1、Designation: F2785 10a F2785 12 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 ca
2、se 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 Scope*1.1 This specification covers requirements and test methods for the characterization of
3、 polyamide 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 This specification does not cover threaded pipe. Generic fusion gu
4、idelines are given in Appendix X1. Design considerationsare discussed in Appendix X2. In-plant quality control programs are specified in Annex A1.1.2 The text of this specification references notes, footnotes, and appendixes which provide explanatory material. These notesand footnotes (excluding tho
5、se 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 standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information only and are not considered stand
6、ard.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 standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.NOTE 1Pipe an
7、d fittings utilizing heat fusion joining techniques produced from compounds meeting the requirements of Group 3, Class 2, and Grade3 (PA323 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 fu
8、sion joining techniques produced from compounds meeting the requirements of Group 4, Class 2 and Grade 3 (PA 423 or PA12)are intended for use with pipe manufactured from compounds meeting the requirements of Group 4, Class 2 and Grade 3. As per the recommendationsof the respective resin manufacturer
9、s, no cross fusion between PA 323 (PA11) and PA 423 (PA12) compounds is permitted.2. Referenced Documents2.1 ASTM Standards:2D256 Test Methods for Determining the Izod Pendulum Impact Resistance of PlasticsD543 Practices for Evaluating the Resistance of Plastics to Chemical ReagentsD618 Practice for
10、 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 Methods for Determination of Solution Viscosities of Polyamide (PA)D790 Test Methods for Flexural Propert
11、ies of Unreinforced and Reinforced Plastics and Electrical Insulating MaterialsD792 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 to Sh
12、ort-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 Installa
13、tion of Thermoplastic Pressure PipingD2290 Test Method for Apparent Hoop Tensile Strength of Plastic or Reinforced Plastic Pipe by Split Disk MethodD2837 Test Method for Obtaining Hydrostatic Design Basis for Thermoplastic Pipe Materials or Pressure Design Basis forThermoplastic Pipe Products1 This
14、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 Dec. 1, 2010Aug. 1, 2012. Published January 2011September 2012. Originally approved in 2009 as F278509. Last previous edition
15、approvedin 2010 as F278510.10a. DOI: 10.1520/F2785-10A.10.1520/F2785-12.2 For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the
16、 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 previous version. Becauseit may not be technicall
17、y 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 Changes section appears at the end of this stand
18、ardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1D3418 Test Method for Transition Temperatures and Enthalpies of Fusion and Crystallization of Polymers by DifferentialScanning CalorimetryD4066 Classification System for Nylon Injecti
19、on and Extrusion Materials (PA)D6779 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-Encirclement-Type Band Clamps for Reinforcement or Repair of Punctu
20、res 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 Fitting for Polyamide(PA) Plastic Pipe and TubingF1973 Specification for
21、 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 Specification for Polyamide 11 (PA 11) and Polyamide 12 (PA12) Mechanic
22、al 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 DistributionF2897 Specification for Tracking and Traceability Encoding S
23、ystem 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 and Distribution Piping Systems2.3 Federal Specifications:5Fed. Std. N
24、o. 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- and Multi-Level Continuous Sampling Procedures and Tables for Inspection by Attributes2.5 ISO Standard
25、s:6307 Plastics - Polyamides - Determination of viscosity number3146 Plastics - Determination of melting behaviour (melting temperature or melting range) of semi-crystalline polymers bycapillary tube and polarizing-microscope methods1183 Plastics - Methods for determining the density of non-cellular
26、 plastics - Part 1: Immersion method, liquid pyknometermethod and titration method5271 Plastics - Determination of tensile properties - Part 1: General principles5272 Plastics - Determination of tensile properties - Part 2: Test conditions for moulding and extrusion plastics178 Plastics - Determinat
27、ion of flexural properties180/1A179 Plastics - Determination of Izod impact strength Charpy impact properties - Part 1: Non-instrumented impact test751 Plastics - Determination of temperature of deflection under load - Part 1: General test method752 Plastics - Determination of temperature of deflect
28、ion 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) : General2.6 Plastic Pipe Institute:7PPI TR3 Policies and Procedures for Developing Hydrostatic Design
29、 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 Maximum Recommended Hydrostatic Design Stresses for Thermoplastic PipingMaterialsPPI TN7 Nature of Hydrost
30、atic Stress Rupture Curves2.7 Other Standards:8National Fire Protection Association: NFPA 58 , Storage and Handling Liquefied Petroleum Gases3. Terminology3.1 DefinitionsDefinitions are in accordance with Terminology F412, and abbreviations are in accordance with TerminologyD1600, unless otherwise s
31、pecified.4 Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.5 Available from Standardization Documents Order Desk, DODSSP, Bldg. 4, Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http:/www.dodssp.daps.mil.6 Avai
32、lable from International Organization for Standardization (ISO), 1, ch. de la Voie-Creuse, Case postale 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 Nati
33、onal Fire Protection Association (NFPA), 1 Batterymarch Park, Quincy, MA 02169-7471, http:/www.nfpa.org.F2785 1223.2 The gas industry terminology used in this specification is in accordance with ANSI B31.8 or CFR OPS Part 192 Title 49,unless otherwise indicated.3.3 The term pipe used herein refers t
34、o 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 rounding equipment, nequipment, devices, clamps, and so forth, used to tem
35、porarily 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 designation code shall consist of the abbreviationfor the polyamide (PA)
36、 followed by Arabic numerals which describe the short term properties in accordance with Classification-sClassification D4066 or D6779, the hydrostatic design stress for water at 73.4F (23C) in units of 100 psi with any decimalfigures dropped. Where the hydrostatic design stress code contains less t
37、han two figures, a zero is used before the number. Thus,a complete 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 stress for water at 73.4F (23C). The hydrostatic design stre
38、sses for gasare 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, by the minimum specified wall thickness, in inches. The standard dimensio
39、n 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 Materials4.1 GeneralThe polyamide material used to make pipe and fitting
40、s 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 ClassificationPolyamide materials suitable for use in the manufacturing of pipe and fitting
41、s under this specification shallbe classified in accordance with ClassificationsClassification D4066 and 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 thecombinations of short- and long-term property re
42、quirements 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 accordance with 6.7.The data obtained shall be
43、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 wall pipes.4.5 Rework MaterialClean rework mate
44、rial of the same commercial designation, generated from the manufacturers 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 includin
45、g percentage and materialclassification (or designation, if applicable) 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
46、be supplied in either coils or straight lengths. Any pipe supplied in 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 defect
47、s. The pipe and fittings shall be as uniform as commercially practicable in color, opacity,density, and other physical properties.5.3 Pipe and Tubing Dimensions and Tolerances:5.3 DimensionThe dimensions shall be specified by wall thickness and outside diameter.5.3.1.1 DiametersThe outside diameter
48、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 the undistorte
49、d outside diameter shall be made no closerthan 1.5 pipe diameters or 11.8 in. (300 mm), whichever distance is less, from the cut end of the pipe. Undistorted outside diametershall meet the requirements of Table 3 or Table 4.F2785 1235.3.1.3 Wall ThicknessThe wall thickness shall be as specified in Table 4 or Table 5 when measured in accordance with6.5.1.2. The minimum wall thickness at any point of measurement shall be not less than the minimum wall thickness specified inTable 4 or Table 5.5.3.1.4 Wall Thickness Eccentricity Ra
