How do I drop pressure below 30 PSI?

I know that the solenoids do not operate after 30 PSI but I was wondering if there was a way to get around this.

Would putting a regulator on the output tubes of the solenoid be legal or even work? That being said, that would allow us to drop the PSI lower than 30 and still have everything operate…right?

I’m not sure where you get your information about the solenoid valves not working below 30psi. From my experience, they will still fire fine even with no air in the system. I would recommend trying to just regulate down to 30psi first. That being said, I dont believe that there is anything prohibiting regulating the output of the valve.

Most of the solenoids we use have to have 20 psi or more to function and change state (Festo, SMC).

I don’t know of any rule that prohibits you from placing a regulator after the solenoid to drop the pressure down to what you need.

The SMC solenoids need more than 30 psi to operate. I think the Festo ones are a little better, but I’m not sure.

The type of valves that are common in FIRST require air to move the shuttle from one side to the other. Without enough air they can become unreliable or even inoperative.

You can test and see how low you can go and still get reliable operation but Murphy has a tendency to rear his ugly head on the competition field and not in practice.

Perhaps you can tell us why you need such low pressure and maybe the smart people on CD can offer a better solution.

I thought I remembered reading somewhere that the solenoids won’t operate below 30 PSI.

We are using Pneumatics to pick up our ball and load it onto our shooter. As of right now, 60 PSI is way too much for this. We have a two different pistons controlling X and Y axises. The X squeezes the ball and the Y loads it onto the shooter.

Y piston comes back to hard and hits our mechanism hard. (We don’t mind it hitting the mechanism, just not so hard)
We haven’t tested X yet but i’m hoping it doesn’t squeeze the ball too hard at that pressure.

We have another piston but that one is doing good at 60 PSI.

An alternative you may want to consider is the on cylinder flow control push connect fittings, with this you can dial in how fast the cylinder moves and still maintain the same overall force.

Thanks! I will definitely be purchasing those. That will be so helpful. I have to check and see if we have some already though.

So that will slow it down, but it will still be at the same force. We still need the X-Axis piston to be a lot less powerful.

What size is your X-axis cylinder (it is not a piston) perhaps you use a smaller diameter cylinder?

I believe it is 11 inches while intruded. But it stretches the length of the mechanism so changing the size of it will change other factors and we will need to add other things to get the size right. I would prefer this solution as my last resort.

I believe Sam was asking for the diameter. Smaller diameter means less force…

Oh, sorry about that. I believe the diameter is .75-1 inch. I don’t see how you can go any skinnier than that.

Big difference of force between 1" & 3/4 bore. Remember the force is proportional to the square of the diameter (or radius)

I really can’t imagine a 3/4 cylinder having enough force to squeeze a ball to much even at 60psi. Unless you are using massive leverage.

It might be a bit late, but there are cylinders down to 7/16 bore.

Air piloted solenoid valves from different manufacturers will specify the minimum pilot pressure each requires.
Usually it’s between 20 and 30 psi. Just check the spec sheet.

Changing cylinder bore will also change the lengths and may impact the overall design.

Adding a regulator to the system between the solenoid and the cylinder you have will reduce the force you are applying.

You can check the rules, and also maybe submit a question to the GDC to confirm.

We have been firing our SMC 24v solenoids at ~20 and ~30 PSI with no problems. Perhaps it’s just the model of solenoid you’re using.

Regulators after valves are legal

Okay, Thank you everyone.

We are using festo solenoids, ours say, 12/24 volts on them so I guess we can use whatever voltage we want. I can hear mine fire even without pressure. Perhaps they work under 20 PSI like someone said.

We decided to just place a regulator after one the of the values. We lowered the PSI to 45 PSI.

The change in 15 PSI really helped.

Thank you everyone. Now theres just one more problem, but I will start new thread for that one.

Older-style Festo solenoids only require about 17 PSI to fire. If you can deal with a lower co-efficient of flow, I’d recommend Humphrey 310 or 410 series solenoids. They can run on anything above 14 PSI. Getting a narrower cylinder is a good idea as well, we have a few Clippard cylinders with a 3/8ths inch bore. This will give you about 6 lb of force on the output