might run into issues with air at those pressures! ...but I've been pondering, if high pressure low volume is efficient, why don't we use it? Instead of building large pressure vessels for 100 to 800 psi, why not tiny pressure vessels for 5000psi? Tiny pressure vessels, tiny valves, less material, ...

That's a clever way to build inline balanced valved Jack :salute:

Thanks for sharing it with us.

That clears things up. Thanks. jsr wrote: vcn wrote: Also on the p2, what is the function of the hole nearest to the pump head? Didn't quite get which hole you were referring to. I am referring to the hole on the right side (with red arrow pointing at it). http://i1260.photobucket.com/albums/ii569/k...

I made an insert that removed about 1cc and got some very disappointing results, at 20 pumps it was giving me 2 shots and at 25 pumps it wasn't firing at all. It can't be that the balanced spool was compromised, because the "balance chamber' is open to the atmosphere and it would not have retained ...