Abstract: The snap connection for sealed and releasable connection of a first tube end (10) with a second tube end (20), with spring arms (33), with a first outer stop projection (14) on the first tube end (10), with a first elastically deformable ring (31) connected with the spring arms (33), and with two first inner stop cams (34) on the first ring (31) cooperating with the first outer stop projection (14), is characterized according to the present invention by a second outer stop projection (23) on the second tube end (20), a second elastically deformable ring (32) connected with the spring arms (33) with distance from the first ring (31), and by two, second inner stop cams (35) on the second ring (32) cooperating with the second outer stop projection (23). Both rings with their stop cams, connected to one another via the spring arms, form a double-connection element (30) separable by and on both tube ends (10, 20), which can be made from a plastic injection molding part.

Abstract: Two-layered or three-layered polymer tubing for use as a pressurized fluid conduit in automobiles can be either walled or have walls continuously or partially corrugated. The tubing has an outer layer of a hard polymer molding material and an inner layer of a soft rubber-like polymer or a polymer mixture. The inner layer can be provided on the innerside with a layer of a thermoplastic adhesion-modified elastomer composition. The a materials are selected for the layers to provide a so-called “hard-soft-combination”. The rubber-like polymer composition has a hardness in the range of 30 Shore A to 60 Shore D, especially of about 30 Shore A to 90 Shore A, the compositions being selected so that they are processable by coextrusion or the so-called conex method and adhere directly to each other non-positively or positively fitted, i. e. without additional bonding agent, without delaminating.