Posted 21 October 2007 - 11:34 PM
The system used here is a copy of the 4B and LBB firing systems. Basically, the tank is divided into two chembers with pipes connecting them (no valves in between, but a cavity is created between the two main chambers for a valve). The valve that dumps the entire tank into the barrel is simply a piece of plastic or other material that forms a seal with a flat surface. The piece is placed inside a lip on the foremost chamber so it can slide back, but not pop out into the barrel. A firing pin extends from the back of this sealing part and into the cavity between the two tank portions. The trigger has a catch face that pulls this bar back against the pressure in the tank and opens the valve.
Advantages:
No springs for the valve itself are needed, the pressure will hold the passage shut.
It is simple to make and cheap compared to other HOMEMADE valves (definitely not practical with store-bought comparisons).
Disadvantages:
The valve needs to be opened against the pressure in the tank, which can lead to problems with high pressures that limit your overall operating limit.
If the valve gets stuck (I.e., the firing pin gets bent and can no longer retract back into the tank), the system is useless.
It is not practical compared to commercially sold valves, especially automatic ones.
The only commonly shared fate among us all is death. I turn to the shadows so that I may not be unfamiliar with hell's corridors when I arrive. - SHADOW HUNTER ALPHA
Founder of the Shadow Militia.
Founder of Nightshade Laboratories and The Nightshade Armament Corporation.