1、Designation: F2785 10aAn 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. Scope1.1 This specification covers requirements and test methodsfor the characterization of polyamide 12 pipe
3、, 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 This specification does not cover threaded pipe. Ge-neric fusion guidelines are give
4、n in Appendix X1. Designconsiderations are discussed in Appendix X2. In-plant qualitycontrol programs are specified in Annex A1.1.2 The text of this specification references notes, footnotes,and appendixes which provide explanatory material. Thesenotes and footnotes (excluding those in tables and fi
5、gures) 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 are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.4 This standard
6、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 and health practices and determine the applica-bility of regulatory limitations prior to use.NOTE 1Pipe and fittings utilizing
7、 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 manufacturedfrom compounds meeting the requirements of Group 3, class 2 and Grade3. Pipe and fittings utilizing heat fusion joining technique
8、s 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 requirements of Group 4, Class 2 and Grade 3. As perthe recommendations of the respective resin manufacturers, no crossfusion betw
9、een PA 323 (PA11) and PA 423 (PA12) compounds ispermitted.2. Referenced Documents2.1 ASTM Standards:2D256 Test Methods for Determining the Izod PendulumImpact Resistance of PlasticsD543 Practices for Evaluating the Resistance of Plastics toChemical ReagentsD618 Practice for Conditioning Plastics for
10、 TestingD648 Test Method for Deflection Temperature of PlasticsUnder Flexural Load in the Edgewise PositionD638 Test Method for Tensile Properties of PlasticsD789 Test Methods for Determination of Solution Viscosi-ties of Polyamide (PA)D790 Test Methods for Flexural Properties of Unreinforcedand Rei
11、nforced Plastics and Electrical Insulating MaterialsD792 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
12、of Plastic Pipe, Tubing, and FittingsD1898 Practice for Sampling of Plastics3D1600 Terminology for Abbreviated Terms Relating toPlasticsD2122 Test Method for Determining Dimensions of Ther-moplastic Pipe and FittingsD2774 Practice for Underground Installation of Thermo-plastic Pressure PipingD2290 T
13、est Method for Apparent Hoop Tensile Strength ofPlastic or Reinforced Plastic Pipe by Split Disk MethodD2837 Test Method for Obtaining Hydrostatic Design Basisfor Thermoplastic Pipe Materials or Pressure Design Basisfor Thermoplastic Pipe ProductsD3418 Test Method for Transition Temperatures and En-
14、thalpies of Fusion and Crystallization of Polymers byDifferential Scanning CalorimetryD4066 Classification System for Nylon Injection and Ex-trusion Materials (PA)1This test method is under the jurisdiction of ASTM Committee F17 on PlasticPiping Systems and is the direct responsibility of Subcommitt
15、ee F17.60 on Gas.Current edition approved Dec. 1, 2010. Published January 2011. Originallyapproved in 2009 as F278509. Last previous edition approved in 2010 asF278510. DOI: 10.1520/F2785-10A.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at ser
16、viceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Co
17、nshohocken, PA 19428-2959, United States.D6779 Classification System for Polyamide Molding andExtrusion Materials (PA)F412 Terminology Relating to Plastic Piping SystemsF1025 Guide for Selection and Use of Full-Encirclement-Type Band Clamps for Reinforcement or Repair of Punc-tures or Holes in Polye
18、thylene Gas Pressure PipeF1473 Test Method for Notch Tensile Test to Measure theResistance to Slow Crack Growth of Polyethylene Pipesand ResinsF1733 Specification for Butt Heat Fusion Polyamide(PA)Plastic Fitting for Polyamide(PA) Plastic Pipe and TubingF1973 Specification for Factory Assembled Anod
19、eless Ris-ers and Transition Fittings in Polyethylene (PE) andPolyamide 11 (PA11) and Polyamide 12 (PA12) Fuel GasDistribution SystemsF2138 Specification for Excess Flow Valves for Natural GasServiceF2145 Specification for Polyamide 11 (PA 11) and Polya-mide 12 (PA12) Mechanical Fittings for Use on
20、OutsideDiameter Controlled Polyamide 11 and Polyamide 12 Pipeand TubingF2767 Specification for Electrofusion Type Polyamide-12Fittings for Outside Diameter Controlled Polyamide-12Pipe and Tubing for Gas Distribution2.2 ANSI Standards:4B 16.40 Manually Operated Thermoplastic Gas Shutoffsand Valves in
21、 Gas Distribution SystemsB 31.8 Gas Transmission and Distribution Piping Systems2.3 Federal Specifications:5Fed. Std. No. 123 Marking for Shipment (Civil Agencies)OPS Part 192 Title 49 ,Title 49 Code of Federal Regulations2.4 Military Standards:6MIL-STD-129 Marking for Shipment and StorageMIL-STD-12
22、35 (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 melting behaviour (melt-ing temperature or melting range) of semi-crystallinepolymers
23、 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 - Determination of tensile properties - Part1: General principles5272 Plastics - Determ
24、ination of tensile properties - Part2: Test conditions for moulding and extrusion plastics178 Plastics - Determination of flexural properties180/1A Plastics - Determination of Izod impact strength751 Plastics - Determination of temperature of deflectionunder load - Part 1: General test method752 Pla
25、stics - Determination of temperature of deflectionunder load - Part 2: Plastics and eboniteISO 22621 Part 1 Plastics piping systems for the supply ofgaseous fuels for maximum operating pressure up to andincluding 2 MPa (20 bar) Polyamide (PA) : General2.6 Plastic Pipe Institute:7PPI TR3 Policies and
26、 Procedures for Developing Hydro-static Design Basis (HDB), Pressure Design Basis (PDB),Strength Design Basis (SDB), and Minimum RequiredStrength (MRS) Ratings for Thermoplastic Piping Mate-rials or PipePPI TR4 Hydrostatic Design Bases and Maximum Recom-mended Hydrostatic Design Stresses for Thermop
27、lasticPiping MaterialsPPI TN7 Nature of Hydrostatic Stress Rupture Curves2.7 Other Standards:8National Fire Protection Association: NFPA 58 , Storageand Handling Liquefied Petroleum Gases3. Terminology3.1 DefinitionsDefinitions are in accordance with Termi-nology F412, and abbreviations are in accor
28、dance with Termi-nology D1600, unless otherwise specified.3.2 The gas industry terminology used in this specificationis in accordance with ANSI B 31.8 or CFR OPS Part 192 Title49, unless otherwise indicated.3.3 The term pipe used herein refers to both pipe and tubingunless specifically stated otherw
29、ise.3.4 Definitions of Terms Specific to This Standard:3.5 re-rounding equipment, nequipment used to reformthe pipe and permanently reduce ovality to 5% or less.3.6 rounding equipment, nequipment, devices, clamps,and so forth, used to temporarily hold the pipe round whileout-of-roundness measurement
30、s are made, or a joining proce-dure (heat fusion, electrofusion, or mechanical) is performed.3.7 standard thermoplastic material designated code,nthe pipe material designation code shall consist of theabbreviation for the polyamide (PA) followed by Arabicnumerals which describe the short term proper
31、ties in accor-dance with Classifications D4066 or D6779, the hydrostaticdesign stress for water at 73.4F (23C) in units of 100 psi withany decimal figures dropped. Where the hydrostatic designstress code contains less than two figures, a zero is used beforethe number. Thus, a complete material desig
32、nation code shallconsist of two letters and five figures for polyamide pipematerials. For example, PA 42316 is a grade of polyamide 12with a 1600 psi design stress for water at 73.4F (23C). Thehydrostatic design stresses for gas are not used in this desig-nation code.4Available from American Nationa
33、l Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.5Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http:/www.dodssp.daps.mil.6Available from International Organization for Stan
34、dardization (ISO), 1, ch. dela Voie-Creuse, Case postale 56, CH-1211, Geneva 20, Switzerland, 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 Battery
35、marchPark, Quincy, MA 02169-7471, http:/www.nfpa.org.F2785 10a23.8 thermoplastic pipe dimension ratio (DR), nthe ratio ofpipe diameter to wall thickness. It is calculated by dividing thespecified outside diameter of the pipe, in inches, by theminimum specified wall thickness, in inches. The standard
36、dimension ratio (SDR) is a common numbering system whichis derived from the ANSI preferred number series R 10.3.9 toe-in, na small reduction of the outside diameter atthe cut end of a length of thermoplastic pipe.4. Requirements for Materials4.1 GeneralThe polyamide material used to make pipeand fit
37、tings 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 TR4.4.2 ClassificationPolyamide materials suitable for use inthe manufacturing of pipe and fitti
38、ngs under this specificationshall be classified in accordance with Classifications D4066and D6779, as shown in Table 1.4.3 Short- and Long-Term PropertiesPolyamide pipe andfittings shall be made from a PA material which also satisfiesthe combinations of short- and long-term property require-ments sh
39、own 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 failure by RCP in accordancewith 6.7. The data obtained shall be made available
40、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 tested and all thinner wall pipes.4.5 Rework MaterialClean rework material of the sam
41、ecommercial 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 documentation system to allow fortraceability of raw materials including percentage and ma
42、terialclassification (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.5. Requirements for Pipe and Fittings5.1 GeneralPipe shall be supplied in either
43、 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, foreigninclusion, blisters, and dents, or other injurious defects. Thepipe and fitting
44、s 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 thickness and outside diameter.TABLE 1 Classifications D4066 and D6779Classification ASTM
45、 Test Method ISO Test Method DesignationPA4 (group)2 (class)3 (grade)PolyamidePA 12Heat stabilizedRelative viscosity, minorViscosity number, min.D789 ISO 307 2.06211Melt point, C D3418 ISO 3146 170185Specific gravity D792 ISO 1183 1.001.06Tensile strength, min,MPaD638 ISO 5271 andISO 527235Elongatio
46、n (ultimate), min, % D638 ISO 5271 andISO 5272150Flexural modulus, min,MPaD790 ISO 178 1000Izod impact resistanceorCharpy impact resistancemin J/MD256 ISO 180/1A 25Deflection temperature,at 1.82 Mpa, min CD648 ISO 751 andISO 75240TABLE 2 Short and Long Term Property RequirementsPA MaterialDesignatio
47、n CodeShort-Term inAccordance withD4066 or D6779Long-Term inAccordance withD2837PA42316 PA423 HDB of 3150 psifor 73F (23C)F2785 10a35.3.1.1 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 accordan
48、ce with 6.5.1.1,the outside diameter at the cut end of the pipe shall not be morethan 1.5 % smaller than the undistorted outside diameter.Measurement of the undistorted outside diameter shall be madeno closer than 1.5 pipe diameters or 11.8 in. (300 mm),whichever distance is less, from the cut end o
49、f the pipe.Undistorted outside diameter shall meet the requirements ofTable 3 or Table 4.5.3.1.3 Wall ThicknessThe wall thickness shall be asspecified in Table 4 or Table 5 when measured in accordancewith 6.5.1.2. The minimum wall thickness at any point ofmeasurement shall be not less than the minimum wall thicknessspecified in Table 4 or Table 5.5.3.1.4 Wall Thickness Eccentricity Range The wallthickness eccentricity range shall be within 12 % whenmeasured in accordance with 6.5.1.3.5.3.1.5 OvalityThe ovality (cross
