Historically, many reciprocating compressors used oil as a lubricant to reduce friction and prevent overheating. While effective, oil compressors have key drawbacks for those who need perfectly clean air, since oil droplets often work their way into the air stream. To minimize this concern, many businesses turn to oil-free reciprocating compressors.
Unfortunately, however, the relative newness of oil-free compressor technology means that many people still do not understand this option. If you would like to improve your knowledge of recent developments in reciprocating compressors, keep reading. This article takes a closer look at three key things to know about oil-free compressors.
1. Oil-Free Compressors Still Contain Oil
The term oil-free causes confusion for those new to this technology. Oil-free compressors still use oil to run properly. The chief difference lies in which parts of the compressor utilize such oil. A traditional reciprocating compressor uses oil to lubricate both its gearbox and the cylinder whose piston actually compresses the air.
An oil-free compressor still requires oil in order to lubricate its gearbox, which contains the gears and bearings vital for proper operation. Yet an oil-free compressor does not need oil in the compression cylinder. Instead, manufacturers cover the walls of the cylinder with a substance called polytetrafluoroethylene — more commonly known as Teflon.
Teflon possesses a unique combination of non-reactive and friction-free properties, allowing it to successfully eliminate the need for secondary lubrication. In addition, Teflon has an extremely high tolerance for temperature extremes.
Teflon can readily withstand temperatures up to approximately 620 degrees Fahrenheit, at which point it will begin to melt. Fortunately, compressors do not generate temperatures anywhere near that limit. As a result, a Teflon cylinder coating can provide effective piston lubrication for many years to come.
2. Oil-Free Compressors Have Lower Operating Costs
Oil-free compressors offer a key advantage with the long-term costs of operation. For one thing, oil-free compressors tend to carry a lower upfront cost compared to models that require oil. But the real savings start to add up as time goes on.
For one thing, oil-free compressors consume much less oil, since the oil in the crankcase remains sealed in place, with no easy way to escape. Most of the oil loss that occurs in a traditional compressor happens because of oil migrating from the walls of the cylinder into the compressed air.
Another key variable involves the condensate that naturally forms inside of an air compressor's tank. This moisture comes from water vapor in the condensing air. In a traditional compressor, this condensate usually contains dispersed oil particles. People must carefully collect and dispose of this contaminated condensate in order to avoid harming the environment.
By contrast, the condensate that forms in an oil-free compressor consists entirely of water and can route right into a drain. Oil-free compressors systems also avoid the need for costly filtration systems meant to separate oil from the downstream air supply.
3. Oil-Free Compressors Require Periodic Maintenance
Many people mistakenly assume that, by investing in an oil-free compressor, they do not need to do any maintenance. This attitude almost certainly will lead to an early death for your compressor.
To ensure an optimal lifespan, be prepared to occasionally perform basic upkeep tasks — or to hire a professional to perform them for you. Important maintenance efforts include testing the safety valve, draining the tank, inspecting the filter, and visually inspecting the various compressor components for signs of damage.
For more information about whether an oil-free compressor would make a good choice for your needs, please contact the rental tool experts at Ever-Joy Rent All Corp. We're happy to answer any questions you have.