(under subclass 81.02) Process or apparatus which removes scale from the inwardly facing surface of the hollow article.
SEE OR SEARCH CLASS
15, Brushing, Scrubbing, and General Cleaning,
88, for a machine having a cleaning instrument of the brush or broom type especially adapted for cleaning wire, rods, or tubes.
134, Cleaning and Liquid Contact With Solids,
22.1+, for a process which includes treating work such as bottles, tubes, or other work having cavities by application of the treating agent to the interior surfaces.
