Abstract: Apparatus for treating open-mouthed cylindrical containers with a fluid adapted to coat, clean or react chemically with the surface of the containers, comprises a turret fitted with pot assemblies spaced around its periphery, each pot assembly having an internal cavity for reception of a container and a lid for closing the cavity, conduit means for passing fluid through the cavity of each pot assembly, a first pump operable to circulate the fluid in a liquid phase from a reservoir through the conduit means and each cavity so that the liquid flows along the surfaces of a container in the cavity and effects treatment of the surfaces, a second pump operable to circulate the fluid in a gaseous phase from a source thereof through the conduit means and each cavity so as to purge liquid from the cavity, a third pump operable to extract fluid in the gaseous phase from each cavity through the conduit means and thereby reduce the pressure therein so as to effect drying of the container and cavity by vaporization of any