Programmable 3 or 4 Way Valve Actuator

The terms 2-way, 3-way, and 4-way refer to the number of connections on a valve (at least that's one of the things they mean). In this respect, a 2-way valve is open or closed or modulating between. A 3-way valve can either divert a common port to either or both of two outlets, or accept input from either or both of two ports and discharge to a common outlet port. A 4-way valve with ports A, B, C, and D (arranged CW or CCW) connects A to B and C to D, or A to D and B to C. In many cases, these are all done with a 90° movement; thus the actuators can be the same for all three types.

I'll try to post more later on controller types. One of the key differences is whether the controller drives the valve only full open or closed, versus modulating it to positions in between. The modulating type would be more versatile.

Get a simple PLC with relay outputs that can handle the current drawn by the actuators. From the scanty information you've given, (What is the voltage to operate actuator?, How many actuators are there?, What are you trying to do with these?, How critical is this process?, etc.) it looks like you won't even need analog I/O, thereby dropping the cost further.

"don't know if there is a difference"

3 way - 2 port valve could do the job for you.

Center being the inlet and left or right could be the outlets. A 90 degree rotary actuator with timer to keep in two positions at required timings.

Thanks to all for the answer so far. By the way what I didn't know was the difference between a controller and an actuator. I made some search on internet and it seem to be different. I was looking for a valve with the actuator and controller already integrated. Would have been easier for me. I know for the PLC. What about an arduino control? What do you think if I use a simple electronic timer and a solid state relay in order to get the good voltage? I think I'll choose this option. (cheaper, robust and more simple) I guess this is what Mikerho had in mind when he state «won't even need analog I/O». By the way there will be two of these valve but they have to switch at the same time so only 1 timer will be need. To answer for the critical question about the process, the precision should be in second. These will be use to automate a chemical process. Thanks again, and sorry for my english, I'm a french speaking chemist coming from Québec.

"there will be two of these valve but they have to switch at the same time so only 1 timer will be need."

Why two valves? Look at the picture in my reply-3 and read the content. One valve with 3 ports - two position should do. This achieves switching off one and switching on the other simultaneously by single stroke of one quoter of a rotation.

"there will be two of these valve but they have to switch at the same time so only 1 timer will be need."

Why two valves? Look at the picture in my reply-3 and read the content. One valve with 3 ports - two position should do. This achieves switching off one and switching on the other simultaneously by single stroke of one quoter of a rotation.

They will be in series not in parallel.

And between them it will have the core of the process. Cannot tell more about it, only one valve is not possible. Thanks anyways.

Maybe you've already thought of this, but what about residential irrigation systems like the systems made by Rain Bird:

http://store.rainbird.com/

Or perhaps something like the 'dancing fountains' that you see in parks and municipal squares.

Yes I've thought of it. The problem is that the wet part of all my system should be in stainless steel in my process, no plastic. The timer may be useful, but it's more expensive than simple indoor programmable timer. Although it might have the correct electrical output to control my valve. I'll have a look.

The actuator, which may may a motor or hydraulic/pneumatic cylinder, mounts to the valve and moves it mechanically. The controller--which may be one or more switches or relays, PLC output(s), or a stand-alone process controller--receives input from pressure or temperature sensors and sends an electrical signal to the actuator. There are many possible variations.