How do you tube up your pneumatics?

I know that there are a couple of different ways to legally tube up your pneumatics system but I want to know what you and/or your team tubes up your pneumatics system. This could help teams that do not know much about pneumatics learn how to make a functioning pneumatics system.
Here is a janky diagram of how I would tube up a pneumatics system

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That is basically right. But the details are important.

Here are a few suggestions:

  1. Use the AM cross fitting to connect the pressure switch and the pressure relief valve to the compressor. While you can use a series of brass fittings, you want to keep the overhung mass that is supported by the compressor output fitting to a minimum. The output fitting on the compressor can fatigue over time and fail if there is too much weight hung on a long arm off of that fitting.

  2. Conversely, do not hook up a press-in fitting and transition to the plastic tubing immediately. The air and the head of the compressor get quite hot and the plastic tubing does not deal well with this high temperature. The cross fitting and those two components seem to have just enough thermal mass to prevent things from getting too hot.

  3. Definitely attach the high pressure gauge downstream of the tank. Upstream of the tank, the air “pulses” coming out of the compressor will cause the needle to jump around a lot. downstream of the tank, those pulses are gone.

  4. You can T the storage tank off the line rather than having the input on one side and the output on the other.

  5. If you have unused channels on your manifold, make sure you install a blanking cap over the top (where the solenoid would go) as well as plugs in the two ports.

  6. Make sure you use a proper tube cutter to cut the plastic tubing. Uneven cuts is probably the biggest cause of leaks that I have seen.

  7. Keep your system as clean as possible when building it. Avoid errant bits of teflon tape or other debris getting into the components. That debris will eventually find its way to your valves or other critical components and cause them to leak during the critical finals match.

There are a lot of other details and tricks that can be used in Pneumatics which are not shown on this diagram. Sizing your cylinders, calculating the storage capacity that you need, ganging multiple cylinders on the same solenoid, etc.


I disagree, that looks like a Nitra PRU14 miniature pressure regulator to me.

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yes, it is the PRU pressure regulator

We usually have a T and the safety relief valve on the compressor, then plastic tube to the brass tees to the high press gauge, storage tank, manual pressure relief valve, and regulator, and then another brass tee to the low press gauge, and off to the solenoid valve inline plastic tees.

Very 2007.

If the robot uses lots of air, we put a little cpu fan next to it, which keeps the hose from melting.

You can also have a low pressure tank (after the regulator) for any air-intensive mechanisms, like a pneumatic catapult. Be sure to pair with a higher flow solenoid as well.

If you are able to, use different tube colors based on the pressure. I think we used black for high pressure (120 psi), red for low pressure (60 psi) , and white for vent last year. Use whatever colors match your teams color scheme as long as you know what they are. I’ve found it helps when troubleshooting problems with tubing and getting through inspection easier. It helps a lot to see the different color of tubing if you have to jam a bunch of air tanks in different places throughout the robot.


On that note as well, translucent tubing can be nice in some places. We’ve had weeeeird issues on some practice robots from water accumulating in low spots.

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On a side note for pneumatics control, do you ever see FIRST allowing pneumatics control with anything other than the control modules over CAN? I ask because many projects I am working with currently are using Ethernet/IP controls for solenoid banks. It’s incredibly fast, wouldn’t be limited to 8 solenoids and would be able to connect to the RIO or hub/switch through a standard ethernet cable.

It seems to be what a lot of industry standard communication protocols are using lately, and it could/would be a good way to introduce kids to that type of programming as well.

My preference for plumbing the pneumatics is to use 4 colors.

High side
Low side


Possibly some day.

The catch is $$, and getting everyone to adopt it.

Take a look at the cost of those banks and see if they’re affordable. Then put a thread up and see if teams are interested. Then hit up the FRC Team Advocate. Be prepared to back up with data, and then wait for the next control system bid cycle.

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That’s a very valid point EricH. Cost could be a pretty huge factor, since anything “industrial” automatically gets a bit of a price boost. Both Emerson Aventis and SMC SY series equipment is capable, and I know the team I was on used SMC valves. Updating to the bank system with the Ethernet/IP would not be cheap. If memory serves, even the dumb (as in not “smart” with the internal solenoid connections) 8 point manifold was pretty costly. And of course, what we have now works very well.

As part of the data that @EricH suggested collecting regarding this suggestion, it would be good to know that the components you are suggesting are available through large, general distributors like Grainger or McMaster Carr and if they are only available from specialty distributors, what hoops have to be jumped through (setting up accounts, minimum order quantities, payment terms). It is likely that schools will already have Grainger and/or McMaster Carr as approved vendors. It will be more difficult for teams to purchase parts if they have to convince the school to add ABC Co. to the approved vendor list.

QFT. 3946 usually used black for high pressure, white for working pressure before solenoid valves, green for extend and orange for retract. Definitely sped up trouble shooting!


I second using different colors for push/ pull.

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1678 uses 2 colors, Black and Green. Black is always the solenoid in one state and Green is the other state. We use single action solenoids for most things and if we use a double acting it gets the same output scheme as the singles.

This bonded, two colour PU tubing is the bomb for plumbing robot pneumatics. Unfortunately I see it’s out of stock! You could maybe use the 3 colour version and strip off the unwanted colour :slight_smile:

One bit of OpEx - don’t use PU tubing right off the compressor. We had an occurance where the hot air coming out of the compressor deformed the tube to where it wouldn’t stay in either compression or push-to-connect fittings. We’ve been using nylon tube for the compressor exit since (but PU tubing everywhere else because it’s niiiiiiice)

One time we ran our robot for a demo at a fair, so it was running near-constantly except for battery swaps. Over time the compressor got so hot that it actually melted the tube at the connector, and the compressed air exploded out the weakened tube. Luckily we had some spare tube to swap, which worked fine until it the replacement heated up and exploded as well.

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Same here, but during a practice session in 2013. The first time we thought we had defective tubing. All the air blowing back out from the tanks cooled the tubing so we didn’t realize how hot it was. We replaced with a different batch and it happened again at the same spot. That’s when we investigated. We had the tubing plugged into a fitting right next to the compressor. After that, we started putting a few inches of hard fittings and components before the switch to tubing to act as a heat sink.

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