Abstract: A flow control valve of the type in which flow through the valve is controlled by means of a diaphragm which operates by differential pressure on its opposite faces to move between open and closed positions with respect to the flow path through the valve. In this type of valve an aperture is formed through the diaphragm to place its opposite faces in communication with the pressure existing in the flow path through the valve and a metering rod extends through the aperture in the diaphragm to meter flow through the aperture and maintain it free of foreign material. The metering rod in the valve of the present invention is mounted so that it can move about one of its ends to allow it to accommodate non-uniform movement of the diaphragm and prevent binding of the metering rod in the diaphragm aperture.