ASTM C924-89(1997)
(Practice)Standard Practice for Testing Concrete Pipe Sewer Lines by Low-Pressure Air Test Method
Standard Practice for Testing Concrete Pipe Sewer Lines by Low-Pressure Air Test Method
SCOPE
1.1 This practice covers procedures for testing concrete pipe sewer lines, when using the low-pressure air test method to demonstrate the integrity of the installed material and the construction procedures. This practice is used for testing 4 to 24-in. circular concrete pipe sewer lines utilizing gasketed joints.
1.2 This practice may also be used as a preliminary test to enable the installer to demonstrate the condition of the line prior to backfill.
1.3 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use (see Section 6, Safety Precautions).
1.4 A complete metric companion to Practice C924 has been developed-C924M; therefore, no metric equivalents are presented in this practice. Note 1-Air test criteria presented in this practice are similar to those in general use. The test and criteria have been used widely and successfully in testing smaller diameter pipe, but additional data are required to confirm the safety and applicability or develop criteria for pipe larger than 24 in. in diameter. Larger pipe may be accepted more conveniently by visual inspection and individual joint testing. Note 2-It should be understood that no correlation has been found between air loss and water leakage.
General Information
Relations
Standards Content (Sample)
Designation:C924–89 (Reapproved 1997)
Standard Practice for Testing
Concrete Pipe Sewer Lines by Low-Pressure Air Test
Method
This standard is issued under the fixed designation C 924; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript 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. Scope 3. Terminology
1.1 Thispracticecoversproceduresfortestingconcretepipe 3.1 Definitions—For definitions of terms relating to con-
sewer lines, when using the low-pressure air test method to crete pipe, see Terminology C 822.
demonstrate the integrity of the installed material and the
4. Summary of Practice
construction procedures. This practice is used for testing 4 to
24-in. circular concrete pipe sewer lines utilizing gasketed 4.1 The sewer line to be tested is plugged.Air is introduced
at low pressures into the plugged line. The amount of air loss
joints.
1.2 This practice may also be used as a preliminary test to is used to determine the acceptability of the sewer line.
enable the installer to demonstrate the condition of the line
5. Significance and Use
prior to backfill.
5.1 This is not a routine test. The values recorded are
1.3 This standard does not purport to address all of the
applicable only to the sewer being tested and at the time of
safety concerns, if any, associated with its use. It is the
testing.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
6. Safety Precautions
bility of regulatory limitations prior to use (see Section 6,
6.1 The air test may be dangerous if a line is not prepared
Safety Precautions).
properly and proper procedures are not followed.
1.4 A complete metric companion to Practice C 924 has
6.2 It is extremely important that plugs be installed and
been developed—C 924 M; therefore, no metric equivalents
braced in such a way as to prevent blowouts. It is also
are presented in this practice.
imperative that the pressure in the pipe be relieved completely
NOTE 1—Air test criteria presented in this practice are similar to those
before any plug is loosened for removal.
in general use. The test and criteria have been used widely and success-
fully in testing smaller diameter pipe, but additional data are required to
NOTE 3—As an example, 4-psi air pressure acting on one side of a
confirm the safety and applicability or develop criteria for pipe larger than
15-in. plug results in a total force of approximately 700 lbf on the plug.
24 in. in diameter. Larger pipe may be accepted more conveniently by
Such a force could cause the expulsion of an improperly installed plug.
visual inspection and individual joint testing.
6.3 Pressurizing equipment should include a 6-psi pressure
NOTE 2—It should be understood that no correlation has been found
relief device to reduce hazards and avoid over-pressurization
between air loss and water leakage.
with possible damage to the line.
2. Referenced Documents
6.4 No one should be allowed in or near the manholes
during pressurization, testing, or depressurization.
2.1 ASTM Standards:
C 822 Terminology Relating to Concrete Pipe and Related
2 7. Capacity of Air Compressor
Products
7.1 To provide satisfactory test results, the air compressor
C 969 Practice for Infiltration and Exfiltration Acceptance
should be capable of pressurizing the sewer test section in the
Testing of Installed Precast Concrete Pipe Sewer Lines
required test time, or less, as determined by 9.1. The compres-
sor capacity required to accomplish the pressurization is equal
1 to the rate necessary to fill the sewer to the desired pressure
This practice is under the jurisdiction of ASTM Committee C-13 on Concrete
Pipe and is the direct responsibility of Subcommittee C13.09 on Methods of Test. plus the allowable air loss rate:
Current edition approved Jan. 27, 1989. Published March 1989. Originally
0.17D L
published as C 924 – 84. Last previous edition C 924 – 86.
C 5 1 Q (1)
Annual Book of ASTM Standards, Vol 04.05. T
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
C924
TABLE 2 Allowable Air Loss for Various Pipe Sizes
where:
C = compressor capacity, cfm,
3 3
D, Nominal Q ft /min D, Nominal Q ft /min
T = required test time, or less, min,
Pipe Size, in. Pipe Size, in.,
D = pipe internal diameter, ft,
L = length of test section, ft, and
4215 4
Q = allowable air loss, rate, cfm.
6218 5
8 2 21 5.5
8. Preparation of the Sewer Line
10 2.5 24 6
12 3
8.1 Where practical, clean the sewer line prior to testing to
wet the pipe surface and eliminate debris.
NOTE 4—A wetted interior pipe surface is desirable and will produce stabilize.The pressure will normally drop until the temperature
more consistent test results. Air may pass through the walls of dry pipe.
of the air in the line stabilizes.
This can be overcome by wetting the pipe. If the problem persists,
9.3 When the pressure has stabilized and is at or above the
segmental testing of the line will establish if there is a significant leak.
starting test pressure of 3.5 psi, commence the test by allowing
8.2 Plug all pipe outlets including laterals, which should be the gage pressure to drop to 3.5 psi at which point the time
given special attention. Review safety precautions in Section 6. recording is initiated. Record the drop in pressure for the test
period.
9. Procedure
9.4 If the drop in pressure is 1 psi or less during the test
9.1 Determine the test time for the sewer line to be tested by
period,accepttheline.Ifthedropinpressureismorethan1psi
using Table 1. Table 1 has been established using the criteria
during the test period, inspect, evaluate, and retest the line to
specified in Table 2, and the formulas contained in the
determine the cause of excessive air loss.
Appendix. The test time is the time required for the pressure to
9.5 Use or failure of this air test shall not preclude accep-
drop from 3.5 psi to 2.5 psi.
tance by appropriate water infiltration or exfiltration testing,
(see Practice C 969), or other means.
NOTE 5—All test pressures are measured as gage pressure
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