Flow regulator adaptable for use with exhaust from a process chamber

Abstract

A regulator including a movably, preferably hingedly, mounted member having a distal face, exposed to a reference pressure, and a frontal face, exposed to fluid passing through the regulator. Attached to the member is a structure that variably impedes fluid flowing through the regulator. The amount that this structure impedes the fluid flow varies as a function of the difference between the pressure of fluid on the frontal face of the member and the reference pressure. The impeder may be an integral part of the piston extending into the path of the fluid flowing through the regulator, or it may be a separate structure attached to the piston. In one embodiment, this impeder includes segmented airfoils segment. Some airfoil segments are movable and attached to the piston, others are fixed. As the piston moves in response to changes in pressure differential across the piston, each movable segment is displaced with respect to its corresponding fixed segment. As the corresponding segments are further displaced with respect to each other, the impedance to flow increases. The movable airfoil segments may also be hingedly attached to the hingedly mounted piston. A restoring force exerts a force on the piston so as to tend to lessen the resistance on the fluid flow, and so that when there is no flow through the passageway the resistance is relatively low.