Frequently Asked Questions about Airpro products and systems

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Who would benefit most from using a Gas Generator?
Generally, generators suit those gas users who have a fairly steady usage of gas. This will be on a weekly or daily basis typically. Generators provide a steady output of gas at a given flow and pressure. This output must be selected to be greater than the customers’ requirements. In some cases, it is desirable to save a surplus supply of gas for use in times of very high demand. Once identified, these demands can be designed for. When users generate their own gas, they can realise very significant savings over purchased gas.
Why is the gas that I purchase now so expensive?

Gas prices vary greatly. The plants that manufacture gases are very large and are generally built to supply large markets. Smaller markets, in more remote areas and on islands, have their gases shipped in over long distances, on special trucks. The smaller markets also have little competition which again make it more expensive for the customer. 

How long will a new generator last?

With reasonable care and very straight forward maintenance, your new generator should last ten years at least, with normal use. Our customers have generators operating in the most severe conditions from oil platforms in the North Sea to desert conditions in the Middle East.

Are savings the only reason to buy gas generators?

No, there are many reasons but the main ones are:


Reliability: Customers also want a secure supply of gas. For example: in remote areas of Africa, deliveries cannot be relied upon; In parts of Canada, the roads are snowed in for many months, making deliveries unpredictable at best; Hospitals on islands must have their oxygen brought in by ship or barge; Industrial disputes can interrupt supplies in any location.


Budget: Customers know that they are not going to be affected by price increases any more. They can budget for their gas use now without having to worry about increases.


Environment: Using on-site generators means saving transport and unnecessary greenhouse gas emissions.


Administration: Customers no longer have to check and pay invoices. Purchased gas supplies do not have to be checked for proper volume or weight. Safety: There is no need for large quantities of hazardous gas to be stored on site. Especially, handling of high pressure cylinders is eliminated.


Safety: There is no need for large quantities of hazardous gas to be stored on site. Especially, handling of high pressure cylinders is eliminated.

How are gases such as Oxygen and Nitrogen manufactured on site?

With customers’ own gas generators, the gas is separated by directing air, under pressure, through a special filter medium or “sieve” which separates the desired gas. Air consists of mainly nitrogen (78%) and oxygen (21%). The remaining one 1% is made up of other gases, mostly argon. With PSA technology, two vessels are filled with the sieve material which adsorbs gas elements.


With AirPro generators, for instance, the nitrogen gas is adsorbed and the oxygen passes through the sieve vessels as the product gas. Before one absorber becomes saturated with nitrogen, the inlet air flow switches to the second absorber. The first absorber is now regenerated by desorbing the nitrogen through depressurisation and purging it with oxygen. The complete cycle is then repeated. Under normal operating conditions, the molecular sieve is completely regenerative and will last indefinitely.


Membrane technology is also well established for nitrogen generation. Atmospheric air is passed through hollow fibre membranes and the oxygen gas component permeates out through the fibre wall and is discarded. With membrane technology a desired blend of oxygen/nitrogen can also be attained, planned at the design stage.