To prevent such catastrophes, FloLogic Inc., Raleigh, N.C., developed a programmable shut-off valve that turns off a building's water main after a user-specified interval. It has two modes, "Home" and "Away." The FloLogic System comes preprogrammed to allow water to flow for 30 min in the Home mode, 30 sec in Away, but these can be changed. When water flow exceeds the programmed limit, the system shuts off flow and sounds a low-decibel alarm. It also has manual override and a battery back-up that powers the unit for up to six days.

The unit consists of a flow sensor with a ferrite core, a motor-driven ball valve, and a wall-mounted control panel and LCD. The ball valve and sensor components are molded out of Ultraform, an acetal copolymer from BASF, Mount Olive, N.J. Ultraform is extremely rigid and absorbs little water, so the flow sensor is accurate and consistent. The compact system (9 3 5.4 3 3.5 in) comes in standard 3Z4 and 1-in. sizes. It is compatible with copper, CPVC, crosslinked polyethylene and other domestic potable water piping.