Patent ID: 6827100
Filing Date: 2004-12-07
Classification: G05D,Y10T

Abstract:
A pressure independent fluid flow regulating valve providing a substantially constant flow rate for each position of an adjustable throttle means regardless of changes in line fluid pressure, comprising:a valve body having an inlet and an outlet, forming a flow passage through said valve body; an adjustable throttle means disposed in said fluid passage to vary the open area of said fluid passage; downstream of said throttling device a seat orifice intersecting said flow passage; a moveable assembly, comprising a disk or cup connected to, and operated by a pressure sensing means member comprising a diaphragm; the disk or cup is located downstream of the seat with which it interacts to vary the flow resistance; said disk or cup has a slightly larger diameter than the opening in the seat; the effective surface area of the disk or cup, is essentially the same as the effective surface area of said pressure sensing means; the pressure sensing means operates inside a cylinder or chamber which it divides in two portions, one portion is connected to the outlet, the other portion via a reference pressure passage connected to a point upstream of the throttle means; spring means biases said moveable assembly.