Controlling Water Flow

Hey there. Jay here.

I'm in a bit of a pickle here. I'm trying to fill a water tank at work that has a sprinkler system setup to control the water flow rate through the filters. The sprinkler system has a timer but there is no certain time that this tank can fill. I have several different Arduinos at my disposal and a couple of water float sensors in the mail. Idea being; I would like to mount a sensor at the bottom to signal Low Water Level, and mount a sensor at the top to signal High Water Level. The flow rate of the water pump is not much, it has a simple plastic swivel cutoff valve built inline with push-fit pneumatic hose. I'm having trouble determining the best way to attack this beast. I can try to get into the solenoid that is built inline before the plastic swivel cutoff. Not really sure what the specs are on it. I could do a servo motor to activate the swivel cutoff, but its rather hard to turn. If I got a different solenoid that I knew would function correctly, what are the best specs to run from Arduino? I don't have pictures of the setup. I meant to take them but unfortunately forgot.

Why use an Arduino at all, or in fact anything electronic? Just use a ball cock valve like they do in cisterns.

Thanks for your advice. Call it my need to over complicate things and the fact that the boss likes the idea and wants to see it happen.

Anything you cobble together is likely to be far less reliable than the ball cock valve, especially if electronics are in a damp environment.

Consider the consequences of a flood!

and the fact that the boss likes the idea and wants to see it happen.

A float valve for a cistern or toilet, and you'll be done in a half a day and $10 or $20 in parts. An electro-mechanical solution will probably take you a few weeks and may cost 10 times as much in parts.

Even if you want to do something fun and "high tech", I'd recommend installing a toilet valve as a quick-fix.

I can try to get into the solenoid that is built inline before the plastic swivel cutoff. Not really sure what the specs are on it.

If it's not marked, get a multimeter to measure the voltage and check if it's running from AC or DC. Then disconnect it from the circuit to measure it's resistance and use Ohm's Law to calculate the required current (Current = Voltage / Resistance).

Note that it will take some additional electronics (or maybe just a mechanical switch) if you want to use your control circuit and the existing timer.

I could do a servo motor to activate the swivel cutoff, but its rather hard to turn. If I got a different solenoid that I knew would function correctly, what are the best specs to run from Arduino?

A proper solenoid valve is the way to go. Turning a regular valve with a servo is difficult and unreliable, and it's a "Mickey Mouse" solution. (You can buy servo valves but they cost a few hundred dollars or more.)

The Arduino cannot drive a solenoid directly... The Arduino puts-out 5V at 40mA or less. [u]Here[/u] is an example of a solenoid driver circuit.

If you buy an 'industrial" solenoid valve from an industrial supplier you'll get all of the specs, but it will be expensive (maybe $100 or more). If you buy one from a home improvement store that's made for sprinkler/irrigation systems, you might have to measure the resistance and calculate the current. Hopefully, they will give you the voltage rating (probably 24V).