Patent ID: 8469053
Filing Date: 2013-06-25
Classification: F16K,G05D,Y10T

Abstract:
1. A constant-flow valve assembly, comprising: a body with a fluid inlet, a fluid outlet, a fluid passageway therebetween, and a piston chamber in fluid communication with the fluid passageway the fluid passageway containing fluid at first, second and third fluid pressures, wherein the third fluid pressure is less than the second fluid pressure, and the second fluid pressure is less than the first fluid pressure; a piston slidably disposed in the piston chamber and a valve assembly coupled to the fluid passageway and being configured to automatically adjust valve position in response to the first, second or third fluid pressures to provide a substantially constant fluid flow from the fluid outlet substantially independent of the pressure differentials between the second and third fluid pressures; and a restrictor assembly with the fluid passageway extending therethrough, the restrictor assembly having a first sealing pad, a second sealing pad, and a restrictor with a fluid pathway extending therebetween, the first sealing pad being positioned to receive fluid at the first fluid pressure from a first portion of the fluid passageway and to direct the fluid to the restrictor, and the second sealing pad being positioned to receive fluid from the restrictor and direct fluid to a second portion of the fluid passageway at the second fluid pressure, the restrictor being axially movable to adjust the position of the fluid pathway to adjust a fluid flow rate of fluid through the fluid pathway to the second portion of the fluid passageway, wherein the restrictor has an outer surface, the fluid pathway includes a restrictor entry portion defined by a plurality of blind notches interconnected by at least one blind channel and in fluid communication with a through hole, the restrictor being movable to allow the first sealing pad to interfere with at least a portion of the restrictor entry portion to adjustably restrict the fluid flow into the blind notches, blind channel, or through hole and to control the fluid flow rate through the adjustable restrictor assembly.