Copyright Goodheart-Willcox Co., Inc. Chapter 16 Conditioning and Distribution of Compressed Air 413 16.3.3 Air Line Lubrication at the Workstation A lubricator is the third of the components in the FRL unit. A lubricator provides the oil needed to improve the performance and service life of pneumatic system valves, actuators, and air-powered tools. A lubricator atomizes a measured amount of oil and mixes it with the compressed air used at system workstations. The lubricator must accurately meter the oil to provide component lubrication. Providing inadequate lubri- cation can result in rapid component wear. Adding excessive amounts of oil is wasteful and can contami- nate work areas around component exhausts. Lubricator design and operation Figure 16-24 shows the internal structure of one type of lubricator. The major external parts are a cast body containing inlet and outlet ports and a clear glass or plastic reservoir. Some designs have a metal reservoir. The internal elements are: • Air passageway leading from the inlet port to the reservoir. This passageway contains a venturi. • Oil-siphon tube connecting the reservoir and the venturi in the air passageway. • Adjustable oil-drip orifi ce. • Passageway leading from the reservoir to the outlet port. • Spring-loaded bypass valve that directly connects the inlet and outlet ports. Outlet port (reduced pressure) Inlet port (supply pressure) Pilot port Pilot-air chamber Goodheart-Willcox Publisher Figure 16-22. In a pilot-operated regulator, the control spring and adjustment screw are replaced with a sealed air chamber. Varying the air pressure in this chamber allows the regulator to be adjusted to the desired operating pressure. Supply air Supply air Pilot output line Outlet air Secondary regulator Pilot-operated regulator (primary regulator) IMI Norgren, Inc. Figure 16-23. The small, remotely located regulator is used to adjust the main system regulator by controlling pilot chamber pressure.