Abstract: The subject matter of the invention is a pipe (2) forming part of a heat exchanger. The pipe (2) is delimited by at least one wall (4, 7) for separating a fluid (3) circulating in the pipe (2) and an external medium (6). The wall (4, 7) is equipped with means (8) of deforming the wall (4, 7). These arrangements are such that at least one of the walls (4, 7) of the pipe (2) is actively deformed, in a precise and controlled manner, by the deformation means (8) in order to precisely conform and configure said, wall (4, 7), the use of the deformation means (8) being in particular placed under the influence of control means in relationship with the deformation means (8).