Filter, regulator, lubricator. Why each matters, when to skip the lubricator, and how to size it.
FRL is three things in one frame: Filter, Regulator and Lubricator. It’s the first thing compressed air meets before it reaches the valves and cylinders — and how long they last depends on it.
Compressed air carries water condensate, compressor oil and solid particles. The filter catches them. 5 µm is standard; for sensitive uses, a fine filter down to 0.01 µm. Water is the main enemy: it causes rust and washes out lubricant.
Line pressure “jumps” with demand. The regulator holds a steady output pressure, so cylinders work with consistent force and speed. A gauge shows the set value.
Many get this wrong. Older equipment needed lubricated air, but modern pneumatics is usually lubricated for life and runs oil-free. Adding oil where it isn’t needed collects dust and causes trouble. Fit a lubricator only if the machine maker specifically requires it — and then consistently for the whole line.
An FRL is chosen by the air flow (l/min) the line consumes, not just the thread size. Too small a unit causes pressure drop and “starvation” at peaks. Also consider condensate draining — manual or automatic (auto is good for the forgetful).
An air preparation assembly: Filter (F) cleans, Regulator (R) holds steady pressure, Lubricator (L) adds oil. It conditions compressed air before the pneumatics.
Often no. Modern pneumatics is usually factory-lubricated and runs oil-free; added oil can even harm it. Fit a lubricator only if the equipment specifically requires it.
Standard pneumatics is fine at 5 µm. Sensitive valves, sensors or painting need a fine filter (down to 0.01 µm) and sometimes a carbon filter.
Send a size, a code or a photo of the machine — we’ll help you pick the right one.
