Abstract: A temperature control device for a fluid heating vessel senses ambient temperature and controls or adjusts the set point at which power is reduced to an element for heating the fluid in the heating vessel, in order to prevent boil-over of the fluid. The The point is increased for an ambient temperature higher than a predetermined ambient temperature and is decreased for an ambient temperature lower than said predetermined ambient temperature.

Abstract: A controller for automatically regulating the supply of secondary combustion air to woodstoves and small furnaces. The controller includes a movable air valve for controlling the amount of secondary air admitted into the chamber. A self powered means monitors the concentration of combustible gases and vapors and actuates the movable air valve to increase the supply of secondary air in response to increasing concentrations of the combustible gases and vapors. The self-powered means can be two fluid filled sensor bulbs, one of which has a coating of a combustion catalyst. Alternatively, the self powered means can be two metallic stripes laminated together, one of which is coated with a combustion catalyst, and when heated, causes the air valve to actuate.

Abstract: A fluid temperature actuated valve for trapping fluids in a system, having particular utility as a steam trap. The valve is closed by the expansion of a wax pellet type thermal actuator working against the valve opening force of an operating spring. The valve may be provided with an ambient sensing on-off control in the form of an air temperature responsive actuator which is coupled to the fluid sensing actuator by a suitable insulator. The air sensing actuator upon the occurrence of a predetermined ambient temperature condition will displace the fluid sensing actuator a sufficient degree to prevent the opening of the valve. The valve with the ambient sensing control may be employed as the only control on a steam tracer line, serving the dual function of a steam trap as well as an on-off control response to the ambient temperature.

Abstract: A three-way changeover valve construction having a housing means provided with an inlet and a pair of outlets. A pair of valve seats are carried by the housing for respectively controlling fluid flow from the inlet through the outlets. A pair of valve members are provided for respectively controlling the valve seats with the valve members being operatively associated together to move substantially in unison relative to the valve seats in response to a condition sensed by a condition responsive device. A changeover device is operatively associated with the valve members to position the same to act respectively on one side of the pair of valve seats or on the other side of the pair of valve seats to change the valve construction from a cooling function thereof to a heating function thereof in response to a temperature change in the flowing medium.