Need a water valve connected to a water sensor

[sparr]

I need to turn off the flow of water through a hose when another adjacent hose/valve/whatever runs out of water. Does a device for this exist? I can roll my own with a water sensor and a solenoid valve and a 12V battery, but would prefer something more robust if there is a commercial option (which I predict would be tiny and run on a 9V battery). This is for part of my shower plans for my camp this year.

[Token]

Ambiguous question.

Is the hose that will “run out of water” - the trigger, pressurized or just flow with minimal pressure?

Is this all gravity fed or is there a pump?

My guess is that you will need to fabricate something custom for your rig.

If you can use water level, as in a float, the solution is easy - a valve from toilet tank installed upside-down will do just that.

[sparr]

Simple plan is gravity fed. I can add a small pump somewhere along the flow if that would help make some other component work, and it wouldn't be terrible to have a bit more pressure at the shower as well.

A float would work fine as the standalone water sensor; I don't mind if it shuts off with an inch or two of water left in the bucket. But I don't think the toilet valve will help; I need to stop the flow of a different part of the hose when the water level drops, not the part right where the level is measured.

[Traveller in Time]

Garden watering automation parts . .
Dish/cloth washers parts . .

[Token]

But I don't think the toilet valve will help; I need to stop the flow of a different part of the hose when the water level drops, not the part right where the level is measured.

Think about this a bit more. It will do exactly what you want. An upside-down float valve will be always-open until the bucket drains, then it will close. The float in the trigger bucket is the measurement device, but the actual valve feeds your other path, not the bucket where you measure.

It would be a reliable low-tech way to solve your problem. Cheap too.

Keep in mind that toilet valves have the main filler line and the small trickle line for topping off the bowl level, so you would need to redirect both into your second circuit.

[BBadger]

Yeah, they don't even need to be toilet float valves. Those hydroponic float valves would work great, controlling a different hose.

[Canoe]

Watch out for the ready made solenoid valves, popular in Arduino and Pi projects. They only work with a pressurized line; gravity feed has insufficient pressure.