... Steel cutting, welding, flame processingIndustrial nitrogen ≥99.5 GB-T3864-1996Bottle Replacement gas and protection gas for ... , metallurgy, and electric industry.Pure nitrogen ≥99.996 GB/8979-96Bottle Chemical industry, glasses, metallurgy, protection Industrial ... hydrogen ≥99.9 GB-T3634-1995Bottle Chemical industry, glasses, synthetic cut stone. ...