(under subclass 290) Gauges wherein one or a plurality of test cocks are placed in communication with a reservoir or water column at various levels so that the liquid level may be determined by the issuance or nonissuance of liquid from the various levels. This subclass also includes the structure of the water column.
SEE OR SEARCH CLASS
116, Signals and Indicators,
227+, for single test indicators.
251, Valves and Valve Actuation, appropriate subclasses for valve structure, per se.
