Abstract: A flush tank having a downwardly open outlet and a valve for filling the tank with a liquid has a flush valve having a tube fitted to the outlet and having an upper end vertically displaceable in the tank. A float fixed to the tube upper tube end has a buoyancy changeable between a high buoyancy capable of holding the tube upper end above a liquid level in the tank and a low buoyancy insufficient to hold the tube upper end above the liquid level. An actuator connected to the float can temporarily change the float from high buoyancy to low buoyancy and thereby sink the tube upper end below the liquid level and cause the is liquid in the tank to flow through the tube out of the outlet. The float has a lower part annularly surrounding the tube and an upper part formed as an upper space having a large upwardly open mouth level with the upper end of the tube and a small opening below its mouth opening into the tube.

Abstract: A flush valve has a valve ring defining a downwardly open valve port and an overflow tube centered on an upright axis and having a lower end seatable on the port. The tube is displaceable relative to the port between a lower closed position and an upper open position. Mechanism inside the tube can lift the tube into the open position and thereby allow water in the tank to move down and out through the port. A lower float vertically fixed in the tank is displaceable between a latching position and a releasing position and is constructed such that when submerged it normally assumes the latching position. A latch on the lower float engageable with the tube can hold the tube in the open position and can release the tube for movement into the closed position and ending of a flushing cycle. An upper float in the tank above the lower float has a part engageable with the lower float for displacing same into the releasing position on downward displacement of the upper float toward the lower float.

Abstract: A self-closing valve assembly has a main valve having a seat between a high-pressure input conduit and a low-pressure output conduit, a main valve element movable into and out of engagement with the seat to block and permit flow from the input conduit to the output conduit, and a chamber behind the main valve element pressurizable to press the main valve element against the seat. A small-diameter passage extends from the input conduit to the chamber so that the chamber can be pressurized via the passage from the input conduit to hold the valve element against the seat. A pilot or control valve connected between the chamber and the output conduit can be opened to depressurize the chamber and thereby lift the valve element off the seat.

Abstract: A flush valve has a valve ring defining a downwardly open valve port, an overflow tube centered on an upright axis and having a lower end opening into the valve port, and a valve body at the tube lower end displaceable relative to the port between a closed blocking position and an open position. Mechanism inside the tube lifts the valve body into the open position. A float in the tank adjacent the port cooperates with a latch system connected to the valve body for holding the body in the open position while the float is generally submerged. The tube is internally formed with an inwardly projecting ridge.