Method of assembling a first pipe length (1, 101) into a second pipe length (2, 102) by means of at least one interface joint (4, 104) wherein the first pipe length (1, 101), the second pipe length (2, 102) and the joint (4, 104) are conductors of current, and in that said at least one joint (4, 104) is overmoulded in at least one of said lengths (1, 2, 101, 102) so as to be in electrical contact with said at least one length (1, 2, 101, 102), said method including a step for inserting the first length (1, 101) of pipe into the second length (2, 102) of pipe so as to position said at least one joint (4, 104) in electrical contact with the other length (1, 2, 101, 102).