Explanatory notes
… or liquefied gases (e.g., helium, oxygen, argon, hydrogen, acetylene, carbon dioxide or butane). Some are strong … welded (e.g., at the bases, round the middle or along the length). Others consist of an inner vessel and one or more … measuring devices such as valves, taps, pressure gauges, level indicators, etc. Some (e.g., for acetylene) contain an …
