Abstract: The anti-siphoning device includes a T-shaped valve body having a downwardly facing opening, an upwardly facing opening and a laterally facing opening. Constrained for vertical movement within the valve body is a hollow cylindrical float valve having a closed lower end for normally closing the lower opening of the valve body, an open upper end so that air can pass downwardly through the upwardly facing opening of the valve body into the interior of the cylindrical float valve, out through the circumferentially spaced holes and then through the laterally facing opening of the valve body. The downwardly facing opening of the valve body is connected to the outlet of the sink or basin to be drained. Waste water entering the valve body via the downwardly facing opening buoys the float valve upwardly, the water passing outwardly through the laterally facing opening along with the air entering the upwardly facing opening of the valve body.

Abstract: A deenergized solenoid operated valve normally closes the drain line of a sink, basin, tub or toilet bowl, the valve thus serving as a stopper. When a pushbutton switch is closed, the solenoid is energized to retract the valve and open the drain, a flow responsive switch maintaining the solenoid energized until all of the water has drained from the sink or bowl. A float responsive switch will also energize the solenoid to retract the valve and open the drain if water accumulates from a leaky faucet. Whenever water is drained, the low pressure or vacuum that results produces an accompanying venting action. The invention may be used with a P or S-type drain connection and/or with a conventional stack vent, but does not require that any of these be employed.