Coupling device for a tube

A coupling device for a tube, comprising:

• a main body defining a rotationally symmetrical housing having an opening for inserting a tube in a direction of insertion, the housing being delimited by an inner surface and comprising a first shoulder forming a widening of the housing in the direction of insertion;
• and
• a retaining ring at least partially inserted into the housing through the opening and comprising, in the direction of insertion, a base and a rotationally symmetrical retaining portion having a diameter smaller than an extent of the base, the retaining portion having a snap-fit collar on a side surface of the retaining portion, the snap-fit collar configured to enable the retaining ring to remain clipped in the housing by way of the snap-fit collar engaging with the first shoulder, the retaining ring defining a channel by which the tube is intended to be inserted into the housing;
• wherein the retaining ring is mounted in the housing with axial play that is not zero so as to adopt either a first position or a second position, the first position requiring the collar to bear against a first shoulder in a direction opposite to the direction of insertion, and the second position requiring the base to bear, in the direction of insertion, against an abutment means formed on the main body, escape paths being provided in a space formed between the side surface and the inner surface, and configured to allow a fluid that may be present in a chamber downstream of the retaining ring to escape toward the outside when the ring, under the effect of a pressure that may be exerted by the fluid, is in the first position, the escape paths being configured so that the flow of the fluid in the escape paths generates an emission of a sound wave.