pic: In-Line Pneumatic Fittings

[Jeff Pahl]

Originally Posted by orangemoore

This is the spec sheet from the automation direct website.

http://www.automationdirect.com/stat...linegauges.pdf

And the spec sheet only says that it regulates from 15-120 PSI. Based on that, it does not meet the 125 PSI requirement in the 2015 rules. I know it passed inspection this year, but that does not mean it should have...

Looks like a fantastic part, and the sort of thing I hope we see more of (if it's legal). My advice would be to file it away for future reference, and wait to see if it's determined to be legal in the future. I hope it is, I want to use it on my robot.

Insert standard disclaimer here about all previous year's rules not applying in all future years

[cgmv123]

Originally Posted by Jeff Pahl

Insert standard disclaimer here about all previous year's rules not applying in all future years

It's that time of year again!

[Thad House]

Originally Posted by Jeff Pahl

And the spec sheet only says that it regulates from 15-120 PSI. Based on that, it does not meet the 125 PSI requirement in the 2015 rules. I know it passed inspection this year, but that does not mean it should have...

Looks like a fantastic part, and the sort of thing I hope we see more of (if it's legal). My advice would be to file it away for future reference, and wait to see if it's determined to be legal in the future. I hope it is, I want to use it on my robot.

Insert standard disclaimer here about all previous year's rules not applying in all future years

I think I'm going to send an email to them, and ask them to add the maximum pressure rating to the spec sheet. I'm sure its higher then 120psi, since it can regulate down to that. There's a similar one on McMaster that should work, and it says 150 maximum, so it would be legal. 8844K11

[EricH]

I assume that this is a relieving regulator, is that correct? If it isn't, I'm going to have to concur on the "maybe shouldn't have passed inspection" crowd. If it is, I think I'll pass the info on to my team...

[orangemoore]

Does this even pass rule 66 G?

R66 The only pneumatic system items permitted on 2015 FRC ROBOTS include the items listed below.
A. Items available in the KOP (except as noted in I),
B. Pneumatic pressure vent plug valves functionally equivalent to those provided in the KOP,
C. Solenoid valves with a maximum 1/8 in. NPT port diameter,
D. Solenoid valves that are rated for a maximum rated pressure that is less than 125 psi rating mandated above are permitted,
however if employed, an additional pressure relief valve must be added to the low pressure side of the main regulator. The
additional relief valve must be set to a lower pressure than the maximum pressure rating for the solenoid valve,
E. Additional pneumatic tubing, with a maximum 0.160 in. inside diameter, functionally equivalent to that provided in the KOP,
F. Pressure transducers, pressure gauges, passive flow control valves (specifically “needle valves”), manifolds, and
connecting fittings,
G. Pressure regulators with a maximum outlet pressure of no more than 60 psi,
H. Pneumatic cylinders,
I. Pneumatic storage tanks (with the exception of White Clippard tanks P/N: AVT-PP-41), and
J. Compressors compliant with R68.

[TheHolyHades1]

Is it worth using these type of fittings when the brass fittings do a good job in serving as a heatsink for the compressors?

[Dunngeon]

Originally Posted by TheHolyHades1

Is it worth using these type of fittings when the brass fittings do a good job in serving as a heatsink for the compressors?

It's not that they serve as a heat sink for the compressor, but that they dissipate heat before it melts the tubing. In any case, weightloss anywhere on the robot is very good, and you won't melt tubing on a competition bot because of the short run times

So yes, if both components are legal then it's worth it to us (and many others)

[GeeTwo]

Originally Posted by Dunngeon

you won't melt tubing on a competition bot because of the short run times

It depends entirely on how much air you need. If you're using air solely to shift gears, probably not. If every function other than drive is pneumatic, quite possibly. We blew out several hoses (with a crack like a .22) during practice for rebound rumble. We had a pneumatic climber, but we didn't even have the climber attached yet. We were just making adjustments to the Frisbee primer that required depressurizing the system. In filling up our (seven?) plastic tanks, we blew out the hose at the end nearest the compressor. The large quantity of air depressurizing through the rupture cooled the tubing back down, so it took us several swaps to figure out that it wasn't just defective tubing. This was followed by closer monitoring to figure out the actual cause. Our solution was to relocate as much of the brass as possible to before the first piece of tubing, and continued monitoring for swollen tubing.

[Dunngeon]

Originally Posted by GeeTwo

It depends entirely on how much air you need. If you're using air solely to shift gears, probably not. If every function other than drive is pneumatic, quite possibly. We blew out several hoses (with a crack like a .22) during practice for rebound rumble. We had a pneumatic climber, but we didn't even have the climber attached yet. We were just making adjustments to the Frisbee primer that required depressurizing the system. In filling up our (seven?) plastic tanks, we blew out the hose at the end nearest the compressor. The large quantity of air depressurizing through the rupture cooled the tubing back down, so it took us several swaps to figure out that it wasn't just defective tubing. This was followed by closer monitoring to figure out the actual cause. Our solution was to relocate as much of the brass as possible to before the first piece of tubing, and continued monitoring for swollen tubing.

Emphasis mine. I said Competition Bot. We use a different compressor that is rated for 100% duty on the practice bot, but use the VIAIR 90C on the competition bot for the obvious weight savings. Nearly our entire bot was pneumatic, and the 90C was capable to compressing for nearly 20 minutes straight before we ever had a blow out. (not that I recommend it)

On the practice bot, we use either a Thomas 215 or another who's name escapes me.

Also, if your tubing was blowing out from only filling 7 (assuming black Clippard?) tanks you may want to re-evaluate both the fittings and tubing you are using. I know in our case, we have melted the O-rings within the 1/4 pneumatic quick connects (but this is after 30+ minutes of running and the crappy FIRST Choice connectors)

Or add a fan.

We use Freelin-Wade tubing, and SMC pneumatic fittings.

[ToddF]

Mounting a KOP computer cooling fan blowing on the compressor head allows the small compressor to be run at 100 percent duty cycle. We have done all day demos with our 2014 bot, with pneumatic catapult, and the compressor barely gets warm. This year our air consumption is less, so we left off the fan. Just filling two tanks gets it scalding hot.

[GeeTwo]

Originally Posted by Dunngeon

Emphasis mine. I said Competition Bot.

We made the corrections during practice and did not have the problem during competition. For UA, our understanding (probably incorrect, as I recently learned from another thread) was that relieving the air pressure between matches was mandatory. As a result, we stressed the system more during competition than we did during pre-climb practices when we were actuating a single 3/4" diameter cylinder with about a 6" stroke.

[EricH]

Originally Posted by TheHolyHades1

Is it worth using these type of fittings when the brass fittings do a good job in serving as a heatsink for the compressors?

Just as a note: If I'm not mistaken, these would be located well downstream from the compressor, say on the other side of the storage tanks. This isn't the pressure relief valve, it's a regulator. The PRV has a specific part number, and must be hard-mounted.

[TheHolyHades1]

Originally Posted by EricH

Just as a note: If I'm not mistaken, these would be located well downstream from the compressor, say on the other side of the storage tanks. This isn't the pressure relief valve, it's a regulator. The PRV has a specific part number, and must be hard-mounted.

Ah. I figured I missed something. Thanks!

[BBray_T1296]

Originally Posted by orangemoore

Does this even pass rule 66 G?

The KOP regulators have the capability of regulating higher pressure than 60PSI if you set them to.

[tr6scott]

Originally Posted by orangemoore

Does this even pass rule 66 G?

No.

Some manufactures offer optional outlet pressure ranges, but I do not see that on this cut sheet.

Should not have passed with >60 outlet pressure.
IMHO, not an inspector.