Patent ID: 6877714
Filing Date: 2005-04-12
Classification: F16K,Y10T

Abstract:
1. A fluid flow control valve, which comprises: (a) a valve housing having an inlet, an outlet, a flow passageway between the inlet and outlet, a valve seat in the flow passageway, and a valve member which closes the valve by moving into engagement with the valve seat for blocking flow between the inlet and the outlet and which opens the valve by moving out of engagement with the valve seat for permitting flow between the inlet and the outlet; (b) a pressure chamber in the valve housing, wherein one side of the valve member is exposed to inlet fluid pressure tending to move the valve member away from the valve seat and the other side of the valve member is exposed to fluid pressure in the pressure chamber tending to move the valve member towards the valve seat; (c) a metering path to meter water into the pressure chamber from upstream of the valve seat to close the valve; and (d) at least two water flow labyrinths with the labyrinths being differently configured relative to one another such that water flows through the labyrinths at different rates, and wherein one or the other of the labyrinths is selectively installed in the metering path to select a desired closing speed for the valve depending upon which labyrinth is in the metering path.