What Is a Combination Air Filter/Regulator/Lubricator (FRL)?f
An FRL combination refers to three pieces of air equipment installed in the middle section of a pneumatic circuit. The components are a filter, a regulator, and a lubricator. It is also called a “three-piece air set” and has been used for a long time.
They are mainly installed in pneumatic circuits to supply air normally. The capacity and other factors are considered and installed according to the operating pressure and the amount of air used. During maintenance, it is necessary to remove water from the filter and replenish the lubricator drive oil.
Uses of FRLs
Rarely an air combination unit is not installed where pneumatic equipment is installed.
They are installed in front of the pneumatic devices that drive the solenoid valves, air cylinders, etc., and are used to protect these devices. Filters are installed to remove moisture, regulators to optimize pneumatic pressure, and lubricators to lubricate drive units. Many oil-free pneumatic systems have been available in recent years so the lubricator may be omitted.
Principle of FRLs
An air combination is divided into three parts, the filter, regulator, and lubricator, each of which has its role.
The filter is initially used to remove moisture from compressed air. Compressed air used in pneumatic circuits contains a lot of moisture. If compressed air is introduced into the drive unit in this state, the moisture will corrode the drive unit. In addition, the drive unit is coated with grease to ensure smooth operation, and the moisture may wash away the grease. Therefore, a filter is used to remove the moisture first.
Next, a regulator maintains the optimum pressure for the equipment. The drive unit has a fixed allowable air pressure, and if the air pressure exceeds the upper limit, the drive unit may fail. The regulator reduces the pressure to prevent excessive pressure from being applied to the drive unit.
Finally, although the drive unit is coated with grease in advance, air pressure and humidity gradually deplete the grease. To supplement this grease, drive oil is supplied by a lubricator.
Thus, the FRL combination is a component that preserves the air drive system through three elements.