Patent ID: 6026849
Filing Date: 2000-02-22
Classification: G05D,Y10T

Abstract:
A flow controller having an inlet port and an outlet port, where the flow controller supplies a substantially constant, predetermined flow of fluid out of the outlet port, the flow controller comprising:housing means defining the inlet port, the outlet port, and an intermediate chamber;first stage means for allowing fluid to flow from the inlet port to the intermediate chamber, where the first stage means maintains a predetermined pressure differential between the inlet port and the outlet port based on an outlet pressure of the fluid at the outlet port;second stage means for allowing fluid to flow from the intermediate port to the outlet port, the second stage means comprisinga flow valve assembly comprising a flow valve stem, wherethe flow valve assembly is arranged to allow fluid to flow from the intermediate chamber to the outlet port,the flow valve assembly is operable between a closed configuration and a fully open configuration by applying a flow control force to the flow valve stem, andbetween the closed configuration and the fully open configuration, the total flow of fluid through the flow valve assembly varies with the magnitude of the flow control force applied to the flow valve stem, andflow feedback means for applying the flow control force to the flow valve stem based on an output pressure of the fluid at the outlet port; andat least one flow restriction element arranged between the intermediate chamber and the outlet port downstream of the flow valve assembly, where the at least one flow restriction element comprises a porous body that creates a predetermined pressure differential between the intermediate chamber and the outlet port.