1、Designation: F 876 06An American National StandardStandard Specification forCrosslinked Polyethylene (PEX) Tubing1This standard is issued under the fixed designation F 876; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year o
2、f last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers crosslinked polyethylene(PEX) tubing that is outside diameter controlled, made instandard
3、 thermoplastic tubing dimension ratios, and pressurerated for water at three temperatures (see Appendix X1).Included are requirements and test methods for material,workmanship, dimensions, sustained pressure, burst pressure,environmental stress cracking, stabilizer migration resistance,and degree of
4、 crosslinking. Methods of marking are also given.1.2 The text of this specification references notes, footnotes,and appendixes which provide explanatory material. Thesenotes and footnotes (excluding those in tables and figures) shallnot be considered as requirements of the specification.1.3 The valu
5、es stated in inch-pound units are to be regardedas the standard. The values given in parentheses are forinformation only.1.4 The following safety hazards caveat pertains only to thetest methods portion, Section 7, of this specification: Thisstandard does not purport to address all of the safety conc
6、erns,if any, associated with its use. It is the responsibility of the userof this standard to establish appropriate safety and healthpractices and determine the applicability of regulatory limita-tions prior to use.2. Referenced Documents2.1 ASTM Standards:2D 618 Practice for Conditioning Plastics f
7、or TestingD 792 Test Methods for Density and Specific Gravity (Rela-tive Density) of Plastics by DisplacementD 1505 Test Method for Density of Plastics by the Density-Gradient TechniqueD 1598 Test Method for Time-to-Failure of Plastic PipeUnder Constant Internal PressureD 1599 Test Method for Resist
8、ance to Short-Time Hydrau-lic Pressure of Plastic Pipe, Tubing, and FittingsD 1600 Terminology for Abbreviated Terms Relating toPlasticsD 1898 Practice for Sampling of Plastics3D 2122 Test Method for Determining Dimensions of Ther-moplastic Pipe and FittingsD 2765 Test Methods for Determination of G
9、el Content andSwell Ratio of Crosslinked Ethylene PlasticsD 2837 Test Method for Obtaining Hydrostatic DesignBasis for Thermoplastic Pipe Materials or Pressure DesignBasis for Thermoplastic Pipe ProductsD 3895 Test Method for Oxidative-Induction Time of Poly-olefins by Differential Scanning Calorime
10、tryF 412 Terminology Relating to Plastic Piping SystemsF 2023 Test Method for Evaluating the Oxidative Resis-tance of Crosslinked Polyethylene (PEX) Tubing andSystems to Hot Chlorinated Water2.2 ANSI Standard:B36.10 Standards Dimensions of Steel Pipe (IPS)42.3 Federal Standard:FED-STD-123 Marking fo
11、r Shipment (Civil Agencies)52.4 Military Standard:MIL-STD-129 Marking for Shipment and Storage52.5 NSF Standard:NSF 14 for Plastic Piping Components and Related Mate-rials62.6 ISO Standard:4ISO R 161-1690 Pipes of Plastic Materials for the Transportof Fluids (Outside Diameters and Nominal Pressures)
12、 Part1, Metric Series2.7 PPI Standard:7PPI TR-4 PPI Listing of Hydrostatic Design Basis (HDB),Strength Design Basis (SDB), Pressure Design Basis(PDB) and Minimum Required Strength (MRS) Ratings1This specification is under the jurisdiction of ASTM Committee F17 on PlasticPiping Systems and is the dir
13、ect responsibility of Subcommittee F17.26 on OlefinBased Pipe.Current edition approved Dec. 15, 2006. Published January 2007. Originallyapproved in 1984. Last previous edition approved 2005 as F 876 05.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Serv
14、ice at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn.4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.5Available from Standardization Documents
15、 Order Desk, Bldg. 4 Section D, 700Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.6Available from NSF International, P.O. Box 130140, 789 N. Dixboro Rd., AnnArbor, MI 48113-0140.7Plastics Pipe Institute (PPI), 105 Decker Court, Suite 825 Irving TX, 75062.http:/www.plasticpipe.org1Copyright A
16、STM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.for Thermoplastic Piping Materials or Pipe3. Terminology3.1 DefinitionsDefinitions are in accordance with Termi-nology F 412, and abbreviations are in accordance with Ter-minology D 1600, unless ot
17、herwise specified. The abbreviationfor crosslinked polyethylene is PEX. Plastic tubing denotes aparticular diameter schedule of plastic pipe in which outsidediameter of the tubing is equal to the nominal size plus18 in.Plastic pipe outside diameter schedule conforms to ANSIB36.10.3.2 Definitions of
18、Terms Specific to This Standard:3.2.1 crosslinked polyethylene plasticsplastics preparedby crosslinking (curing) polyethylene compounds.3.2.2 hydrostatic design stress (HDS)the estimated maxi-mum tensile stress the material is capable of withstandingcontinuously with a high degree of certainty that
19、failure of thetube will not occur. This stress is circumferential when internalhydrostatic water pressure is applied. The HDS is equal to thehydrostatic design basis (HDB) times the design factor (DF)for water. For this standard, the design factor is equal to 0.50.HDS 5 HDB 3 DF5 HDB 3 0.50 for this
20、 standard!3.2.3 hydrostatic design basis (HDB)one of a series ofestablished stress values (specified in Test Method D 2837) fora plastic compound obtained by categorizing the long-termhydrostatic strength determined in accordance with TestMethod D 2837.3.2.4 pressure rating (PR)the estimated maximum
21、 waterpressure the tube is capable of withstanding continuously witha high degree of certainty that failure of the tube will not occur.3.2.5 relation between dimensions, hydrostatic designstress, and pressure ratingthe following expression, com-monly known as the ISO equation,8is used in this specif
22、icationto relate dimensions, hydrostatic design stress, and pressurerating:2S/P 5DO/t! 2 1 (1)or2S/P 5 R 2 1where:S = hydrostatic design stress, psi (or MPa),P = pressure rating, psi (or MPa),DO= average outside diameter, in. (or mm),t = minimum wall thickness, in. (or mm), andR = standard dimension
23、 ratio, SDR.3.2.6 standard dimension ratio (SDR)the ratio of outsidediameter to wall thickness. For PEX-tubing, it is calculated bydividing the average outside diameter of the tubing in inches orin millimetres by the minimum wall thickness in inches ormillimetres. If the wall thickness calculated by
24、 this formula isless than 0.070 in. (1.78 mm) it shall be arbitrarily increased to0.070 in. except for sizes18 in. and smaller. The SDR valuesshall be rounded to the nearest 0.5.3.2.7 standard thermoplastic tubing materials designationcodeThe tubing material designation code shall consist ofthe abbr
25、eviation for the type of plastic (PEX) followed by fourArabic digits that describe short-term properties in accordancewith applicable ASTM standards.(1) The first digit is for chlorine resistance tested in accor-dance with Test Method F 2023. A digit “1” indicates the PEXtubing has been tested and m
26、eets the F 876 requirement forminimum chlorine resistance at the end use condition of 25%at 140F (60C) and 75% at 73F (23C). A digit “0” indicatesit does not meet this requirement or it has not been tested.(2)The second digit is a “0”. This digit is reserved foranother PEX tubing property.(3) The la
27、st two digits are the hydrostatic design stress forwater at 73F (23C) in units of 100 psi with any decimalfigures dropped. Where the hydrostatic design stress codecontains less than two figures, a zero is used before the number.Thus, a complete material designation code for PEX tubingshall consist o
28、f the three letters “PEX” and four digits. Forexample, PEX 1006 is PEX tubing with a 630-psi design stress(1250-psi HDB) for water at 73F (23C) that meets theminimum chlorine resistance requirement. PEX material des-ignation codes are listed in PPI TR-4.4. Tubing Classification4.1 GeneralThis specif
29、ication covers one PEX tubingmaterial in one standard dimension ratio and having pressureratings for water of three temperatures. The pressure ratingsdecrease as the temperature is increased.4.2 Standard Thermoplastic Pipe Dimension Ratio (SDR)This specification covers PEX tubing in one standard dim
30、en-sion ratio (SDR 9). The pressure ratings are uniform for allnominal tubing sizes.5. Materials5.1 GeneralCrosslinked polyethylene tubing, meeting therequirements of this specification, are primarily defined bymeans of three criteria, namely, (1) nominal density, (2) degreeof crosslinking, and (3)
31、long-term strength tests. There is astrong correlation between nominal density and results ofshort-term strength tests.NOTE 1PEX tubing intended for use in the transport of potable watershould be evaluated and certified as safe for this purpose by a testingagency acceptable to the local health autho
32、rity. The evaluation should bein accordance with requirements for chemical extraction, taste, and odorthat are no less restrictive than those included in NSF 14. The seal or markof the laboratory making the evaluation should be included on the tubing.5.2 Basic MaterialsPEX tubing shall be made from
33、poly-ethylene compounds which have been crosslinked by perox-ides, Azo compounds, or silane compounds in extrusion, or byelectron beam after extrusion, or by other means such that thetubing meets the performance requirements of Section 6. Forthe use temperatures that the tubing will be marked for, t
34、hematerials, procedure for mixing, and the process for crosslink-ing shall result in a product with long term hydrostatic stressratings equal to or better than those shown in Table 1, whendetermined in accordance with procedures no less restrictive8ISO R161-1690.F876062than those of PPI TR-3/92.9See
35、 Appendix X1 for additionalinformation on PPI hydrostatic stress ratings.NOTE 2Tubing produced by crosslinking by peroxides, Azo com-pounds, or silane compounds in extrusion, or by electron beam afterextrusion have met the requirements of Section 6. There are several otherprocesses for producing cro
36、sslinked polyethylene tubing. However, eachprocess must be established as meeting the requirements of this specifi-cation.5.3 Tubing Material DesignationThe tubing meeting therequirements of this specification shall be designated PEX.6. Requirements Requirements6.1 WorkmanshipThe tubing shall be hom
37、ogeneousthroughout and free of visible cracks, holes, foreign inclusions,or other defects. The pipe shall be as uniform as commerciallypracticable in color, opacity, density, and other physical prop-erties.6.2 Dimensions and Tolerances:6.2.1 Outside DiametersThe outside diameters and toler-ances sha
38、ll be as shown in Table 2, when measured inaccordance with 7.4 and 7.4.1.6.2.2 Wall ThicknessThe wall thickness and tolerancesshall be as shown in Table 3, when measured in accordancewith 7.4 and 7.4.2.6.3 DensityWhen determined in accordance with 7.5, thecrosslinked polyethylene tubing material sha
39、ll have a minimumdensity of 0.926 Mg/m3.6.4 Sustained PressureThe tubing shall not fail, balloon,burst, or weep as defined in Test Method D 1598, at the testpressures given in Table 4 when tested in accordance with 7.6.6.5 Burst PressureThe minimum burst pressure for PEXplastic tubing shall be as gi
40、ven in Table 5, when determined inaccordance with 7.7.6.6 Environmental Stress Cracking There shall be no lossof pressure in the tubing, when tested in accordance with 7.8.6.7 Degree of CrosslinkingWhen tested in accordancewith 7.9, the degree of crosslinking for PEX tubing materialshall be within t
41、he range from 65 to 89 % inclusive. Depending9PPI Technical Report TR-3/92, Policies and Procedures for DevelopingRecommended Hydrostatic Design Stresses for Thermoplastic Pipe Materials.TABLE 1 Hydrostatic Design Stresses and Pressure Ratings forPEX SDR 9 Plastic Tubing for Water at Different Tempe
42、raturesRated TemperatureHydrostatic DesignStressPressure Rating forWaterF C psi (MPa) psi (MPa)73.4 23 630 (4.34) 160 (1.10)180 82.2 400 (2.76) 100 (0.69)200 93.3 315 (2.17) 80 (0.55)TABLE 2 Outside Diameters and Tolerances for PEX TubingNominal Tubing SizeAverage OutsideDiameterTolerances for Avera
43、ge Diameter Out-of-RoundnessAin. mm in. mm in. mm in. mm18 3 0.250 6.35 60.003 60.08 0.008 0.2014 7 0.375 9.52 60.003 60.08 0.008 0.20516 8 0.430 10.92 60.003 60.08 0.008 0.2038 10 0.500 12.70 60.003 60.08 0.012 0.3212 13 0.625 15.88 60.004 60.10 0.016 0.4058 16 0.750 19.05 60.004 60.10 0.016 0.4034
44、 19 0.875 22.22 60.004 60.10 0.016 0.401 25 1.125 28.58 60.005 60.12 0.020 0.48114 32 1.375 34.92 60.005 60.12 0.020 0.48112 38 1.625 41.28 60.006 60.16 0.024 0.602 51 2.125 53.98 60.006 60.16 0.030 0.76212 64 2.625 66.68 60.007 60.18 0.038 0.953 76 3.125 79.38 60.008 60.20 0.045 1.14312 89 3.625 92
45、.08 60.008 60.20 0.046 1.164 102 4.125 104.78 60.009 60.23 0.052 1.32412 114 4.625 117.48 60.009 60.23 0.059 1.495 127 5.125 130.18 60.010 60.25 0.065 1.656 152 6.125 155.58 60.011 60.28 0.072 1.83AThe Out-of-Roundness specification applies only to tubing prior to coiling.TABLE 3 Wall Thickness and
46、Tolerances for PEX SDR 9 PlasticTubingANominal Tubing Minimum Wall Thickness Tolerancein. mm in. mm in. mm18 3 0.047B1.19B+0.007 +0.1814 7 0.062B1.57B+0.010 +0.25516 8 0.064 1.63 +0.010 +0.2538 10 0.070B1.78B+0.010 +0.2512 13 0.070B1.78B+0.010 +0.2558 16 0.083 2.12 +0.010 +0.2534 19 0.097 2.47 +0.01
47、0 +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 +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 +
48、1.276 152 0.681 17.29 +0.060 +1.52AThe 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 plus the stated tolerance. All tolerances are on the plus side of theminimum requirement.BFor tubing s
49、izes of12 in. and below, wall thickness minimums are notfunctions of SDR.F876063on the process used, the following minimum percentagecrosslinking values shall be achieved: 70 % by peroxides, 65 %by Azo compounds, 65 % by electron beam, or 65 % by silanecompounds.NOTE 3Techniques as found in Test Methods D 2765.6.8 Stabilizer Functionality Stabilizer Functionality shallbe tested in accordance with 7.10.6.9 Oxidative Stability in Potable Chlorinated WaterApplicationsPEX tubing intended for use in the transport ofpotable
