PRODUCTION OF HEAT EXCHANGER

PURPOSE:To prevent a tube of copper or a copper alloy in which a medium is passed through from generating ant's nest like corrosion even if the high temperature is applied onto it in a state that a volatile lubricating oil remains. CONSTITUTION:A plate like fin 1 installed with plural number of tube inserting holes of aluminum or an aluminum alloy is formed. A cylinder like fin collar is installed onto the inserting hole of the plate like fin 1, a plurality of the fins 1 are arranged parallel, a tube 2 of copper or a copper alloy is inserted into the fin collar of the inserting hole of each fin 1, the tube 2 is expanded so as to be attached closely to each fin collar, and the tube 2 and the fin 1 are fixed. Then, an end of one tube 2 and an end of the adjoining other tube 2 are joined through a half circular shaped tube 4 of copper or copper alloy. In such a way, plural tubes are joined sequentially so as to be made into one continuous tube. In a production process of the fin tube type heat exchanger, the lubricating oil that the pH value of the water phase part of testing liquid is more than 4 in the test of degree of heat stability of the lubricating oil decided with the ASTM D2619 is used.