1、Designation: F2767 18 An American National StandardStandard Specification forElectrofusion Type Polyamide-12 Fittings for OutsideDiameter Controlled Polyamide-12 Pipe and Tubing for GasDistribution1This standard is issued under the fixed designation F2767; the number immediately following the design
2、ation indicates the year oforiginal adoption or, in the case 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 polya
3、mide- 12 electrofusionfittings for use with outside diameter-controlled polyamide- 12pipe, covered by Specification F2785. Requirements formaterials, workmanship, and testing performance are included.Where applicable in this specification “pipe” shall mean “pipe”or “tubing.”1.2 Polyamide 12 electrof
4、usion fittings are intended for usein polyamide 12 systems only. As per the manufacturersrecommendations, no cross fusion between PA12, PA11 and PEis permitted.1.3 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI u
5、nits that are provided for information onlyand are not considered standard.1.4 The following safety hazards caveat pertains only to thetest method portion, Section 9, of this specification: Thisstandard does not purport to address all of the safety concerns,if any, associated with its use. It is the
6、 responsibility of the userof this standard to establish appropriate safety, health, andenvironmental practices and determine the applicability ofregulatory limitations prior to use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-iz
7、ation established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D638 Test Method for Tensile Properties of PlasticsD
8、1598 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 FittingsD1600 Terminology for Abbreviated Terms Relating to Plas-ticsD2122 Test Method for Determining Dimensions of Ther-
9、moplastic Pipe and FittingsD4066 Classification System for Nylon Injection and Extru-sion Materials (PA)D6779 Classification System for and Basis of Specificationfor Polyamide Molding and Extrusion Materials (PA)F412 Terminology Relating to Plastic Piping SystemsF905 Practice for Qualification of Po
10、lyethylene Saddle-Fused JointsF2785 Specification for Polyamide 12 Gas Pressure Pipe,Tubing, and Fittings3. Terminology3.1 Definitions are in accordance with Terminology F412,and abbreviations are in accordance with Terminology D1600,unless otherwise specified.3.2 Definitions of Terms Specific to Th
11、is Standard:3.2.1 electrofusiona heat fusion joining process where theheat source is an integral part of the fitting, such that whenelectric current is applied, heat is produced that melts and joinsthe plastics.3.2.2 fusion interfacesurface in the heat fusion processwhere the plastic materials of th
12、e products being joined bondtogether.3.2.3 fusion zone lengthtotal length of the melted materialin the fitting cross-section under evaluation.4. Materials and Manufacture4.1 This specification covers fittings made from polyamide12 (PA12) meeting the requirements for Group 4, Class 2, andGrade 3, (PA
13、423 16) as prescribed in Specification D6779 andD4066.4.2 Rework MaterialClean rework polyamide- 12 mate-rial of the same resin, free of any wire or contaminants1This specification is under the jurisdiction of ASTM Committee F17 on PlasticPiping Systems and is the direct responsibility of Subcommitt
14、ee F17.60 on Gas.Current edition approved April 1, 2018. Published April 2018. Originallyapproved in 2009. Last previous edition approved in 2012 as F276712. DOI:10.1520/F2767-18.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org.
15、 For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis
16、 international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TB
17、T) Committee.1generated from the fitting manufacturers own production, maybe used by the same manufacturer, as long as the fittingsproduced conform to the requirements of this specification.4.3 Heating MechanismThe heat mechanism shall be ofmaterials not detrimental to the performance of the fitting
18、 orthe pipe to which it is intended to be joined.5. Performance Requirements5.1 The following requirements are for electrofusion jointsthat have been joined using the manufacturers recommendedjoining procedures. These requirements must be met by eachelectrofusion joint design, on each size and type
19、of pipematerial for which the manufacturer recommends use of theirfitting. Any revisions to the electrofusion joint design orprocessing by the manufacturer after the initial testing requiresretesting to ensure these requirements can still be met. Fittingsintended for use in the distribution of natur
20、al gas or liquidpetroleum gas shall also meet the requirements of SpecificationF2785.5.1.1 It is not required that each configuration of a fitting betested to meet all of these qualifications (that is, 2 in. mainsaddle joint with multiple outlet configurations offered) as longas the electrofusion jo
21、int design is not altered in the configu-ration differences.NOTE 1It is permissible when accomplishing these tests, to do so onthe highest and lowest dimension ratio of the same pipe material. If inthose tests all performance requirements are met, all dimension ratiosbetween those tested may be cons
22、idered as having met the requirements.These tests do not have to cover the full range of dimension ratiosavailable, only the dimension ratio range on which the manufacturerrecommends his fitting be used.5.2 Pressure Requirements:5.2.1 Minimum Hydraulic Burst PressureThe minimumhydraulic burst pressu
23、re of the test specimen shall not be lessthan that required to produce 3900psi (26.9MPa) fiber stress inthe pipe being used in the test when tested in accordance with9.1. The test equipment, procedures, and failures definitionsshall be as specified in Test Method D1599.5.2.2 Sustained PressureThe fi
24、tting and fused joint shallnot fail when tested in accordance with 9.2.5.3 Tensile Strength Requirements (Coupling Type JointsOnly)The fitting or the pipe to fitting joint made on pipe shallnot fail when tested in accordance with 9.3. Specimens shall besubjected to a tensile stress that causes the p
25、ipe to yield orcauses the pipe to break outside the joint area. Tensile testsmust be made on specimens as joined, not on straps cut fromthe specimen. Yielding must be measured only in the pipe,independent of the fitting or joint.5.4 Impact Resistance (Saddle Type Joints Only)The jointmade on the spe
26、cimen shall not fail when impacted with a forcesufficient to break the body or other portion of the specimen.Tests of 500 ft-lb or higher impact with no failures noted shallbe considered as a “pass” impact test. The device for testingand the methods shall be as defined in Practice F905.5.5 Joint Int
27、egrity Tests(Couplings and Saddle TypeJoints)The joint made on the specimen shall meet therequirements in 9.4 and 9.5 of this specification, when tested inaccordance with 9.4.6. Dimensions, Mass, and Permissible Variations6.1 Dimension shall be measured using Test Method D2122.Dimensions and toleran
28、ces of electrofusion fittings must besuch that heat fusion is possible to outside diameter (OD)controlled PA-12 pipes such as those listed in SpecificationF2785, such that the joints will satisfy the performancerequirements in Section 5.NOTE 2Because of the varying designs for electrofusion fittings
29、, theactual spread of dimensions may be quite different from manufacturer tomanufacturer. A table of dimensions and tolerances encompassing thesedifferences would be meaningless and without value and, therefore, isomitted from this specification.6.2 The manufacturer shall furnish to the user the ele
30、ctricalresistance, critical dimensions, and tolerances of his fittings.This information must include at least the following dimen-sions and tolerances:6.2.1 Coupling inside diameter,6.2.2 Temperature joining limits, and6.2.3 Operating pressure of the fitting.NOTE 3There are other items that fall bey
31、ond the scope of thisspecification which would be of interest to the user for proper applicationof the fittings and is recommended as additional information to befurnished. A few of these are: (1) maximum pipe out of round allowed atjoint area; (2) minimum/maximum pipe SDR capability of the fitting,
32、 and(3) for saddles intended for use on a live main, the maximum allowableline pressure when making the joint.7. Workmanship, Finish and Appearance7.1 The manufacture of these fittings shall be in accordancewith good commercial practice so as to produce fittingsmeeting the requirements of this speci
33、fication.7.2 The fittings shall be homogeneous throughout, exceptwhere a heating coil or electrical connectors are incorporated,and free of cracks, holes, foreign inclusions, or injuriousdefects such as gouges, dents, cuts, etc. The fittings shall be asuniform as commercially practicable in opacity,
34、 density, andother physical properties. Any heating coils, connecting cables,connectors, and related electrical power source shall be de-signed to prevent electrical shock to the user.8. Specimen Preparation8.1 Conditioning:8.1.1 Unless otherwise specified, condition the specimens(pipe and fittings)
35、 prior to joining at the minimum pipetemperature allowable for fusion as recommended by themanufacturer, for not less than 16 h and make the fusion jointat that temperature for those tests where conditioning isrequired.8.1.2 Unless otherwise specified, condition the specimens(pipe and fittings) prio
36、r to joining at the maximum pipetemperature allowable for fusion as recommended by themanufacturer, for not less than 16 h and make the fusion jointat that temperature for those tests where conditioning isrequired.8.1.3 Unless otherwise specified, condition the fittings priorto joining at ambient te
37、mperature and the pipe at the minimumtemperature allowable for fusion as recommended by theF2767 182manufacturer, for not less than 16 h and make the fusion jointat the minimum pipe temperature for those tests where condi-tioning is required8.2 Test ConditionsConduct the tests at the StandardLaborat
38、ory Temperature of 23 6 2 C (73.4 6 3.6 F) unlessotherwise specified.8.3 Preparation of Specimens for Testing:8.3.1 Prepare test specimens so that the minimum length ofunreinforced pipe on one side of any fitting is equal to threetimes the diameter of the pipe, but in no case less than 12 in.(304 mm
39、). It is permissible to test multiple fittings togetherprovided they are separated by a minimum distance equal tothree times the diameter of the pipe, but in no case less than 12in. (304 mm).8.3.2 Fuse all fitting outlets with the appropriate size pipein accordance with the manufacturers recommended
40、 proce-dures.8.3.3 All saddle fusion joint specimens conditioned as in8.1.2 and destined for quick burst testing as in 9.1 andsustained pressure testing as in 9.2, are to be joined with thepipe at no less than maximum allowable operating pressure ofthe pipe system or fitting, whichever is lowest, wh
41、en beingprepared for those tests. The pipe should be left under pressurefor a time period not less than recommended by the manufac-turer for cooling in the field prior to disturbing the joint. Saddlejoint specimens destined for mechanical/destructive type testssuch as impact as in 5.4 or crush tests
42、 as in 9.4, or specimensconditioned for cold temperature joining as in 8.1.1, may bemade on unpressured pipe specimens.9. Test Methods9.1 Minimum Hydraulic Burst Pressure Test:9.1.1 Select four fittings at random and prepare specimensin accordance with Section 8. From the four specimens,condition tw
43、o specimens each in accordance with 8.1.1 and8.1.2.9.1.2 Test the specimens in accordance with Test MethodD1599.9.1.3 Failure of the fitting or joint shall constitute specimenfailure.9.1.4 Failure of any one of the four specimens shall consti-tute failure of the test. Failure of one of the four spec
44、imenstested is cause for retest of four additional specimens, joined atthe failed specimens joining temperature. Failure of any ofthese four additional specimens constitutes a failure of the test.9.2 Sustained Pressure Test:9.2.1 Select four fittings at random and prepare specimensin accordance with
45、 Section 8 of this specification. From thefour specimens, condition two specimens each in accordancewith 8.1.1 and 8.1.2.9.2.2 Test the specimens in accordance with Test MethodD1598. All tests shall be conducted at 80 6 2 C. Theassemblies are to be subjected to pipe fiber stresses of 1850 psi(12.8 M
46、Pa) for 170 h. Joint specimens shall not fail withinthese time periods. Any failures within these time periods mustbe of the pipe, independent of the fitting or joint and must beof a “brittle” type pipe failure, not “ductile.” If ductile pipefailures occur, reduce the pressure of the test and repeat
47、 until170-h results or pipe brittle failures are achieved.9.2.3 Failure of the fitting or joint shall constitute specimenfailure.9.2.4 Failure of one of the four specimens tested is cause forretest of four additional specimens, joined at the failed-specimens-joining temperature. Failure of any of th
48、ese fouradditional specimens shall constitute a failure of the test.9.3 Tensile Strength Test:9.3.1 Select four fittings at random and prepare specimensin accordance with Section 8. If the limits of tensile machinewill not allow 25 % elongation with pipe specimens ofthree-pipe diameters on pipe size
49、s above 4 in. (102 mm) IPSthan the minimum free pipe length can of 20 in. (304 mm).From the four specimens, condition two specimens each inaccordance with 8.1.1 and 8.1.2.9.3.2 Test the specimens using the apparatus of Test MethodD638. Test at a pull rate of 0.20 in. (5.0 mm) per min, 625 %.9.3.3 Failure of the fitting or joint as defined in 5.3, shallconstitute specimen failure. Failure of one of the four speci-mens tested is cause for retest of four additional specimens,joined at the failed specimens joining temperature. Failure ofany of these four additional
