ASTM A746-18(2022)
(Specification)Standard Specification for Ductile Iron Gravity Sewer Pipe
Standard Specification for Ductile Iron Gravity Sewer Pipe
ABSTRACT
This specification covers ductile iron gravity sewer pipe centrifugally cast with push-on joints. This also covers trench load design procedures for both cement-lined pipe and flexible-lined pipe. Maximum depths of cover tables are included for both types of linings. Each pipe shall be subjected to a hydrostatic test and maybe performed either before or after the outside coating and inside coating have been applied, but shall be performed before the application of cement-mortar lining or of a special lining. The standard acceptance tests and additional control tests shall also be performed.
SCOPE
1.1 This specification covers 4 to 64 in. ductile iron gravity sewer pipe, centrifugally cast, with push-on joints. This specification may be used for pipe with other types of joints, as may be agreed upon at the time of purchase.
1.2 This specification covers trench load design procedures for both cement-lined pipe and flexible-lined pipe. Maximum depth of cover tables are included for both types of linings.
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
Relations
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:A746 −18 (Reapproved 2022)
Standard Specification for
Ductile Iron Gravity Sewer Pipe
This standard is issued under the fixed designation A746; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
3,4
1. Scope 2.2 ANSI/AWWA Standards:
C104/A21.4Cement Mortar Lining for Ductile-Iron Pipe
1.1 This specification covers 4 to 64 in. ductile iron gravity
and Fittings
sewer pipe, centrifugally cast, with push-on joints. This speci-
C111/A21.11Rubber-Gasket Joints for Ductile-Iron Pres-
ficationmaybeusedforpipewithothertypesofjoints,asmay
sure Pipe and Fittings
be agreed upon at the time of purchase.
C150/A21.50Thickness Design of Ductile-Iron Pipe
1.2 This specification covers trench load design procedures
C600Installation of Ductile-Iron Water Mains and Their
for both cement-lined pipe and flexible-lined pipe. Maximum
Appurtenances
depth of cover tables are included for both types of linings.
2.3 ASCE Standards:
Manuals and Reports on Engineering Practice, No.
1.3 The values stated in inch-pound units are to be regarded
37,(WCPF Manual of Practice No. 9), “Design and
as standard. The values given in parentheses are mathematical
Construction of Sanitary and Storm Sewers”
conversions to SI units that are provided for information only
and are not considered standard. 2.4 AASHTO Standard:
AASHTO T 99Standard Method of Test for the Moisture-
1.4 This international standard was developed in accor-
DensityRelationsofSoilsUsinga5.5lb(2.5kg)Rammer
dance with internationally recognized principles on standard-
and a 12 in. (305 mm) Drop
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
3. Terminology
mendations issued by the World Trade Organization Technical
3.1 Symbols:
Barriers to Trade (TBT) Committee.
3.1.1 A—outside radius of pipe,
2. Referenced Documents
D
ft 5
2.1 ASTM Standards:
D2487Practice for Classification of Soils for Engineering D
inmetres 5
S D
Purposes (Unified Soil Classification System) 2000
2 2
D3282 Practice for Classification of Soils and Soil-
3.1.2 a—conversionfactor,lb/ft topsi=144(kN/m tokPa
Aggregate Mixtures for Highway Construction Purposes
=1)
E8/E8MTest Methods for Tension Testing of Metallic Ma-
3.1.3 B—1.5 ft (0.457 m)
terials
3.1.4 b—effective pipe length: 36 in. (0.914 m)
E23Test Methods for Notched Bar Impact Testing of Me-
tallic Materials 3.1.5 C—surface load factor, Table 1
3.1.6 D—outside diameter, in., Table 2
This specification is under the jurisdiction of ASTM Committee A04 on Iron
Castings and is the direct responsibility of Subcommittee A04.12 on Pipes and Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
Tubes. 4th Floor, New York, NY 10036, http://www.ansi.org.
Current edition approved Oct. 1, 2022. Published October 2022. Originally Available fromAmericanWaterWorksAssociation (AWWA), 6666W. Quincy
approved in 1977. Last previous edition approved in 2018 as A746–18. DOI: Ave., Denver, CO 80235, http://www.awwa.org.
10.1520/A0746-18R22. Available fromAmerican Society of Civil Engineers (ASCE), 1801Alexander
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Bell Dr., Reston, VA 20191, http://www.asce.org.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Available from American Association of State Highway and Transportation
Standards volume information, refer to the standard’s Document Summary page on Officials (AASHTO), 444 N. Capitol St., NW, Suite 249, Washington, DC 20001,
the ASTM website. http://www.transportation.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
A746−18 (2022)
TABLE 1 Surface Load Factors for Single Truck on Unpaved Road
Pipe Size – in.
Depth
of Cover, 3 4 6 8 10 12 14 16 18
ft
Surface Load Factor – C
2.5 0.0589 0.0713 0.1020 0.1328 0.1615 0.1901 0.2178 0.2443 0.2698
3 0.0437 0.0530 0.0759 0.0990 0.1207 0.1424 0.1637 0.1843 0.2044
4 0.0265 0.0321 0.0460 0.0602 0.0736 0.0871 0.1005 0.1136 0.1265
5 0.0176 0.0213 0.0306 0.0401 0.0490 0.0581 0.0672 0.0761 0.0849
6 0.0125 0.0151 0.0217 0.0284 0.0348 0.0413 0.0478 0.0542 0.0606
7 0.0093 0.0113 0.0162 0.0212 0.0260 0.0308 0.0357 0.0405 0.0453
8 0.0072 0.0087 0.0125 0.0164 0.0201 0.0238 0.0276 0.0313 0.0350
9 0.0057 0.0069 0.0099 0.0130 0.0160 0.0190 0.0219 0.0249 0.0279
10 0.0046 0.0056 0.0081 0.0106 0.0130 0.0154 0.0179 0.0203 0.0227
12 0.0032 0.0039 0.0056 0.0074 0.0091 0.0108 0.0125 0.0142 0.0159
14 0.0024 0.0029 0.0042 0.0055 0.0067 0.0080 0.0092 0.0105 0.0117
16 0.0018 0.0022 0.0032 0.0042 0.0051 0.0061 0.0071 0.0080 0.0090
20 0.0012 0.0014 0.0020 0.0027 0.0033 0.0039 0.0045 0.0052 0.0058
24 0.0008 0.0010 0.0014 0.0019 0.0023 0.0027 0.0032 0.0036 0.0040
28 0.0006 0.0007 0.0010 0.0014 0.0017 0.0020 0.0023 0.0026 0.0030
32 0.0005 0.0006 0.0008 0.0011 0.0013 0.0015 0.0018 0.0020 0.0023
Depth Pipe Size – in.
of Cover, 20 24 30 36 42 48 54 60 64
ft Surface Load Factor – C
2.5 0.2941 0.3390 0.3962 0.4437 0.4813 0.5115 0.5366 0.5488 0.5592
3 0.2237 0.2602 0.3085 0.3507 0.3857 0.4153 0.4412 0.4543 0.4657
4 0.1391 0.1635 0.1972 0.2284 0.2559 0.2808 0.3040 0.3164 0.3277
5 0.0936 0.1106 0.1347 0.1576 0.1786 0.1982 0.2173 0.2278 0.2377
6 0.0669 0.0793 0.0970 0.1143 0.1304 0.1458 0.1612 0.1698 0.1781
7 0.0500 0.0594 0.0730 0.0863 0.0988 0.1111 0.1235 0.1306 0.1374
8 0.0387 0.0461 0.0567 0.0672 0.0773 0.0871 0.0973 0.1031 0.1088
9 0.0309 0.0367 0.0453 0.0538 0.0620 0.0700 0.0784 0.0833 0.0880
10 0.0251 0.0299 0.0370 0.0440 0.0507 0.0574 0.0644 0.0685 0.0725
12 0.0176 0.0210 0.0259 0.0309 0.0357 0.0405 0.0456 0.0486 0.0515
14 0.0130 0.0155 0.0192 0.0229 0.0265 0.0301 0.0339 0.0362 0.0384
16 0.0100 0.0119 0.0147 0.0176 0.0204 0.0232 0.0262 0.0279 0.0297
20 0.0064 0.0076 0.0095 0.0113 0.0131 0.0149 0.0169 0.0181 0.0192
24 0.0045 0.0053 0.0066 0.0079 0.0091 0.0104 0.0118 0.0126 0.0134
28 0.0033 0.0039 0.0049 0.0058 0.0067 0.0077 0.0087 0.0093 0.0099
32 0.0025 0.0030 0.0037 0.0044 0.0052 0.0059 0.0067 0.0071 0.0076
A746−18 (2022)
TABLE 2 Nominal Thicknesses for Standard Pressure Classes of Ductile Iron Pipe
Pressure Class
Outside Diameter,
Size, in. 150 200 250 300 350
in. (mm)
Nominal Thickness, in. (mm)
A
3 3.96 (100.6) . . . . . . . . . . . . 0.25 (6.4)
A
4 4.80 (121.9) . . . . . . . . . . . . 0.25 (6.4)
A
6 6.90 (175.3) . . . . . . . . . . . . 0.25 (6.4)
A
8 9.05 (229.9) . . . . . . . . . . . . 0.25 (6.4)
10 11.10 (281.9) . . . . . . . . . . . . 0.26 (6.6)
12 13.20 (335.3) . . . . . . . . . . . . 0.28 (7.1)
14 15.30 (388.6) . . . . . . 0.28 (7.1) 0.30 (7.6) 0.31 (7.9)
16 17.40 (442.0) . . . . . . 0.30 (7.6) 0.32 (8.1) 0.34 (8.6)
18 19.50 (495.3) . . . . . . 0.31 (7.9) 0.34 (8.6) 0.36 (9.1)
20 21.60 (548.6) . . . . . . 0.33 (8.4) 0.36 (9.1) 0.38 (9.7)
24 25.80 (655.3) . . . 0.33 (8.4) 0.37 (9.4) 0.40 (10.2) 0.43 (10.9)
30 32.00 (812.8) 0.34 (8.6) 0.38 (9.7) 0.42 (10.7) 0.45 (11.4) 0.49 (12.4)
36 38.30 (972.8) 0.38 (9.7) 0.42 (10.7) 0.47 (11.9) 0.51 (12.9) 0.56 (14.2)
42 44.50 (1130.3) 0.41 (10.4) 0.47 (11.9) 0.52 (13.2) 0.57 (14.5) 0.63 (16.0)
48 50.80 (1290.3) 0.46 (11.7) 0.52 (13.2) 0.58 (14.7) 0.64 (16.3) 0.70 (17.8)
54 57.56 (1450.3) 0.51 (12.9) 0.58 (14.7) 0.65 (16.5) 0.72 (18.3) 0.79 (20.1)
60 61.61 (1564.9) 0.54 (13.7) 0.61 (15.5) 0.68 (17.3) 0.76 (19.3) 0.83 (21.1)
64 65.67 (1668.0) 0.56 (14.2) 0.64 (16.3) 0.72 (18.3) 0.80 (20.3) 0.87 (22.1)
A
Calculated thicknesses for these sizes and pressure ratings are less than those shown above. Presently, these are the lowest nominal thicknesses available in these
sizes.
6 6
3.1.7 E—modulus of elasticity, 24 × 10 psi (165.5 × 10 4.3 Unless otherwise specified, pipe shall have a nominal
kPa) lengthof18or20ft(5.5or6.1m).Amaximumof20%ofthe
total number of pipe of each size specified in an order may be
3.1.8 E'—modulus of soil reaction, psi, Table 3
furnishedasmuchas24in.(610mm)shorterthanthenominal
3.1.9 F—impact factor, 1.5
laying length, and an additional 10% may be furnished as
3.1.10 f—designbendingstress,48 000psi(331×10 kPa)
muchas6in.(152mm)shorterthanthenominallayinglength.
3.1.11 H—depth of cover, ft (m)
5. Tolerances or Permitted Variations
3.1.12 K —bending moment coefficient, Table 3
b
5.1 Dimensions—The spigot end, bell, and socket of the
3.1.13 K —deflection coefficient, Table 3
x
pipe and the accessories shall be gaged with suitable gages at
3.1.14 P—wheel load, 16 000 lb (7257 kg)
sufficiently frequent intervals to ensure that the dimensions
comply with the requirements of this specification. The small-
3.1.15 P —earth load, psi (kPa)
e
estinsidediameter(ID)ofthesocketsandtheoutsidediameter
3.1.16 P—truck load, psi (kPa)
t
(OD) of the spigot ends shall be tested with circular gages.
3.1.17 P —trench load, psi (kPa) = P + P
v e t
Othersocketdimensionsshallbegagedasmaybeappropriate.
3.1.18 R—reductionfactorwhichtakesintoaccountthefact
5.2 Thickness—Minus thickness tolerances of pipe shall not
that the part of the pipe directly below the wheels is aided in
exceed those shown in Table 5.
carryingthetruckloadbyadjacentpartsofthepipethatreceive
NOTE 1—An additional minus tolerance of 0.02 in. (0.5 mm) shall be
little or no load from the wheels, Table 4
permitted along the barrel of the pipe for a distance not to exceed 12 in.
3.1.19 t—net thickness, in. (mm)
(305 mm).
3.1.20 t —minimum manufacturing thickness, in., t + 0.08,
6. Coating and Lining
(in mm, t + 2.0)
6.1 Outside Coating—The outside coating for use under
3 3
3.1.21 w—soil weight, 120 lb/ft (18.85 kN/m )
normal conditions shall be a shop-applied coating approxi-
3.1.22 ∆X—design deflection, in. (mm),
mately 1 mil (0.025 mm) thick.The coating shall be applied to
the outside of all pipe, unless otherwise specified.The finished
@∆X 5 0.03D#,or @~∆X 5 0.05D! forflexiblelinings#
coating shall be continuous and smooth, neither brittle when
4. General Requirements cold nor sticky when exposed to the sun, and shall be strongly
adherent to the pipe.
4.1 ThepipeshallbeductileironinaccordancewithSection
9. 6.2 Cement-Mortar Linings—Unless otherwise specified,
the lining shall be cement-mortar in accordance with ANSI/
4.2 Push-on joints shall comply with all applicable require-
AWWA C104/A21.4.
ments ofANSI/AWWAC111/A21.11. Pipe with other types of
joints shall comply with the joint dimensions and weights 6.3 Special Linings—For severely aggressive wastes, other
agreed upon at the time of purchase, but in all other respects types of linings may be available. Such special linings shall be
shall fulfill the requirements of this specification. specified in the invitation for bids and on the purchase order.
A746−18 (2022)
A
TABLE 3 Design Values for Standard Laying Conditions
Bedding
B
Laying Condition Description E' psi K K
b x
Angle, °
C D
Flat-bottom trench loose backfill. 150 30 0.235 0.108
C
Flat-bottom trench. Backfill lightly consolidated to 300 45 0.210 0.105
centerline of pipe.
E
Pipe bedded in 4 in. (102 mm) min loose soil. Backfill 400 60 0.189 0.103
lightly consolidated to top of pipe.
Pipe bedded in sand, gravel, or crushed stone to depth of 500 90 0.157 0.096
⁄8 pipe diameter, 4 in. (102 mm) min. Backfill compacted
to top of pipe. (Approximately 80 percent Standard
F
Proctor, AASHTO T 99.)
Pipe bedded in compacted granular material to centerline of 700 150 0.128 0.085
pipe, 4 in. (102 mm) minimum under pipe. Compacted
G E
granular or select material to top of pipe. (Approxi-
mately 90 percent Standard Proctor, AASHTO T 99.)
Pipe bedded to the top of the pipe with angular graded 1500 150 0.128 0.085
1 1
stone ( ⁄4 to 1 ⁄2 in.) or well-graded gravel. Minimum under
pipe. Compact the angular graded stone or well-graded
gravel to top of pipe. (Approximately 95 percent Standard
Proctor, AASHTO T 99.)
Type “Deep Bury”
A
Consideration of the pipe-zone embedment conditions included in this table may be influenced by factors other than pipe strength. For additional information see
ANSI/AWWA C600, Standard for installation of Ductile-Iron Water Mains and Their Appurtenances.
B
1 psi = 6.894757 kPa.
C
Flat-bottom is defined as undisturbed earth.
D
For pipe 14 in. (350 mm) and larger, consideration should be given to use of laying conditions other than Type 1.
E
Loose soil or select material is defined as native soil excavated from the trench, free of rocks, foreign materials, and frozen earth.
F
American Association of State Highway and Transportation Officials, 444 N. Capitol Street, N.W., Suite 225, Washington, DC 20001.
G
Granular materials are defined per AASHTO Soil Classification System (Practice D2487), with the exception that gravel bedding and gravel backfill adjacent to the pipe
is limited to 2 in. maximum particle size per ANSI/AWWA C600.
A746−18 (2022)
TABLE 4 Reduction Factors (R) for Truck Load Calculations
Depth of Cover, ft (m)
4to7 >7 to 10
Size, in. <4 (1.2) >10 (3.0)
(1.2 to 2.1) (2.4 to 3.0)
Reduction Factor
3 to 12 1.00 1.00 1.00 1.00
14 0.92 1.00 1.00 1.00
16 0.88 0.95 1.00 1.00
18 0.85 0.90 1.00 1.00
20 0.83 0.90 0.95 1.00
24 to 30 0.81 0.85 0.95 1.00
36 to 64 0.80 0.85 0.90 1.00
TABLE 5 Allowances for Casting Tolerance
7.4 Step 4—Add the casting allowance.
Size, in. Casting Tolerance, in. (mm)
7.4.1 Add the casting allowance from Table 5 to the
3–8 0.05 (1.3) minimum manufacturing thickness t . The resulting thickness
10–12 0.06 (1.5)
is the total calculated thickness.
14–42 0.07 (1.8)
48 0.08 (2.0)
7.5 Step 5—Selection of nominal thickness and standard
54–64 0.09 (2.3)
pressure class.
7.5.1 Use the total calculated thickness from 7.4.1 to select
a standard pressure class thickness from Table 2. When the
calculatedthicknessisbetweentwonominalthicknesses,select
7. Pipe Design
the larger of the two. When specifying and ordering pipe,
7.1 Step 1—Design for trench load.
specifythepressureclasslistedinTable2correspondingtothis
7.1.1 Determinethetrenchload,P .Table6givesthetrench
v
nominal thickness.
load,includingtheearthload,P ,plusthetruckload,P,for2.5
e t
NOTE 2—On specific projects, manufacturers may be willing to furnish
to 32 ft (0.76 to 9.75 m) of cover.
pipe with thicknesses that fall between standard classes.
7.1.2 Determine the standard laying condition from the
descriptions in Table 3 an
...
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