1、Designation: F2785 18 An 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 revi
2、sion, the 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 pip
3、e, tubing, andfittings 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
4、 threads. Joining 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
5、specification references 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 value
6、s given in parentheses 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 estab
7、lish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.NOTE 1Pipe and fittings utilizing heat fusion joining techniquesproduced from compounds meeting the requirements of Group 3, Class 2,and Grade 3 (PA323 or PA11) are i
8、ntended for use with pipe manufacturedfrom 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 manu
9、factured from com-pounds meeting the 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 internati
10、onally recognized principles on standard-ization 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 Prac
11、tices for Evaluating the Resistance of Plastics 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 Methods for Determinat
12、ion of Solution Viscosi-ties of Polyamide (PA)D792 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 Pla
13、stic Pipe, Tubing, and FittingsD1898 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 P
14、ipingD2290 Test Method for Apparent Hoop 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
15、Polyamide Molding and Extrusion Materials (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 April 15, 2018. Publishe
16、d June 2018. Originallyapproved in 2009 as F278509. Last previous edition approved in 2012 asF278512. DOI: 10.1520/F2785-18.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, r
17、efer 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 Barr Harbor Drive, PO Box C700, West Conshohocken, PA
18、19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Te
19、chnical Barriers to Trade (TBT) Committee.1F1025 Guide for Selection and Use of Full-Encirclement-Type Band Clamps for Reinforcement or Repair of Punc-tures or Holes in Polyethylene Gas Pressure PipeF1473 Test Method for Notch Tensile Test to Measure theResistance to Slow Crack Growth of Polyethylen
20、e Pipesand ResinsF1733 Specification for Butt Heat Fusion Polyamide(PA)Plastic Fitting for Polyamide(PA) Plastic Pipe and TubingF1973 Specification for Factory Assembled Anodeless Ris-ers and Transition Fittings in Polyethylene (PE) andPolyamide 11 (PA11) and Polyamide 12 (PA12) Fuel GasDistribution
21、 SystemsF2138 Specification for Excess Flow Valves for Natural GasServiceF2145 Specification for Polyamide 11 (PA 11) and Poly-amide 12 (PA12) Mechanical Fittings for Use on OutsideDiameter Controlled Polyamide 11 and Polyamide 12 Pipeand TubingF2767 Specification for Electrofusion Type Polyamide-12
22、Fittings for Outside Diameter Controlled Polyamide-12Pipe and Tubing for Gas DistributionF2897 Specification for Tracking and Traceability EncodingSystem of Natural Gas Distribution Components (Pipe,Tubing, Fittings, Valves, and Appurtenances)2.2 ANSI Standards:4B 16.40 Manually Operated Thermoplast
23、ic Gas Shutoffs andValves in Gas Distribution SystemsB 31.8 Gas Transmission and Distribution Piping Systems2.3 Federal Standards:5Fed. Std. No. 123 Marking for Shipment (Civil Agencies)OPS Part 192 Title 49 ,Title 49 Code of Federal Regulations49 CFR Part 192.283 Plastic pipe: Qualifying joiningpro
24、cedures.2.4 Military Standards:6MIL-STD-129 Marking for Shipment and StorageMIL-STD-1235 (ORD) Single- and Multi-Level Continu-ous Sampling Procedures and Tables for Inspection byAttributes2.5 ISO Standards:6307 Plastics - Polyamides - Determination of viscositynumber3146 Plastics - Determination of
25、 melting behaviour (melt-ing temperature or melting range) of semi-crystallinepolymers by capillary tube and polarizing-microscopemethods1183 Plastics - Methods for determining the density ofnon-cellular plastics - Part 1: Immersion method, liquidpyknometer method and titration method5271 Plastics -
26、 Determination of tensile properties - Part1: General principles5272 Plastics - Determination of tensile properties - Part2: Test conditions for moulding and extrusion plastics178 Plastics - Determination of flexural properties179 Plastics - Determination of Charpy impact properties -Part 1: Non-ins
27、trumented impact test751 Plastics - Determination of temperature of deflectionunder load - Part 1: General test method752 Plastics - Determination of temperature of deflectionunder load - Part 2: Plastics and eboniteISO 22621 Part 1 Plastics piping systems for the supply ofgaseous fuels for maximum
28、operating pressure up to andincluding 2 MPa (20 bar) Polyamide (PA) : General2.6 Plastic Pipe Institute:7PPI TR3 Policies and Procedures for Developing Hydro-static Design Basis (HDB), Pressure Design Basis (PDB),Strength Design Basis (SDB), and Minimum RequiredStrength (MRS) Ratings for Thermoplast
29、ic Piping Mate-rials or PipePPI TR4 Hydrostatic Design Bases and Maximum Recom-mended Hydrostatic Design Stresses for ThermoplasticPiping MaterialsPPI TN7 Nature of Hydrostatic Stress Rupture Curves2.7 Other Standards:8National Fire Protection Association: NFPA 58 , Storage andHandling Liquefied Pet
30、roleum Gases3. Terminology3.1 DefinitionsDefinitions are in accordance with Termi-nology F412, and abbreviations are in accordance with Termi-nology D1600, unless otherwise specified.3.2 The gas industry terminology used in this specificationis in accordance with ANSI B31.8 or CFR OPS Part 192 Title
31、49, unless otherwise indicated.3.3 The term pipe used herein refers to both pipe and tubingunless specifically stated otherwise.3.4 Definitions of Terms Specific to This Standard:3.4.1 re-rounding equipment, nequipment used to reformthe pipe and permanently reduce ovality to 5% or less.3.4.2 roundin
32、g equipment, nequipment, devices, clamps,and so forth, used to temporarily hold the pipe round whileout-of-roundness measurements are made, or a joining proce-dure (heat fusion, electrofusion, or mechanical) is performed.3.4.3 standard thermoplastic material designated code,nthe pipe material design
33、ation code shall consist of theabbreviation for the polyamide (PA) followed by Arabicnumerals which describe the short term properties in accor-dance with Classification D6779, the hydrostatic design stressfor water at 73.4F (23C) in units of 100 psi with any decimalfigures dropped. Where the hydros
34、tatic design stress codecontains less than two figures, a zero is used before the number.Thus, a complete material designation code shall consist of twoletters and five figures for polyamide pipe materials. For4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, Ne
35、w York, NY 10036, http:/www.ansi.org.5Available from DLA Document Services, Building 4/D, 700 Robbins Ave.,Philadelphia, PA 19111-5094, http:/quicksearch.dla.mil.6Available from International Organization for Standardization (ISO), 1, ch. dela Voie-Creuse, Case postale 56, CH-1211, Geneva 20, Switze
36、rland, http:/www.iso.ch.7Available from Plastics Pipe Institute (PPI), 105 Decker Court, Suite 825,Irving, TX 75062, http:/www.plasticpipe.org.8Available from National Fire Protection Association (NFPA), 1 BatterymarchPark, Quincy, MA 02169-7471, http:/www.nfpa.org.F2785 182example, PA 42316 is a gr
37、ade of polyamide 12 with a 1600 psidesign stress for water at 73.4F (23C). The hydrostatic designstresses for gas are not used in this designation code.3.4.4 thermoplastic pipe dimension ratio (DR), nthe ratioof pipe diameter to wall thickness. It is calculated by dividingthe specified outside diame
38、ter of the pipe, in inches, by theminimum specified wall thickness, in inches. The standarddimension ratio (SDR) is a common numbering system whichis derived from the ANSI preferred number series R 10.3.4.5 toe-in, na small reduction of the outside diameter atthe cut end of a length of thermoplastic
39、 pipe.4. Requirements for Materials4.1 GeneralThe polyamide material used to make pipeand fittings shall be virgin or reworked material (see 4.5 ) andshall have a Plastics Pipe Institute (PPI) long-term hydrostaticdesign stress and hydrostatic design basis rating as determinedper PPI TR3 and PPI TR4
40、.4.2 ClassificationPolyamide materials suitable for use inthe manufacturing of pipe and fittings under this specificationshall be classified in accordance with Classification D6779,asshown in Table 1.4.3 Short- and Long-Term PropertiesPolyamide pipe andfittings shall be made from a PA material which
41、 also satisfiesthe combinations of short- and long-term property require-ments shown in Table 2.4.4 Resistance to Rapid Crack Propagation (RCP) forMaterialslThe material classification (formulation) used inthe manufacture of pipe and fittings under this specificationshall be tested for resistance to
42、 failure by RCP in accordancewith 6.7. The data obtained shall be made available uponrequest without limitations on disclosure, and shall not subse-quently be subject to disclosure limitations when used byothers. The values obtained are applicable to all pipes with thewall thickness of the pipe test
43、ed and all thinner wall pipes.4.5 Rework MaterialClean rework material of the samecommercial designation, generated from the manufacturersown pipe and fitting production shall not be used unless thepipe and fittings produced meet all the requirements of thisspecification.4.6 DocumentationA documenta
44、tion system to allow fortraceability of raw materials including percentage and materialclassification (or designation, if applicable) of rework materialsused in the manufacture of the pipe product meeting therequirements of this specification shall exist and be supplied tothe purchaser, if requested
45、.5. Requirements for Pipe and Fittings5.1 GeneralPipe shall be supplied in either coils orstraight lengths.Any pipe supplied in coils must meet the samerequirements before and after coiling.5.2 WorkmanshipThe pipe and fittings shall be homoge-neous throughout and free of visible cracks, holes, forei
46、gninclusion, blisters, and dents, or other injurious defects. Thepipe and fittings shall be as uniform as commercially practi-cable in color, opacity, density, and other physical properties.5.3 Pipe and Tubing Dimensions and Tolerances:5.3.1 DimensionThe dimensions shall be specified bywall thicknes
47、s and outside diameter.5.3.1.1 DiametersThe outside diameter shall meet therequirements given in Table 3 or Table 4 when measured inaccordance with 6.5.5.3.1.2 Toe-InWhen measured in accordance with 6.5.1.1,the outside diameter at the cut end of the pipe shall not be morethan 1.5 % smaller than the
48、undistorted outside diameter.Measurement of the undistorted outside diameter shall be madeno closer than 1.5 pipe diameters or 11.8 in. (300 mm),TABLE 1 Classification D6779Classification ASTM Test Method ISO Test Method DesignationPA4 (group)2 (class)3 (grade)PolyamidePA 12Heat stabilizedViscosity
49、number, min. D789 ISO 307 211Specific gravity D792 ISO 1183 1.001.06Tensile strength, min,psi (MPa)D638 ISO 5271 andISO 52725000 (35)Tensile Modulus, min,psi (MPa)ISO 5271 andISO 5272145000 (1000)Charpy impact resistance,minISO 179 25Deflection temperature,at 264 psi (1.82 MPa), min F (C)D648 ISO 751 andISO 75295 (35)TABLE 2 Short and Long Term Property RequirementsPA MaterialDesignation CodeShort-Term inAccordance withD6779Long-Term inAccordance withD2837PA42316 PA423 HDB of 3150 psifor 73F (23C)F2785 183whichever dista
