1、Designation:F278518aAn American National StandardStandard Specification forPolyamide 12 Gas Pressure Pipe,Tubing,and Fittings1This standard is issued under the fixed designation F2785;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,t
2、he year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This specification covers requirements and test methodsfor the characterization of polyamide 12 pipe,tubing,and
3、fittings for use in fuel gas mains and services for direct burialand reliner applications.The pipe and fittings covered by thisspecification are intended for use in the distribution of naturalgas.1.1.1 Pipe and fittings covered by this specification shall notbe joined using taper pipe threads.Joinin
4、g methods qualified inaccordance with the requirements of Title 49 CFR Part 192.283are acceptable.Generic fusion guidelines are given in Appen-dix X1.Design considerations are discussed in Appendix X2.In-plant quality control programs are specified in Annex A1.1.2 The text of this specification refe
5、rences notes,footnotes,and appendixes which provide explanatory material.Thesenotes and footnotes(excluding those in tables and figures)shallnot be considered as requirements of the specification.1.3 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses
6、are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety,h
7、ealth,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.NOTE1Pipe and fittings utilizing heat fusion joining techniquesproduced from compounds meeting the requirements of Group 3,Class 2,and Grade 3(PA323 or PA11)are intended for use with pipe manufa
8、cturedfrom compounds meeting the requirements of Group 3,class 2 and Grade3.Pipe and fittings utilizing heat fusion joining techniques produced fromcompounds meeting the requirements of Group 4,Class 2 and Grade 3(PA423 or PA12)are intended for use with pipe manufactured from com-pounds meeting the
9、requirements of Group 4,Class 2 and Grade 3.As perthe recommendations of the respective resin manufacturers,no crossfusion between PA 323(PA11)and PA 423(PA12)compounds ispermitted.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-iza
10、tion established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D543 Practices for Evaluating the Resistance of Plastics
11、toChemical ReagentsD618 Practice for Conditioning Plastics for TestingD648 Test Method for Deflection Temperature of PlasticsUnder Flexural Load in the Edgewise PositionD638 Test Method for Tensile Properties of PlasticsD789 Test Method for Determination of Relative Viscosityof Concentrated Polyamid
12、e(PA)SolutionsD792 Test Methods for Density and Specific Gravity(Rela-tive Density)of Plastics by DisplacementD1598 Test Method for Time-to-Failure of Plastic PipeUnder Constant Internal PressureD1599 Test Method for Resistance to Short-Time HydraulicPressure of Plastic Pipe,Tubing,and FittingsD1898
13、 Practice for Sampling of Plastics(Withdrawn 1998)3D1600 Terminology forAbbreviated Terms Relating to Plas-ticsD2122 Test Method for Determining Dimensions of Ther-moplastic Pipe and FittingsD2774 Practice for Underground Installation of Thermoplas-tic Pressure PipingD2290 Test Method for Apparent H
14、oop Tensile Strength ofPlastic or Reinforced Plastic PipeD2837 Test Method for Obtaining Hydrostatic Design Basisfor Thermoplastic Pipe Materials or Pressure Design Basisfor Thermoplastic Pipe ProductsD6779 Classification System for and Basis of Specificationfor Polyamide Molding and Extrusion Mater
15、ials(PA)F412 Terminology Relating to Plastic Piping Systems1This test method is under the jurisdiction of ASTM Committee F17 on PlasticPiping Systems and is the direct responsibility of Subcommittee F17.60 on Gas.Current edition approved Sept.1,2018.Published November 2018.Originallyapproved in 2009
16、 as F278509.Last previous edition approved in 2018 asF278518.DOI:10.1520/F2785-18A.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 B