The Willoughby T4A Toilet Overflow Preventer, w/ Auto-Reset, is a self-contained water sensor for use with specially modified Willoughby toilet fixtures installed in high vandalism environments.
The T4A auto-reset overflow preventer system consists of a vacuum operated disabler (TOP-4 valve), a vacuum generator (welded to the modified toilet fixture), overflow sensor (also welded), float sensor canister, and connecting tubing. The system operates on vacuum produced by water flowing through the fixture. When the vacuum can move unrestricted through the overflow sensor, the disabler valve remains open; but when water is drawn into the sensor as a result of a clog or blockage in the fixture, the water will be drawn into the float canister. As the float canister fills, the float inside the canister rises and redirects the vacuum, closing the disabler valve and preventing any additional flushing.
Once the disabler valve has closed, the toilet will not flush until the water level in the toilet bowl falls below the overflow sensor, allowing the water in the float canister to drain, redirecting the vacuum to reopen the disabler valve. The T4A auto-reset overflow preventer system is recommended for facilities with high risk for vandalism, such as prisons, schools, parks, etc., and can be used with most models of Willoughby back-supply toilets and combination units provided with a (preferably accessible) mechanical chase.