A pressure reducing regulator's primary function is to match the flow of gas through the regulator to the demand for gas placed upon it, whilst maintaining a sufficiently constant output pressure. If the load flow decreases, then the regulator flow must decrease as well. If the load flow increases, then the regulator flow must increase in order to keep the controlled pressure from decreasing due to a shortage of gas in the pressure system. It is desirable that the controlled pressure does not vary greatly from the set point for a wide range of flow rates, but it also desirable that flow through the regulator is stable and the regulated pressure is not subject to excessive oscillation.