(under the class definition) Apparatus including a combustion chamber that has at its outlet distinct structure, which in the performance of its intended function, establishes or maintains a pressure within the combustion space distinctly above or below the pressure of the ambient which pressure is critical in the operation of the apparatus.
(1) Note. A gravity type exhaust flue is not by itself considered to establish a pressure critically distinct from the pressure of the ambient.
SEE OR SEARCH THIS CLASS, SUBCLASS:
19, for a burner having a control responsive to combustion chamber pressure.
20, for automatic control of or by an exhaust damper or pump.
SEE OR SEARCH CLASS
110, Furnaces, 147+, for a device that acts directly on the products of combustion of a solid fuel burner after they leave the firebox, to affect the velocity of the products.
