Procyon wrote:What's the rating on your valve? When the 200 pops on my RPG everyone around jumps. I can definitely see good potential for a strong shooter with a 200 psi valve going off with 250 behind it. Nice thinking. I'll be joining those giving it a try. I would think you could also control rate of fire as well by adjusting input pressure. Great idea!
The body has PN16 stamped on it, so it will happily take 235 psi. The pop-off rating however is marked as 0-3 BAR, so that's around 45 psi maximum pop-off pressure.
The thing about using standard pop-offs it that they are not optimised for "full auto" operation, I determined that a succesful valve used in this manner needs the following criteria:
1) The piston seat must be significantly bigger than the outlet to the barrel, to ensure that the piston chamber fills with pressure faster than it can empty and the piston has time to actually pop
2) The piston must be significantly wider than the piston seat, in order for there to be enough area for the pressure to act on and overcome the spring strength.
The 1" valve is currently being modded to satisfy these conditions. I had ended up making my own pop-off with the above parameters in mind, take a look at version 1
and version 2
Hook it up to a barrel and magazine and it works
Polyconn will make ones for higher psis as well. They have larger port openings as well.
I had made an HPA version
but given my limited construction facilities the porting is relatively tiny.