Abstract: An accumulator-reservoir device in a liquid cooling system utilizes a piston and metallic bellows to separate system pressures that are high and low in relation to one another. A piston position indicator is used sensing less than the full piston stroke in a manner to yield an accurate quantity measurement without undue elongation of parts.

Abstract: A valve assembly in which a longitudinally shiftable shuttle or spool valve is positioned by varying the fluid pressure in a pressure chamber at one end thereof. Solenoid valves open and close in a pulsed response to a changing fluid condition, the flow of which fluid is regulated by the spool valve. The solenoid valves control the admission of a pressure fluid to the pressure chamber and its exhaust therefrom.

Abstract: In a liquid coolant circulating or like system an accumulator--reservoir device of the bootstrap type. The reservoir device has a sliding seal construction, in which a piston is subject to high and low pressure influences as these relate to discharge and intake sides of a liquid circulating pump. External leakage from the device is minimized by an arrangement avoiding the need to seal against high pressure loss direct to ambient. Overall length is reduced by the arrangement which places a high pressure chamber between low pressure chambers. A hollow piston construction permits packaging system components within the reservoir, introducing further opportunity for simplicity and compactness of design.

Abstract: A tubular heat exchanger, the core of which is comprised of two sets of U-shaped tubes facing in opposite directions. A header plate receives the ends of one set of tubes. Another, longitudinally spaced, header plate receives the ends of the other set of tubes, and the sets of tubes between the header plates are in a substantially interfitting relation. A manifolding means at the one header plate provides for flow of a first fluid at one temperature into the one ends of the one set of tubes and out the other ends thereof. Other manifolding means at the other header plate provides for similar flow of a second fluid at a different temperature through the other set of tubes. Intermediate their ends, the tubes of the different sets are in a nested, companion relation promoting a transfer of heat between the different flowing fluids. The core can be surrounded by a shell apertured for venting or draining of a leaked fluid or for flow of a third fluid over and around the assembled tubes.