1、Designation: F876 13aF876 15 An American National StandardStandard Specification forCrosslinked Polyethylene (PEX) Tubing1This standard is issued under the fixed designation F876; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the
2、 year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This specification covers crosslinked polyethylene (PEX) tubing that incorporates an optional polymeric inner, m
3、iddle orouter layer and that is outside diameter controlled, made in nominal SDR9 tubing dimension ratios except where noted, andpressure rated for water at three temperatures (see Appendix X1). Included are requirements and test methods for material,workmanship, dimensions, burst pressure, hydrosta
4、tic sustained pressure, excessive temperature pressure, environmental stresscracking, stabilizer functionality, bent-tube hydrostatic pressure, oxidative stability in potable chlorinated water, and degree ofcrosslinking. Requirements for tubing markings are also given.1.2 The text of this specificat
5、ion 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 standard. The values given
6、 in parentheses are mathematicalconversions to SI units that are provided for information only and are not considered standard.1.4 The following safety hazards caveat pertains only to the test methods portion, Section 7, of this specification:This standarddoes not purport to address all of the safet
7、y concerns, if any, associated with its use. It is the responsibility of the user of thisstandard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plas
8、tics for TestingD792 Test Methods for Density and Specific Gravity (Relative Density) of Plastics by DisplacementD1505 Test Method for Density of Plastics by the Density-Gradient TechniqueD1598 Test Method for Time-to-Failure of Plastic Pipe Under Constant Internal PressureD1599 Test Method for Resi
9、stance to Short-Time Hydraulic Pressure of Plastic Pipe, Tubing, and FittingsD1600 Terminology for Abbreviated Terms Relating to PlasticsD1898 Practice for Sampling of Plastics (Withdrawn 1998)3D2122 Test Method for Determining Dimensions of Thermoplastic Pipe and FittingsD2765 Test Methods for Dete
10、rmination of Gel Content and Swell Ratio of Crosslinked Ethylene PlasticsD2837 Test Method for Obtaining Hydrostatic Design Basis for Thermoplastic Pipe Materials or Pressure Design Basis forThermoplastic Pipe ProductsD3895 Test Method for Oxidative-Induction Time of Polyolefins by Differential Scan
11、ning CalorimetryF412 Terminology Relating to Plastic Piping SystemsF1281 Specification for Crosslinked Polyethylene/Aluminum/Crosslinked Polyethylene (PEX-AL-PEX) Pressure PipeF2023 Test Method for Evaluating the Oxidative Resistance of Crosslinked Polyethylene (PEX) Tubing and Systems to HotChlorin
12、ated WaterF2657 Test Method for Outdoor Weathering Exposure of Crosslinked Polyethylene (PEX) Tubing2.2 ANSI Standard:B36.10 Standards Dimensions of Steel Pipe (IPS)41 This specification is under the jurisdiction of ASTM Committee F17 on Plastic Piping Systems and is the direct responsibility of Sub
13、committee F17.26 on Olefin BasedPipe.Current edition approved Aug. 1, 2013June 1, 2015. Published August 2013September 2015. Originally approved in 1984. Last previous edition approved 2013 asF876 13.F876 13a. DOI: 10.1520/F0876-13A.10.1520/F0876-15.2 For referencedASTM standards, visit theASTM webs
14、ite, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer 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.4 Available from American
15、 National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.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 techni
16、cally 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 s
17、tandardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States12.3 Federal Standard:FED-STD-123 Marking for Shipment (Civil Agencies)52.4 Military Standard:MIL-STD-129 Marking for Shipment and Storage52.5 NSF Standard:NSF/ANSI 14 for Plastic
18、Piping Components and Related Materials62.6 ISO Standards:4ISO 1167 Thermoplastics pipes, fittings and assemblies for the conveyance of fluids - Determination of the resistance to internalpressure - Part 1: General methodISO 13760 Plastics pipes for the conveyance of fluids under pressure - Miners r
19、ule - Calculation method for cumulativedamageISO R 161-1690 Pipes of Plastic Materials for the Transport of Fluids (Outside Diameters and Nominal Pressures) Part 1, MetricSeries2.7 PPI Standard:7PPI TR-4 PPI Listing of Hydrostatic Design Basis (HDB), Strength Design Basis (SDB), Pressure Design Basi
20、s (PDB) andMinimum Required Strength (MRS) Ratings for Thermoplastic Piping Materials or Pipe3. Terminology3.1 DefinitionsDefinitions are in accordance with Terminology F412, and abbreviations are in accordance with TerminologyD1600, unless otherwise specified. The abbreviation for crosslinked polye
21、thylene is PEX. Plastic tubing denotes a particulardiameter schedule of plastic pipe in which outside diameter of the tubing is equal to the nominal size plus 18 in. Plastic pipe outsidediameter schedule conforms to ANSI B36.10.3.2 Definitions of Terms Specific to This Standard:3.2.1 crosslinked pol
22、yethylenea polyethylene material which has undergone a change in molecular structure using a chemicalor a physical process whereby the polymer chains are chemically linked.5 Available from Standardization Documents Order Desk, DODSSP, Bldg. 4, Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098
23、, http:/www.dodssp.daps.mil.DLA Document Services Building 4/D 700 Robbins Avenue Philadelphia, PA 19111-5094 http:/quicksearch.dla.mil/6 Available from NSF International, P.O. Box 130140, 789 N. Dixboro Rd., Ann Arbor, MI 48113-0140, http:/www.nsf.org.7 Plastics Pipe Institute (PPI), 105 Decker Cou
24、rt, Suite 825 Irving TX, 75062. http:/www.plasticpipe.orgTABLE 1 Wall Thickness and Tolerances for Nominal PEX SDR 9Plastic TubingANominal Tubing Minimum WallThickness Tolerancein. mm in. mm in. mm18 3 0.047B 1.19B +0.007 +0.1814 7 0.062B 1.57B +0.010 +0.25516 8 0.064 1.63 +0.010 +0.2538 10 0.070B 1
25、.78B +0.010 +0.2512 13 0.070B 1.78B +0.010 +0.2558 16 0.083 2.12 +0.010 +0.2534 19 0.097 2.47 +0.010 +0.251 25 0.125 3.18 +0.013 +0.33114 32 0.153 3.88 +0.015 +0.38112 38 0.181 4.59 +0.019 +0.482 51 0.236 6.00 +0.024 +0.61212 64 0.292 7.41 +0.030 +0.763 76 0.347 8.82 +0.033 +0.84312 89 0.403 10.23 +
26、0.035 +0.894 102 0.458 11.64 +0.040 +1.02412 114 0.514 13.05 +0.045 +1.145 127 0.569 14.46 +0.050 +1.276 152 0.681 17.29 +0.060 +1.52A The minimum is the lowest wall thickness of the pipe at any cross section. Themaximum permitted wall thickness, at any cross section, is the minimum wallthickness pl
27、us the stated tolerance. All tolerances are on the plus side of theminimum requirement.B For tubing sizes of 12 in. and below, wall thickness minimums are not functionsof SDR.F876 1523.2.2 hydrostatic design stress (HDS)the estimated maximum tensile stress the material is capable of withstandingcont
28、inuously with a high degree of certainty that failure of the tube will not occur. This stress is circumferential when internalhydrostatic water pressure is applied. The HDS is equal to the hydrostatic design basis (HDB) times the design factor (DF) forwater. For this standard, the design factor is e
29、qual to 0.50.HDS5HDB3DF5HDB30.50 for this standard!3.2.3 hydrostatic design basis (HDB)one of a series of established stress values (specified in Test Method D2837) for a plasticcompound obtained by categorizing the long-term hydrostatic strength determined in accordance with Test Method D2837.3.2.3
30、.1 DiscussionA listing of HDB and HDS values are contained in PPI publication PPI TR4.3.2.4 pressure rating (PR)the estimated maximum water pressure the tube is capable of withstanding continuously with a highdegree of certainty that failure of the tube will not occur.3.2.5 relation between dimensio
31、ns, hydrostatic design stress, and pressure ratingthe following expression, commonly knownas the ISO equation,8 is used in this specification to relate dimensions, hydrostatic design stress, and pressure rating:2S/P 5 DO/t!21 (1)or2S/P 5 R 2 1where:S = hydrostatic design stress, psi (or MPa),P = pre
32、ssure rating, psi (or MPa),DO = average outside diameter, in. (or mm),t = minimum wall thickness, in. (or mm), andR = standard dimension ratio, SDR.3.2.6 standard dimension ratio (SDR)the ratio of outside diameter to wall thickness. For PEX-tubing, it is calculated bydividing the average outside dia
33、meter of the tubing in inches or in millimetres by the minimum wall thickness in inches ormillimetres. If the wall thickness calculated by this formula is less than 0.070 in. (1.78 mm) it shall be arbitrarily increased to 0.070in. except for sizes 516 in. and smaller, as specified in Table 1. The SD
34、R values shall be rounded to the nearest 0.5.3.2.7 standard thermoplastic tubing materials designation codeThe tubing material designation code shall consist of theabbreviation for the type of plastic (PEX) followed by four Arabic digits that describe short-term properties in accordance withapplicab
35、le ASTM standards and as shown in Table 2. See Fig. 1.3.2.7.1 DiscussionThe first digit is for chlorine resistance tested in accordance with Test Method F2023.(1) A digit “0” indicates that the PEX tubing either has not been tested for chlorine resistance or that the PEX tubing does notmeet the mini
36、mum requirement for chlorine resistance.(2) A digit “1” indicates the PEX tubing has been tested and meets the F876requirement of 6.10 for minimum chlorineresistance at the end use condition of 25% at 140F (60C) and 75% at 73F (23C).8 ISO R161-1690.For example ASTM F876 PEX tubing marked with the ma
37、terial designation code PEX 1106 is a PEX tubing meeting the chlorine resistance requirement for 25% of thetime at 140F and 75% of the time at 73F having a Minimum UV resistance of 1 month and having an HDS for water at 73F of 630psi (HDB of 1250 psi).FIG. 1 Standard Thermoplastic Tubing Materials D
38、esignation CodeF876 153(3) A digit “2” is reserved for future application.(4) A digit “3” indicates that the PEX tubing has been tested and meets the F876requirement of 6.10 for minimum chlorineresistance at end use condition of 50% at 140F and 50% at 73F.(5) A digit “4” is reserved for future appli
39、cation.(6) A digit “5” indicates that the PEX tubing has been tested and meets the requirement of 6.10 for minimum chlorineresistance at end use conditions of 100% of the time at 140F3.2.7.2 DiscussionThe second digit is for demonstrated UV resistance of PEX material when tested in accordance with T
40、est Method F2657. For PEXtubing with the first digit of the material designation code equal to 1, 3, or 5 the second digit shall be one of the classification digitslisted in Table 2 for the Nominal Exposure Time Period from Table 1 in Test Method F2657 where the decreased average failuretime from 10
41、.3 of Test Method F2657 is less than or equal to 21%. For PEX tubing with the first digit of the material designationcode equal to 0, the second digit shall be one of the classification digits from Table 2 for the Nominal Exposure Time Period fromTable 1 of Test Method F2657 where the UV-exposed sam
42、ples meet the requirement of 7.10 Stabilizer Functionality, oralternatively using the criteria for potable water piping found in the preceding sentence of this clause.3.2.7.3 DiscussionThe 21% pass/fail criteria originates from the statistical analysis of an aggregate of data sets generated using Te
43、st Method F2023and represents the mean Lower Predictive Limit (95% two sided) compared to the expected failure times based on three stresslevels at each of three temperatures. Thus, this value represents the limit for statistical differentiation in failure times using TestMethod F2023 at the 95% con
44、fidence level (2 sided). This research was conducted for the Plastics Pipe Institute in 2005.9(1) The UV resistance shall be demonstrated on representative pipe samples for the original validation of pipe made from aparticular PEX material, that material being the combination of PEX resin and its ad
45、ditive system.(1) The UV resistance shall be demonstrated on representative pipe samples for the original validation of pipe made from aparticular PEX material, that material being the combination of PEX resin and its additive system.(2) The last two digits are the hydrostatic design stress for wate
46、r at 73F (23C) in units of 100 psi with any decimal figuresdropped. Where the hydrostatic design stress code contains less than two figures, a zero is used before the number. Thus, acomplete material designation code for PEX tubing shall consist of the three letters “PEX” and four digits.(2) The las
47、t two digits are the hydrostatic design stress for water at 73F (23C) in units of 100 psi with any decimal figuresdropped. Where the hydrostatic design stress code contains less than two figures, a zero is used before the number. Thus, acomplete material designation code for PEX tubing shall consist
48、 of the three letters “PEX” and four digits.4. Tubing Classification4.1 GeneralThis specification covers one PEX tubing material in one standard dimension ratio and having pressure ratingsfor water of three temperatures. The pressure ratings decrease as the temperature is increased.4.2 Standard Ther
49、moplastic Pipe Dimension Ratio (SDR)This specification covers PEX tubing in one standard dimensionratio (SDR 9) for nominal diameters 58 in. and larger, and with a specified wall thickness for smaller diameters. The pressureratings are uniform for all nominal tubing sizes.9 PPI Technical literature, Final Report Proposal for the Evaluation of the Chlorine Resistance of UV Exposed PEX Pipe.TABLE 2 Material Designation Code CellsProperty Standard 0 1 2 3 4 5 6 7 8 9ChlorineResistanceF2023 Not testedor rated75 %at 73Fand
