1、Designation: D2992 12 An 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 designa
2、tion 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*1.1 This practice establishes two pr
3、ocedures, 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 testing pipe or fittings, or both, of the samematerials and construction, either se
4、parately 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 includenatural polymers.1.2 This practice can be used for the HDB determination forf
5、iberglass 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 pressures which,by the hoop-stress equation, are approximately 20 % of the derivedhydr
6、ostatic 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 prod-ucts or systems where complex stress fields seriously inhibitthe use of hoop s
7、tress.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, and the HDB is applicablefor stresses developed only in the hoop direction.1.4.2
8、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 stresses inducedby loadings where the longitudinal stress exceeds 50 % of theHDS.1.
9、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 not purport to address all of thesafety concerns, if any, associated with its use
10、. 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 Standards:2D618 Practice for Conditioning Plastics for TestingD883 Terminology Relating
11、 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 forAbbreviated Terms Relating to Plas-ticsD2143 Test Method for Cyclic Pressure Str
12、ength ofReinforced, Thermosetting Plastic PipeD3567 Practice for Determining Dimensions of “Fiberglass”(Glass-Fiber-Reinforced Thermosetting Resin) Pipe andFittingsF412 Terminology Relating to Plastic Piping SystemsF948 Test Method for Time-to-Failure of Plastic PipingSystems and Components Under Co
13、nstant Internal Pres-sure With Flow2.2 ISO Standard:3 Preferred NumbersSeries of Preferred Numbers31This practice is under the jurisdiction ofASTM Committee D20 on Plasticsandis the direct responsibility of Subcommittee D20.23 on Reinforced Plastic PipingSystems and Chemical Equipment.Current editio
14、n 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 Book of ASTMStandard
15、s volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM Interna
16、tional, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13. 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,
17、 free-enda sealing device or mechanismfastened 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 tes
18、t specimen or anexternal structure to resist 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 wallfra
19、cture, localized leaking, or weeping at a 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 r
20、einforcement embedded in or surrounded by curedthermosetting-resin; the composite structure may containaggregate, granular or platelet fillers, thixotropic agents,pigments, or dyes; thermoplastic or thermosetting liners orcoatings may be included.3.1.6 reinforced polymer mortar pipe (RPMP)a fibergla
21、sspipe with aggregate.3.1.7 reinforced 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
22、5 PD 2 tr!/2tr(1)where:S = hoop stress, 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 co
23、mplex shapes may bebased on pressure.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 appl
24、iedcyclically (Procedure A) or continuously (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 hydrostati
25、c pressure that can beapplied cyclically (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
26、 pressure that, when appliedcyclically, will cause failure of the pipe after a specifiednumber of cycles by Procedure A or a specified number ofhours by Procedure B.NOTE 6The time for determination of LTHS or LTHP is specified bythe product standard. Typically, the time is 150 106or 657 106cyclesfor
27、 Procedure A and 100 000 or 438 000 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 P
28、rocedure B.3.1.14 pressure design 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
29、 high degree of certainty that 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
30、correspondingpressure rating 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 Specifi
31、c to This Standard:3.2.1 average outside diametera measurement obtained inaccordance 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 an
32、d nonreinforced coating and lining 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
33、/min and at severaldifferent pressures. Elevated test temperatures are obtained bycirculating a hot liquid through the specimens or by testing inan air environment where the temperature is controlled.4.1.1 The cyclic LTHS or cyclic LTHP of a pipe or fitting isobtained by an extrapolation of a log-lo
34、g 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 forms a part ofthis practice. When any part of the procedure is not inD2992 122agreement with Test Method
35、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 exposing a minimum of 18specimens of pipe or fittings, or both, to constant internalhydrostatic pr
36、essures 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-temperature water bath, bytesting in an air environment where the temperature iscontrolled, or by circula
37、ting a temperature-controlled fluidthrough the 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 or static LTHP of a pipe or fitting isobtained by an extrapolation of a log-log linear regression li
38、nefor 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 part of this practice. When anypart of this practice is not in agreement with the selectedmethod, t
39、he 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 by categorizing theLTHS in accordance with Section 7 or Section 10.4.4 The PDB category is obtained
40、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 HDB or PDB for AlteredConstructionsWhen a product already has an HDB or PDBdetermined in accordance w
41、ith 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 the specifiedcriteria.5. Significance and Use5.1 This practice is useful for establishing the hoop st
42、ress orinternal pressure versus time-to-failure relationships, underselected internal and external environments which simulateactual anticipated product end-use conditions, from which adesign basis for specific piping products and materials can beobtained. This practice defines an HDB for material i
43、n 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 strainversus time-to-failure relationships employs a strain basis HDBinstead of the stress basis HDB
44、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 is neces-sary to establish the stress versus cycles or time to failure, orpressure versus cycles or
45、 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 single line canadequately represent the data. Therefore, the confidence limitsshould be established.5.
46、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 used both for test specimens and thepiping in question.5.4 Pressure ratings at each temperature for c
47、omponentsother 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 specimens are used for the components, (2) for joints, thejoining materials and procedures used to pre
48、pare 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 further verified byshort-time testing in accordance with Test Method D1599.5.5 Results obtained at one se
49、t 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 or fitting only solong as the specimens are truly representative of that materialand manufactur
