Connector for connecting a container (2, 200, 4) to a dispensing conduit, in particular a container containing a liquid concentrate for dialysis, characterized in that the connector is constituted by: - a base provided with • a tubular wall, • a bottom wall oriented radially with respect to a main axis (a) and closing a first end of the tubular wall, at least one through-opening being provided in the bottom wall and/or in the tubular wall; - a membrane provided with • an annular flexible wall having a central opening, • a tubing placed in the central opening of the annular flexible wall so that it projects axially on one side of the flexible wall, a conduit passing right through the tubing; - sealing means for preventing a liquid from leaving the connector through the conduit of the tubing; the base and the membrane being fixed to each other in a liquid-tight manner so that the tubing projects outside the connector, the flexible wall being dimensioned to allow axial displacement of the tubing relative to the bottom wall so that the tubing can be moved between a closed position, in which the sealing means prevent a liquid from leaving the connector through the conduit of the tubing, and an open position, which is located farther axially from the bottom wall than the closed position, and in which the sealing means do not prevent a liquid from leaving the connector through the conduit of the tubing, retaining means (12, 222a) being provided to maintain the tubing in the closed position with a force that is sufficient to resist the pressure exerted by a product contained in a container equipped with the connector, but can be overcome manually to move the tubing into the open position. - a base provided with • a tubular wall, • a bottom wall oriented radially with respect to a main axis (a) and closing a first end of the tubular wall, at least one through-opening being provided in the bottom wall and/or in the tubular wall; • a tubular wall, • a bottom wall oriented radially with respect to a main axis (a) and closing a first end of the tubular wall, - a membrane provided with • an annular flexible wall having a central opening, • a tubing placed in the central opening of the annular flexible wall so that it projects axially on one side of the flexible wall, a conduit passing right through the tubing; • an annular flexible wall having a central opening, • a tubing placed in the central opening of the annular flexible wall so that it projects axially on one side of the flexible wall, - sealing means for preventing a liquid from leaving the connector through the conduit of the tubing; the base and the membrane being fixed to each other in a liquid-tight manner so that the tubing projects outside the connector, the flexible wall being dimensioned to allow axial displacement of the tubing relative to the bottom wall so that the tubing can be moved between a closed position, in which the sealing means prevent a liquid from leaving the connector through the conduit of the tubing, and an open position, which is located farther axially from the bottom wall than the closed position, and in which the sealing means do not prevent a liquid from leaving the connector through the conduit of the tubing, retaining means (12, 222a) being provided to maintain the tubing in the closed position with a force that is sufficient to resist the pressure exerted by a product contained in a container equipped with the connector, but can be overcome manually to move the tubing into the open position. the base and the membrane being fixed to each other in a liquid-tight manner so that the tubing projects outside the connector, the flexible wall being dimensioned to allow axial displacement of the tubing relative to the bottom wall so that the tubing can be moved between a closed position, in which the sealing means prevent a liquid from leaving the connector through the conduit of the tubing, and an open position, which is located farther axially from the bottom wall than the closed position, and in which the sealing means do not prevent a liquid from leaving the connector through the conduit of the tubing, retaining means (12, 222a) being provided to maintain the tubing in the closed position with a force that is sufficient to resist the pressure exerted by a product contained in a container equipped with the connector, but can be overcome manually to move the tubing into the open position.