Patent ID: 6202683
Filing Date: 2001-03-20
Classification: G05D,Y10T

Abstract:
A fluid flow fuse for automatically shutting off an excessive rate of flow of fluid in a system, comprising:a body having a fluid inlet passage and a fluid outlet passage, connected by a valve seat opening;a first pressure-measuring passageway formed in the body and connected between the fluid inlet passage and a first pressure-sensing chamber;a restrictor held in the first pressure-measuring passageway;a valve member connected to a diaphragm and movable through a guide means between a normally open position and a closed position against the valve seat opening;the diaphragm connected between the body and the valve member, downstream of the valve seat, above the guide means so as to form a lower annular area and a separate upper area forming the first pressure-sensing chamber;the valve member cooperating with the guide means to form a restricted passageway between the fluid inlet passage and the lower annular area;a second, separate pressure-measuring passageway formed in the body and connected between the fluid outlet passage and the lower annular area, between the guide means and the diaphragm;at least one spring cooperating with the valve member, and the valve member and the at least one spring being sized and dimensioned so that when the flow of fluid through the body reaches a predetermined amount, a pressure differential will be created to slowly move the valve member through various positions to the closed position, against the valve seat, without causing water hammer; andthe valve member being held in the valve seat in such a manner to allow fluid to bleed by the valve member to enable the valve member to automatically reset itself to the normally open position, when pressure applied thereto is bled away.