Airline water separators are devices used in compressed air systems to remove moisture, oil, and other contaminants from the air before it reaches spray guns or pneumatic tools. This is crucial in automotive painting and other precision applications, as clean, dry air ensures a smooth, defect-free finish and prevents issues like fisheyes or bubbling in the paint. Installed along the air line, water separators help extend the life of tools and improve the overall quality of the work.