Reverse flow direction on SMC valves

I searched for an answer to this but could find no mention of it.

Is it possible to reverse the air flow direction of the SMC valves?

Currently port “P” is the pressure source, ports “A” and “B” go to the piston and ports “EA” and “EB” are the exhausts.

Is it possible to have the air pressure supplied on ports “A” and “B” and have the supply out to the piston leaving on port “P”?

I have read the rules and see no reason it would be prohibited.

I don’t believe there to be any rule violation here, however, I don’t know that the valve would operate as intended. If you could describe your goal to us, we might be able to better help you.

If you simply want to switch pressure on and off to something they make valves with 1 input and 1 output.

I agree, there really “shouldn’t” be a rule violation. I read carefully through the rules and found nothing prohibiting it.

Now the answer to why I would want to do this might take away a strategic advantage :yikes:

OK, I’ll let the cat out of the bag. See the picture below for more info.





I’m assuming the EA/EB ports on the two ‘backwards’ valves are plugged?

If so, seems like it would work, so long as the valves will work that way. I know the valves are piloted, and only work when supplied with a 20psi minimum… I just dont know if it cares what port that 20psi is coming from.

Also, congrats on the creative pneumatic circuit. We’ve created ones before to stop cylinders in mid-travel.

Yes, plugging EA and EB will stop the bleed off of the unused lines.

Tell you what, I will do some testing this evening and provide feedback. I was hoping someone had tried this before and either had success, or not.

I won’t swear to this, but here is what I believe:

The valve is a pilot operated valve, with a small pilot solenoid mounted on the end. This pilot solenoid must have access to pressure at all times for the valve to function. It receives this pressure from a small port within the P port. If at any time, there is no pressure on the P port, the valve will cease to function. So, your proposal might work since it looks like you will always have pressure on the P port, but I don’t know what will happen as the valve shifts and the pressure drops between positions.

This was my concern as well. Actual testing will will determine if this will work or not.

OK, tonights testing was quite promising. Using the valves in reverse did work fairly reliably. There is one caveat: You must have the pressure of the lowest feed above the minimum pressure for the valve. This would be the case as well with the valve in the normal configuration. Also, don’t forget to plug “EA” and “EB”.