FRL; the industry acronym for Filter, Regulator and Lubricator.

FRL's are devices used in preparing compressed air for use in your system or tools.

There's no shortage of information on this site about problems that are created by the air compressor while compressing air and the FRL is designed to reduce or eliminate some of them.

FRL is an acronym for Filter, Regulator and Lubricator.

If you are using a complete FRL assembly, make sure that this is the order in which the individual components of the FRL need to be installed.

The compressed air filter first to remove particulates and free water before the dirty wet air gets to the regulator. Then the regulator so that the compressed air is filtered and pressure regulated before it flows to the lubricator, if one is required for the device. The conditioned compressed air will flow through the lubricator and pick up the necessary lubricant for the tool or actuator.

The picture shows a somewhat typical FRL. To the left is the filter, the regulator is in the middle, and the lubricator is to the right.

The filter will have a female NPT port for the air to flow in from the left and the lubricator will have the same for the air to flow out of the unit on the right. Note the arrow on the filter and lubricator caps. The arrow shows the route for the air flow. None of the components in the FRL will work properly if the air flows against the flow design.

This filter has an automatic float type drain, inside the bowl, though this isn't visible from the picture. I know as I disassembled this particular unit after I took the photo.

There is a sight glass on both the filter and lubricator. The purpose is to show the liquid level inside the metal bowl.







If the filter was a manual drain, something I never recommend, the sight glass will show the maintenance operator the level of fluid inside to ensure that the filter bowl gets drained regularly.

For the lubricator, the sight glass on the bowl allows the maintenance operator to check the level of lubricant in the bowl without having to remove it.

On top of the lubricator is another sight glass and adjusting screw with which the maintenance operator can ensure that the lubricant is dripping into the air stream, and to see the results as they adjust the flow.

When it comes to using a lubricator, less is more! Don't become one of the many who think that more lubricant is better than a little. Once you start lubricating a device, the lubricant you add will ultimately "wash out" the factory lubricant, and it is then necessary to keep lubricating that device for life.

While lubricant rates are predicated on the device and the cycle time, a drop every 2-3 minutes should be adequate for all but most trying applications.

The regulator can be installed in this modular type FRL oriented as it shows in the picture, or inverted so that the adjusting knob is at the top. The preference depends on the application. The adjustment knob can be ordered as a locking unit to help prevent unauthorized pressure adjustment.

This particular regulator is a general purpose unit. It can be installed on either side of the regulator, again depending on the requirements of the applications.

Precision regulators offering a tighter pressure tolerance are an available option with many manufacturers offering these as alternatives to the general purpose unit.

Regulators are available with a variety of pressure ranges to suit any application.

The gauge in this photo is general purpose as well. Options for gauges include liquid filled, stainless steel, a variety of pressure read-out-ranges, among others.







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