COAXIAL HIGH-PRESSURE COUPLING WITH OVERPRESSURE RELIEF

The invention relates to a coaxial high-pressure coupling for hoses or pipelines, comprising a plug part (10) and a receptacle part (30) that accommodates the plug part in the coupled state, the plug part (10) and the receptacle part (30) each having a valve body (11, 31) having an inner channel (13, 33) and an outer channel (16, 36) concentric to the inner channel and the inner channels (13, 33) and the outer channels (16, 36) of the plug part (10) and of the receptacle part (30) being connected to each other in the coupled state, and in the inner channel (13) of the valve body (11) of the plug part (10) a closing cone (18) and in the outer channel (16) of the plug part (10) a closing sleeve (23) each being movable against spring action (21, 25) and being displaceable into the opening position thereof by the receptacle part (30) during the coupling process, is characterized in that a valve bore (61), which is connected to the inner channel (13) at one end and has a connection to the atmosphere at the other end and has a valve piston (62) movably arranged in the valve bore, is arranged inside the inner channel (13) formed by an inner pipe (14) and that the valve piston (62) is preloaded by spring action (63) into the blocking position of the valve piston, in which the connection between the valve bore (61) and the inner channel (13) is blocked, and can be displaced into a leakage position by an overpressure in the inner channel (63). that acts against the spring (63).