Abstract: There is disclosed a non-electric fluid actuated gate valve assembly of the type intended for interposition between a static structure and a municipal sewer line to prevent sewer back-up in flood conditions formed by an enclosed chamber having a water inlet and a water outlet spaced therefrom and adapted for placement in the static structure and interposed in the main sewer line thereof, the water inlet having a fluid actuated gate valve assembly associated therewith, the gate valve assembly formed by gate means for alternately opening and closing the water inlet, and fluid actuated control means in operative relation with the gate means and being in fluid communication with the source of fluid under pressure such that the gate means is operated by a fluid under pressure in response to the sewer water level within the enclosed chamber thereby to open and close the gate means alternatively, and in response to the water level within the enclosed chamber.

Abstract: There is disclosed a system for automatically closing a gate valve of the type customarily installed in a sewer pipe system, the gate valve being positioned such as to divide the pipe into a forward exit section and a rear exit section, the system including fluid sensing means positioned in the forward exit section of the pipe adapted to sense the fluid level, a two phase motor having a forward phase and a reverse phase operationally associated with the gate valve for alternately opening and closing the gate valve, electrical means interconnecting the fluid sensing means and the motor to activate the motor in response to the fluid level sensed by the fluid sensing means, the motor including switch activation means associated therewith and mounted for arcuate movement about a pivot point, and switch means for alternately controlling the forward and reverse phases of the motor, the switch means being mounted in position within the arcuate path of travel of the switch activation means.

Abstract: A pneumatic valve system for sealing off the flow of a liquid at the intersection of two pipes, one of the pipes being vertically disposed with respect to the other pipe. A sensing probe senses liquid at a pre-established height in the vertically disposed height which signals a control system to activate the pneumatic valve system. An expandable, inflatable bladder is positioned from the vertically disposed pipe into the second pipe and is inflated, thereby sealing off the flow of liquid past the bladder. When normal fluid flow is to return, the bladder is deflated and positioned back into its original position within the vertically disposed pipe.