Abstract: A diaphragm valve is provided, and includes a diaphragm moveable over a range from a first position to a second position, to open and close an outlet. A control bleed hole extends from a first side of the diaphragm to a second side, opposite the first side. A closing member is moveable to open and close the control bleed hole, to modify the pressure on either side of the diaphragm, and to cause the movement the diaphragm over at least part of the range. A mechanical means is arranged to move the closing member to open and close the control bleed hole. The mechanical means is configured to engage the diaphragm and cause movement of the diaphragm over at least part of the range.