Aidan Karley wrote:
In article , Badger.badger
wrote:
Multi cylinder packs, used as fuel in o2/h2 burners to work silica.

H2 would be two nines or so pure ; chromatographic grade
hydrogen (should be / is) five nines. 99.999% Every bottle needs it's
certificate of conformity, and they aren't issued for more than a few
months after production and testing.

Only N5.0? We used certified N6.0 or better gases for processes!, The
burning grade h2 IIRC was N4.5 last time we had some...