99.999% helium gas puritystandardunitApplicationoxygen≥99.5GB-T3863-1995bottle/cylinder Steel cutting, welding, flame processingnitrogen≥99.5GB-T3864- ... chemical industry, metallurgy, and electric industry.hydrogen≥99.9GB-T3634-1995bottle/cylinderChemical industry, glasses, synthetic ... industry, chemical industry, analysis Pure argon ≥99.99 GB/T4842-95Bottle Welding shielded welding, stainless steel ...