MrCrowley wrote:What about an 8000psi piston valve made from titanium or magnesium with a large sealing face but tiny seat?
Actually, in contrary to what most believe, a piston valve will actuate faster with a larger seat, as the pressure in the pilot needs to fall lower for the piston to start to move, and therefore once the full front face of the piston is exposed, the piston will have a greater net force on it - which of course results in faster opening.
That's the reason HEAL's piston was modified to have the largest practically possible seat and sealing face (22.1mm, compared to the barrel's 20.3mm ID).
Not only does it give more flow, but it opens faster. It's been nearly a year since I first made HEAL, and in spite of a new in-flux of other high pressure cannons, it's valve has still got that significant advantage.
I sometimes wonder what the results of the piston design will be on the cannon to be known as 3vo - think HEAL, but built to be even more efficent, run at 500 psi, and semi-automatic to about 120 rpm.
Just the system to supply two full 35 bar fills a second is going to be a heck of lot of work.