SpudFiles

This valve would be constructed using a Cross fitting any size would work and instead of the pilot valve releasing pressure it would apply pressure and move the piston against the spring and when the pilot valve is released the piston would move back into place.

I have an example picture of it below this is just an idea and someone else can prolly draw it better or assemble it better.

This won't work. When you design a valve, you have to keep in mind that this isn't a 2-dimensional object. The O-Rings will only stop air from going past them and if you put O-Rings onto the entire thing there would be too much friction. This has been thought up before here...
http://forums.spudtech.com/topic.asp?TOPIC_ID=12065
This gives me some inspiration towards a combo of this and one of my old ideas though.

ok throw out the o rings and that one u linked to isnt the same it used a pilot valve to release air preasure and a bypass to increase pressure this one the pilot valve moves the piston with air pressure

The point I'm trying to make is that the air is just gonna flow around the piston. It's like sticking a pole in the middle of a river.