Clamping ring for tubes, tube being provided with such a clamping ring and method of blocking the rotation of such a clamping ring on a tube

The collar (1) has a circumferential clamping strip (2) with two ends (2a, 2b) overlapping in an overlap region of the strip with two radially internal and external overlapping faces. A strip clamping member (3) is mounted in contact with the overlapping faces. A non-metallic blocking cover (6) is mounted on the clamping member for blocking rotation of the collar in a circumferential groove (11) by rotational abutment of the cover against a lateral rim (12) of the groove. The cover bears on the external overlapping face and covers the clamping member radially outside the external face. An independent claim is also included for a method for blocking the rotation of a clamping collar.