Linearly actuated quick connect pipe couplings which include a male element and a female element adapted to fit into each other along a principal axis. One of the elements includes at least one ramp for receiving a radial projection mounted to the other element which locks the elements together by axial movement of the elements relative to one another. One of the ramp or the projection is formed with a ring mounted to rotate but is fixed in translation along the principal axis of one of the male or female elements. The ramp forms a first seat for locking the projection when the coupling is in a configuration to permit fluid passage and a second seat, offset axially with respect to the first seat, for locking the projection when the coupling is in a configuration to permit decompression of fluid within the coupling.