Abstract: A method for producing a channel arrangement, a channel arrangement, a metal profile and use of a channel arrangement. The method includes arranging a first metal profile towards a second metal profile. The first profile includes elongated trench-like portions mutually separated by flat portions. The first profile is joined to the second profile so that channels between the first profile and the second profile are defined. The channels are separated by flat regions. In the arranging, at least one of the profiles is a profile including an incipient cut to be located in at least one of the flat regions. Material is removed from the at least one flat region so that the thickness of a part of the at least one flat region becomes less than the sum of the thicknesses of the profiles.

Abstract: A brazing method is provided for brazing a metallic material for brazing to another metallic material. The metallic material for brazing includes a base material portion made of copper or a copper alloy containing chrome by a predetermined amount, and a metallic film portion made of a material having a melting point lower than a heating temperature in brazing, and provided on the surface of the base material portion. The brazing method includes a step of assembling the metallic material for brazing and the another metallic material to form an assembly, a step of heating and brazing the assembly, in which the metallic film portion is melted to diffuse chrome into a surface of the metallic material for brazing, and a step of forming a chrome oxide film by using the chrome diffused into the surface of the metallic material for brazing in atmosphere after the brazing step.

Abstract: The invention relates to a method and an apparatus for positioning solder or braze material on the fin material to be used in a heat exchanger, as a radiator for vehicle, in which method the fin material, as a corrugated strip, is partly covered with solder or braze material. According to the invention the fin material (8) is transferred to the vicinity of a cladding device (1,2) so that when the fin material (8) is passed by the cladding device (1,2), the fin material (8) is cladded by solder or braze material (11) at least in one side of the fin material (8) essentially at the curved parts (10) of the fin material (8).

Abstract: The invention relates to a heat exchanger unit to be used in a gas-fired water heater in which heater a heat exchanger unit contains tubes with fins. According to the invention the heat exchanger unit contains flat oval tubes (1,21,31) having a fin (3,22,32) at least on one flat part (4,24,33). The flat oval tubes (1,21,31) as well as the fins (3,22,32) are made of copper, copper-based alloy, aluminium or aluminium-based alloy.

Abstract: The invention relates to a heat exchanger unit to be used in a gas-fired water heater in which heater a heat exchanger unit contains tubes with fins. According to the invention the heat exchanger unit contains flat oval tubes (1, 21, 31) having a fin (3, 22, 32) at least on one flat part (4, 24, 33). The flat oval tubes (1, 21, 31) as well as the fins (3, 22, 32) are made of copper, copper-based alloy, aluminium or aluminium-based alloy.