GB/T 34020.3-2017 Double wall copper-brazed steel tubes—Part 3:Tubing system for air conditioner and refrigeration

GB/T 34020.1-2017 Double wall copper-brazed steel tubes—Part 1:Tubing system for refrigerator GB/T 34020.2-2017 Double wall copper-brazed steel tubes—Part 2:Tubing system for automobiles

GB/T 228.1-2010 Metallic materials—Tensile testing—Part 1:Method of test at room temperature GB/T 5270-2005 Metallic coatings on metallic substrates—Electrodeposited and chemically deposited coatings—Review of methods available for testing adhesion GB/T 7735-2016 Automated eddy current testing of seamless and welded(except submerged arc-welded) steel tubes for detection of imperfections GB/T 11605-2005 Methods of humidity measurement GB/T 222-1984 Method of sampling steel for determination of chemical composition and permissible variations for product analysis GB/T 222-2006 Permissible tolerances for chemical composition of steel products GB/T 241-1990 Metal tubes—Hydrostatic pressure testing GB/T 241-2007 Metal materials—Tube—Hydrostatic pressure test GB/T 242-1997 Metallic materials—Tube—Drift expanding test GB/T 242-2007 Metal materials—Tube—Drift-expending test GB/T 244-1997 Metallic materials—Tube—Bend test GB/T 244-2008 Metallic materials-tube—Bend test GB/T 244-2020 Metallic materials—Tube—Bend test method GB/T 246-1997 Metallic materials—Tube—Flattening test GB/T 246-2007 Metal materials—Tube—Flattening test GB/T 246-2017 Metallic materials—Tube—Flattening test GB/T 682-2002 Chemical reagent—Trichloromethane GB/T 686-1989 Chemical reagent—Acetone GB/T 686-2008 Chemical reagent—Acetone GB/T 686-2023 Chemical reagent—Acetone GB/T 688-2011 Chemical reagent—Carbon tetrachloride GB/T 2102-1988 Acceptance, packing, marking, and certification of pipe GB/T 2102-2006 Acceptance, packing, marking and quality certification of steel pipe GB/T 2102-2022 Acceptance,packaging,marking and quality certification for steel tubular products GB/T 2975-1998 Steel and steel products—Location and preparation of test pieces for mechanical testing GB/T 2975-2018 Steel and steel products—Location and preparation of samples and test pieces for mechanical testing GB/T 4955-1997 Metallic coatings—Measurement of coating thickness—Coulometric method by anodic dissolution GB/T 4955-2005 Metallic coatings—Measurement of coating thickness—Coulometric method by anodic dissolution GB/T 4956-2003 Non-magnetic coatings on magnetic substrates—Measurement of coating thickness-Magnetic method GB/T 6462-1986 Metallic and oxide coatings—Measurement of coating thickness—Microscopical method GB/T 6462-2005 Metallic and oxide coatings—Measurement of coating thickness—Microscopical method GB/T 10125-1997 Corrosion tests in artificial atmospheres—Salt spray tests GB/T 10125-2012 Corrosion tests in artificial atmospheres—Salt spray tests GB/T 10125-2021 Corrosion tests in artificial atmospheres—Salt spray tests GB/T 15749-1995 Manual measuring method in quantitative metallography GB/T 15749-2008 Measuring method in quantitative metallography GB/T 34020.1-2017 Double wall copper-brazed steel tubes—Part 1:Tubing system for refrigerator YB/T 069-1995 Copper-coated steel strips for welded pipe HJ 637-2012 Water quality determination of oil and animal/vegetable fats by infrared spectrophotometry HJ 637-2018 Water quality determination of oil and animal/vegetable fats by infrared spectrophotometry GB/T 688-1992 Chemical reagent--Carbon tetrachloride YB/T 069-2007 Copper-coated steel strips for welded pipe GB/T 241-2025 Metallic materials—Tube—Hydrostatic pressure test GB/T 222-2025 Steels and alloys—Permissible deviations of product analyzed chemical composition GB/T 4956-2025 Non-magnetic coatings on magnetic substrates—Measurement of coating thickness—Magnetic method GB/T 6462-2025 Metallic and oxide coatings—Measurement of coating thinckness—Microscopical method