Posted By burnzy232 on 27 Mar 2010 07:22 AM
out of interest how much psi can the cannons handle without being dangerous?
Burnzy, Big Gun clubs have several different safety standards, which all cannons are required to meet.
1) Maximum accumulator pressure. As Darren mentioned, all Big Gun clubs have an absolute maximum pressure limit for accumulators. In the US, most clubs limit accumulators to 150PSI. Please note that this is specifically an accumulator limit, and not all clubs extend it to all components.
2) Manufacturer's rating. As I mentioned earlier, the max pressure limit only universally applies to accumulators and other store-bought components. Store-bought components are different, in that they have their own specific pressure ratings that you cannot exceed. For example, the lightweight firing valve SMAV-3 is only rated for 100PSI.
3) Penetration test. All Big Gun cannons must undergo a penetration test, in which they cannot shoot through more than 2 inches of DOW square-edge extruded polystyrene foam. In the AusBG, this is replaced with a 165FPS maximum velocity. No cannon may be operated in excess of the pressure used to pass the foam (or velocity) test.
After meeting all three standards, does this mean the cannon isn't dangerous? Unfortunately, no. The Big Gun cannons being developed by Strike Models are capable of holding an accumulator full of liquid CO2 at full pressure without suffering any plastic (permanent) deformation, in the event of regulator failure, but safety-wise, these cannons are the exception, not the rule. Most cannons are constructed with PVC, ABS, aluminum, or copper accumulators, and rarely engineered to the same standards as Strike Models. While such materials are sturdy and usually enough to survive regular operating pressures, and even somewhat higher pressures in periods of heavy operation, they will not hold together in case of total regulator failure or battle damage. In fact, the trial-and-error method usually used in cannon construction sometimes results in accumulators that will not even safely survive 150PSI. So just because your cannons have met all three safety standards is no guarantee of safety. Proper maintenance of air components and good blast shields are just as important as the safety standards themselves, as is safe pressure testing when the cannons are first constructed.