The coupling system comprises insert part and part for its reception. Either one or other part has ring-shaped groove, in which O-ring is fitted

摘要

The coupling system (6) comprises an insert part and a part for its reception. Either the one or the other part has a ring-shaped groove in which an O-ring is fitted. In the one or the other of the parts, a further groove is provided at an axial distance from the ring-shaped groove and a further O-ring is fitted in it. The effective sealing diameters of the two O-rings are different. The engagement surfaces of the grooves for the O-rings can be stepped to improve grip or are purely cylindrical. The coupling system is for the parts (5) of a pipe used for transporting cement or grout into a borehole (2).