Should You Lubricate Your Pneumatic System?

The question of whether or not to supply airline lubrication often comes up during the installation of pneumatic components, in the design of new machinery, or when rebuilding or retrofitting existing equipment.  Understanding the pros and cons of using airborne lubrication can save you time, money, and trouble.  To get started, first check the component’s lubrication requirement by reading the manufacturer’s product precautions.  Neglecting this simple step may void the product warranty, so doing this easy homework up front pays off. 

When lubrication is required, the desired effect is to provide just enough airborne oil to create a thin film of lubricant between the mating surfaces of moving parts to extend the life of the pneumatic component.  Careful attention must be given to specifying, installing, and correctly adjusting lubrication equipment and using the correct lubricant to accomplish this task successfully.  Again the manufacturer’s product literature will likely be the best source of information to correctly match the product’s capabilities to the application requirements. 

We must also be aware that some applications have environmental extremes that require special attention to component lubrication.  In high heat environments, machinery is subjected to being washed down for cleaning, or where chemical contamination may occur, the lubricant may be compromised or rinsed away and need to be replaced on a regular basis to extend the life of a pneumatic component, primarily linear actuators. 

In these situations, the life of the pneumatic component may be extended for a period of time by providing airborne lubrication, and there is a reasonable argument for supplying it.  By the same token, it is important to note these underlying factors actually exist and that oil is not being used simply because “that’s the way we’ve always done it.”

So now that you have read the manufacturer’s product precautions and checked for conditions that might require lubrication, what if nothing indicates that lubrication should be used?  Should you install a lubricator anyway, perhaps just to “play it safe”?

Consider the consequences first.  For example, standard lubricators are adjusted with a general procedure based on counting the number of drops per minute through a sight dome and correcting with a needle valve typically as the machine is running.  How many drops per minute is often a matter of guess-timate rather than careful experimentation based on peak air flow demand, distance the lubrication has to travel, and the nature of the equipment’s lubrication requirements.  Given this, excessive lubrication is often applied.

The lubricant ends up underneath machinery and in the surrounding air.  In extreme cases of over-lubrication, oil mist may be visible as a haze throughout the surrounding environment.  If the lubricator is over-adjusted to correct the issue, machine damage from lack of lubrication may occur, and often over-lubrication is tolerated for this reason.