Self-regulating fluid control valves

Abstract

A self-regulating tide gate is installed on a conduit connecting an open body of water with a protected body of water. The tide gate comprises a mounting plate secured to the conduit at its end in the open body of water, the mounting plate defining an opening into the conduit. A door has its upper edge pivotally mounted at the top of the conduit, a door float is mounted to the door on its edge opposite the hinged edge and counterfloats are mounted to counterfloat arms extending from the door across the pivot axis thereof. When the water is below a critical level at which it is desired that the door close, the door float maintains the lower edge of the door on the surface of the water, thereby maintaining the door open and blocking debris from jamming the mouth of the conduit. As the water level rises, it acts on the counterfloat to pivot the door towards its closed position, whereafter the door is caught in the flow of water entering the conduit and rapidly pivoted to its closed position. The counterfloats are attached to the counterfloat arms by links, the length of which is selected to achieve closure of the door at the desired critical level. A vacuum break conduit comprises an air pipe intersecting the conduit adjacent the mounting plate for the door, the air pipe extending above the critical water level. A lid is provided on the open end of the air pipe and a counterweighted float maintains the lid open until water rises to near the open end of the conduit whereafter the counterweighted float closes the lid to block the air pipe. The air pipe is open when the door closes, and permits air to enter the conduit immediately behind the door to reduce the pressure differential across the door immediately after it closes.