Patent ID: 7237807

Claim:
A set of pipe connecting structures for a heat exchanger, comprising: a header tank having a connect opening that is uncladded with brazing material; a connector block having a passage configured to connect a pipe thereto; an adapter configured to connect the header tank and the connector block to each other, the adapter having a first cylindrical part to be connected to the connect opening of the header tank, a second cylindrical part to be connected to the passage of the connector block, and a flange radially extending between the first and second cylindrical parts and being interposed between joint areas of the header tank and connector block; and a brazing material clad to a joint area of the flange to be joined to the header tank and a joint area of the flange to be joined to the connector block, so as to join the header tank and connector block together by brazing, wherein the adapter is formed by bending a straight cylindrical material that has brazing materials on inside and outside thereof, the adapter having an inner cylindrical portion, an outer cylindrical portion that is folded back onto an outside of the inner cylindrical portion, and a flange portion extending radially outwardly from the outer cylindrical portion.