For water tanks serving apartments there is a risk of overflow, this could occur if the ballcock/stop valve has failed and does not trigger the water shut off. If the tank is at the top of the building or there are individual tanks in the apartments, this could cause significant damage and disruption to the apartments and the tenants belongings.
If the tank is in a basement plant room, the water could also cause damage to other important plant equipment.
Installing an overflow sensor (AT-350A / AT-600A) into the tank or into the relief drain of a water heater. These can be linked to any of the alarm panels.
For water tanks, the sensor is installed over the top of the tank and securing at the point of detection or by screwing a threaded probe into the side of the tank at the level required. This way if the water rises above the probe then an alarm will be triggered and personnel alerted before potential damage can be done.