1、Designation: F2785 18F2785 18a 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 cas
2、e of revision, 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 methods for the characterization of polyam
3、ide 12 pipe, tubing, and fittingsfor use in fuel gas mains and services for direct burial and reliner applications. The pipe and fittings covered by this specificationare intended for use in the distribution of natural gas.1.1.1 Pipe and fittings covered by this specification shall not be joined usi
4、ng taper pipe threads. Joining methods qualified inaccordance with the requirements of Title 49 CFR Part 192.283 are acceptable. Generic fusion guidelines are given in AppendixX1. Design considerations are discussed in Appendix X2. In-plant quality control programs are specified in Annex A1.1.2 The
5、text of this specification references notes, footnotes, and appendixes which provide explanatory material. These notesand footnotes (excluding those in tables and figures) shall not be considered as requirements of the specification.1.3 The values stated in inch-pound units are to be regarded as sta
6、ndard. The values given in parentheses are mathematicalconversions to SI units that are provided for information only and are not considered standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this
7、 standard to establish appropriate safety, health, and environmental practices and determine the applicability ofregulatory limitations prior to use.NOTE 1Pipe and fittings utilizing heat fusion joining techniques produced from compounds meeting the requirements of Group 3, Class 2, and Grade3 (PA32
8、3 or PA11) are intended for use with pipe manufactured from compounds meeting the requirements of Group 3, class 2 and Grade 3. Pipe andfittings utilizing heat fusion joining techniques produced from compounds meeting the requirements of Group 4, Class 2 and Grade 3 (PA 423 or PA12)are intended for
9、use with pipe manufactured from compounds meeting the requirements of Group 4, Class 2 and Grade 3. As per the recommendationsof the respective resin manufacturers, no cross fusion between PA 323 (PA11) and PA 423 (PA12) compounds is permitted.1.5 This international standard was developed in accorda
10、nce with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Stan
11、dards:2D543 Practices for Evaluating the Resistance of Plastics to Chemical ReagentsD618 Practice for Conditioning Plastics for TestingD648 Test Method for Deflection Temperature of Plastics Under Flexural Load in the Edgewise PositionD638 Test Method for Tensile Properties of PlasticsD789 Test Meth
12、od for Determination of Relative Viscosity of Concentrated Polyamide (PA) SolutionsD792 Test Methods for Density and Specific Gravity (Relative Density) of Plastics by DisplacementD1598 Test Method for Time-to-Failure of Plastic Pipe Under Constant Internal PressureD1599 Test Method for Resistance t
13、o Short-Time Hydraulic Pressure of Plastic Pipe, Tubing, and FittingsD1898 Practice for Sampling of Plastics (Withdrawn 1998)3D1600 Terminology for Abbreviated Terms Relating to PlasticsD2122 Test Method for Determining Dimensions of Thermoplastic Pipe and FittingsD2774 Practice for Underground Inst
14、allation of Thermoplastic Pressure Piping1 This test method is under the jurisdiction of ASTM Committee F17 on Plastic Piping Systems and is the direct responsibility of Subcommittee F17.60 on Gas.Current edition approved April 15, 2018Sept. 1, 2018. Published June 2018November 2018. Originally appr
15、oved in 2009 as F278509. Last previous edition approvedin 20122018 as F278512.18. DOI: 10.1520/F2785-18.10.1520/F2785-18A.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refe
16、r to the standards Document Summary page on the ASTM website.3 The last approved version of this historical standard is referenced on www.astm.org.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the pr
17、evious version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of C
18、hanges section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1D2290 Test Method for Apparent Hoop Tensile Strength of Plastic or Reinforced Plastic PipeD2837 Test Method for Obtaining Hydrostatic De
19、sign Basis for Thermoplastic Pipe Materials or Pressure Design Basis forThermoplastic Pipe ProductsD6779 Classification System for and Basis of Specification for Polyamide Molding and Extrusion Materials (PA)F412 Terminology Relating to Plastic Piping SystemsF1025 Guide for Selection and Use of Full
20、-Encirclement-Type Band Clamps for Reinforcement or Repair of Punctures or Holesin Polyethylene Gas Pressure PipeF1473 Test Method for Notch Tensile Test to Measure the Resistance to Slow Crack Growth of Polyethylene Pipes and ResinsF1733 Specification for Butt Heat Fusion Polyamide(PA) Plastic Fitt
21、ing for Polyamide(PA) Plastic Pipe and TubingF1973 Specification for Factory Assembled Anodeless Risers and Transition Fittings in Polyethylene (PE) and Polyamide 11(PA11) and Polyamide 12 (PA12) Fuel Gas Distribution SystemsF2138 Specification for Excess Flow Valves for Natural Gas ServiceF2145 Spe
22、cification for Polyamide 11 (PA 11) and Polyamide 12 (PA12) Mechanical Fittings for Use on Outside DiameterControlled Polyamide 11 and Polyamide 12 Pipe and TubingF2767 Specification for Electrofusion Type Polyamide-12 Fittings for Outside Diameter Controlled Polyamide-12 Pipe andTubing for Gas Dist
23、ributionF2897 Specification for Tracking and Traceability Encoding System of Natural Gas Distribution Components (Pipe, Tubing,Fittings, Valves, and Appurtenances)2.2 ANSI Standards:4B 16.40 Manually Operated Thermoplastic Gas Shutoffs and Valves in Gas Distribution SystemsB 31.8 Gas Transmission an
24、d 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 joining procedures.2.4 Military Standards:6MIL-STD-129 Marking for Shipment and StorageMI
25、L-STD-1235 (ORD) Single- and Multi-Level Continuous Sampling Procedures and Tables for Inspection by Attributes2.5 ISO Standards:6307 Plastics - Polyamides - Determination of viscosity number3146 Plastics - Determination of melting behaviour (melting temperature or melting range) of semi-crystalline
26、 polymers bycapillary tube and polarizing-microscope methods1183 Plastics - Methods for determining the density of non-cellular plastics - Part 1: Immersion method, liquid pyknometermethod and titration method5271 Plastics - Determination of tensile properties - Part 1: General principles5272 Plasti
27、cs - Determination of tensile properties - Part 2: Test conditions for moulding and extrusion plastics178 Plastics - Determination of flexural properties179 Plastics - Determination of Charpy impact properties - Part 1: Non-instrumented impact test751 Plastics - Determination of temperature of defle
28、ction under load - Part 1: General test method752 Plastics - Determination of temperature of deflection under load - Part 2: Plastics and eboniteISO 22621 Part 1 Plastics piping systems for the supply of gaseous fuels for maximum operating pressure up to and including2 MPa (20 bar) Polyamide (PA) :
29、General2.6 Plastic Pipe Institute:7PPI TR3 Policies and Procedures for Developing Hydrostatic Design Basis (HDB), Pressure Design Basis (PDB), StrengthDesign Basis (SDB), and Minimum Required Strength (MRS) Ratings for Thermoplastic Piping Materials or PipePPI TR4 Hydrostatic Design Bases and Maximu
30、m Recommended Hydrostatic Design Stresses for Thermoplastic PipingMaterialsPPI TN7 Nature of Hydrostatic Stress Rupture Curves2.7 Other Standards:8National Fire Protection Association: NFPA 58 , Storage and Handling Liquefied Petroleum Gases4 Available from American National Standards Institute (ANS
31、I), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.5 Available from DLA Document Services, Building 4/D, 700 Robbins Ave., Philadelphia, PA 19111-5094, http:/quicksearch.dla.mil.6 Available from International Organization for Standardization (ISO), 1, ch. de la Voie-Creuse, Case p
32、ostale 56, CH-1211, Geneva 20, Switzerland, http:/www.iso.ch.7 Available from Plastics Pipe Institute (PPI), 105 Decker Court, Suite 825, Irving, TX 75062, http:/www.plasticpipe.org.8 Available from National Fire Protection Association (NFPA), 1 Batterymarch Park, Quincy, MA 02169-7471, http:/www.nf
33、pa.org.F2785 18a23. Terminology3.1 DefinitionsDefinitions are in accordance with Terminology F412, and abbreviations are in accordance with TerminologyD1600, unless otherwise specified.3.2 The gas industry terminology used in this specification is in accordance with ANSI B31.8 or CFR OPS Part 192 Ti
34、tle 49,unless otherwise indicated.3.3 The term pipe used herein refers to both pipe and tubing unless specifically stated otherwise.3.4 Definitions of Terms Specific to This Standard:3.4.1 re-rounding equipment, nequipment used to reform the pipe and permanently reduce ovality to 5% or less.3.4.2 ro
35、unding equipment, nequipment, devices, clamps, and so forth, used to temporarily hold the pipe round whileout-of-roundness measurements are made, or a joining procedure (heat fusion, electrofusion, or mechanical) is performed.3.4.3 standard thermoplastic material designated code, nthe pipe material
36、designation code shall consist of the abbreviationfor the polyamide (PA) followed by Arabic numerals which describe the short term properties in accordance with ClassificationD6779, the hydrostatic design stress for water at 73.4F (23C)73.4 F (23 C) in units of 100 psi with any decimal figuresdroppe
37、d. Where the hydrostatic design stress code contains less than two figures, a zero is used before the number. Thus, acomplete material designation code shall consist of two letters and five figures for polyamide pipe materials. For example, PA42316 is a grade of polyamide 12 with a 1600 psi design s
38、tress for water at 73.4F (23C).73.4 F (23 C). The hydrostatic designstresses for gas are not used in this designation code.3.4.4 thermoplastic pipe dimension ratio (DR), nthe ratio of pipe diameter to wall thickness. It is calculated by dividing thespecified outside diameter of the pipe, in inches,
39、by the minimum specified wall thickness, in inches. The standard dimension ratio(SDR) is a common numbering system which is derived from the ANSI preferred number series R 10.3.4.5 toe-in, na small reduction of the outside diameter at the cut end of a length of thermoplastic pipe.4. Requirements for
40、 Materials4.1 GeneralThe polyamide material used to make pipe and fittings shall be virgin or reworked material (see 4.5 ) and shallhave a Plastics Pipe Institute (PPI) long-term hydrostatic design stress and hydrostatic design basis rating as determined per PPITR3 and PPI TR4.4.2 ClassificationPoly
41、amide materials suitable for use in the manufacturing of pipe and fittings under this specification shallbe classified in accordance with Classification D6779, as shown in Table 1.4.3 Short- and Long-Term PropertiesPolyamide pipe and fittings shall be made from a PA material which also satisfies the
42、combinations of short- and long-term property requirements shown in Table 2.4.4 Resistance to Rapid Crack Propagation (RCP) for MaterialslThe material classification (formulation) used in themanufacture of pipe and fittings under this specification shall be tested for resistance to failure by RCP in
43、 accordance with 6.7.The data obtained shall be made available upon request without limitations on disclosure, and shall not subsequently be subjectto disclosure limitations when used by others. The values obtained are applicable to all pipes with the wall thickness of the pipetested and all thinner
44、 wall pipes.TABLE 1 Classification D6779Classification ASTM Test Method ISO Test Method DesignationPA4 (group)2 (class)3 (grade)PolyamidePA 12Heat stabilizedViscosity number, min. D789 ISO 307 211Specific gravity D792 ISO 1183 1.001.06Tensile strength, min,psi (MPa)D638 ISO 5271 andISO 52725000 (35)
45、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)F2785 18a34.5 Rework MaterialClean rework material of the same commercial designation, generated from the manufact
46、urers own pipeand fitting production shall not be used unless the pipe and fittings produced meet all the requirements of this specification.4.6 DocumentationA documentation system to allow for traceability of raw materials including percentage and materialclassification (or designation, if applicab
47、le) of rework materials used in the manufacture of the pipe product meeting therequirements of this specification shall exist and be supplied to the purchaser, if requested.5. Requirements for Pipe and Fittings5.1 GeneralPipe shall be supplied in either coils or straight lengths. Any pipe supplied i
48、n coils must meet the samerequirements before and after coiling.5.2 WorkmanshipThe pipe and fittings shall be homogeneous throughout and free of visible cracks, holes, foreign inclusion,blisters, and dents, or other injurious defects.The pipe and fittings shall be as uniform as commercially practica
49、ble in color, opacity,density, and other physical properties.5.3 Pipe and Tubing Dimensions and Tolerances:5.3.1 DimensionThe dimensions shall be specified by wall thickness and outside diameter.5.3.1.1 DiametersThe outside diameter shall meet the requirements given in Table 3 or Table 4 when measured in accordancewith 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 th
