navigation, search

Neutral gases are often called inert gases, even this is not correct. "Inert" comes from the Latin, and means stagnant and non-reactive. That means that these gases do not initiate chemical reactions by themselves.


Nitrogen is an inert gas. It does not react under normal conditions.
Operating Festo products within the parameters of the catalogue and data sheet specifications is possible without any reservations.
Nitrogen is often very moist. In order to avoid saponification or washing out the life-time lubrication through "contamination" with water, nitrogen must only be used in a dried condition. Nitrogen (Latin: Nitrogenium) is a chemical element with the symbol N. As dinitrogen N2, nitrogen is the main component of air at 78%.

Noble gases

Helium (He), Neon (Ne), Argon (Ar), Xenon (Xe)
Noble gases do not create any chemical reactions whatsoever.
Except for helium, operation is possible without reservations using these gases. Because helium molecules are very "small" and lighter than air (balloon gas), this gas can diffuse through almost all materials, which causes leakages. At the moment, Festo is conducting calculations on the diffusion behaviour of gases through pneumatic tubes.
Results are already available for tubes made of polyethylene:
due to the high diffusion speed of helium and possibly also neon into polyethylene, these two gases do not represent an appropriate pressure medium.
Hydrogen is the first element in the periodic table of chemical elements, and has the symbol H. Due to its "size", this gas diffuses extremely well through all materials, which prevents its use as a pressure medium.
Furthermore, hydrogen is extremely flammable (Zeppelin catastrophe in Lake Hurst).
Mixtures of hydrogen and air result in so-called oxyhydrogen gas, which is extremely explosive.


Oxygen has the element symbol O. Due to its extremely strong oxidising effect, oxygen can only be used in systems which are free of mineral oils or greases. There are individual DIN standards for oxygen bottles and valves and fittings. The reason for this is that, on pneumatic actuation, the boiling or flashpoints of organic substances such as oils and greases are exceeded and the valves and fittings start to burn. For operation with oxygen, you require oxygen-certified lubricating greases such as Fomblin RT 15. This is only possible as a special design.
Standard products from Festo cannot be operated using oxygen.

Carbon dioxide

 Carbon dioxide is the combustion product from carbon with the element symbol C02, and is the typical gas exhaled by humans. It is also very slow to react and can be used as a pressure medium. No problems will occur under Festo standard conditions. In some circumstances, carbon dioxide can diffuse into elastomers and, at excessive pressure fluctuations, destroy the material.


This mixture, known as camping gas, can be used as a pressure medium if it is mixed together with sufficient nitrogen so that no flammable air/gas mixture can occur when it is mixed with air.


Article in Wikipedia on inert gases