Connection system for interconnecting a heat exchanger and a pipe union

A connection system for interconnecting a heat exchanger and a pipe union, with the pipe union opening out into a connection tube of a water box of the heat exchanger, the pipe union being fixed firstly to a flexible pipe by permanent connection means, and secondly to the tube by resilient connection means constituted by co-operation between an annular neck formed in the union and an internal annular shoulder formed in the tube and intended to engage resiliently in said neck, with sealing being provided by an elastomer ring for being radially compressed between the tube and the union, wherein:

• said neck is delimited at the leading end of the pipe union by a snap-fastening flange for engaging the internal shoulder of the tube, which flange is discontinuous and constituted by snap-fastening catches which are uniformly spaced around the circumference of said leading end;
• the neck includes portions which are delimited by said snap-fastening catches alternating with portions which are not delimited by snap-fastening catches, with those portions of the neck which are not delimited by snap-fastening catches being separated from those portions which are delimited by snap-fastening catches by means of axial slots extending from the leading end of the union over substantially the entire length of the neck, thereby dividing the end of the union into a plurality of axial fingers which carry said catches and which are radially resilient, and a plurality of cylindrical portions for guiding the union inside the tube;
• said internal annular shoulder of the tube is also discontinuous, in a manner complementary to said snap-fastening flange, said shoulder comprising a first plurality of axial grooves and a second plurality of axial grooves, with each groove in the first plurality:
• being intended to pass a corresponding finger with its snap-fastening catch while the union is being assembled to the tube;
• being located between two grooves of said second plurality;
• and
• being separated from said grooves of said second plurality by projecting shoulder portions over which said cylindrical portions of the pipe union slide;
• whereas each groove of said second plurality serves for releasing a corresponding finger when disconnecting the union from the tube, by rotating the union so as to bring its fingers from a locking position in which they are in alignment with said grooves of the first plurality to an unlocking position in which the fingers are in alignment with the grooves of said second plurality.