Standard No.:	GB 27790-2011
English Name:	City Gas Pressure Regulators
Chinese Name:	城镇燃气调压器
Chinese Classification:	P47    Gas supply engineering
Professional Classification:	GB    National Standard
Issued by:	AQSIQ
Issued on:	30-Dec-11
Implemented on:	2012-11-1
Status:	superseded
Superseded by:	GB 27790-2020 City gas pressure regulator
Superseded on:	2021-12-1
Language:	English
File Format:	PDF
Word Count:	13000 words
Price(USD):	120.0
Delivery:	via email in 1 business day

1 Scope This standard specifies terms, definitions and symbols, classification and labelling, structure and materials, requirements, test methods, inspection rules, marking, label, operating instructions and packing, transport and storage of gas pressure regulators (hereinafter referred to as regulators) used in the transmission and distribution system of city gas (manufactured gas and natural gas, the same below). This standard is applicable to the regulators with a nominal diameter up to 300mm, a lower limit not less than the dew point temperature of the gas, an operating temperature range (temperature range of the media and proper at which the regulators components and fixtures may work at normal state) from -20℃ to 60℃, and an inlet pressure up to 4.0MPa. This standard may be a reference to the regulators used for transmission and distribution system of pipeline liquefied petroleum gas and liquefied petroleum gas mixed with air. This standard is not applicable to the pressure stabilizer, bottled gas regulators and regulators for dimethyl ether. Every pressure value not indicated in this standard is the gauge pressure value, in MPa. 2 Normative References The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the normative document (including any amendments) applies. GB/T 191 "Packaging-Pictorial Marking for Handling of Goods"(GB/T 191-2008, ISO 780:1997, MOD) GB/T 229 "Metallic Materials-Charpy Notch Impact Test" (GB/T 229-2007, ISO 148-1:2006, MOD) GB/T 699 "Quality Carbon Structural Steels" GB/T 1173 "Casting Aluminium Alloys" GB/T 1220 "Stainless Steel Bars" GB/T 1239.2 "Cold Coiled Helical Springs Technical Specifications-Part 2: Compressions Spring" GB/T 1348 "Spheroidal Graphite Iron Castings" (GB/T 1348-2009, ISO 1083:2004, MOD) GB/T 1527 "Drawn Tube of Copper and Copper Alloys" GB/T 1591 "High Strength Low Alloy Structural Steels" GB/T 1690 "Rubber Vulcanized or Thermoplastic-Determination of the Effect of Liquids" GB/T 3191 "Aluminium and Aluminium Alloys Extruded Bars, Rods" GB/T 3452.1 "Fluid Power Systems-O-rings-Part 1: Inside Diameters, Cross-sections, Tolerances and Size Identification Code"(GB/T 3452.1-2005, ISO 3601-1:2002, MOD) GB/T 3452.2 "Fluid Power Systems-O-rings-Part 2: Quality Acceptance Criteria" (GB/T 3452.2-2007, ISO 3601-3:2005, IDT) GB/T 6388 "Transport Package Shipping Mark" GB/T 7306.1 "Pipe Threads with 55 Degree Thread Angle where Pressure-tight Joints are Made on the Threads-Part 1: Parallel Internal and Taper External Threads" (GB/T 7306.1-2000, eqv ISO 7-1:1994) GB/T 7306.2 "Pipe Threads with 55 Degree Thread Angle where Pressure-tight Joints are Made on the Threads-Part 2: Taper Internal and External Threads" (GB/T 7306.2-2000, eqv ISO 7-1:1994) GB/T 9112 "Types and Parameters for Steel Pipe Flanges" GB/T 9440 "Malleable Iron Castings" GB/T 9969 "General Principles for Preparation of Instructions for Use of Industrial Products" GB/T 12226 "General Purpose Industrial Valve-Specification of Flake Graphite Iron Castings" GB/T 12227 "General Purpose Industrial Valve-Specification of Spheroidal Graphite Iron Castings" GB/T 12229 "General Purpose Industrial Valve-Specification of Spheroidal Graphite Iron Castings" GB/T 12716 "Pipe Threads with the Thread Angle of 60 Degrees Where Pressure-tight Joints are Made on the Threads" (GB/T 12716-2002, ASME B1.20.1:1992, EQV) GB/T 13306 "Plates" GB/T 13384 "General Specification for Packagings of Mechanical and Electrical Products" GB/T 15115 "Die Casting Aluminum Alloys" GB/T 23934 "Hot Coiled Helical Compression Springs-Technical Specifications" HG/T 20592 "Steel Pipe Flanges (PN Series)" HG/T 20615 "Steel Pipe Flanges (Class Designated)" JB/T 7944 "Sampling Procedures for Inspection by Attributes of Coied Helical Springs" 3 Terms, Definitions and Symbols 3.1 Terms and Definitions

Foreword I 1 Scope 2 Normative References 3 Terms, Definitions and Symbols 3.1 Terms and Definitions 3.2 Symbols 4 Classification and Labelling 4.1 Classification 4.2 Labelling 5 Structure and Materials 5.1 General Requirements 5.2 Structrual Requirement 5.3 Material Requirements 6 Requirements 6.1 Appearance 6.2 Hydraulic Strength of Pressure Containing Part 6.3 Inspection of Finished Diaphragm 6.4 External Seal 6.5 Performance 6.6 Flow Coefficient Cg 6.7 Adaptability at Limit Temperature 6.8 Durability 7 Test Methods 7.1 General Requirements 7.2 Appearance 7.3 Hydraulic Strength of Pressure Containing Part 7.4 Testing of Finished Diaphragm 7.5 External Seal 7.6 Performance 7.7 Flow Coefficient Cg 7.8 Adaptability at Limit Temperature 7.9 Durability 8 Inspection Rules 8.1 Inspection Items 8.2 Judging Rules 9 Mark, Label and Operation Instruction 9.1 Marks and Labels 9.2 Operating Instructions 10 Package, Transport and Storage 10.1 Package 10.2 Transport 10.3 Storage Appendix A (Normative) Physical and Mechanical Properties of Rubber Materials Appendix B (Informative) Service Life for Rubber Parts of Regulators Appendix C (Informative) Alternative Method for Determining Flow Coefficient of Mass Flow Regulators Appendix D (Informative) Flow Characteristic