Abstract

A pneumatically servoed gas pressure regulator capable of providing a relatively wide range of gas flow rates with precision outlet pressure control includes a dome loaded gas pressure regulator and a pressure sensor controller integrated in a single unit. The controller senses the regulator outlet gas pressure, compares it to a pressure setting of the controller, and operates a pneumatic servo valve of the controller for generating a control signal dome gas pressure for the dome loaded gas pressure regulator as a function of the deviation between the sensed outlet pressure and the pressure setting of the controller, independently of the gas through flow rate. A relatively large change in the size of the valved passage in the regulator is made with only a relatively small deviation of less than or equal to a few psi between the sensed outlet pressure and the pressure setting of the controller. The relatively large change in the size of the passage in the regulator effectively uses the entire flow capacity Cv of the regulator for precise controlling the outlet gas pressure over a relatively wide range of gas flow rates.