Abstract: A flat heat exchanger tube is formed from a single metal strip and comprising two opposite spaced apart broad sides in a thickness direction of said tube and two opposite nose-forming narrow sides in a width direction of said tube. The strip has two longitudinal edges, the first longitudinal edge being contiguous to the first broad side and the second longitudinal edge being contiguous to the second broad side. The two longitudinal edges of the strip are joined together at a first one of the narrow sides, both longitudinal edges being convex-shaped so that the first edge forms an outer convex bend and the second edge forms an inner convex bend that fits in the outer convex bend and conforms to its internal curvature.

Abstract: A flat heat exchanger tube is formed from a single metal strip and comprising two opposite spaced apart broad sides in a thickness direction of said tube and two opposite nose-forming narrow sides in a width direction of said tube. The strip has two longitudinal edges, the first longitudinal edge being contiguous to the first broad side and the second longitudinal edge being contiguous to the second broad side. The two longitudinal edges of the strip are joined together at a first one of the narrow sides, both longitudinal edges being convex-shaped so that the first edge forms an outer convex bend and the second edge forms an inner convex bend that fits in the outer convex bend and conforms to its internal curvature.

Abstract: A heat exchanger joint between a pipe and a header wall defines an endless transition for conveying the heat exchange medium closely over a control surface of a radius or a chamfer between the interior surface and the pipe to reduce turbulence and pressure loss. The radiused or chamfered flow control surface expands radially as it opens axially into the interior surface of the header wall.

Abstract: A metal tank cap is integral with a reinforcing member via a narrow connection and is flared outwardly at the narrow connection portion to be over an open end of the tank simultaneously with moving the metal tubes of the core into the tank. By unbending the connection portion, the respective tank caps are deflared into the open ends of the respective tanks and the entire assembly is placed in a furnace and brazed together.

Abstract: A heat exchanger is disclosed. A plurality of guides are integrally formed with the walls of a header tank and are used to position an oil cooler inside the tank to align a pair of fittings carried by the cooler with a pair of spaced openings in the tank.

Abstract: A secondary heat exchanger subassembly, such as a transmission oil cooler, is disposed in a metal tank of a radiator and has a pair of metal fluid fittings. Either a connector ring engages a fitting extending through the opening in the tank or a connector nut extends into the opening to threadedly engage the fitting whereby the metal fittings are held to the metal tank and inserted into a furnace for being brazed into sealed relationship with the metal tank.

Abstract: A one-piece header tank includes side edges that are overlapped and brazed together to form a joint positioned within the interior of the tank. The tank also includes an integrally formed mounting flange that may be fabricated without jeopardizing the leak integrity of the tank.