I am dealing with an above ground, non-pressurized, water storage tank (full storage, not a break tank) that has a large visible float gauge on the outside, an electronic low water sensor, and an electronic high water sensor.
The high and low water sensors are placed so near each other on the wall of the tank that the altitude valve cannot reliably stop in between them (they are separated by 12” on a 28’ water column). If the automatic fill valve is set so that it always fills higher than the low water sensor – it frequently over-fills and trips the high water sensor. If the fill valve is calibrated so that it does not trip the high-water sensor, it frequently stops too soon and does not fill enough to turn off the low water sensor. The valve manufacturer has confirmed that this is the design accuracy of the valve – nothing to be ‘fixed’ with it. Also, the tank has an overfill discharge/dump pipe that is much larger than the fill line (2” fill, 4” overflow) so if the refill valve were to jam open, it would dump the water onto a parking lot (not great, but visible, and not damaging to the tank). QUESTION: Is it necessary to have the high-water sensor? My first thought for a solution is to disable the high-water sensor and calibrate the altitude valve so it always fills enough to satisfy the low-water sensor, but not enough to overflow. That is a wide enough spread that it can hit it reliably. I can’t find anything in the code that says the high-water sensor is required at all, but I wanted to run the idea by the forum. What do you think? Thanks!! Matt
_______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
