1、Designation: F2023 13F2023 15Standard Test Method forEvaluating the Oxidative Resistance of CrosslinkedPolyethylene (PEX) Pipe, Tubing and Systems to HotChlorinated Water1This standard is issued under the fixed designation F2023; the number immediately following the designation indicates the year of
2、original 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 test method describes the general requirements for ev
3、aluating the long-term, chlorinated water, oxidative resistance ofcross-linked polyethylene (PEX) pipe or tubing produced in accordance with SpecificationPEX F876 or PEX tubing/fittingsystemsspecifications, such as Specification F876 in accordance with or Specification F877F2788/F2788M used in hot-a
4、nd-coldwater distribution systems by exposure to hot, chlorinated water. This test method outlines the requirements of a pressurizedflow-through test system, typical test pressures, test-fluid characteristics, failure type, and data analysis.NOTE 1Other known disinfecting systems (chlorine dioxide,
5、ozone, and chloramines) are also used for protection of potable water. Free-chlorine isthe most common disinfectant in use today. A PPI research project examined the relative aggressiveness of free chlorine and chloramines on PEX pipes,both at the same 4.0 ppm concentration and the same test tempera
6、tures. The results of the testing showed pipe failure times approximately 40% longerwhen tested with chloramines compared to testing with free chlorine, at the tested conditions. Based on these results, the data suggests that chloraminesare less aggressive than free chlorine to PEX pipes.1.2 Guideli
7、nes and requirements for test temperatures, test hoop stresses, and other test criteria have been established by priortesting of PEX pipe or tubing produced by the three most common commercial methods of cross-linking: silane, peroxide, andelectron-beam (see Note 2). Other related system components
8、that typically appear in a PEX hot-and-cold water distribution systemcan be evaluated with the PEX pipe or tubing. When testing PEX pipe or tubing and fittings as a system, it is recommended thatthe anticipated end-use fitting type(s) and material(s) be included in the test circuit since it is known
9、 that some fitting types andmaterials can impact failure times. Specimens used shall be representative of the piping product(s) and material(s) underinvestigation.NOTE 2The procedures described in this test method (with some modifications of test temperatures or stresses, or both) have been used to
10、evaluatepipes manufactured from polybutylene (PB), polyethylene (PE), polypropylene (PP), multilayer (polymer-metal composite), copper, and stainless steel.1.3 This test method is applicable to PEX pipe or tubing and systems used for transport of potable water containing free-chlorinefor disinfectin
11、g purposes. The oxidizing potential of the test-fluid specified in this test method exceeds that typically found inpotable water systems across the United States.1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematicalconversions to S
12、I units that are provided for information only and are not considered standard.1.5 The following precautionary caveat pertains only to the test method portion, Section 12, of this specification. This standarddoes not purport to address all of the safety concerns, if any, associated with its use. It
13、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:2D1600 Terminology for Abbreviated Terms Relating to PlasticsD2122 Test Method for D
14、etermining Dimensions of Thermoplastic Pipe and FittingsF412 Terminology Relating to Plastic Piping SystemsF876 Specification for Crosslinked Polyethylene (PEX) Tubing1 This test method is under the jurisdiction of ASTM Committee F17 on Plastic Piping Systems and is the direct responsibility of Subc
15、ommittee F17.40 on Test Methods.Current edition approved Nov. 1, 2013Dec. 1, 2015. Published December 2013January 2016. Originally approved in 2000. Last previous edition approved in 20102013as F2023 10.F2023 13. DOI: 10.1520/F2023-13.10.1520/F2023-15.2 For referencedASTM standards, visit theASTM we
16、bsite, 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.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indicat
17、ion of what changes have been made to the previous 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 cons
18、idered the official document.*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 States1F877F2788/F2788M Specification for For Metric and Inch-sized Crosslinked Polyethylene (PEX)
19、Hot- and Cold-WaterDistribution SystemsPipeF948 Test Method for Time-to-Failure of Plastic Piping Systems and Components Under Constant Internal Pressure With Flow2.2 ISO Standards:ISO 9080 Thermoplastic Pipe for Transport of FluidsMethods of Extrapolation of Hydrostatic Stress Rupture Data toDeterm
20、ine the Long Term Strength of Thermoplastic PipeISO 13760 Plastic Pipe for the Conveyance of Fluids Under PressureMiners RuleCalculation Method for CumulativeDamage32.3 Plastics Pipe Institute (PPI) Document:TN-16 Rate Process Method for Projecting Performance of Polyethylene Piping Components42.4 A
21、merican Water Works Association (AWWA) Document:1996 WATER:STATS Survey53. Terminology3.1 Definitions:3.1.1 Definitions are in accordance with Terminology F412 and abbreviations are in accordance with Terminology D1600,unless otherwise indicated.3.1.2 brittle failure (Stage II), nfailure in the pipe
22、 or tubing wall that is characterized by little or no material deformation inthe failure area and is the result of a single crack emanating from the interior of the pipe or tubing to the outside surface typicallyresulting in a pinhole leak, see Fig. 1. Brittle failures produced with this test method
23、 shall not be used for data analysis.3.1.3 ductile failure (Stage I), nfailure in the pipe or tubing wall that is characterized by obvious localized deformation of thematerial visible with the unaided eye, see Fig. 1. Ductile failures produced with this test method shall not be used for data analysi
24、s.3.1.4 environmental or oxidative failure (Stage III), nfailure in the pipe or tubing wall characterized by a large number ofcracks emanating from the interior surface of the pipe or tubing wall, see Fig. 1.3.1.4.1 DiscussionStage III failures may also be identified by a color shift in the failure
25、area (typically brown or reddish-brown). Identification ofenvironmental or oxidative failure, when not obvious by inspection with the unaided eye, can be performed with a 25 microscopeor other similar device yielding the same level of magnification. Only Stage III environmental or oxidative failures
26、 shall be usedfor data analysis.3.1.5 hot-and-cold water distribution system, na combination of components such as pipe or tubing, fittings, valves, and soforth, that when installed as a complete system, make up the interior water supply system of a commercial or residential structure.Available from
27、 American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.4 Available from Plastics Pipe Institute (PPI), 105 Decker Court, Suite 825, Irving, TX 75062, http:/www.plasticpipe.org.5 Available from American Water Works Association (AWWA), 6666 W.
28、Quincy Ave., Denver, CO 80235, http:/www.awwa.org.FIG. 1 Pictorial Illustration of Failure TypesF2023 1523.1.6 long-term oxidative resistance, nthe extrapolated time-to-failure prediction as determined by analysis of time-to-failuretest data by multiple linear regression utilizing the rate process m
29、ethod of PPI TN-16 or Model Q of ISO 9080. Where applicable,application of Miners Rule in accordance with ISO 13760 can be used to estimate time-to-failure at several differing conditionsof temperature or stress, or both.3.1.7 multiple linear regression, na three or four coefficient mathematical mod
30、el used to analyze time-to-failure data fromdifferent temperatures and stresses to extrapolate projected time-to-failure at selected temperatures or stresses.3.1.8 Miners Rule, na mathematical method for estimating the cumulative, irreversible damage that results from exposure toeach of several diff
31、ering conditions of stress or temperature, or both.3.1.9 oxidation reduction potential (ORP), na measure of the total oxidizing power of a solution by means of a platinum-redoxelectrode. For a further explanation of ORP see Appendix X2.3.1.10 unaided eye, nobservable without visual enhancement beyon
32、d correction for normal vision.4. Summary of Test Method4.1 The PEX pipe or tubing or tubing/fittingpipe/tubing/fitting assemblies are exposed to pressurized test-fluid until failure. Alltime-to-fail data used for analysis shall be the result of oxidative degradation (Stage III). A minimum number of
33、 test temperatureand hoop stress conditions are required to allow accurate data analysis and time-to-failure extrapolations.5. Significance and Use5.1 Environment or oxidative time-to-fail data derived from this test method, analyzed in accordance with Section 13, aresuitable for extrapolation to ty
34、pical end-use temperatures and hoop stresses.The extrapolated value(s) provides a relative indicationof the resistance of the tested PEX pipe or tubing or system to the oxidative effects of hot, chlorinated water for conditionsequivalent to those conditions under which the test data were obtained. T
35、he performance of a material or piping product underactual conditions of installation and use is dependent upon a number of factors including installation methods, use patterns, waterquality, nature and magnitude of localized stresses, and other variables of an actual, operating hot-and-cold water d
36、istributionsystem that are not addressed in this test method. As such, the extrapolated values do not constitute a representation that a PEXtube or system with a given extrapolated time-to-failure value will perform for that period of time under actual use conditions.6. Apparatus6.1 Pressurized Flow
37、-Through Test SystemAsystem comprised of the necessary pump(s), fittings, piping, heaters, sensors, andmeters that is capable of maintaining the required test pressures within the tolerance specified in 9.1.3, the required testtemperatures within the tolerance of 9.1.2, and flow the test-fluid throu
38、gh the specimens continually at a flow rate within thetolerance specified in 9.1.4. Cyclic pressure variations, such as those produced by some pumping systems, shall not producepressure excursions that exceed the tolerance stated in 9.1.3.6.1.1 Recirculating Test SystemAflow-through test system that
39、 repeatedly reconditions the test-fluid and passes it through thespecimens. For purposes of this test method, the test-fluid shall be monitored at a sufficient frequency to ensure that it continuouslymeets the test-fluid parameters and water quality criteria. A portion of the total system volume sha
40、ll be purged and replaced withfresh test-fluid continually.6.1.2 Single-Pass Test SystemA flow-through test system that passes the test-fluid through the specimens only once and isdiscarded.6.2 Specimen HoldersTest specimens shall be supported to minimize or eliminate externally induced stresses. Sp
41、ecimens shallbe allowed to freely expand bi-directionally.7. Sampling, Test Specimens, and Test Units7.1 SamplingSelect at random, a sufficient amount of pipe or tubing to satisfy the specimen requirements of this test method.When testing as a system, randomly select a sufficient quantity of fitting
42、s.7.2 Test Specimen SizeThe PEX pipe or tubing specimens shall be 12 to 18 in. (300 to 460 mm) in length between fittingclosures or between fitting joints.7.2.1 Dimensions MeasurementMeasure and record the critical dimensions for pipe or tubing and fittings. For pipe or tubing,measure the average ou
43、tside diameter and wall-thickness in accordance with Test Method D2122. For fittings, measure thosedimensions critical to the function of the joint, as well as minimum body wall thickness.7.3 Testing as a SystemWhen testing PEX pipe or tubing and related system components (such as fittings) as a sys
44、tem, theother components shall be attached to the PEX pipe or tubing in the same manner as in actual service. For fittings, the particularfitting style shall be installed in accordance with the manufacturers instructions or the ASTM specification when applicable.7.4 Minimum Required Test UnitsA mini
45、mum of six test units is required. A test unit is comprised of two or more individualtime-to-failure data points at the same temperature and hoop stress condition. Statistical reliability of the analysis of the resultantdata will be benefited by obtaining additional data points at each temperature/h
46、oop stress condition.F2023 1537.4.1 Test Unit DistributionTime-to-failure data points shall be obtained at 2 test hoop stresses at each of a minimum of 3 testtemperatures for a minimum of 12 data points. As an alternate, obtain time-to-failure data for the temperature/hoop stresscombinations of the
47、three-temperature matrix of PPI TN-16, see Note 3. Hoop stresses shall be separated by a least 80 psi (0.55MPa).NOTE 3When using the PPI TN-16 matrix, Temperature T3, which requires testing at only one stress, refers to the lowest test temperature.7.4.2 Test Temperature SelectionTemperatures of 239F
48、 (115C), 221F (105C), and 203F (95C) have been utilized in priortesting of PEX, see Note 4. Adjacent test temperatures shall be separated by at least 18F (10C). Other test temperatures may beused, but the maximum test temperature shall not exceed 239F (115C).NOTE 4Prior testing indicates that for th
49、e test temperatures stated in 7.4.2, hoop stresses to yield Stage III failures within reasonable testing timesare between 160 psi (1.10 MPa) and 400 psi (2.76 MPa). For a true SDR9 tube, those hoop stresses correspond to test pressures of 40 psig (275.9 kPa)to 100 psig (689.7 kPa). If a selected test hoop stress produces Stage I or Stage II failures, the stress will need to be reduced to produce Stage III failuresat all temperatures.7.4.2.1 Relationship of Internal Pressure to Hoop StressThe hoop stress in the pipe or tubing wall is
