restoring old valve radio

[4pyros]

Yea, fittings that are not in the mainstay. Good to 1000 F and ...: helium leak tested to a
maximum leak rate of 4 3 10 –9 std cm3/s with silver-plated and copper gaskets and to a maximum leak rate of 4 3 10 –11
std cm3/s with unplated gaskets." and for 1/4" pressure ratings around 5000 PSI.

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CDkQFjAB&url=https://www.swagelok.com/downloads/webcatalogs/EN/MS-01-24.pdf&ei=FfmMU4iND47ksAT_noCoBw&usg=AFQjCNGjdhbs8X55rUNBYKwUiRhey4NZ1A&sig2=OVwcsLSopukDbG1oW1SDSQ&bvm=bv.68191837,d.cWc&cad=rja

VCO fittings use an O-ring seal.

https://edmonton.swagelok.com/blog/bid/325525/The-Advantages-of-Swagelok-VCR-and-VCO-Fittings

Not much info on orbital welding: https://www.swagelok.com/Columbiasc/Services/Orbital Welding.aspx

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CDwQFjAA&url=https://en.wikipedia.org/wiki/Orbital_welding&ei=jvuMU6u_KLXesATfkIDoCg&usg=AFQjCNGfLVbhwisbLNE8mVOA8N2hFdKuuw&sig2=2zuUZZK1V38FQaXUT7t6ig&bvm=bv.68191837,d.cWc

Thanks, vary interesting. Still learning something new every day.