Proportional water flow control

I've been looking at water flow control with Arduino and I'm finding a huge difficulty in managing to do an 'analog' control on water flow. The mainstream solution seems to be the well known solenoid valve, however those seem to be binary (full flow, no flow), and I'm looking for a more variable answer.

Is it possible to get middlegrounds with solenoids? Maybe actuating them with less voltage or amperage will cause it to partially actuate? If not, does anyone know of embedded solutions using servos or steppers maybe?

If you Google Proportional Water Valve you'll get hits. They are expensive (generally over $100 USD).

I believe I have seen those earlier today when I was searching for a solution, but as you mentioned they are totally out of my budget :frowning:

You could try using a regular ball valve and moving it with a heavy duty servo.

Another option might be to use a DC motor driving a threaded rod with the nut connected to the handle of the ball valve.

...R

Robin2:
You could try using a regular ball valve and moving it with a heavy duty servo.

Another option might be to use a DC motor driving a threaded rod with the nut connected to the handle of the ball valve.

...R

agreed, a "normal" solenoid valve is not going to be "proportional" as you asked

actuating a ball or gate valve will do it. assuming you are dealing with higher pressures

a parastaltic pump can "meter" lower pressure flows

How big is the flow?

if you can split it up in e.g. 8 separate flows that you switch on/off, would that be an option?

Maybe a valve like this
Driven by a stepper like this
Or a motor like this (+ driver board) if the stepper does not have enough torque.
I would also have a solenoid valve inline with this just in case motor jams/dies.

robtillaart:
How big is the flow?

if you can split it up in e.g. 8 separate flows that you switch on/off, would that be an option?

I'm trying to control a shower, so the flow of the showerhead. Splitting flows would take up too much space I believe, I was hoping to integrate it all in or near to the shower head.

Riva:
Maybe a valve like this
Driven by a stepper like this
Or a motor like this (+ driver board) if the stepper does not have enough torque.
I would also have a solenoid valve inline with this just in case motor jams/dies.

I had considered that, I just have no idea how to realiably hook it up. I have access to a 3d printer, maybe print a support?

Showers usually have flow control faucets within easy reach, so why do you want a complicated electromechanical control on the showerhead?

jremington:
Showers usually have flow control faucets within easy reach, so why do you want a complicated electromechanical control on the showerhead?

cause he can i guess, or maybe he wants to play a trick on his sister while she is in the shower

Turn the hot water off when people are too long in the shower?
Now that's mean...