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TM_C_924_
_02
Designation:C 924 02Standard Practice forTesting Concrete Pipe Sewer Lines by Low-Pressure AirTest Method1This standard is issued under the fixed designation C 924;the number immediately following the designation 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(e)indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1.Scope1.1 This practice covers procedures for testing concrete pipesewer lines,when using the low-pressure air test method todemonstrate the integrity of the installed material and theconstruction procedures.This practice is used for testing 4 to24-in.circular concrete pipe sewer lines utilizing gasketedjoints.1.2 This practice is also used as a preliminary test to enablethe installer to demonstrate the condition of the line prior tobackfill.1.3This 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(see Section 6,Safety Precautions).1.4 A complete metric companion to Practice C 924 hasbeen developedC 924 M;therefore,no metric equivalentsare presented in this practice.NOTE1The user of this practice is advised that air test criteriapresented in this practice are similar to those in general use.The test andcriteria have been used widely and successfully in testing smaller diameterpipe,but additional data are required to confirm the safety and applica-bility or develop criteria for pipe larger than 24 in.in diameter.Larger pipewill be accepted more conveniently by visual inspection and individualjoint testing.NOTE2The user of this practice is advised that no correlation hasbeen found between air loss and water leakage.2.Referenced Documents2.1 ASTM Standards:C 822 Terminology Relating to Concrete Pipe and RelatedProducts2C 969 Practice for Infiltration and Exfiltration AcceptanceTesting of Installed Precast Concrete Pipe Sewer Lines23.Terminology3.1 DefinitionsFor definitions of terms relating to con-crete pipe,see Terminology C 822.4.Summary of Practice4.1 The sewer line to be tested is plugged.Air is introducedat low pressures into the plugged line.The amount of air lossis used to determine the acceptability of the sewer line.5.Significance and Use5.1 This is not a routine test.The values recorded areapplicable only to the sewer being tested and at the time oftesting.6.Safety Precautions6.1 The air test will be dangerous if a line is not preparedproperly and proper procedures are not followed.6.2 It is extremely important that plugs be installed andbraced in such a way as to prevent blowouts.It is alsoimperative that the pressure in the pipe be relieved completelybefore any plug is loosened for removal.NOTE3As an example,4-psi air pressure acting on one side of a15-in.plug results in a total force of approximately 700 lbf on the plug.Such a force is capable of causing the expulsion of an improperly installedplug.6.3 Pressurizing equipment shall include a 6-psi pressurerelief device to reduce hazards and avoid over-pressurizationwith possible damage to the line.6.4 No one shall be allowed in or near the manholes duringpressurization,testing,or depressurization.7.Capacity of Air Compressor7.1To provide satisfactory test results,the air compressorshall be capable of pressurizing the sewer test section in therequired test time,or less,as determined by 9.1.The compres-sor capacity required to accomplish the pressurization is equalto the rate necessary to fill the sewer to the desired pressureplus the allowable air loss rate:1This practice is under the jurisdiction of ASTM Committee C13 on ConcretePipe and is the direct responsibility of Subcommittee C13.09 on Methods of Test.Current edition approved Aug.10,2002.Published October 2002.Originallypublished as C 924 84.Last previous edition C 924 89(1997).2Annual Book of ASTM Standards,Vol 04.05.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.C 50.17D2LT1 Q(1)where:C=compressor capacity,cfm,T=required test time,or less,min,D=pipe internal diameter,ft,L=length of test section,ft,andQ=allowable air loss,rate,cfm.8.Preparation of the Sewer Line8.1 Where practical,clean the sewer line prior to testing towet the pipe surface and eliminate debris.NOTE4The user of this practice is advised that a wetted interior pipesurface is desirable and will produce more consistent test results.Air maypass through the walls of dry pipe.This can be overcome by wetting thepipe.If the problem persists,segmental testing of the line will establish ifthere is a significant leak.8.2 Plug all pipe outlets including laterals,which shall begiven special attention.Review safety precautions i