1、Designation: F3253 17F3253 18 An American National StandardStandard Specification forCrosslinked Polyethylene (PEX) Tubing with Oxygen Barrierfor Hot- and Cold-Water Hydronic Distribution Systems1This standard is issued under the fixed designation F3253; the number immediately following the designat
2、ion 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 Scope*1.1 This specification covers r
3、equirements, test methods, and marking requirements for crosslinked polyethylene (PEX) tubingwith a polymeric oxygen barrier layer, made in one standard dimension ratio (SDR 9), and distribution system componentsintended for hydronic heating and cooling applications up to and including a maximum wor
4、king temperature of 200F(93C).200 F (93 C).1.1.1 Components are comprised of tubing, fittings, valves, and manifolds. Tubing made to this specification incorporates asingle outer or middle wall oxygen barrier layer intended for inhibiting the transmission or permeation of oxygen through thetubing wa
5、ll. Requirements and test methods are included for materials, workmanship, tubing dimensions and tolerances, burstpressure, sustained pressure, excessive temperature and pressure, thermo-cycling, bent tube, oxidative resistance, layer adhesion,UV resistance, oxygen permeation, and fitting pull-out s
6、trength tests. The components covered by this specification are intendedfor use in residential and commercial hydronic heating and cooling systems. Requirements for potable water applications areoutside the scope of this specification.1.2 The text of this specification references notes, footnotes, a
7、nd 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 in parentheses are mathematicalco
8、nversions to SI units that are provided for information only and are not considered standard.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, health, and en
9、vironmental practices and determine the applicability ofregulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standard
10、s, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD792 Test Methods for Density and Specific Gravity (Relative Density) of Plastics by Displacem
11、entD1505 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 Resistance to Short-Time Hydraulic Pressure of Plastic Pipe, Tubing, and FittingsD1600 Terminology for Abbreviated
12、 Terms Relating to PlasticsD2122 Test Method for Determining Dimensions of Thermoplastic Pipe and FittingsD2749 Symbols for Dimensions of Plastic Pipe FittingsD2765 Test Methods for Determination of Gel Content and Swell Ratio of Crosslinked Ethylene PlasticsD2837 Test Method for Obtaining Hydrostat
13、ic Design Basis for Thermoplastic Pipe Materials or Pressure Design Basis forThermoplastic Pipe ProductsF412 Terminology Relating to Plastic Piping Systems1 This specification is under the jurisdiction of ASTM Committee F17 on Plastic Piping Systems and is the direct responsibility of Subcommittee F
14、17.61 on Water.Current edition approved Dec. 1, 2017Aug. 1, 2018. Published February 2018August 2018. Originally approved in 2017. Last previous edition approved in 2017 asF325317. DOI: 10.1520/F32531710.1520/F3253182 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM
15、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 indication of what changes have been made t
16、o 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 considered the official document.*A Summ
17、ary 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 States1F876 Specification for Crosslinked Polyethylene (PEX) TubingF877 Specification for Crosslinked Polyethylene (PEX) Hot- and Cold-
18、Water Distribution SystemsF1281 Specification for Crosslinked Polyethylene/Aluminum/Crosslinked Polyethylene (PEX-AL-PEX) Pressure PipeF1588 Test Method for Constant Tensile Load Joint Test (CTLJT)F1960 Specification for Cold Expansion Fittings with PEX Reinforcing Rings for Use with Cross-linked Po
19、lyethylene (PEX)TubingF1961 Specification for Metal Mechanical Cold Flare Compression Fittings with Disc Spring for Crosslinked Polyethylene(PEX) Tubing (Withdrawn 2018)3F1807 Specification for Metal Insert Fittings Utilizing a Copper Crimp Ring for SDR9 Cross-linked Polyethylene (PEX) Tubingand SDR
20、9 Polyethylene of Raised Temperature (PE-RT) TubingF1865 Specification for Mechanical Cold Expansion Insert Fitting With Compression Sleeve for Cross-linked Polyethylene(PEX) Tubing (Withdrawn 2018)3F2023 Test Method for Evaluating the Oxidative Resistance of Crosslinked Polyethylene (PEX) Pipe, Tub
21、ing and Systems toHot Chlorinated WaterF2080 Specification for Cold-Expansion Fittings with Metal Compression-Sleeves for Crosslinked Polyethylene (PEX) Pipe andSDR9 Polyethylene of Raised Temperature (PE-RT) PipeF2159 Specification for Plastic Insert Fittings Utilizing a Copper Crimp Ring for SDR9
22、Cross-linked Polyethylene (PEX)Tubing and SDR9 Polyethylene of Raised Temperature (PE-RT) TubingF2434 Specification for Metal Insert Fittings Utilizing a Copper Crimp Ring for SDR9 Cross-linked Polyethylene (PEX) Tubingand SDR9 Cross-linked Polyethylene/Aluminum/Cross-linked Polyethylene (PEX-AL-PEX
23、) TubingF2657 Test Method for Outdoor Weathering Exposure of Crosslinked Polyethylene (PEX) TubingF2735 Specification for Plastic Insert Fittings For SDR9 Cross-linked Polyethylene (PEX) and Polyethylene of RaisedTemperature (PE-RT) Tubing2.2 AWWA Standard:4Manual M-11, Steel Pipe Design and Install
24、ation2.3 Federal Standard:5FED-STD-123 Marking for Shipment (Civil Agencies)2.4 ISO Standards:6ISO 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
25、 of fluids under pressure - Miners rule - Calculation method for cumulativedamageISO 17455 Plastics piping systems Multilayer pipes Determination of the oxygen permeability of the barrier pipeISO R161-1690 Pipes of Plastic Materials for the Transport of Fluids (Outside Diameters and Nominal Pressure
26、s) Part 1, MetricSeries2.5 Military Standard:5MIL-STD-129 Marking for Shipment and Storage2.6 NSF Standard:7NSF/ANSI Standard No. 14 for Plastic Piping Components and Related Materials2.7 PPI Standard:8PPI TR-3 Policies and Procedures for Developing Hydrostatic Design Basis (HDB), Hydrostatic Design
27、 Stresses (HDS),Pressure Design Basis (PDB), Strength Design Basis (SDB), Minimum Required Strength (MRS) Ratings, and CategorizedRequired Strength (CRS) for Thermoplastic Piping Materials or PipePPI TR-4 PPI Listing of Hydrostatic Design Basis (HDB), Strength Design Basis (SDB), Pressure Design Bas
28、is (PDB) andMinimum Required Strength (MRS) Ratings for Thermoplastic Piping Materials or Pipe3. Terminology3.1 The terminology used in this specification is in accordance with Terminology F412, Terminology D1600, and SymbolsD2749, unless otherwise specified. The abbreviation for crosslinked polyeth
29、ylene is PEX.3.2 Definitions of Terms Specific to This Standard:3 The last approved version of this historical standard is referenced on www.astm.org.4 Available from American Water Works Association (AWWA), 6666 W. Quincy Ave., Denver, CO 80235, http:/www.awwa.org.5 DLA Document Services Building 4
30、/D 700 Robbins Avenue Philadelphia, PA 19111-5094 http:/quicksearch.dla.mil/6 Available from International Organization for Standardization (ISO), ISO Central Secretariat, BIBC II, Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva,Switzerland, http:/www.iso.org.7 Available from NSF International,
31、 P.O. Box 130140, 789 N. Dixboro Rd., Ann Arbor, MI 48113-0140, http:/www.nsf.org.8 Plastics Pipe Institute (PPI), 105 Decker Court, Suite 825 Irving TX, 75062. http:/www.plasticpipe.orgF3253 1823.2.1 barrier layera very thin polymeric film within the tube wall or around the circumference of the tub
32、ing which providesa means for greatly reducing the transmission of oxygen from the atmosphere and into the fluid within the tube.3.2.2 hydrostatic design basis (HDB)As defined by Terminology F412 is one of a series of established stress values (specifiedin Test Method D2837) for a plastic compound o
33、btained by categorizing the long-term hydrostatic strength determined inaccordance with Test Method D2837.3.2.2.1 DiscussionA voluntary listing of HDB, and HDS values are contained in PPI publication PPI TR-4.3.2.3 hydrostatic design stress (HDS)As defined by Terminology F412 is the estimated maximu
34、m tensile stress the materialis capable of withstanding continuously with a high degree of certainty that failure of the tube will not occur. This stress iscircumferential when internal hydrostatic water pressure is applied. The HDS is equal to the hydrostatic design basis (HDB) timesthe design fact
35、or (DF) for water; HDS5HDB3DF. For this specification, the design factor is less than or equal to 0.50.3.2.4 hydrostatic strength equivalency (HSE)a pressure testing evaluation methodology where hydrostatic testing is conductedon PEX tubing that is constructed with a barrier layer or layers in the m
36、iddle or outside wall of the tubing, and is constructed withPEX material that has an established HDB. HSE methodology is applied where the barrier layer or layers reduce the thickness ofthe HDB rated PEX material in the wall such that the PEX wall thickness excluding the barrier layer(s) is slightly
37、 less than thatrequired for SDR 9.0.3.2.4.1 DiscussionHSE testing is conducted to confirm that the pressure rating of the PEX tubing having a barrier layer or layers as described hereinis at least equal to comparable SDR 9.0 PEX tubing that does not have a barrier layer or layers. When PEX tubing ha
38、s a barrierlayer(s) that does not reduce the thickness of the HDB-rated PEX material below that required for SDR 9.0, it is not necessary toconduct HSE testing because pressure rating is determined using the ISO equation (3.2.6).3.2.5 HSE-SDR 9an identifying term for the tubing where the minimum PEX
39、 wall thickness falls outside the calculated SDR9 values yet the tubing as constructed meets the pressure rating requirements of this standard as demonstrated by HSE evaluationtesting.3.2.6 ISO equation and pressure rating (PR)The relationship between dimensions, hydrostatic design basis, hydrostati
40、cdesign stress, and pressure rating as defined by Terminology F412 is illustrated as follows specific to this specification.The following is commonly referred to as the ISO equation (See ISO R161-1690.) :S 5POD2t!2t For outside diameter controlled pipe! (1)where:S = hoop stress,P = pressure,OD = ave
41、rage outside diameter,t = minimum wall thicknessThe pressure rating (PR) and HDS/HDB are related by the following equation:PR52HBD!DF!SDR21!52HDS!SDR 2 1! (2)(being specific to this specification with DF=0.50 and SDR 9)PR 52HDB!0.50!921!52HDS!8 (3)Example: PEX with HDB of 800 PSI at 180 F made accor
42、ding to this specification to SDR 9PR 52800!0.50!921!5100 PSI (4)3.2.7 manifoldan appurtenance that has at least one inlet and multiple outlets3.2.8 standard dimension ratio (SDR)the ratio of outside diameter to wall thickness as defined by Terminology F412 exceptthis standard uses the minimum total
43、 wall thickness, inclusive of layers, to establish SDR. When the total wall thickness calculatedby the given formula is less than 0.070 in. (1.78 mm) then the total wall thickness is arbitrarily increased to 0.070 in. except forNTS 516 and smaller which are prescriptively assigned.3.2.9 standard the
44、rmoplastic tubing materials designation codeThis material designation code consists of the abbreviation forthe type of plastic (PEX) followed by four Arabic digits that describe those properties in accordance with applicable ASTMstandards and as shown in Table 1. This material designation code solel
45、y addresses the PEX material and does not address anyother polymeric materials which might be used in the construction of oxygen barrier tubing.3.2.9.1 DiscussionF3253 183The first digit is for chlorine resistance. Since this standard is specific to hydronic distribution systems, chlorine resistance
46、 is nota mandatory requirement of this application and the default “0” is used if oxidative stability is evaluated only per 6.1.9.1 (stabilizerfunctionality). If oxidative stability is evaluated per 6.1.9.2 (chlorine resistance), this digit is defined by Specification F876 asfollows:(1) A digit “0”
47、indicates that the PEX tubing either has not been tested for chlorine resistance or that the PEX tubing does not meet the minimum requirementfor chlorine resistance.(2) A digit “1” indicates the PEX tubing has been tested and meets the requirement of 6.1.9.2 for minimum chlorine resistance at the en
48、d use condition of 25%at 140F (60C) and 75% at 73F (23C).(2) A digit “1” indicates the PEX tubing has been tested and meets the requirement of 6.1.9.2 for minimum chlorine resistance at the end use condition of 25%at 140 F (60 C) and 75% at 73 F (23 C).(3) A digit “2” is reserved for future applicat
49、ion.(4) A digit “3” indicates that the PEX tubing has been tested and meets the requirement of 6.1.9.2 for minimum chlorine resistance at end use condition of 50%at 140F and 50% at 73F.(4) A digit “3” indicates that the PEX tubing has been tested and meets the requirement of 6.1.9.2 for minimum chlorine resistance at end use condition of 50%at 140 F and 50% at 73 F.(5) A digit “4” is reserved for future application.(6) A digit “5” indicates that the PEX tubing has been tested and meets the requirement of 6.1.9.2 fo
