Oil bath

It is a container of oil that is heated by a hot plate or (in rare cases) a Bunsen burner.

If higher temperatures are needed, a silicone oil or a sand bath may be used instead.

[2][better source needed] Silicone oil baths are effective in the 25 °C (77 °F) - 230 °C (446 °F) range.

This type of air filter was used in car and tractor engines, but has been replaced by modern paper air filters; some small engines continue to use this system.

In some cases oil baths are used to heat bearings so they expand before installing them on shafts of aircraft engines and tractors.

A pot of oil on a heat source
An oil bath air filter at the upper left in a GAZ-21 engine