pic: It's systems integration time!

[EricLeifermann]

Originally Posted by Sparky3D

Actually, the Q&A already dealt with the alternate uses of manual valves (Q235). You are only allowed one, and it can only be used to vent pressure for the system.

Answer of Q235

"No. Per R89 only one pressure vent plug valve may be used on the ROBOT which, when manually actuated, must vent to the atmosphere to relieve all stored pressure."

Bolded for my emphasis, doesn't state that the valve must be manually actuated to prevent air from being relieved. Though this question was asked about a different topic, its answer allows for spring actuated relief valves.

[ToddF]

We must have cross posted.

Full disclosure: We are going to install one and let the inspectors decide.

[Nate Laverdure]

Originally Posted by ToddF

Another example would be a weight which is held up by a motor that has power as long as the robot is operating. In case of a dead robot, the weight drops on a push button valve, which ejects the ball from the robot.

You can accomplish this with a single-acting solenoid. In the case of a dead robot, the coil is deenergized and the opposing spring throws the valve.

[ToddF]

Originally Posted by ToddF

Full disclosure: We are going to install one and let the inspectors decide.

Well, we finally got an authoritative answer. We installed a push button dump valve, and it passed inspection at both of our regionals. At the championship, the inspector flagged it. The question went to Al himself. Al said that part of the function of the valve was that the handle visually indicates whether the valve is open or closed. It's not immediately visually obvious with a push button valve if the system is vented. Looking at the pressure gauges doesn't count. (I heard this second hand, as I was on a plane when the robot was being inspected.)

We swapped valves and competed with a valve with a handle.

[Al Skierkiewicz]

Originally Posted by ToddF

That's really cool. I love the idea of using a spring loaded valve for the dump valve. I hope that someday they will become legal to use.

For now, this would not be legal. I had several teams remove the springs at Champs. We (volunteers) and everyone needs to know that the pneumatic system is open/vented when working on or near your robot.