Quick Exhause Valve

Hello, we are wondering if we can use a quick exhaust valve in order to dump air quickly into a pneumatic cylinder. Is this legal? it will be an off the shelf part and there are no clear restrictions in the manual, we just wanted to make sure.

Thanks,

Mitch Guzman

You’ll need to more clearly define “Quick exhaust valve”. If you mean to use the type mentioned in <R72 B> then it appears you CAN use such a valve to allow pneumatic pressure in to or out of your cylinder. You’ll need some way to turn that valve that does not violate <R73 B>.

If you mean something else, then explain more please. Ideally a manufacturer and part number.

It may be worth noting that air volume is only one of the constraints you are battling. In other words, getting a lot of air in to a cylinder fast might not make it move as fast as you might like.

Oh, yes: This is my opinion only. My opinion will be completely worthless at any Competition. To get a decisive answer, ask at the official FIRST Q&A. Word of warning: ask your question very carefully, thoroughly and precisely so it cannot be misinterpreted.

A quick exhaust valve, sometimes called a “quick dump” valve (no jokes please) is a 3 port valve, “in”, “out” and “exhaust”. when you pressurize the “in” port, air flows through to the “out” port. When you release pressure on the “in” port, air from the “out” port flows freely though the “exhaust” port, therefore it doesn’t have to flow back to the solenoid valve through all the tubing and fittings. A very useful item. Unfortunately, I interpret the rules to say that it is not legal for FIRST use. <R72> is a list of items expressly permitted (in addition to the KOP items) for pneumatic system use. If it isn’t listed in <R72> it isn’t permitted. A quick exhaust valve doesn’t fit any of the descriptions in <R72>, therefore, is not permitted.

Our team is using a quick exhaust valve, and we have yet to find anything in the rules that says that we are not allowed to use one. However, one thing that worries me about the “dump valve” is that it has a 3/8" exhaust port and that we might need to neck it down, but again we have not seen anything that says that this is against the rules

If it meets <R72-C> you’re fine, but I doubt it does if it’s a quick exhaust.

Here are the relevant Q&A posts:

http://forums.usfirst.org/showthread.php?t=14463
http://forums.usfirst.org/showthread.php?t=14227

I beleive all valves are limited ot 1/8" internal port size and 1/8" ipt threaded outlets.
Chances are that if you have a 3/8" IPT output thread your internal port size is too big and will not be pemitted.

Consider using two smaller cylinders each with its own valve regulator and storage tanks

1784 and 1086 asked Q&A about this and we were told no.:mad:
http://forums.usfirst.org/showthread.php?t=14516
http://forums.usfirst.org/showthread.php?t=14516