(under the class definition) Apparatus which controls a flow of a fluid in response to a variation in a condition of, or in the surrounding environment.
(1) Note. To be classifiable in this or indented subclasses the apparatus must include a sensing means responsive to changes in environmental conditions and there must be a disclosure that the control is in response to such changes. Devices which employ a sensing means using environmental pressure merely as a standard against which some internal pressure or condition is measured are not classified in this or indented subclass but are classified elsewhere on a basis appropriate to the system.
(2) Note. This and indented subclasses include devices which include means for sensing changes in an environmental condition and exercising a compensating effect so as to neutralize any effect the change in environmental condition would otherwise have on the operation of the device.
(3) Note. See the class definition, section 3, for search notes on the automatic control of fluid handling systems.
SEE OR SEARCH THIS CLASS, SUBCLASS:
59+, for device which sense the existence of freeze condition in the atmosphere and in response thereto operate to prevent freezing of liquid in the system.
