Looking for a tool that will offer a complete air treatment solution? In our latest blog, we outline the definition of an FRL boxset, explaining the three main functions of an FRl unit and how an FRL unit works.

frl definition

What is an FRL Boxset?

An FRL combined box set is made up of a filter/regulator, a lubricator and the associated fittings and wall mounting brackets. The FRL boxset offers a complete air treatment solution. The potential applications of an FRL unit can vary depending on various accessories, including:

  • 3/2 way shut off valves
  • Pressure switches

FRL unit functions

The features of an FRL unit include:

  • Optimum machinery functionality
  • Ease of access
  • Prolonged system life
  • Reduced installation costs
  • Shut off valves for isolated systems
  • Can be mounted by wall brackets

How an FRL unit works

Here at MGA Controls, we have a wide range of FRL combined boxsets to choose from. To understand how an FRL unit works we will explain the three major FRL unit functions individually, starting with the Filter.


Filtering compressed air is widely regarded as the initial phase of air preparation. To allow machinery and pneumatic components to work at their optimum, they must be fed with clean, filtered air that is free of dust, water and other particles. Various filtration levels are available between 5 and 40 microns.

Pressure Regulators

Air pressure regulators benefit the FRL boxset in many ways. Firstly, and most importantly it provides an element of safety. Subsequent to this, it also helps to reduce costs. The role of a regulator is to control the air pressure to air tools, air gauging equipment and cylinders. The air pressure is regulated by a spring which acts through a diaphragm.

Pneumatic Lubricators

Like pressure regulators, the lubricator function of an FRL unit ensures that the air is dosed with a small amount of lubrication oil to help pneumatic components work effectively. Lubricators ensure that the correct amount of oil is being used to reduce the friction between moving components. This feature is very important to ensure a long machinery life span.

Maintaining your FRL Box Set

Each FRL boxset requires different maintenance for the relevant filters, regulators and lubricators. Guidelines on how to maintain your FRL boxset model will be provided when purchased but involve cleaning and removing the filtration drains, and making sure that Lubricators are topped up with the correct grade of oil. You can contact one of our experts for further product information by calling 01704 898980 .

Contact MGA about uses of an FRL unit

Need more information? Contact one of our technical experts at MGA controls by calling +44 1704 898980. Alternatively, email sales@mgacontrols.co.uk with any questions.