The invention relates to an escape valve for a timepiece including an outlet channel arranged to be capable of being in fluid communication with the interior of a case of the timepiece when the valve is in an open configuration to evacuate an excess of fluid. The valve includes a tube to be fixed in the case of the timepiece and a valve head provided with a cover and an axial skirt adapted to be placed in different axial positions, a pressure control module separate from the valve head arranged in the interior of a fluid conduit provided in the tube and axial guide elements by screwing defined in the valve head and the tube playing a part in the control of the displacement of the valve head relative to tube in the different axial positions, blocking elements preventing a disassociation between the valve head and the tube.