NEPT Maximum Pressure

[willowchar]

Just wondering if anyone knows what psi. a 1lb. New England paper tube will fail?

Not under loading pressure, rather working pressure.

At what pressure will the tube cato?

 

Thanks

[Smokelvr]

wouldn't that be a function of the paper x layers, so if you know their source/paper type you can look up the strength spec's, most paper is rated, either meeting a specific standard or belonging to a class, hence meeting the class minimum

then come technique and binder, I believe that if the paper is rolled under tension that can change burst properties, along with the glue/binder

 

That said, usually rammed clay and it's 'hold' is weaker than the tube, but CATO's happen not because of tube weakness, but that combustion/deflageration reaction snowballs, it can happen with any containment, and I believe one of the ways that a paper tube fails is burn-through from 'focused' flame and increased local pressure

[shockie]

I don't know exactly but cored BP rockets even at 75/15/10 probably only have a chamber pressure of 400 psi....whereas NEPT tubing is on the order of 6K psi minimum. This is an educated guess, based upon various readings.

 

As the other poster said, The mechanical bond between the pressed clay nozzle and the paper tube will likely result in the nozzle ejecting itself long before the tube itself bursts.

 

BP burning at a chamber pressure of say 250 psi versus 500 psi is only going to raise the specific impulse by 10 to 15%.

 

The length and diameter of the core and the shape itself will determine to a great extent what the combustion chamber pressure will be.

Edited January 5, 2021 by shockie