1、Designation: D2992 12An American National StandardStandard Practice forObtaining Hydrostatic or Pressure Design Basis for“Fiberglass” (Glass-Fiber-Reinforced Thermosetting-Resin)Pipe and Fittings1This standard is issued under the fixed designation D2992; 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.This standard has been approved for use by age
3、ncies of the Department of Defense.1. Scope*1.1 This practice establishes two procedures, Procedure A(cyclic) and Procedure B (static), for obtaining a hydrostaticdesign basis (HDB) or a pressure design basis (PDB) forfiberglass piping products, by evaluating strength-regressiondata derived from tes
4、ting pipe or fittings, or both, of the samematerials and construction, either separately or in assemblies.Both glass-fiber-reinforced thermosetting-resin pipe (RTRP)and glass-fiber-reinforced polymer mortar pipe (RPMP) arefiberglass pipe.NOTE 1For the purposes of this standard, polymer does not incl
5、udenatural polymers.1.2 This practice can be used for the HDB determination forfiberglass pipe where the ratio of outside diameter to wallthickness is 10:1 or more.NOTE 2This limitation, based on thin-wall pipe design theory, servesfurther to limit the application of this practice to internal pressu
6、res which,by the hoop-stress equation, are approximately 20 % of the derivedhydrostatic design stress (HDS). For example, if HDS is 5000 psi (34 500kPa), the pipe is limited to about 1000-psig (6900-kPa) internal pressure,regardless of diameter.1.3 This practice provides a PDB for complex-shaped pro
7、d-ucts or systems where complex stress fields seriously inhibitthe use of hoop stress.1.4 Specimen end closures in the underlying test methodsmay be either restrained or free, leading to certain limitations.1.4.1 Restrained EndsSpecimens are stressed by internalpressure only in the hoop direction, a
8、nd the HDB is applicablefor stresses developed only in the hoop direction.1.4.2 Free EndsSpecimens are stressed by internal pres-sure in both hoop and longitudinal directions, such that thehoop stress is twice as large as the longitudinal stress. Thispractice may not be applicable for evaluating str
9、esses inducedby loadings where the longitudinal stress exceeds 50 % of theHDS.1.5 The values stated in inch-pound units are to be regardedas the standard. The values in parentheses are given forinformation purposes only.NOTE 3There is no known ISO equivalent to this standard.1.6 This standard does n
10、ot 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.2. Referenced Documents2.1 ASTM Standar
11、ds:2D618 Practice for Conditioning Plastics for TestingD883 Terminology Relating to PlasticsD1598 Test Method for Time-to-Failure of Plastic PipeUnder Constant Internal PressureD1599 Test Method for Resistance to Short-Time HydraulicPressure of Plastic Pipe, Tubing, and FittingsD1600 Terminology for
12、 Abbreviated Terms Relating toPlasticsD2143 Test Method for Cyclic Pressure Strength of Rein-forced, Thermosetting Plastic PipeD3567 Practice for Determining Dimensions of “Fiber-glass” (Glass-Fiber-Reinforced Thermosetting Resin) Pipeand FittingsF412 Terminology Relating to Plastic Piping SystemsF9
13、48 Test Method for Time-to-Failure of Plastic PipingSystems and Components Under Constant Internal Pres-sure With Flow1This practice is under the jurisdiction ofASTM Committee D20 on Plastics andis the direct responsibility of Subcommittee D20.23 on Reinforced Plastic PipingSystems and Chemical Equi
14、pment.Current edition approved April 1, 2012. Published May 2012. Originallyapproved in 1971. Last previous edition approved in 2006 as D2992 06. DOI:10.1520/D2992-12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual
15、Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.2.2 ISO Stand
16、ard:3 Preferred NumbersSeries of Preferred Numbers33. Terminology3.1 Definitions:3.1.1 GeneralDefinitions are in accordance with Termi-nologies D883 and F412, and abbreviations are in accordancewith Terminology D1600, unless otherwise indicated.3.1.2 closure, free-enda sealing device or mechanismfas
17、tened to the end of the test specimen so that internal pressureproduces longitudinal tensile stresses in addition to hoop andradial stresses in the test specimen.3.1.3 closure, restrained-enda sealing device or mecha-nism which relies on a rod through the test specimen or anexternal structure to res
18、ist the end thrust produced by internalpressure, thereby limiting the stresses in (straight) specimens tothe hoop and radial directions only.3.1.4 failurethe transmission of the test fluid through thebody of the specimen in any manner, whether it be a wallfracture, localized leaking, or weeping at a
19、 distance greaterthan one diameter from the end closure.NOTE 4For this practice, specimens which have not failed may beincluded as failures under the specific conditions given in 6.3, 9.3, and12.2.3.1.5 fiberglass pipea tubular product containing glassfiber reinforcement embedded in or surrounded by
20、 curedthermosetting-resin; the composite structure may contain ag-gregate, granular or platelet fillers, thixotropic agents, pig-ments, or dyes; thermoplastic or thermosetting liners or coat-ings may be included.3.1.6 reinforced polymer mortar pipe (RPMP)a fiberglasspipe with aggregate.3.1.7 reinfor
21、ced thermosetting resin pipe (RTRP)a fiber-glass pipe without aggregate.3.1.8 hoop stressthe tensile stress in the wall of the pipingproduct in the circumferential direction due to internal pres-sure; hoop stress will be calculated by the ISO equation, asfollows:S 5 PD 2 tr!/2tr(1)where:S = hoop str
22、ess, psi (kPa),D = average reinforced outside diameter, in. (mm),P = internal pressure, psig (kPa), andtr= minimum reinforced wall thickness, in. (mm).NOTE 5Hoop stress should only be determined on straight hollowcylindrical specimens. Product evaluation of more complex shapes may bebased on pressur
23、e.3.1.9 hydrostatic design basis (HDB)a hoop stress devel-oped for fiberglass pipe by this practice and multiplied by aservice design factor to obtain an HDS.3.1.10 hydrostatic design pressure (HDP)the estimatedmaximum internal hydrostatic pressure that can be appliedcyclically (Procedure A) or cont
24、inuously (Procedure B) to apiping component with a high degree of certainty that failure ofthe component will not occur.3.1.11 hydrostatic design stress (HDS)the estimatedmaximum tensile stress in the wall of the pipe in the hoopdirection due to internal hydrostatic pressure that can beapplied cycli
25、cally (ProcedureA) or continuously (Procedure B)with a high degree of certainty that failure of the pipe will notoccur.3.1.12 long-term hydrostatic strength (LTHS)the esti-mated tensile stress in the wall of the pipe in the hoop directiondue to internal hydrostatic pressure that, when applied cycli-
26、cally, will cause failure of the pipe after a specified number ofcycles by Procedure A or a specified number of hours byProcedure B.NOTE 6The time for determination of LTHS or LTHP is specified bythe product standard. Typically, the time is 150 3 106or 657 3 106cyclesfor Procedure A and 100 000 or 4
27、38 000 h for Procedure B.3.1.13 long-term hydrostatic pressure (LTHP)the esti-mated internal pressure of the piping product that, whenapplied cyclically, will cause failure of the product after aspecified number of cycles by Procedure A or a specifiednumber of hours by Procedure B.3.1.14 pressure de
28、sign basis (PDB)an internal pressuredeveloped for fiberglass piping product by this practice andmultiplied by a service design factor to obtain an HDP.3.1.15 pressure rating (PR)the estimated maximum pres-sure in the pipe or fitting that can be exerted continuously witha high degree of certainty tha
29、t failure of the piping componentwill not occur.3.1.16 service design factora number equal to 1.00 or lessthat takes into consideration all the variables and degree ofsafety involved in a fiberglass piping installation so that whenit is multiplied by the HDB, an HDS and correspondingpressure rating
30、is obtained, or when it is multiplied by the PDB,a pressure rating is obtained directly, such that in either case asatisfactory and safe piping installation results when goodquality components are used and the installation is madeproperly.3.2 Definitions of Terms Specific to This Standard:3.2.1 aver
31、age outside diametera measurement obtainedin accordance with Practice D3567 less any veil-reinforced andnonreinforced exterior coating thicknesses.3.2.2 minimum reinforced wall thicknessa measurementobtained in accordance with Practice D3567, excluding veil-reinforced and nonreinforced coating and l
32、ining thicknesses;wall thickness of fittings is determined at the thinnest section ofthe fitting body.4. Summary of Practice4.1 Procedure A consists of exposing a minimum of 18specimens of pipe or fittings, or both to cyclic internalpressures at a cycle rate of 25 cycles/min and at severaldifferent
33、pressures. Elevated test temperatures are obtained bycirculating a hot liquid through the specimens or by testing inan air environment where the temperature is controlled.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.D2
34、992 1224.1.1 The cyclic LTHS or cyclic LTHP of a pipe or fitting isobtained by an extrapolation of a log-log plot of the linearregression line for hoop stress or internal pressure versuscycles to failure.4.1.2 The experimental basis for Procedure A shall be inaccordance with Test Method D2143, which
35、 forms a part ofthis practice. When any part of the procedure is not inagreement with Test Method D2143, the provisions of thispractice shall be used.4.1.3 Joints between pipe and fitting specimens shall betypical of those normally used for the kind of piping beingtested.4.2 Procedure B consists of
36、exposing a minimum of 18specimens of pipe or fittings, or both, to constant internalhydrostatic pressures at differing pressure levels in a controlledenvironment and measuring the time to failure for eachpressure level. Test temperatures are obtained by immersingthe specimens in a controlled-tempera
37、ture water bath, bytesting in an air environment where the temperature is con-trolled, or by circulating a temperature-controlled fluid throughthe specimen.NOTE 7Testing in a water bath precludes the detection of weepingfailure, (see 3.1.4) by either visual or electronic means.4.2.1 The static LTHS
38、or static LTHP of a pipe or fitting isobtained by an extrapolation of a log-log linear regression linefor hoop stress or internal pressure versus time to failure.4.2.2 The experimental basis for Procedure B shall be inaccordance with either Test Method D1598 or Test MethodF948, or both, which form a
39、 part of this practice. When anypart of this practice is not in agreement with the selectedmethod, the provisions of this practice shall be used.4.2.3 Joints between pipe and fitting specimens shall betypical of those normally used for the kind of piping beingtested.4.3 The HDB category is obtained
40、by categorizing theLTHS in accordance with Section 7 or Section 10.4.4 The PDB category is obtained by categorizing the LTHPin accordance with Section 8 or Section 11.4.5 Hydrostatic design stresses for pipe are obtained bymultiplying the HDB values by a service design factor.4.6 Reconfirmation of H
41、DB or PDB for AlteredConstructionsWhen a product already has an HDB or PDBdetermined in accordance with this practice and a change ofprocess or material is made, a reconfirmation of the originalHDB or PDB may be attempted in accordance with Section 12.At least six specimens must be tested and meet t
42、he specifiedcriteria.5. Significance and Use5.1 This practice is useful for establishing the hoop stress orinternal pressure versus time-to-failure relationships, underselected internal and external environments which simulateactual anticipated product end-use conditions, from which adesign basis fo
43、r specific piping products and materials can beobtained. This practice defines an HDB for material in straight,hollow cylindrical shapes where hoop stress can be easilycalculated, and a PDB for fittings and joints where stresses aremore complex.5.1.1 An alternative design practice based on initial s
44、trainversus time-to-failure relationships employs a strain basis HDBinstead of the stress basis HDB defined by this practice. Thestrain basis HDB is most often used for buried pipe designswith internal pressures ranging from 0 to 250 psig (1.72 MPa).5.2 To characterize fiberglass piping products, it
45、 is neces-sary to establish the stress versus cycles or time to failure, orpressure versus cycles or time to failure relationships overthree or more logarithmic decades of time (cycles or hours)within controlled environmental parameters. Because of thenature of the test and specimens employed, no si
46、ngle line canadequately represent the data. Therefore, the confidence limitsshould be established.5.3 Pressure ratings for piping of various dimensions at eachtemperature may be calculated using the HDS determined bytesting one size of piping provided that the same specificprocess and material are u
47、sed both for test specimens and thepiping in question.5.4 Pressure ratings at each temperature for componentsother than straight hollow shapes may be calculated using theHDP determined by testing one size of piping provided that (1)the specific materials and manufacturing process used for thetest sp
48、ecimens are used for the components, (2) for joints, thejoining materials and procedures used to prepare the testspecimens are used for field joining, and (3) scaling of criticaldimensions is related to diameter and pressure rating of thecomponent.NOTE 8Scaling of fittings and joints should be furth
49、er verified byshort-time testing in accordance with Test Method D1599.5.5 Results obtained at one set of environmental conditionsshould not be used for other conditions, except that highertemperature data can be used for design basis assignment forlower application temperatures. The design basis should bedetermined for each specific piping product. Design andprocessing can significantly affect the long-term performanceof piping products, and therefore should be taken into consid-eration during any evaluation.5.6 This practice is valid for a given pipe
