Abstract: A control arrangement for a gas-fired system. Three diaphragm-operated valves are in series providing a stage operation. The valves are pilot controlled. A booster pump is provided for cooperation with the pilot valves to boost the line pressure to the first of the valves, the boosted pressure being sufficient to operate the diaphragm valves, and the boosted pressure being controlled by the pilot valves. The booster pump operates only when needed. Diaphragm-operated pilot valves means are provided which operate two separate pilot valves which control the pressure on the opposite sides of the diaphragm of the diaphragm valves. The system provides stage operation, the stages including a first stage which is closing of a vent valve connected between disphragm control valves, opening of a first diaphragm valve, and a third stage which is a controlled slow opening of the second diaphragm control valve. The first diaphragm valve is both a control valve and a pressure regulator.

Abstract: A control arrangement for a gas-fired system. Three diaphragm-operated valves are in series providing a stage operation. The valves are pilot controlled. A booster pump is provided for cooperation with the pilot valves to boost the line pressure to the first of the valves, the boosted pressure being sufficient to operate the diaphragm valves, and the boosted pressure being controlled by the pilot valves. The booster pump operates only when needed. Diaphragm-operated pilot valves means are provided which operate two separate pilot valves which control the pressure on the opposite sides of the diaphragm of the diaphragm valves. The system provides stage operation, the stages including a first stage which is closing of a vent valve connected between diaphragm control valves, opening of a first diaphragm valve, and a third stage which is a controlled slow opening of the second diaphragm control valve. The first diaphragm valve is both a control valve and a pressure regulator.

Abstract: A thermally actuated switch which embodies an active unit which includes a heat responsive element which is part of an enclosure enclosing electrical resistance elements for heating. Heat is applied internally to the enclosure and cooling is by way of dissipation of heat externally from the enclosure. The thermally responsive element is in the form of a flat plate which expands lengthwise. The plate engages the shorter arm of a pivoted bell crank lever, which along with the leaf spring engages the actuating member to be actuated.

Abstract: An improved thermopile construction particularly adapted for use as an electric generator for producing a signalin response to heat from a pilot flame. Groups of elongated elements of dissimilar metals are assembled or arrayed in a circle within a metal sleeve to produce a pilot generator. The first group of elements is arrayed against the inside wall of the metal sleeve and the second group of elements is assembled radially inwardly from the first group. Respective ends of the elements of the first group and the second group are joined with the opposite end of the respective end of the element of the second group being joined to the opposite end of the next adjacent element of the first group. Individual elements of each group have a cross-sectional configuration to provide for optimum heat transfer between the sleeve and elements of the first group and to provide for assembly of the elements of the second group in a circle of smaller diameter.

Abstract: Automatic electrical control systems for gas fired equipment. The systems embody electrical ignition. The systems eliminate the need for a constantly burning pilot. In one form, wherein the main burner is electrically ignited the pilot is omitted altogether. The systems are adapted to retrofit of existing systems having a pilot to provide for electrical ignition, eliminating constant burning of the pilot. Safety interlocks are embodied and responsive to a thermocouple, providing an assured safe and positive operation under all possible conditions.