Female quick-connect coupling element, for joining two pressurised-fluid pipes, this female coupling element being able to cooperate, along a longitudinal axis (X-X') of the female element, with a complementary male coupling element, the female coupling element comprising: - a body through which a fluid-flow conduit passes, - at least one locking member (60; 70) able to move between a locking position of the male element with respect to the body of the female coupling element in a coupled configuration of the coupling, and a release position, in which the female and male elements (A, B) of the coupling can be uncoupled, - a control ring (90; 150; 160) able to move in translation along the longitudinal axis (X-X') between a first position in which each locking member (60; 70) is held in its locking position, and a second position in which each locking member (60; 70) is able to move into its release position, - a piston comprising an active surface in fluid contact with said conduit and being able to move sealingly in a housing passing through the body in a transverse direction (Y-Y') from the fluid-flow conduit towards the outside of the body, the piston extending from the active surface opposite to the fluid-flow conduit, - a blocking member (100; 130) the movement of which parallel to the transverse direction is integral with the movement of the piston, - the piston being able to move from an internal position in which the blocking member (100; 300) does not block the movement of the control ring (90; 150; 160), to an external position in which the blocking member (100; 130) prevents the translation of the control ring (90; 150; 160) to its second position, and - at least one element for the elastic return of the piston to its internal position, characterised in that - the elastic return element is mounted in a housing of the body of the female coupling element situated outside the housing of the piston, the housing of the elastic return element being fluidically isolated from the fluid-flow conduit, and - the female coupling element comprises transmission means (100; 126), disposed between the return element and the piston, for returning the piston to its internal position. - a body through which a fluid-flow conduit passes, - at least one locking member (60; 70) able to move between a locking position of the male element with respect to the body of the female coupling element in a coupled configuration of the coupling, and a release position, in which the female and male elements (A, B) of the coupling can be uncoupled, - a control ring (90; 150; 160) able to move in translation along the longitudinal axis (X-X') between a first position in which each locking member (60; 70) is held in its locking position, and a second position in which each locking member (60; 70) is able to move into its release position, - a piston comprising an active surface in fluid contact with said conduit and being able to move sealingly in a housing passing through the body in a transverse direction (Y-Y') from the fluid-flow conduit towards the outside of the body, the piston extending from the active surface opposite to the fluid-flow conduit, - a blocking member (100; 130) the movement of which parallel to the transverse direction is integral with the movement of the piston, - the piston being able to move from an internal position in which the blocking member (100; 300) does not block the movement of the control ring (90; 150; 160), to an external position in which the blocking member (100; 130) prevents the translation of the control ring (90; 150; 160) to its second position, and - at least one element for the elastic return of the piston to its internal position, - the elastic return element is mounted in a housing of the body of the female coupling element situated outside the housing of the piston, the housing of the elastic return element being fluidically isolated from the fluid-flow conduit, and - the female coupling element comprises transmission means (100; 126), disposed between the return element and the piston, for returning the piston to its internal position.