Detail of GB 26255.2-2010

Introduction of GB 26255.2-2010

1 Scope This part of GB 26255 specifies terms and definitions, symbols and abbreviations, materials, general requirements, performance requirements, test method, mark and labels, packaging, transportation and storage for gas polyethylene pipe systems for connecting, to polyethylene (PE) pipes, a metal pipe or fitting, conforming to GB 15558, of nominal outside diameter greater than 63 mm. It is applicable to mechanical fittings in which all load-bearing elements of the joint are metal and specifies the anti-load capability at the end. This part specifies the fittings intended for use with PE pipes, including metal straight joint, elbow, flange, tee metal converter, these fittings producing either permanent joints or joints which can be dismantled. If it is intended for assembly with a metal pipe or fitting, such connections may be flanged or welded connections. This part is applicable only to mechanical fittings with normal operating-temperature limits between -20℃ and +40℃. It is the purpose of this part to provide performance requirements that will ensure full sealing and loading capacity of metal fitting and PE pipe connection joint so that the PE piping will yield rather than pull out of the mechanical joint when subjected to tensile forces or pressure. Note: This part is not intended for all the safety aspects, it is the responsibility of the users for this part of GB 26255 to establish suitable safe and health operation specifications and identify safety to apply the fittings in this part even though it is connected with the application. 2 Normative References The following documents contain provisions which, through reference in this part of GB 26255, constitute the provisions of this part. For dated reference, subsequent amendments to (excluding any amendments), or revisions of, any of these publications do not apply. However, parties to agreements based on this part are encouraged to investigate the possibility of applying the most recent editions of the documents. For any undated references, the latest edition of the document referred to applies. GB/T 2828.1-2003 Sampling Procedures for Inspection by Attributea - Part1: Sampling Schemes Indexed by Acceptance Quality Limit (AQL) for Lot-by-lot Inspection (ISO 780: 1997, MOD) GB/T 6111-2003 Thermoplastics Pipes for the Conveyance of Fluids - Resistance to Internal Pressure - Test Method (idt ISO 1167:1996) GB/T 8163-2008 Seamless Steel Tubes for Liquid Service (EN 10216-1: 2004, NEQ) GB/T 9112-2000 Types and Parameters for Steel Pipe Flanges GB/T 9113-2000 (all the parts) Steel Pipe Flanges GB/T 9114-2000 Hubbed Screwed Steel Pipe Flanges with Raised Face (neq ISO 7005-1:1992) GB/T 9115-2000 (all the parts) Steel Pipe Welding Neck Flanges GB/T 9116-2000 (all the parts) Hubbed Slip-on-welding Steel Pipe Flanges GB/T 9117-2000 (all the parts) Hubbed Socket Welding Steel Pipe Flanges GB/T 9118-2000 (all the parts) Loose Hubbed Steel Pipe Flanges with Welding Neck Collor GB/T 9119-2000 Slip-on-welding Plate Steel Pipe Flanges with Flat Face or Raised Face GB 15558.1 Buried Polyethylene (PE) Piping Systems for the Supply of Gaseous Fuels - Part 1: Pipes (ISO 4437:1997, MOD) GB 15558.2-2005 Buried Polyethylene (PE) Piping Systems for the Supply of Gaseous Fuels - Part 2: Fittings (ISO 8085-2:2001, MOD; ISO 8085-3:2001, MOD) GB/T 18252-2008 Plastics Piping and Ducting Systems - Determination of the Long - Term Hydrostatic Strength of Thermoplastics Materials in Pipe Form by Extrapolation GB/T 18475-2001 Thermoplastics Materials for Pipes and Fittings for Pressure Applications - Classification and Designation - Overall Service (Design) Coefficient (eqv ISO 12162:1995) GB/T 18684-2002 Specifications of Zinc/Chromate Coatings GB/T 19278-2003 General Terms and their Definitions of Thermoplastic Pipes, Fittings and Valves HG/T 3092-1997 Rubber Materials for Seal Ring in Gas Supply Pipe and Accessories (idt ISO 6447:1983) SY/T 0315-2005 Technological Standard of FBE External Fusion Bonded Epoxy Coating for Steel Pipeline SY/T 0413-2002 Technical Standard of Polyethene Coating for Buried Steel Pipeline 3 Terms and Definitions For the purpose of this part, terms and definitions established in GB/T 19278-2003 and those listed below apply. 3.1 Maximum operating pressure Maximum pressure at which a system can be operated continuously. 3.2 Mechanical fitting Fitting for assembling PE pipes with each other or with a metal pipe or fitting, which includes one or more compression zones to provide pressure integrity, leaktightness and resistance to end loads.

Contents of GB 26255.2-2010

Foreword I 1 Scope 2 Normative References 3 Terms and Definitions 4 Symbols and Abbreviated Terms 5 Materials 6 General Requirements for Steel-PE-transition Fitting 7 Specimen preparation 8 Requirements 9 Test Methods 10 Inspection Rules 11 Marking 12 Packaging and Storage Appendix A (Normative) Internal Pressure Leakage Test Method Bibliography