1、Designation:D277421aAn American National StandardStandard Practice forUnderground Installation of Thermoplastic Pressure Piping1This standard is issued under the fixed designation D2774;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision
2、,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.INTRODUCTIONIn general,thermoplastics pressure piping materials behave as ductile materials under load,meaningthat they c
3、an undergo considerable deformation without damage.Piping made from such materials hasthe ability to bend under a load without breaking and to deform in other ways,while offering continuedresistance.This flexibility allows ductile thermoplastic pipe to activate through pipe deformationlateral soil f
4、orces which create a pipe/soil system capable of safely supportingeven in pipes subjectto little or no internal pressurethe earth and superimposed loads which are encountered in most pipeinstallations.However,proper installation techniques are required to ensure that the necessary supportat the bott
5、om and passive soil pressures at the sides of the pipe are developed and maintained.Soils in which trenches are dug shall be examined and identified and the trenches prepared andbackfilled in accordance with sound bedding procedures and this practice.1.Scope*1.1 This practice governs procedures and
6、references ASTMspecifications for underground installation of thermoplasticpressure piping,63 in.(1372 mm)nominal size and smaller.Itis beyond the scope of this practice to describe these proce-dures in detail since it is recognized that significant differencesexist in their implementation depending
7、 on kind and type ofpipe material,pipe size and wall thickness,soil conditions,andthe specific end use.1.1.1 This practice assumes that over the range of antici-pated operating conditions,including maximum external load-ing and minimum internal pressure,the soil/pipe system willoffer sufficient stru
8、ctural stability to resist possible excessivediametrical deformation,or even collapse.In cases,particu-larly with large diameter thinner-walled pipe,for which thevalidity of this assumption may be in question,the selection ofpipe and recommended installation conditions shall be deter-mined by a qual
9、ified engineer.1.1.2 Specific pipe characteristics and end-use requirementsshall dictate addition to,or modification of the proceduresstated or referenced herein.1.2 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI
10、units that are provided for information onlyand are not considered standard.1.3 This 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,health,and environmental practices
11、and deter-mine the applicability of regulatory limitations prior to use.Specific precautionary statements are given in Sections 10 and11.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principl
12、es for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D1600 Terminology forAbbreviated Terms Relating to Plas-ticsD2487 Practice for Classification of Soil
13、s for EngineeringPurposes(Unified Soil Classification System)D2488 Practice for Description and Identification of Soils(Visual-Manual Procedures)E11 Specification for Woven Wire Test Sieve Cloth and TestSievesF412 Terminology Relating to Plastic Piping SystemsF1668 Guide for Construction Procedures
14、for Buried PlasticPipe1This practice is under the jurisdiction of ASTM Committee F17 on PlasticPiping Systems and is the direct responsibility of Subcommittee F17.61 on Water.Current edition approved July 1,2021.Published October 2021.Originallyapproved in 1969.Last previous edition approved in 2021
15、 as D2774 21.DOI:10.1520/D2774-21A.2For 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.*A Summary of Changes section a
16、ppears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1F1674 Test Method for Joint Restraint Produ
