What is the purpose of an FRL unit in a pneumatic system?

• A. Reservoir to store air, Heater to warm air, and Sensor to detect leaks.
• B. To convert electrical energy to pneumatic.
• C. Only a filter component to clean air.
• D. Filter to remove contaminants, Regulator to set pressure, and Lubricator to lubricate moving parts.

Answer: (C)

An FRL unit conditions compressed air so pneumatic components operate reliably. It combines three essential functions: filtering, regulation, and lubrication. The filter removes contaminants and moisture that could clog valves, cause wear, or lead to leaks. The regulator sets and maintains the desired system pressure, ensuring actuators receive consistent, safe performance. The lubricator adds a light oil to the air stream to lubricate moving parts, reducing wear and preventing stiction in cylinders and valves. Because of these combined functions, an FRL unit provides clean, properly pressurized, and lubricated air to the system, protecting components and improving performance. An option that mentions only a filter is incomplete, since it omits the needed regulation and lubrication.