GB/T 18604-2023 Measurement of natural gas flow by gas ultrasonic flow meters

GB/T 18604-2014 Measurement of natural gas flow by gas ultrasonic flow meters

GB/T 2624.2-2006 Measurement of fluid flow by means of pressure differential devices inserted in circular cross-section conduits running full—Part 2:Orifice plates GB 3836.1-2000 Electrical apparatus for explosive gas atmospheres—Part 1:General requirements GB 3836.1-2010 Explosive atmospheres—Part 1:Equipment—General requirements GB/T 3836.1-2021 Explosive atmospheres—Part 1:Equipment—General requirements GB 3836.2-2000 Electrical apparatus for explosive gas atmospheres—Part 2:Flameproof enclosure “d” GB 3836.2-2010 Explosive atmospheres—Part 2:Equipment protection by flameproof enclosures "d" GB/T 3836.2-2021 Explosive atmospheres—Part 2:Equipment protection by flameproof enclosures “d” GB 3836.4-2000 Electrical apparatus for explosive gas atmospheres—Part 4:Intrinsic safety“i” GB 3836.4-2010 Explosive atmospheres—Part 4:Equipment protection by intrinsic safety "i" GB/T 3836.4-2021 Explosive atmospheres—art 4:Equipment protection by intrinsic safety “i” GB 4208-1993 Degrees of protection provided by enclosure (IP code) GB/T 4208-2008 Degrees of protection provided by enclosure(IP code) GB/T 4208-2017 Degrees of protection provided by enclosure(IP code) GB/T 11062-1998 Natural gas—Calculation of calorific values, density, relative density and Wobbe index from composition GB/T 11062-2014 Natural gas—Calculation of calorific values,density,relative density and Wobbe index GB/T 11062-2020 Natural gas—Calculation of calorific values,density,relative density and Wobbe indices from composition GB/T 13610-2003 Analysis of natural gas by gas Chromatography GB/T 13610-2014 Analysis of natural gas composipion—Gas chromatography GB/T 13610-2020 Analysis of natural gas composition—Gas chromatography GB/T 17747.1-1999 Natural gas—Calculation of compression factor—Part 1:Introduction and guidelines GB/T 17747.1-2011 Natural gas—Calculation of compression factor—Part 1:Introduction and guidelines GB/T 17747.2-1999 Natural gas—Calculation of compression factor—Part 2:Calculation using molar-composition analysis GB/T 17747.2-2011 Natural gas—Calculation of compression factor—Part 2:Calculation using molar composition analysis GB/T 17747.3-1999 Natural gas—Calculation of compression factor—Part 3:Calculation using physical properties GB/T 17747.3-2011 Natural gas—Calculation of compression factor—Part 3:Calculation using physical properties GB/T 21446-2008 Measurement of natural gas flow by means of standard orifice meter GB/T 30500-2014 Ultrasonic gas flow meter performance online audit—Method using speed of sound checking GB/T 35186-2017 Performance evaluation of measuring system for natural gas JJG 1030-2007 Ultrasonic Flowmeters SY/T 0599-2018 Natural gas ground facilities technical specifications for metal materials that resist sulfide stress cracking and stress corrosion cracking SY/T 0599-2006 The metal materials for natural gas ground facilities require resistance to sulfide stress cracking and stress corrosion cracking SY/T 0599-1997 Natural gas surface facilities require metal materials that are resistant to sulfide stress cracking GB/T 35186-2025 Performance evaluation of measuring system for natural gas GB/T 21446-2025 Measurement of natural gas flow by means of standardized orifice meter