... , welding, flame processingIndustrial nitrogen ≥99.5GB-T3864-1996CylinderReplacement gas and protection gas for chemical industry, metallurgy, and electric industry.Industrial hydrogen ... 85CylinderChemical industry, welding, casting moldIndustrial helium ≥99GB/4844-95CylinderElectronic industry, leak testing, floating balloon.Dissolved acetylene ≥98GB6819-1996CylinderWelding, cutting, heating, ...