maximum psi for big gun cannons

Discussion in 'Weapons & Pneumatics' started by burnzy232, Mar 27, 2010.

  1. burnzy232

    burnzy232 Member

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    hi all
    i just wanted to know if the the psi pressure that you run to your cannons has a maximum limit, rules wise(big gun), not physical strength. is it as much as you want or is there a max psi value in the rule set?
     
  2. DarrenScott

    DarrenScott -->> C T D <<--

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    Max pressure permitted in AusBg was 140 psi, but I'm not sure of the current ruleset.
    You should ask your club Tech Officer for a copy of the current construction rules.
     
  3. burnzy232

    burnzy232 Member

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    aahhh, so there are rules that limit psi, yeah i would ask my club tech officer but there arnt any local clubs in adelaide, theres clubs everywere else in OZ but not in adelaide:crying: i guess i can sift through the big pdf file for ausbg rules, cheers for the info Darren
    out of interest how much psi can the cannons handle without being dangerous?
     
  4. Kotori87

    Kotori87 Well-Known Member

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    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.
     
  5. burnzy232

    burnzy232 Member

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    cheers Kotori, that has answered my question and many more, i guess i will be buying my cannons form stike modles then:)
     
  6. DarrenScott

    DarrenScott -->> C T D <<--

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    We do have a cannon constructor here in Australia now. I'll have to ask and find out who.
    BTW, the AusBg only uses PVC accumulators. We consider it better to have a failure at a relatively low pressure, than have a metal accumulator which fails at a much higher pressure and could become dangerous shrapnel.
     
  7. burnzy232

    burnzy232 Member

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    do we?, goody for me, that saves on shipping then, especialy when ordeing 5 cannons:), i was wondering who made cannons here because i emailed a few people that have websites saying that they make cannons but dint get any responce. i eagerly await your findings Darren