Patent ID: 7424896

Claim:
An automatic flow shut-off system for closing a valve in a water supply line to shut off the flow of water to an appliance when a leak develops at said appliance; said system comprising: a valve actuator adapted to be connected to said valve to close said valve when said valve actuator is actuated; and a tripper unit responsive to said leak for actuating said valve actuator; said tripper unit comprising: a cylindrical housing adapted to be positioned substantially vertically on a substantially horizontal surface adjacent said appliance when in an operable position, said housing having openings therein to allow the flow of water from said surface into said housing; a hollow, cartridge mounted in said housing; a water reactive material across at least one end of said hollow cartridge, the integrity and strength of said material weakening when contacted by water; a plunger positioned so that the lower end of said plunger rests on and is supported by said water reactive material across said at least one end of said cartridge when said material is dry, said plunger being free to move into said cartridge when said water reactive material comes into contact with water; and means adapted for connecting said plunger to said valve actuator whereby said valve actuator is actuated upon downward movement of said plunger in said housing of said tripper unit.