SpudFiles

After Technician pointed out the obvious failure of my previous configuration, I came up with this design, which seems to me to overcome the issue of tearing off the front o-ring. I have also replaced the compression spring with an air spring, which is far more adjustable. Useful comments much appreciated.

Old Design:


New Design

Is this a valve housed in a cross fitting? Looks like it and I like it.
But my question is why you don't just funnel the two chambers into one tee fitting and make a regular piston valve?

The piston you are using in the new design looks huge and heavy, that's reason enough to build something simpler in my opinion.

On the other hand, I would like to see a cannon like this.