Abstract: Flow of liquid fuel to a vaporization tube of a heating device is controlled by a vertically adjustable float valve, with the vertical height of a surface level of the fuel in a float valve chamber being set to correspond to a desired operating level of the liquid fuel in the vaporization tube. Liquid fuel is permitted to free-flow from the float valve chamber to the lower end of the vertical vaporization tube without metering, the rate of flow and the level of the fuel in the vaporization tube being determined solely by the hydraulic head created by the surface level of the fuel in the float valve chamber. Raising of the float valve chamber produces a corresponding raising of the level of the fuel in the vaporization tube to increase the tube inner surface area which is contacted or wetted by the fuel in the tube, thus causing an increase in the rate of vaporization and a corresponding increase in heat output of the heating device.

Abstract: A tubular valve for controlling the flow of fluids includes an outer tubular shell having pairs of ports on diametrically opposed surfaces and an inner coaxial transfer tube having pairs of openings which are selectively rotated into or out of alignment with the outer tubular ports. Deformable grommets enclose and seal the space between the outer shell and inner tube and provide lateral tubular extensions projecting through the outer ports for connection to external sources and apparatus. The inner transfer tube, which is rotatable within the grommets, provides communication for fluid flow between inlet and outlet ports and openings. Different fluids may be selectively controlled and supplied through separate outlets.During assembly, each deformable grommet is folded around an insertion device which is inserted into the outer tubular shell and twisted to release the tubular extension which projects laterally from the port.