1、Designation: F2785 091An 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.1NOTETable 1 was editorially revised in March 2010.1. Scope1.1 This specification covers requirements and test m
3、ethodsfor the characterization of polyamide 12 pipe, 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
4、 threaded pipe. Ge-neric fusion guidelines are given 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. Theseno
5、tes 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 are mathematicalconversions to SI units that are provided for information onl
6、yand 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 and health practices and determine the applica-bility of regulatory limitat
7、ions 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 intended for use with pipe manufacturedfrom compounds meeting the requirements of Group 3, class 2 and Grade3. Pipe a
8、nd 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 requirements of Group 4, Class 2 and Grade 3. As perthe recommendations of the
9、respective resin manufacturers, no crossfusion between PA 323 (PA11) and PA 423 (PA12) compounds ispermitted.2. Referenced Documents2.1 ASTM Standards:2D543 Practices for Evaluating the Resistance of Plastics toChemical ReagentsD618 Practice for Conditioning Plastics for TestingD638 Test Method for
10、Tensile Properties of PlasticsD789 Test Methods for Determination of Solution Viscosi-ties of Polyamide (PA)D1598 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
11、 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 Test Method for Apparent Hoop Tensile Stren
12、gth 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 ProductsD4066 Classification System for Nylon Injection and Ex-trusion Materials (PA)D6779 Classificati
13、on 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 Polyethylene Gas Pressure Pipe1This test method is under the jur
14、isdiction of ASTM Committee F17 on PlasticPiping Systems and is the direct responsibility of Subcommittee F17.60 on Gas.Current edition approved Aug. 1, 2009. Published September 2009. DOI:10.1520/F2785-09E01.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Custom
15、er Service at serviceastm.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
16、Box C700, West Conshohocken, PA 19428-2959, United States.F1473 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 Specifi
17、cation for Factory Assembled Anodeless 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
18、) Mechanical Fittings for Use on 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 Thermo
19、plastic Gas Shutoffsand Valves in 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 f
20、or Shipment and StorageMIL-STD-1235 (ORD) Single- and Multi-Level Continu-ous Sampling Procedures and Tables for Inspection byAttributes2.5 ISO Standards:7ISO 22621 Part 1 Plastics piping systems for the supply ofgaseous fuels for maximum operating pressure up to andincluding 2 MPa (20 bar) Polyamid
21、e (PA) : General2.6 Plastic Pipe Institute:8PPI 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 Thermoplastic Piping Mate-rials or PipePPI TR4 Hydrostatic Design Bases
22、and Maximum Recom-mended Hydrostatic Design Stresses for ThermoplasticPiping MaterialsPPI TN7 Nature of Hydrostatic Stress Rupture Curves2.7 Other Standards:National Fire Protection Association: NFPA 58 , Storageand Handling Liquefied Petroleum Gases3. Terminology3.1 DefinitionsDefinitions are in ac
23、cordance 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 B 31.8 or CFR OPS Part 192 Title49, unless otherwise indicated.3.3 The term pipe used herein
24、refers to both pipe and tubingunless specifically stated otherwise.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 te
25、mporarily hold the pipe round whileout-of-roundness measurements 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)
26、followed by Arabicnumerals which describe the short term properties 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
27、 zero is used beforethe number. Thus, a complete material designation 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
28、used in this desig-nation code.3.8 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 standarddimension ratio (SDR) is a commo
29、n 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 fittings shall be virgin or reworke
30、d 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 fittings under this specificationshal
31、l 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 shown in Table 2.4.4 Resistance to
32、 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 upon4Available from American Nat
33、ional 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
34、Standardization (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 Bat
35、terymarchPark, Quincy, MA 02169-7471, http:/www.nfpa.org.F2785 0912request 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
36、 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 documentation system to all
37、ow 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.5. Requirements f
38、or 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, foreigninclusion, blist
39、ers, 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 thickness and outside diam
40、eter.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 undistorted outsid
41、e 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 of the pipe.Undistorted outside diameter shall meet the requirements ofTable 3 or Table 4.5.3.1.3 Wall ThicknessThe wall thickne
42、ss 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
43、 shall be within 12 % whenmeasured in accordance with 6.5.1.3.5.3.1.5 OvalityThe ovality (cross section) of 3 in. IPS(88.9 mm) and smaller pipe shall not exceed 5 % whenmeasured in accordance with 6.5.3. Measurements of coiledpipe shall be made on a sample cut from the coil, and in caseof disagreeme
44、nt, conditioned per 6.3.NOTE 2Other factors, that is, installation compaction, static soilloading, and dynamic vehicular loads may increase the ovality; therefore,5 % was chosen as the limit for the amount contributed by manufacturing,packing, in-plant storage, and shipping.(1) Before or during inst
45、allation, coiled pipe larger than 3 in. IPS (88.9mm) shall be processed by the installer through re-rounding equipmentthat corrects ovality to 5% or less.NOTE 3Ovality is a packaging condition that occurs when roundablepipe is wound into a coilthe pipe flattens out as it is coiled. Ovality isTABLE 1
46、 Classifications D4066 and D6779Classification DesignationPA Polyamide4 (group) 12 nylon2 (class) Heat stabilized3 (grade)Relative viscosity, min 2.06Melt point, CSpecification D789170195Specific gravity 1.001.06Tensile strength, min,Test Method D63835 MPaElongation (ultimate), min, 150 %Flexural mo
47、dulus, min,Test Method D6381000 MpaCharpy or Izod impact 25 resistance, min, J/MDeflection temperature, 35 min at 1.82 MpaMoisture “as received”, %,Specification D7890.10 maxThis table was editorially revised in March 2010.TABLE 2 Short and Long Term Property RequirementsPA MaterialDesignation CodeS
48、hort-Term inAccordance withD4066 or D6779Long-Term inAccordance withD2837PA42316 PA423 HDB of 3150 psifor 73F (23C)TABLE 3 Outside Diameters and Tolerances for PA12 Pipe, in. (mm)Nominal Pipe Size Outside Diameter Tolerance Maximum out-of-roundness(SDR 13.5 SDR 11)12 0.840 (21.3) 60.004 (60.102) 0.0
49、16(0.406)34 1.050 (26.7) 60.004 (60.102) 0.02(0.508)1 1.315 (33.4) 60.005 (60.127) 0.02(0.508)114 1.660 (42.1) 60.005 (60.127) 0.024(0.61)2 2.375 (60.3) 60.006 (60.152) 0.024(0.61)3 3.500 (88.9) 60.008 (60.203) 0.03(0.762)4 4.500 (114.3) 60.009 (60.229) 0.03(0.762)5 5.563 (141.3) 60.010 (60.254) 0.06(1.524)6 6.625 (168.3) 60.011 (60.279) 0.07(1.778)8 8.625 (219.1) 60.013 (60.330) 0.08(2.04)10 10.750 (273.0) 60.015 (60.381) 0.1(2.5)12 12.750 (323.8) 60.017(60.432) 0.1(2.5)F2785 0913corrected when joining equipment is applied to round
