Building a actuated valve.

bal_jop

I was looking at 2 inch actuated valves. In the Indian market they cost around 12,000 rupees(~$220). I have a couple of car window control motors. I was thinking of building a valve with it.

I would appreciate your thoughts on some simple design.

Danger

Valves for what substance? Water... methanol... liquid nitrogen... some type of gas...? The substance will largely determine what sort of seals are required.
If it's just a simple liquid, either a rotary ball or cylinder, or a wedge-type gate, would be fine.

bal_jop

The valve is for agricultural irrigation purpose.

Danger

In that case, you don't need tremendous precision or chemical-resistant material.
I might, however, have misunderstood the question. I took it to mean that you want to build the whole thing from scratch, but is it that you just want to attach a motor to a store-bought manual valve?

bal_jop

yeha, I want to power a PVC plastic gate valve with the 12 v motor, but I need to know when to stop powering the motor, i.e. when the valve is fully open or fully closed.

Danger

Ahh... no problem. Just toss in a couple of limit switches. What kind to use depends upon how the motor is connected to the valve.

bal_jop

I want the valve to be either fully open or fully closed no intermittent states......

Danger

Understood. What I actually meant, though, is how the motor is attached. Are you wanting to use a lead-screw (screwjack), a gear train, chain and sprockets, or etc.? Any kind of switch can be used as a limit switch, but the physical set-up determines which ones are most practical. As a general rule, you can't go wrong with momentary buttons or mini-levers.

bal_jop

hmmm... I am not sure, I am thinking of attaching the turn lever with the shaft of the motor directly. I am a novice when it comes to engineering... but I am gonna give it a try.... What do you suggest would be a good limit switch?

Danger

Your mention of a lever rather than a wheel indicates that there's probably less than a 360° throw between open and closed. If that's the case, you can just mount SPST/NC momentary pushbutton switches on brackets attached to the valve body or support structure in positions which will cause them to be pushed to "off" by the lever itself at the end of its travel in either direction. You'll probably want weatherproof units.

Travis_King

Don't forget to consider limit switches.

Danger

Do you mean the things that we've been discussing since post #6?

Travis_King

heh, specifically post #10. Yea, I didn't read it all...I just saw "building an actuated valve" and read the first few posts. whoops!

Danger

No sweat; I do that all the time.

bal_jop

okay after a long time....
I would like to know what is the best limit switch I could use?

pfeinstein

BalJop:

The limit switches you need for this application are very simple; you might even find them in your local hardware store.