Abstract: The present invention relates to a connecting system in two parts (1, 2), for a pipe (3) with a first lumen (4) in the axis A of the pipe, and a second lumen (5) outside of the axis A of the pipe (3), the first part (1) having two coaxial cones (6, 7) as connecting elements, the first lumen (4) leading to the first internal cone (6), and the second lumen (5) leading to the space (8) present between the first cone (6) and the second cone (7). The second part (2) of the connecting system has two coaxial cones (9, 10) as connecting elements, which are complementary to the two cones (6, 7) of the first part (1), the two cones (9, 10) of the first part (1) co-operating in a water and/or airtight manner with the two cones (9, 10) of the second part (2), in order to establish a water and/or airtight continuity between the two lumina (4, 5) of the first and second part, respectively.