... ≥99.5GB-T3863-1995bottle/cylinder Steel cutting, welding, flame processingnitrogen≥99.5GB-T3864-1996bottle/cylinderReplacement gas ... and protection gas for chemical industry, metallurgy, and electric industry.hydrogen ... analysis Pure argon ≥99.99 GB/T4842-95Bottle Welding shielded welding, stainless steel smelting, container, steel structure manufacture, ...