A small device designed to maintain water pressure in a building after a toilet is flushed. This device would consist of an electronic device which monitors water pressure and contains a valve to control flow to the toilet. In addition to the valve, the device would have pressure sensors and a small circuit board to control operation.
The device would function by initially having its valve closed. Once it detects a pressure drop on the toilet, it would check the pressure on the supply side of the valve. If the supply side has adequate pressure, the valve is opened and left open until the pressure on the toilet side spikes (signalling that the fill valve has closed). If the supply side valve does not have adequate pressure when the toilet is flushed, the valve does not open. It will wait until the supply side pressure is sufficiently high (signalling that the water isn't being used for anything else) and then it will open the valve to allow the tank to refill.
The entire device would be battery powered and screw on between the supply line and the filler connection. The device would contain a mechanical override to move the valve to the open position in case of battery failure.
With additional logic, this device could also be prevent some other scenarios such as overflowing toilets or shut off water to flush valves which are stuck open. It could even replace the fill valve entirely if a water level sensor is added.-- ftzdomino, Nov 09 2004 Oh good, another band-aid solution to poorly designed plumbing systems. I'm going to bun this because it's a creative solution. However, while you wait to get past the development stage of this complex battery powered device, try closing the water valve that supplies the toilet down to a trickle. This will make the tank fill up much more slowly and should fix your problem (of course a real fix of upsizing your main or any piping between you and the street is far preferable).-- Worldgineer, Nov 09 2004 Anything that could fix the highly-variable water pressure in my flat would be welcome!
Being a Georgian era listed building, the water supply was retrofitted as an afterthought and then the building was split into flats. Chances of getting all the flat owners (most of whom don't even live here) to agree to pay for changes are virtually nil.-- prufrax, Nov 10 2004 oh no no no no, this idea would only make your toilet gross at a party, where people enter the toilet continously.-- Pericles, Nov 10 2004 Useful idea, but why does everything have to be electronic? Yeah, I'm an electrical engineer, so I shouldn't complain, but it seems like the default solution to every problem now days is to put a microcontroller in it. In this case, all you need is a simple device that reduces the flow when the pressure on the input side is below some threshold.
Actually, I'd be surpirised if this sort of pressure regulator didn't already exist. Unfortunately I didn't find anything online. It would help if I knew what it was called. It looks like a differencial pressure regulator ought to work fairly well for this application, but is more complicated than it needs to be.-- scad mientist, Nov 10 2004 A small orifice in the toilet supply line would limit the pressure drop on the rest of the system, while causing your tank to fill oh-so-slowly. Much more simple than adding electricity to your throne.-- wittyhoosier, May 17 2006 [Worldgineer] had it first go. Just partially close the tap.
Partially closed vs. partially open: you decide.-- Texticle, May 17 2006 I recall a scenario in "SimCity 2000", where all the residents of the metropolis flush their toilets simultaneously, causing the nuclear power plant to meltdown for lack of water.
Could a device like this could prevent nuclear disasters? Pastry.-- ed, May 17 2006 random, halfbakery