Have you been working with pneumatic systems for many years and are no longer seeing lubricators like you once did? Do you wonder if your pneumatic system needs an inline lubricator or what to do with an existing pneumatic lubricator? Let’s look at the reasons why you may or may not need lubricators in your pneumatic system.
First, what is a lubricator? A lubricator is one component in the air preparation combination typically referred to as an FRL. FRL is actually an abbreviation for three components. F stands for Filter. R stands for Regulator and L stands for Lubricator. The order of the letters is of importance as well. The first component is the filter which removes contaminants from getting downstream into the other pneumatic components. Then comes the regulator which sets the desired pressure for the pneumatic system and finally the lubricator. The lubricator takes the clean and properly set pressurized air and injects particles of oil lubrication into the air stream.
There are mainly two types of lubricators we will touch on; mist and micro mist lubricators. A mist lubricator takes large droplets of oil and sends the entire droplet of oil directly into the air stream. You can view and count how many droplets of oil are going into your air stream by looking into the sight glass. You can count the number of droplets and, as a general rule of thumb, you need 1 drop of oil for every 10 to 15 SCFM of air flow. Also, 25 drops per minute equals approximately 1 ounce per hour of supplied oil. A micro mist lubricator is very different. Instead of 100% of the visible oil going into your system, only about 3% of the visible oil in the sight glass of a micro mist lubricator makes its way into the air stream. The micro mist lubricator injects very small particles of oil into the system and the reason for this is primarily 2 fold. First, the mist lubricator and its large droplets of oil can only travel a few feet in a pneumatic system and the lubricator should be installed above the component it’s lubricating due to the oils difficulty traveling long distances or uphill. However, the fine mist particles in a micro mist lubricator can travel further distances and are less effected by elevation compared to the standard mist lubricator. The second factor is amount of oil needed. If you have a component that only needs a very small amount of lubrication, a micro mist lubricator may be desired over the standard mist lubricator.
Pneumatic lubricators were a staple in any industrial pneumatic system for decades. Due to the seals, pre-installed lubrication and surface finish of pneumatic components used many years ago, the oil supplied by a lubricator was necessary to fill the tiny gaps between the seals and metal components of the pneumatic components and to keep them moving. Not only was it necessary to keep the lubricator filled with oil, but it was just as important to use the correct oil. Any old oil laying around a can in the shop would not properly lubricate the system or be compatible with the pneumatic components seals. You had to make sure you used the correct pneumatic lubrication that’s compatible with your pneumatic components in your system. Also, many times the lubricators were tucked back in a machine and were out of sight and out of mind and did not get the attention they needed. If a lubricated system runs out of oil, the residual oil that’s left behind dries out and becomes a sticky varnish in the system which will likely cause valve spools and cylinder seals to become stuck and not move as they should.
So, what has changed in all these years? With advancements in seal technology; new and advanced space age lubrication and very smooth surface finish on pneumatic components; many pneumatic components come directly from the manufacturer “lubed for life”. What that means is that if you supply these components with clean (under 40 microns or better), dry (40 degree dew point or less) air, these components do not require any additional pneumatic lubrication. What we are talking about here are industrial pneumatic components such as actuators and valves. These components can last in your pneumatic application for many trouble free years as long as you supply them with clean dry air. However, one thing to keep in mind with these new components is even though they are lubed for life, they are not bullet proof. As an example, if you install a “lubed for life” cylinder into an existing pneumatic system that is lubricated, the lubrication actually washes away the lubrication that was installed by the factory. If you then allow the lubricator to run dry, the lubrication in the cylinder will dry and varnish and cause wear and sticking in the cylinder. The exact same effect would also happen to pneumatic valves installed in this scenario.
However, like always, there’s an exception to every rule. Many pneumatic hand tools still require lubrication. There are also components such as air motors and chucks that require lubrication. The best practice for sizing your lubricator for your component needing lubrication is looking at the specification for your component. Find out how much SCFM is required and how much oil is needed and you can then install the proper lubricator. However, take care to install the lubricator immediately up stream and as close as possible to that component only. Also, try to install the lubricator in a highly visible and accessible area so it is not hard to reach or out of sight so it gets its proper attention.
If you need assistance or advice on whether or not your system needs a lubricator or if you need help sizing a lubricator, please don’t hesitate to contact us at the RG Group. With our factory trained and certified pneumatic specialists, we can assist you with your applications and give you the confidence you need in specifying and maintaining your pneumatic systems.