I am not sure of the exact mathematical equation to figure out the maximum pressure for my gun, But i am sure someone with some experience will be able to give it a rough guess.
There are a few older pics of my gun in one of my threads (Click on my guns in my signature to take a look)
I have used pressure PVC pipe and glue.
In total, There is about 47 inch worth of pipe for my tank @ 15mm diameter.
What do you think its capable of? Is there some sort of calculator that will work this out?