split ring 11 is made with a plastic or metal material whose elasticity allows it starting from a non stressed or non deformed state of the ring 11 in which its inner diameter is smaller than the outer diameter of the tubes 20 to deform elastically and to grip said tube 20 when it is inserted into said device together the truncated chamber 5 the longitudinal rib 7 an the split ring 11 comprise a hooking means which serves to hold the tube 20 in the connection device on the outside the main body 1 can have external longitudinal ribs 1 a 1 b designed to make the connection device easier to grasp and handle this makes it easier to turn the connection device in the invention manually with or without a specific tool the body 1 advantageously has a particularly resistant central zone this central zone located between the truncated chambers 5 has an increased thickness and the longitudinal external ribs la make it possible to reinforce the body 1 which can resist high pressures for example on the order of 50 bar in one given embodiment the split ring 11 has threads 12 on the inside with a diameter smaller than the outer diameter of.