A Filter Regulator Unit (FRL) is a pneumatic device used to clean compressed air and control its pressure before the air reaches pneumatic equipment.
FRL = Filter + Regulator + Lubricator
Filter – Removes dust, dirt, water, and other contaminants from compressed air.
Regulator – Reduces and maintains the air pressure at the required level.
Lubricator – Adds a small amount of oil mist to lubricate pneumatic components.
Typical arrangement:
Compressor → Filter → Regulator → Lubricator → Pneumatic actuator/valve
Why FRL is used
Protects pneumatic components
Maintains constant operating pressure
Removes moisture and contaminants
Improves equipment life and performance
Note: Modern pneumatic systems often use FR (Filter + Regulator) without a lubricator because many components are designed to operate without additional oil.
