Patent ID: 6901951
Filing Date: 2005-06-07
Classification: F16K,Y10T

Abstract:
1. A float valve for controlling flow of a pressurized fluid, the valve comprising: an upstream chamber having an inlet and an outlet, the inlet being communicable with a source of fluid under pressure; a downstream chamber in communication with the upstream chamber and having an outlet; a primary valve member which is movable between positions closing and opening communication between the inlet and outlet of the upstream chamber; and a secondary valve member which is movable between positions closing and opening the upstream chamber; wherein the primary valve member has associated therewith upstream and downstream control surfaces of unequal cross sectional area of which the control surface of greater cross sectional area is exposed to the downstream chamber such that when the secondary valve member opens the outlet of the downstream chamber the primary valve member is urged to its open position by fluid pressure on the control surface of lesser cross sectional area thereby communicating the inlet of the upstream chamber with the outlet thereof, the secondary valve member being a non-return valve biased towards the closed position by the pressure of the pressurized fluid; wherein the primary valve member is a piston reciprocal in a bore which connects the upstream and downstream chambers and is attached to a diaphragm, spanning the upstream side of the downstream chamber, with a screw formed with a coaxial bore, the screw engaging in the coaxial bore of the piston thereby communicating the upstream and downstream chambers of the valve.