SpudFiles

Alright i just thought this up so be easy. First you close the large ball valve between the union and the barrel. then you open the small equilization valve. then you can pressurise your chamber to the desired pressure. then close the small ball valve then quickly open the large one and the burst disk will pop

That doesn't make sense, why is there an equalization hole in the barrel?

A simple way would be to just add a ball valve right before the burst disk.

P.S. You should have put this in the theories section.

the ecuilization is through the small ball valve. this allows you to put as much pressure us u want then you close the valve.
when you open the big valve the pressure goes out on one side but not the other thus truggering the burst disk

its a neat idea... but i think i'll have to stare at it for another minute or 2 until i understand how it basically works... in the future put labels on the parts in your drawings, it would make things much easier to understand.