Pressure control system for low pressure operation

Abstract

A pressure control system for controlling the pressure of a process fluid stream at a certain location having a pressure regulator disposed in the process fluid stream, through which the process fluid stream flows. A first pilot controller senses the pressure of the process fluid at the location and receives a control pressure from a control source. A second pilot controller receives the control pressure from the control source and provides added pressure. An inspirator receives the added pressure from the second pilot controller and generates a differential pressure. The differential pressure is used to control the pressure of the process fluid stream within the pressure regulator. The pressure regulator comprises a first chamber and a second chamber therein separated by a flexible element and a divider is disposed in the first chamber and operative to abut against the flexible element to divide the first chamber into separate spaces. Preferably, the pressure regulator is disposed such that the flexible element extends substantially in vertical direction and the divider extends substantially in horizontal direction.