Variable 3 Way Valve


Thread Starter

Graham Best

This is a great site!

I am looking for a way to divide the flow of liquid (water) with a PC. The requirement is for a type of valve that will accept a 1/2" or 3/8" port from a water pump that is rated up to 1100 GPH. The valve will divide the flow of water between two output ports. The flow out of one of the ports will be much greater than the other, but not off completely.

I'm hoping to find a valve that can be controlled with +12V pulse width mode or analog DC. Is there anything such as a variable 3 way valve? Or is there another device that I should use? I considered using a regular 3 way value with a solenoid and controlling it with PWM, but I don't think the valves I've found can be switched so quickly.

Anyone have any ideas?

Graham Best
The only one I've run into (but I haven't used it myself) is from Staefa (

They have adapters allowing 0-10V or 4-20mA control, but I don't know if they have the capacity you're looking for.

Don Zunti, P. Eng.
Delco Automation Canada
I can't understand what you mean by this sentence (see below).

If the necessary flow rates are fixed, I'd use two 2-way valves.

Willy Smith
Numatics, Inc.
Costa Rica

Sean Croxford


Many different options on the market.

What is the outlet pressure from the pump? What is the lowest amount of flow the pump can see before it is dead headed? What is your actual

Do you want to be able to diagnose Torque values / over rotation of the ball within the valve to determine when the valve needs to be
serviced. How often will the valve be used? (24-7)?

North America is almost standardized on HART protocol as a digital communication for process devices. Europe has several. This is where the PC comes into place.

What do you think it will cost to purchase the valve and Automation package?

Digital solenoids are around $900 Canadian depending on air supply and voltage required.

My employer, Process and Steam Specialties ( "": ) provides engineering regarding proper selection of control / automated / manual
valves. If you want more information, give me a call.

Sean ph: (519) 384-1990