Oil-free compressors are used for numerous applications in different industries ranging from offshore to food and beverage. But the question whether compressors have absolutely no oil in them is a much debated and controversial topic. General Manager, Louwrens Erasmus of Rand-Air, a market leader in portable compressed air rental speaks to us about Rand-Air’s products and how they differ from competitors. “It is quite simple really, our compressors do have oil in them, however, the compression process doesn’t and neither does the compressed air at the output,” he explains.
The compressed air is 100% oil-free…
“Most of our fleet of Atlas Copco Rental’s oil-free compressors are rotary screw compressors. Inside the compression chamber, Teflon-coated elements effectively compress the air without the need for oil. This means that absolutely no oil is injected in the process, therefore no oil needs to be removed resulting in 100% oil-free air. In fact, Atlas Copco avoids all oil in components such as seals, hoses and valves that could potentially and possibly come in contact with the air.”
… but the compressors aren’t.
“With that said, there is oil in our oil-free rotary screw compressors. Our diesel-driven units need oil for their engine. In addition to this, the bearings and the compressor’s gear box are lubricated with oil, purely because is the most efficient way to lubricate. It is important to note that these oil circuits are always completely separate from the compression process and the laws of physics prevent the oil from spilling into the process. Over and above this, the oil in the bearings is shielded off from the compression chamber by a set of patented labyrinth gears. Over 50 years of experience has been the result of the spill-free design and even if the seals falter, over-pressure in the compression chamber will prevent the oil from getting into the air.”
The proof of safety
An oil-free compressor is the only way to achieve 100% oil-free air. “TÜV introduced the ISO rating for air purity and Atlas Copco had all its oil-free compressors tested and certified according to this standard. All our oil-free compressors hold an ISO 8573-1 (2010) CLASS 0 certificate which is the highest industry standard. This gives our customers peace of mind that when using an oil-free compressor from Rand-Air that they are using 100% safe, oil-free compressed air.”