1、Designation: F 2785 09An American National StandardStandard Specification forPolyamide 12 Gas Pressure Pipe, Tubing, and Fittings1This standard is issued under the fixed designation F 2785; the number immediately following the designation indicates the year oforiginal adoption or, in the case of rev
2、ision, 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 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 This specification does not cover threaded pipe. Ge-neric fusion guidelines are giv
4、en 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 f
5、igures) 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 utilizin
7、g 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 techniqu
8、es 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 bet
9、ween PA 323 (PA11) and PA 423 (PA12) compounds ispermitted.2. Referenced Documents2.1 ASTM Standards:2D 543 Practices for Evaluating the Resistance of Plastics toChemical ReagentsD 618 Practice for Conditioning Plastics for TestingD 638 Test Method for Tensile Properties of PlasticsD 789 Test Method
10、s for Determination of Solution Viscosi-ties of Polyamide (PA)D 1598 Test Method for Time-to-Failure of Plastic PipeUnder Constant Internal PressureD 1599 Test Method for Resistance to Short-Time Hydrau-lic Pressure of Plastic Pipe, Tubing, and FittingsD 1898 Practice for Sampling of Plastics3D 1600
11、 Terminology for Abbreviated Terms Relating toPlasticsD 2122 Test Method for Determining Dimensions of Ther-moplastic Pipe and FittingsD 2774 Practice for Underground Installation of Thermo-plastic Pressure PipingD 2290 Test Method for Apparent Hoop Tensile Strength ofPlastic or Reinforced Plastic P
12、ipe by Split Disk MethodD 2837 Test Method for Obtaining Hydrostatic DesignBasis for Thermoplastic Pipe Materials or Pressure DesignBasis for Thermoplastic Pipe ProductsD 4066 Classification System for Nylon Injection and Ex-trusion Materials (PA)D 6779 Classification System for Polyamide Molding an
13、dExtrusion Materials (PA)F 412 Terminology Relating to Plastic Piping SystemsF 1025 Guide for Selection and Use of Full-Encirclement-Type Band Clamps for Reinforcement or Repair of Punc-tures or Holes in Polyethylene Gas Pressure PipeF 1473 Test Method for Notch Tensile Test to Measure theResistance
14、 to Slow Crack Growth of Polyethylene Pipesand ResinsF 1733 Specification for Butt Heat Fusion Polyamide(PA)Plastic Fitting for Polyamide(PA) Plastic Pipe and TubingF 1973 Specification for Factory Assembled Anodeless Ris-ers and Transition Fittings in Polyethylene (PE) andPolyamide 11 (PA11) and Po
15、lyamide 12 (PA12) Fuel GasDistribution SystemsF 2138 Specification for Excess Flow Valves for NaturalGas Service1This 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 Aug. 1, 2
16、009. Published September 2009.2For 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.3Withdrawn. The last approved v
17、ersion of this historical standard is referencedon www.astm.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.F 2145 Specification for Polyamide 11 (PA 11) and Polya-mide 12 (PA12) Mechanical Fittings for Use on OutsideDiameter Con
18、trolled Polyamide 11 and Polyamide 12 Pipeand TubingF 2767 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 Gas Distribution
19、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-1235 (ORD) Single- a
20、nd 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) Polyamide (PA) : General2.6 Plastic Pipe Institute:8PPI TR3
21、 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 and Maximum Recom-mended Hydrostatic Design Stresse
22、s 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 accordance with Termi-nology F 412, and abbreviations
23、 are in accordance with Ter-minology D 1600, 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
24、 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 temporarily hold the pipe round whileout-of-roundne
25、ss 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) followed by Arabicnumerals which describe the sho
26、rt term properties in accor-dance with Classifications D 4066 or D 6779, 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 complet
27、e 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 used in this desig-nation code.3.8 thermoplasti
28、c 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 common numbering system whichis derived from the ANS
29、I 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 reworked material (see 4.5 ) andshall have a Plastics
30、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 specificationshall be classified in accordance with Classificati
31、ons D 4066and D 6779, 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 Rapid Crack Propagation (RCP) forMaterialslT
32、he 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 uponrequest without limitations on disclosure, and shall not subse-quently be
33、 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 samecommercial designation, generated from the manufacturersown pipe and fitting
34、 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 material4Available from American National Standards Institute (ANSI), 25 W. 43r
35、d 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 Standardization (ISO), 1, ch. dela Voie-Cre
36、use, 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 BatterymarchPark, Quincy, MA 02169-7471, http:
37、/www.nfpa.org.F2785092classification (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 su
38、pplied 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, blisters, and dents, or other injurious defects. The
39、pipe 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 diameter.5.3.1.1 DiametersThe outside diameter shal
40、l 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 outside diameter.Measurement of the undistorted outsi
41、de 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 thickness shall be asspecified in Table 4 or Table 5 w
42、hen 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 accordanc
43、e 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 disagreement, conditioned per 6.3.NOTE 2Other factors, th
44、at 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 installation, coiled pipe larger than 3 in. IPS (88
45、.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 iscorrected when joining equipment is applied to roundab
46、le pipe, or by fieldprocessing roundable pipe through re-rounding and straightening equip-ment during installation.5.3.1.6 LengthThe pipe shall be supplied in straightlengths or coils as agreed upon between the manufacturer andthe purchaser. The length shall not be less than the minimumlength agreed
47、 upon when corrected to 73F (23C).5.3.1.7 When sizes other than those listed in Table 3, Table4or Table 5 are used, tolerances shall be: for outside diameter,TABLE 1 Classifications D 4066 and D 6779Classification DesignationPA Polyamide4 (group) 12 nylon2 (class) Heat stabilized3 (grade)Relative vi
48、scosity, min 2.06Melt point, CSpecification D 789170195Specific gravity 1.001.06Tensile strength, min,Test Method D 63835MPaElongation (ultimate), min, 150%Flexural modulus, min,Test Method D 6381000MpaCharpy or Izod impact 25resistance, min, J/MDeflection temperature,Test Method D 64835min at 1.82
49、MpaMoisture “as received”, %, 0.10maxSpecification D 789TABLE 2 Short and Long Term Property RequirementsPA MaterialDesignation CodeShort-Term inAccordance withD 4066 or D 6779Long-Term inAccordance withD 2837PA42316 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) 0.016(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
