SpudFiles

D_Hall wrote:Are these real problems? I have no idea. They're just two possibilities that pop into my mind.

Of course, these days, there are plastics which have relatively low melting points - Polycaprolactone has a melting point of around 60 degrees C.

Whether or not these materials are practical in other ways is a matter I'm far from knowledgeable enough to talk about, but a material with a melting point that low does get around the second problem you mentioned, and helps with the first pretty well.

A 6" ID chamber with an OD of 30"...

Even with a relatively low grade steel, that's a static yield pressure of around 150k psi, and I don't think LGGs are made of very low grade steel. With a higher grade steel, we're talking over 400k psi.

I've never really heard an accurate figure of the chamber pressure generated by these things, but I'm guessing it's high enough that there's not a tremendous safety factor on the pump tube.

DYI wrote:I've never really heard an accurate figure of the chamber pressure generated by these things, but I'm guessing it's high enough that there's not a tremendous safety factor on the pump tube.

We were operating in the 120-140 ksi region.

um, i know this is kinda random, but if you would fill the chamber with some water would that cushion the piston so that it wouldn't be destroyed?

um, i know this is kinda random, but if you would fill the chamber with some water would that cushion the piston so that it wouldn't be destroyed?

1. Water is incompressible, so liquid water can't really absorb any shock at all.

2. That made absolutely no sense...

sandman wrote:um, i know this is kinda random, but if you would fill the chamber with some water would that cushion the piston so that it wouldn't be destroyed?

Why dont you try it?

And it's that shock at the end that generates the insane pressures. Let the piston gracefully stop and those pressures go away. Ergo, you've defeated the purpose of having the gun to begin with.

kk, i didnt think it was that easy, just wondering