Flow sensitive fluid shutoff safety device

Abstract

A fluid shutoff device for use as a safety device to cut off the water supply to a building in the event of overly high water consumption due to a leak or break in the plumbing in the building is provided with a motor that is responsive to remote actuation to rotate a three position selector valve to a desired flow setting. The selector valve is settable in a position which allows water to flow freely through the safety flow control device as if it were not there, a position which diverts water through a safety flow pathway, or a position that prevents water flow into the main water line entrance of the building, thereby allowing the invention to act as a shutoff valve. At least one optoelectronic device is included in the safety device to monitor the flow position of the selector valve by detecting the absence or presence of light reflected off a sensor drum that rotates in synchronism with the selector valve. When the device is operating as a safety flow control device, a piston having apertures therethrough is spring biased away from a shoulder to allow water to pass through the device; when the water pressure is large, indicating a downstream plumbing break or leak, the water pressure will overcome the force exerted by the spring and force the piston against the shoulder, blocking the safety flow pathway and stopping flow through the device.