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How To Maximize Air Tool Performance Part #2 | Proper Conditioning of Compressed Air

How To Maximize Air Tool Performance Part #2 | Proper Conditioning of Compressed Air

Posted by Mark Schieber on 15th May 2020

At  International Air Tool Company we are proponents of the only cry once philosophy. Meaning, buy quality the first time around rather than throwing bad money after good. We understand it stings to pay $500 of your hard earned cash for a die grinder, but if properly cared for that tool could last you 5, 10, or even 20 years. In fact, we frequently receive tune up kit inquiries for tools that were manufactured in the eighties! A good quality tool will pay dividends in the form of productivity and reduced down time; allowing you to complete the job faster and with better results.

What's worrisome is when we receive a call from a customer claiming that their industrial grade air tool lasted no longer than their last Harbor Freight model. This instantly raises a red flag as to the quality of air being supplied to the tool. Regardless of purchase price, any pneumatic tool being fed a steady diet of dirt, rust, and contaminated water will surely suffer a premature fate. In this article, we will discuss the number one way to maximize the life of your air tools: through the use of an FRL or filter, regulator lubricator unit.

The act of compressing air increases atmospheric contaminants by 800%. As compressed air travels through the tubing to the work station, it picks up moisture, debris, scale, and other contaminants. Even if a refrigerated dryer is used after the air compressor, in the best case scenario we are still looking at a 125 PSI sand storm destined directly for the air motor of your tool. In the worst of conditions, add to this mixture high levels of moisture, and you create an abrasive slurry that grinds away at your tools components while simultaneously rusting them too. In an ideal world, every compressed air system would be equipped with drain traps, redundant filters, dryers, oil separators and the works, but due to budget and time restraints this is not always possible. Therefore, an economical way to give your tools some added protection is by installing a filter, regulator lubricator at each workstation.

Just as the name implies, an FRL is a three piece combination unit comprised of an air filter, pressure regulator, and inline oiler also known as a lubricator. These units should be installed as close to the point of use as possible and ideally should be populated one FRL per work cell. Diluting the beneficial properties of an FRL among too many air tools will decrease the FRL's effectiveness. The first tool in the chain will also receive most the oil, while the others downstream will run drier.

Now let's break down the components of an FRL trio by form and function:


Compressed air filters are the first line of defense as the air arrives at the FRL station. These filters are designed to remove airborne solid and liquid contaminants. They can be ordered with different type filter elements, including the coalescing style, which can remove particles as small as 0.3 microns. Off the shelf however, most FRL filters are equipped with a 5 micron element which still provides adequate filtration for most industrial environments. FRL air filters are offered in either manual drain or automatic drain versions. With manual drain filters, the unit is equipped with a small relieving valve on the underside of the catch bowl which must be opened periodically to release captured water and contaminants. If the water is not removed and the bowl fills to capacity, the incoming air will not be filtered; bypassing the unit entirely. In contrast, automatic drain units let off a constant slow drip of moisture and debris caught by the filter. Since the moisture drips from the bottom, some maintenance professionals will connect a small clear tube to the units drain outlet in order to redirect the drain water. This prevents personnel from slipping in the relieved condensation.

When sizing an air filter for your pneumatic tools it is important to make sure that the CFM (cubic feet per minute) flow rating of the filter meets or exceeds the CFM requirements of your tool. Pneumatic tools are air hogs and under-powered tools won't perform. For example, you wouldn't want to pair a 1/4" FRL with a 1" drive industrial impact wrench. Try to match the FRL to the plant tubing as best you can without creating drastic drops in diameter. It's always best to have more air flow than not enough. For more information on pressure and flow, check out the first article in this series,  How to Maximize Air Tool Performance Part #1 | Pressure and Flow.


Almost all air tools, regardless of size, are designed to be ran at 90 PSI. Under pressurized tools won't run to specifications and tools that are over pressurized will prematurely wear. Inline air regulators provide a convenient way to keep an eye on pressure. They provide controlled, consistent air pressure required for specific applications. Air pressure regulators are standard equipped with a dial gauge that ranges from 0 to 140 PSI. However, different spring ranges are offered to suit different requirements. Standard air regulators are of the relieving variety, meaning that unneeded pressure is bled off before it reaches the next step in the FRL trio which is the lubricator. When setting the pressure of your regulator, make sure you do so with the tool at the end of the line running full throttle. You want the dial to read 90 PSI when the tool is wide open!


Atomizing (mist) type lubricators ensure that your pneumatic tools receive the lubrication required for peak performance. Proper air tool lubrication is essential for maximum tool life. Inline air lubricators are designed to provide the correct amount of oil required by emitting a fine mist of oil into the air line. While a small amount of the mist travels in atomized form directly to the air motor of your tool, much of it accumulates along in the inside walls of your air hose. As the oil accumulates it forms small beads which subsequently drop into the air stream. Therefore, in order to avoid oily work pieces, it is a good idea to limit the amount of oil released from your lubricator. Most lubricators are equipped with an adjustable sight glass valve used to regulate the flow of oil. You can monitor the frequency of drops passing through the sight glass by using a stopwatch or other timer. Smaller air tools up to around 25 CFM only require a drop or so per minute. However, as the CFM of the tool increases it is a good idea to increase the ratio accordingly. This is not an exact science. Excess oil in the exhaust air or on the workpiece is a sign of over lubrication. While this most likely won't do your tool any harm, it will waste money and create a dirty work environment. Conversely, an under lubricated tool will prematurely burn up the tool's motor vanes, bearings, and end plates.

Regarding the air tool oil itself, while they are many brands of air tool oil out there; we have had good luck with the Ingersoll Rand Air Tool Oil and Marvel Mystery Oil. However, truthfully, any non-detergent 10 weight motor oil will work just fine in a pinch.

That wraps up our discussion on filter, regulator, lubricators. Keep in mind that no matter how well you care for your tools, anything mechanical will eventually need maintenance. When that time comes we offer  air tool repair service for most major brands.

Thanks for reading.

Mark Schieber


International Air Tool and Industrial Supply Company