1、Designation: F2786 16Standard Practice forField Leak Testing of Polyethylene (PE) Pressure PipingSystems Using Gaseous Testing Media Under Pressure(Pneumatic Leak Testing)1This standard is issued under the fixed designation F2786; the number immediately following the designation indicates the year o
2、foriginal 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 practice provides information on apparatus, safety,p
3、re-test preparation and procedures for conducting field tests ofpolyethylene pressure piping systems after installation usinggaseous testing media such as unodorized inert non-toxic gasor air, and applying pressure to determine if leaks exist in thesystem (pneumatic leak testing). This practice appl
4、ies only totesting to discover leakage. Testing for other purposes such astesting to establish operating pressure is beyond the scope ofthis practice.1.2 Leak testing with pressurized gaseous testing mediashall be used only if one or both of the following conditionsexists:1.2.1 The piping system is
5、so designed that it cannot befilled with a liquid, or1.2.2 The piping system service cannot tolerate traces ofliquid testing fluid.1.3 Where hydrostatic testing is specified in contract docu-ments or by the authority having jurisdiction, testing usingpressurized gaseous testing media (pneumatic) tes
6、ting shall notbe substituted without the express consent and authorization ofthe authority having jurisdiction.1.4 Some manufacturers prohibit or restrict testing of theirproducts with pressurized gaseous testing media. Contactcomponent manufacturers for information. Where the manu-facturer of a tes
7、t section component prohibits or restrictstesting with pressurized gaseous testing media testing inaccordance with this practice shall not be used without theexpress consent and authorization of the authority havingjurisdiction and the component manufacturer.NOTE 1Components that are not suitable fo
8、r testing with gaseoustesting fluid may not be suitable for service with pressurized gaseous fluid.1.5 This practice does not address leak testing using pres-surized liquids (hydrostatic testing). For field leak testing usingpressurized liquids, see Practice F2164.1.6 This practice does not apply to
9、 leak testing of non-pressure, negative pressure (vacuum), or non-PE piping sys-tems. For field acceptance testing of plastic non-pressure sewerlines, see Test Method F1417.1.7 This practice does not apply to fuel gas piping systemsthat extend from the point of delivery to the applianceconnections.
10、For other than undiluted liquefied petroleum gas(LP-Gas) systems, the point of delivery shall be considered tobe the outlet of the service meter assembly or the outlet of theservice regulator or service shutoff valve where no meter isprovided. For undiluted LP-Gas, the point of delivery shall becons
11、idered to be the outlet of the final pressure regulator,exclusive of line gas regulators, in the system. Testing for thesesystems can be found in NFPA54 /ANSI Z223.1. This practicedoes not apply to LP-Gas systems covered under NFPA 58.1.8 This practice is intended for use with polyethylenepressure p
12、iping that conveys gaseous media under pressure(compressed gas) if the owner or operator or installer of theline does not have an established leak testing procedure that isacceptable to the authority having jurisdiction.1.9 WarningFailure during a pressurized gaseous testingmedia leak test can be ex
13、tremely violent and dangerousbecause energy that is applied to compress the gaseous testingmedia and to pressurize the system will both be suddenlyreleased.NOTE 2To illustrate the violent hazard of failure, assumea5Hpcompressor is used to raise the test section to test pressure and that it takes1 h
14、to achieve test pressure. If sudden rupture occurs, energy release mayoccur in 2 s. Therefore, the horsepower of the energy release would be 5HP 1 h 3600 sec/h / 2 s = 9,000 Hp. Further, if diameter is doubled,energy release is four times greater. For an example test section that istwice the diamete
15、r, energy release would be 36,000 Hp.1.10 The values stated in inch-pound units are to be re-garded as standard. The values given in parentheses aremathematical conversions to SI units that are provided forinformation only and are not considered standard. Numbered1This practice is under the jurisdic
16、tion of ASTM Committee F17 on PlasticPiping Systems and is the direct responsibility of Subcommittee F17.40 on TestMethods.Current edition approved Feb. 1, 2016. Published March 2016. Originallyapproved in 2010. Last previous edition approved in 2010 as F278610.DOI:10.1520/F278616.*A Summary of Chan
17、ges section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1notes and information in parentheses in the text of the practiceare non-mandatory information. Table notes are mandatoryinformation.1.11 Th
18、is standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Additional safetyinf
19、ormation is presented in Section 7 and throughout thispractice.2. Referenced Documents2.1 ASTM Standards:2D1600 Terminology forAbbreviated Terms Relating to Plas-ticsF412 Terminology Relating to Plastic Piping SystemsF1417 Practice for Installation Acceptance of Plastic Non-pressure Sewer Lines Usin
20、g Low-Pressure AirF2164 Practice for Field Leak Testing of Polyethylene (PE)and Crosslinked Polyethylene (PEX) Pressure PipingSystems Using Hydrostatic Pressure2.2 Other Standard:3PPI TR-4 PPI Listing of Hydrostatic Design Basis (HDB),Pressure Design Bases (PDB) and Minimum RequiredStrength (MRS) Ra
21、tings for Thermoplastic Piping Mate-rialsPPI Handbook of Polyethylene Pipe, Second Edition2.3 NFPA Standards:4NFPA 54 / ANSI Z223.1 National Fuel Gas CodeNFPA 58 Liquefied Petroleum Gas Code3. Terminology3.1 Abbreviations and terms are in accordance with Termi-nology D1600 and Terminology F412 unles
22、s otherwise indi-cated.3.2 Definitions of Terms Specific to This Standard:3.2.1 authority having jurisdiction, nThe organization,office or individual responsible for “approving“ equipment andinstallation, or a procedure.3.2.1.1 DiscussionThe term “authority having jurisdic-tion“ is used in this prac
23、tice in a broad manner since jurisdic-tions and “approval“ agencies vary, as do their responsibilities.Where public safety is concerned, the “authority havingjurisdiction“ may be a federal, state, local or other regionaldepartment or individual such as a Fire Chief, Fire Marshall,chief of a fire pre
24、vention bureau, labor department, buildingofficial, or others having statutory authority. For insurancepurposes, an insurance inspection department, rating bureau orother insurance company representative may be the “authorityhaving jurisdiction. In many circumstances, the property owneror his author
25、ized engineer or agent assumes the role of the“authority having jurisdiction“; at government installations, thecommanding officer or departmental official may be the “au-thority having jurisdiction.“3.2.2 approve, vAcceptable to or authorized by the au-thority having jurisdiction. (approved, approvi
26、ng, approval)3.2.3 authorized persons, nPersons that are fully informedof the testing procedure and hazards of field pressure testing,and that are qualified to operate the onsite testing equipment,and that are qualified to perform onsite leak detection.3.2.3.1 DiscussionAuthorized persons may be age
27、nts orrepresentatives or inspectors for the authority havingjurisdiction, or may be employees of the party conducting thetest. Contract documents may identify responsibilities, butregardless of assigned responsibilities, only authorized personsshall be allowed in proximity of test sections when test
28、ing (perSection 9) is underway.3.2.4 gaseous testing media, na non-toxic, non-flammablefluid substance that is chemically compatible with pipingsystem components, and at testing temperature, exists in anon-solid, non-liquid state.3.2.5 pressure piping system, nA piping system where allcomponents in
29、the system are pressure rated and intended forconveying a fluid under continuous internal pressure. (See alsoTerminology F412, pressure pipe, and non-pressure pipe.) Toverify suitability for pressure service, consult the componentmanufacturer.3.2.5.1 DiscussionPPI TR-4 provides information aboutstre
30、ss ratings for some plastic materials and products.3.2.6 restraint, nTemporary or permanent structural mea-sures or devices that restrict, guide, prevent, or safely limitdisjoining and movement of the piping system and pipingcomponents while the system is under pressure during testingor service cond
31、itions. Restraint may include backfill, anchors,thrust blocks, external clamps and tie rods (joint restraints),pipe guides, etc.3.2.6.1 DiscussionRestraint means that if violent separa-tion or failure occurs during pressurization or testing, anymovement of components or parts is sufficiently constra
32、ined orprevented such that damage or injury is prevented.3.2.7 system design pressure, nThe limiting continuousinternal pressure specified by the piping system designer.System design pressure may be less than the pressure ratings ofcomponents in the system. System design pressure may belimited by co
33、mponent pressure ratings, by code or applicationrequirements, or by other restrictions.3.2.8 visible leakage, nThe visible escape (bubbles, drip,spray, stream, flow, etc.) of test fluid from the test sectionthrough components, joints, connections, appurtenances andthe like in the test section. Visib
34、ility of gaseous media leakageis enhanced by the application of leak detection fluid at joints,seals or seams where leakage is likely.4. Summary of Practice4.1 The section of the piping system to be tested shall beisolated from other parts of the system, and shall be restrainedas described in 3.2.6.
35、 Components that are not to be subjected2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from Plast
36、ics Pipe Institute (PPI), 105 Decker Court, Suite 825,Irving, TX 75062, http:/www.plasticpipe.org.4Available from National Fire Protection Association (NFPA), 1 BatterymarchPark, Quincy, MA 02169-7471, http:/www.nfpa.orgF2786 162to test pressure or that could be damaged by test pressure shallbe remo
37、ved, or shall be isolated and vented to atmosphere. Thetest section is filled with the gaseous testing media, raised tothe test pressure and allowed to stabilize. The system isinspected or monitored for leakage, and then test pressure isrelieved. If repairs or corrections are necessary, they areperf
38、ormed only when the test section is depressurized. Ifnecessary, retesting is performed after leak repairs or correc-tions and a relaxation period. At the conclusion of an accept-able test (approval), the test section may be placed in service.Purging or disposal of the gaseous testing media from the
39、testsection may be necessary.4.2 Test pressure and test duration are dependent on pipingsystem volume and piping system temperature. The volume ofcompressed gaseous testing media available or compressorcapacity will determine the test section length that can beraised to test pressure within specifie
40、d test duration and testpressure limits. Elevated temperatures anywhere in the testsection especially where test section areas are exposed tosunlight heating require reduced test pressure.4.3 Acceptance is determined by the approval of the author-ity having jurisdiction.4.4 If applicable, the author
41、ity having jurisdiction specifiesprocedures or requirements for gaseous testing media disposalor containment during depressurizing or purging.5. Significance and Use5.1 If required by the authority having jurisdiction, pressur-ized gaseous testing media leak testing is conducted afterinstallation to
42、 discover and correct or repair leaks or faults ina newly constructed or modified polyethylene pressure pipingsystem before placing the system in service. Leakage or faultsusually occur at connections, joints, and mechanical sealswhere sealing under pressure is required.5.2 Safety is of paramount im
43、portance when conductingpressurized gaseous testing media leak tests because testingresults include no leaks, leaks, sudden violent rupture, orcatastrophic failure.5.3 Systems that contain lower pressure rated or non-pressure rated components that cannot be isolated or removedfrom exposure to test p
44、ressure, or where temporary caps orclosures are not practical, are not suitable for testing inaccordance with this practice.5.4 Leakage AllowanceLeakage is not allowed for butt,socket and saddle fusion joints, electrofusion joints, andrestrained gas-tight mechanical joints. See 7.6. Contact thejoint
45、, connection or component manufacturer for leakagecorrection information if leakage occurs at a joint, connectionor component having a mechanical seal. See 9.8.5.5 Poisson-Effect Expansion and ContractionWhen testpressure is applied to plastic piping systems that have fullyrestrained joints such as
46、heat fusion, electrofusion, boltedflanges, etc., either reduction of overall pipe length or anincrease in longitudinal stress results from diametrical expan-sion of the pipe. Disjoining (pull-out) of partially restrained ornon-restrained connections or joints such as bell-and-spigotjoints having ins
47、ufficient resistance to pull-out stress or lengthreduction is possible when partially restrained or unrestrainedjoints are in-line with the fully restrained test section. Toprevent Poisson-effect disjoining of partially restrained ornon-restrained joints take measures such as installing externaljoin
48、t restraints (diametrical clamps and tie-rods) on in-linepartially restrained or non-restrained joints, installing in-linethrust anchors at the ends of fully restrained piping sections toprevent end movement of the fully restrained section, orisolating a fully restrained test section from piping wit
49、hunrestrained or partially restrained joints.NOTE 3A tensile stress applied to a material will cause elongation inthe direction of the applied stress, and will cause a decrease in dimensionat right angles to the direction of the applied stress. The ratio of decreaseto elongation is the Poisson ratio. Under test pressure, piping materialswill expand slightly in diameter and contract in length slightly accordingto the Poisson ratio of the material.6. Apparatus and Equipment6.1 Isolation and closure components such as caps, valves,blind flanges, and other device
