laminated glass tubes

Why not make samples and test them by breaking them at 200 bar and seeing what the result is?

Any restriction on thickness (bullet -proof glass)? Any restriction on wire?

I do make explosion tests with display tubes filled to higher than normal pressure. But acquiring the materials costs money and making the pressure and protective tubes is a lot of work so I try to pick the ideal materials at first.

Not unless they remain practical. I'm currently thinking of 60 mm total outer diameter with 7 mm wall thickness for the outer tube, 1-3 mm gap material and 2 mm inner tube of the protective tube. That's 10-12 mm total wall thickness of the protective tube. Length is 20-25 cm.

The pressure tube within the protective tube is 10 mm OD.

But I could not find bullet proof glass *tubes*. I did find laminated glass tubes intended as pillars in building construction. However, they cost near 100 Euro per 25cm piece.

I thought of using laminated glass panes, which are easier to make. But a tube looks much better than a cuboid. Also how do I join the panes so they will not open at the edges when the pressure tube explodes.

The purpose is to watch the pressure tube in detail. So I will try without wires.

Bernhard

If you use a thick-wall tube of toughened glass then why would you need a protective tube at all? Seems to me you are making hard work for yourself taking a precaution that is excessive, but then I don't know what your costs are. Have you approached any glass manufacturers and obtained quotes?

What about a box that is metal on all sides but one, the latter being the laminated plate glass?

Or maybe metal on all sides with a video camera and lamp inside with the tube.

Why do people use CO2? Wouldn't one of those other molecules be a lot safer? What would be the safest candidate?

CO2 is cheap and available. It has an excellent critical temperature. You can make it critical with body heat or other low power heating and cool it below critical with ambient temperature. It is non toxic, non ozone depleting (influences availability). Its (super)critical pressure is low enough so it can be contained in glass tubes.

CClF3 has great critical data (29°C, 39 bar), but it is ozone depleting and hard to get. C2F6 has even lower pc (33 bar), but Tc is silghtly too low (19 °C) so it would have to be cooled to go subcritical. It's expensive (compared to CO2) and I would have to buy or rent a pressure bottle. And even at 33 bar (or more if supercritical) a protective case is very preferable. So I just use CO2. Supercritical CO2 is also used industrially and so is particularly interesting for people to watch.

Ohh, BTW, Helium would be the safest candidate: 2.3 bar, but at 5 K. :) Or something like C7F16 with 16 bar and 202 °C in an oil bath might be an option.

Bernhard