
· Nitrogen, used to inflate tires on everything from jet aircraft to Formula 1 and stock cars, is finding its way into everyday passenger vehicles.
· Nitrogen is an inert gas that makes up 78.1 per cent of the air we breathe.
· It's been used for decades in racing cars and aircraft, where high operating temperatures are potentially dangerous, and on heavy-duty commercial vehicles and construction equipment.
· Oxygen and water are a tire's enemies. Oxygen permeates the tire and breaks down the rubber over time. It can also cause water vapour is also an issue, especially if a tire is already under-inflated.
· "Water vapour causes major expansion or contraction of air in the tire and changes the temperature of the tire." The hotter your tire is running the quicker it destroys that tire.''
· Badly maintained air compressors that haven't been purged of water buildup can exacerbate the problem by pumping more water vapour into the tire.
· Nitrogen inflation _ typically 95 per cent nitrogen and the rest unpurged air _ helps by reducing oxidation, heat-related pressure changes under use and pressure loss over time.
· The nitrogen is produced by a machine attached to the service centre's air compressor that strips nitrogen from the air.
· Heel corrosion that reduces the tight seal between wheel and tire, causing air loss.
· The safety issue aside, improperly inflated tires reduce fuel economy and increase tire wear.
Nitrogen is present as a component of air; it accounts for 78% followed
by Oxygen at 21% and other gases at 1% and moisture being a final component of
air. Nitrogen in its purest form is a naturally occurring, non flammable, dry,
inert gas that can be used for tire inflation without negative environmental
impacts.
Over time, air will slowly seep through the tread and sidewall
of a tire, resulting in a gradual under inflation of tires, if not periodically
topped up. Since a nitrogen molecule is larger than oxygen, it will not seep out
as fast as it does with air inflated tires. This means that the gradual decrease
in tire inflation pressure with air filled tires (approximately 1 to 2 pounds
per square inch (PSI) per month) will be less for tires inflated with nitrogen.
Nitrogen inflation has another potential advantage over air. Nitrogen
inflation reduces the amount of moisture, in the form of water vapour, in a
tire. The presence of moisture (normally present in air) is the main reason tire
inflation pressure varies with temperature. As the air in a tire heats or cools,
typically inflation pressure may change by 2 PSI for every 5 degree Celsius
change in temperature. This variation can normally be expected to be less for
nitrogen inflated tires.
Another potential benefit of reduced levels of
moisture in a nitrogen inflated tire is reduced degradation of the tire
components over time, caused by oxidation. Normally, the life of a passenger
tire is determined by tread wear, rather than aging of the tire, so this may not
be a significant factor in many cases.
Consumers interested in nitrogen
inflation should evaluate the cost/benefits by consulting a tire specialist.
Who Else Uses Nitrogen?
NASCAR. NASCAR
teams use Nitrogen because it allows them to more accurately predict tire
pressure fluctuation. Nitrogen fluctuates with temperature change, but it does
so less than when water vapour is present. In addition, higher Nitrogen levels
eliminate the explosive properties of Oxygen (Oxygen loses its explosive
properties at around 9% or less).
Commercial Airlines. The Federal
Aviation Administration requires Nitrogen in aircraft tires because it reduces
the potential for water vapour freezing at high altitudes. In addition, airlines
such as Boeing use Nitrogen membranes or "OBIGGS" on-board inert gas generation
systems (OBIGGS) to layer fuel tanks with inert Nitrogen. Again, this reduces
the potential for explosions.
Government Agencies. NASA and the U.S.
military use Nitrogen for many of the same reasons it's used in commercial
aircraft.
Food Processors and Packagers. Oxygen hastens both the
chemical breakdown and microbial spoilage of many foods such as meats, potato
chips, dairy products and cookies. To help preserve foods longer, processors and
packagers often use modified atmosphere packaging (MAP) and controlled
atmosphere packaging (CAP) that replaces some or all of the Oxygen in the air
inside the
package with Nitrogen.
Industry. Many industries use
Nitrogen because of its dry and inert properties. Nitrogen is used in
electronics manufacturing to eliminate moisture. It is used in chemical
manufacturing to reduce oxidative degradation of the product. It is also used to
prevent explosive conditions due to its inert characteristics.
How is Nitrogen separated from other gases in air?
Hollow
fibre membrane tubes are the heart of any Nitrogen tire inflation system. Just
like tire rubber, the membranes are permeable. When thousands of these permeable
tubes are filled with air at high pressures, smaller molecules leak out while
the larger Nitrogen molecules travel through the tubes into a holding tank to
fill your tires or for other uses such as detecting leaks in air conditioning
systems.
Whether your tires are inflated with air or Nitrogen, measuring
tire pressure at least "once a month" is critical. Drivers will benefit by
increased safety, handling and braking performance, longer tire service life,
better fuel economy and reduced greenhouse gas emissions that contribute to
climate change and affect air quality.