valve protectors (cat!)

[zintolo]

If you prefer to avoid glass, the best material I've seen for in-line chemical analysers is Polyetheretherketone (you can find it as PEEK), and it can work constantly at 260°C amd can be transparent when thin:
Victrex PEEK Polymers | Engineering Thermoplastics - Victrex

 

[adamus]

 

[adamus]

problem solved, dropped the standoffs, and used a couple of aluminium drawer handles (£3 off the bay)

 

[pelayostyle]

Very clever and aesthetically appealing too.

 

[rotaspec]

Pen holder. Cheap option for larger tubes:

 

[astouffer]

Perfection.