Filter Regulator Lubricator

What is a Filter Regulator Lubricator (FRL)? An FRL consists of three elements - a filter (F) to, generally, remove particles above 40 micron in size and water, a regulator (R), which controls pressure and a lubricator (L), to provide a controlled quantity of oil into the system. A regulator is used to control the speed and precision of the flow of liquids and air, whereas the filter cleans the air that travels from the compressor. What happens is the airline filter scrubs, strains and traps solid particles (dust, dirt, rust) and separates liquids (water, oil) within the compressed air.