SpudFiles

Hi, I am new to the forums, but have been spudding a while. Anyway, I had this idea of using cast iron pipe for my pneumatic, mainly because the store that carries it, carries the extreme pressure (6000 PSI). I was wanting to use a ball valve with a 2" ball I.D. but ball valves take so long to open compared to burst discs. My idea was to drill a small hole in the end of the handle, and then either welding a loop on the pressure chamber, or putting a screw into it, then using a very high tension spring to open the valve quickly.

That will work fine. It has been done many times.

What, screwing it in, or welding it on? I am not thrilled about the idea of a screw shooting out with 5500 PSI behind it

The screw wn't pop out with 5,500 psi (how the hell would you get pressure that frickin, high?!) behind it. The surface area is so small that only a fraction of that pressure, like 100 psi would launch it anywhere if it did pop out, which is almost impossible to have happen. The threads will hold it in very tightly. If there IS 100 psi shooting the screw out, it will go about 19 (random number, I think you know that already) inches because the flow the the "valve" that has just been made is about 1/4" max.

Yikes! Don't try 5500 PSI in cast iron! That's asking for death, besides, unless you have an extremely long barrel, you're not gonna notice much speed benefits.

Keep the pressure low, it's safer and just as fun, for your safety.

If you didn't read my earlier post, here is a repeat: The store near me only sells the extreme pressure cast iron pipe capable of sustaining 6000 PSI.

Do you have a compressor that can pump up to 5500psi?

I don't personally, but I can rent a scuba tank and fill it to 5500PSI for about $35 USD. The tank is about 1500 CI

I won't weld it on either, as that might weaken the metal or something... so I'd use a screw into a peice of plastic, and then epoxy the plastic to the metal.

Ahh, me and my misreading. I thought that you meant extreme pressure as in pressure tanks. In that case you'll be fine, my bad.