ASTM A674-00
(Practice)Standard Practice for Polyethylene Encasement for Ductile Iron Pipe for Water or Other Liquids
Standard Practice for Polyethylene Encasement for Ductile Iron Pipe for Water or Other Liquids
SCOPE
1.1 This practice covers materials and installation procedures for polyethylene encasement to be applied to underground installations of ductile iron pipe. It may also be used for polyethylene encasement of fittings, valves, and other appurtenances to ductile iron pipe systems.
1.2 This standard does not purport to address all of the safety concerns, if any, 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.
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Designation:A674–00
Standard Practice for
Polyethylene Encasement for Ductile Iron Pipe for Water or
Other Liquids
This standard is issued under the fixed designation A 674; 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.
1. Scope 3.1.1 polyethylene encasement—polyethylene material, in
tube or sheet form, that is used to encase ductile iron pipe.
1.1 This practice covers materials and installation proce-
3.1.2 securing overlap—any one of various methods of
dures for polyethylene encasement to be applied to under-
holding polyethylene encasement in place at the point of
groundinstallationsofductileironpipe.Itmayalsobeusedfor
overlapuntilbackfillingoperationsarecompleted.Thismaybe
polyethylene encasement of fittings, valves, and other appur-
accomplished with adhesive tape or plastic tie straps.
tenances to ductile iron pipe systems.
3.1.3 linear low-density polyethylene film—Film extruded
1.2 This standard does not purport to address all of the
from virgin linear low-density polyethylene raw material.
safety concerns, if any, associated with its use. It is the
3.1.4 high-density, cross-laminated polyethylene film—Film
responsibility of the user of this standard to establish appro-
extruded from virgin high-density polyethylene raw material,
priate safety and health practices and determine the applica-
which is then molecularly oriented by stretching. Two single-
bility of regulatory limitations prior to use.
ply layers of the film are then laminated together with their
2. Referenced Documents
orientations at 90° to one another to form the final product.
2.1 ASTM Standards:
4. Requirements
D 149 Standard Test Method for Dielectric Breakdown
4.1 Materials:
Voltage and Dielectric Strength of Solid Electrical Insu-
4.1.1 Linear low-density polyethylene film—Linear low-
lating Materials at Commercial Power Frequencies
density polyethylene film shall be manufactured of virgin
D 882 Standard Test Method for Tensile Properties of Thin
polyethylene material conforming to the requirements of
Plastic Sheeting
Specification D 4976 shown in Table 1.
D 1709 Standard Test Methods for Impact Resistance of
4.1.1.1 Thickness—Linear low-density polyethylene film
Plastic Film by the Free-Falling Dart Method
shall have a minimum thickness of 0.008 in. (0.20 mm).
D 1922 Standard Test Method for Propagation Tear Resis-
4.1.2 High-density cross-laminated polyethylene film—
tance of Plastic Film and Thin Sheeting by Pendulum
High-density cross-laminated polyethylene film shall be manu-
Method
factured of virgin polyethylene material conforming to the
D 4976 Standard Specification for Polyethylene Plastics
requirements of Specification D 4976 shown in Table 2.
Molding and Extrusion Materials
4.1.2.1 Thickness—High-density cross-laminated polyeth-
2.2 ANSI/AWWA Standards:
ylene film shall have a minimum thickness of 0.004 in. (0.10
C 600, Installation of Ductile Iron Water Mains and Their
mm).
Appurtenances
4.2 Tube Size—Thetubesizeforeachpipediametershallbe
C 105/A21.5, Polyethylene Encasement for Ductile-Iron
as listed in Table 3.
Pipe Systems
4.3 Color—Polyethylene film may be supplied with its
3. Terminology
natural color, colors including white and black, or black
(weather-resistant) containing not less than 2 percent carbon
3.1 Definitions:
black with an average particle diameter of 50 mm or less. A
minimum of 2 percent of a hindered-amine ultraviolet inhibitor
This practice is under the jurisdiction of ASTM Committee A04 on Iron
is required in any natural or colored film except black film
Castings and is the direct responsibility of Subcommittee A04.12 on Pipes and
containing 2 percent or more carbon black.
Tubes.
Current edition approved Oct. 10, 2000. Published November 2000. Originally 4.4 Marking requirements—The polyethylene film supplied
published as A 674 – 72. Last previous edition A 674 – 95.
shall be clearly marked, at a minimum of every 2-ft along its
Annual Book of ASTM Standards, Vol 08.01.
length, containing the following information:
Available from American Water Works Association, 6666 W. Quincy Ave.,
(a) Manufacturer’s name or registered trademark
Denver, CO 80235.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
A674
A
TABLE 1 Linear Low-Density Polyethylene Characteristics TABLE 3 Polyethylene Tube Sizes for Push-On Joint Pipe
Raw Material Used to Manufacture Polyethylene Encasement Material Nominal Pipe Diameter, in. Recommended Polyethylene
B
Flat Tube Width, in. (cm)
Group, density, and dielectric strength in accordance with the latest
revision of Specification D 4976 3 14 (36)
Group 2 (Linear) 4 14 (36)
Density 0.910 to 0.935 g/cm 6 16 (41)
Dielectric strength, volume resistivity 10 ohm-cm, min 8 20 (51)
10 24 (61)
12 27 (69)
Polyethylene Encasement Material
14 30 (76)
16 34 (86)
Tensile strength 3600 psi (24.83 MPa), min (ASTM
18 37 (94)
D 882)
20 41 (104)
Elongation 800 %, min (ASTM D 882)
24 54 (137)
Dielectric strength 800 V/mil (31.5 V/µm) thickness,
30 67 (170)
min (ASTM D 149)
36 81 (206)
Impact resistance 600 g, min (ASTM D 1709 Method
42 81 (206)
B)
48 95 (241)
Propagation tear resistance 2550 gf, min (ASTM D 1922)
54 108 (274)
60 108 (274)
64 121 (307)
A
These wrap sizes should work with most push-on joint pipe and fitting bell
TABLE 2 High-Density Cross-Laminated Polyethylene sizes. Where bell circumferences are larger than the sheet sizes shown, the bell
Characteristics areas should be carefully wrapped with cut film sections, effectively lapping and
securing cut edges as necessary; or, alternatively, sufficiently large tube or sheet
Raw Material Used to Manufacture Polyethylene Encasement Material
film to effectively cover these joints should be ordered.
B
For flat sheet polyethylene, see 5.2.3.
Group, density, and dielectric strength in accordance with the latest revision
of Specification D 4976
Group 2 (Linear)
Density 0.940 to 0.960 g/cm
Dielectric strength, volume resistivity 10 ohm-cm, min
cientslackshallbeprovidedincontouringtopreventstretching
the polyethylene bridging irregular surfaces, such as bell-
High-Density Cross-Laminated Polyethylene Encasement Material
spigot interfaces, bolted joints, or fittings, and to prevent
damage to the polyethylene due to backfilling operations.
Tensile strength 6300 psi (43.47 MPa), min
Elongation 100 %, min
Overlaps and ends shall be secured by the use of adhesive tape
Dielectric strength 800 V/mil (31.5 V/µm) thickness, min
or plastic tie straps.
Impact resistance 800 g, min. (ASTM D 1709 Method B)
Propagation tear resistance 250 gf, min. (ASTM D 1922) 5.1.3 For installations below the water table or in areas
subject to tidal actions, or both, it is recommended that
tube-form polyethylene be used with both ends sealed as
thoroughly as possible with adhesive tape or plastic tie straps
atthejointoverlap.Itisalsorecommendedthatcircumferential
(b) Year of manufacture
wraps of tape or plastic tie straps be placed at 2 ft (0.6 m)
(c) ASTM A 674
intervalsalongthebarrelofthepipetohelpminimizethespace
(d) Minimum film thickness and material type (LLDPE or
between the polyethylene and the pipe.
HDCLPE)
5.2 Pipe—This practice includes three different methods for
(e) Applicable range of nominal pipe diameter size(s)
the installation of polyethylene encasement. Method A and B
(f) Warning—Corrosion Protection—Repair Any Damage
are for use with polyethylene tubes and Method C is for use
4.4.1 Marking height—Letters and numerals used for mark-
with polyethylene sheets.
ing items a through e in Section 4.4 shall not be less than 1 in.
5.2.1 Method A (see Fig. 1):
(25.4 mm) in height. Item f in Section 4.4 shall be not less than
5.2.1.1 Cut the polyethylene tube to a length approximately
1 ⁄2in. (38.10 mm) in height.
2 ft (0.6 m) longer than the length of the pipe section. Slip the
5. Installation
tube around the pipe, centering it to provide a 1-ft (0.3-m)
overlap on each adjacent pipe section, and bunching it accor-
5.1 General:
dion fashion lengthwise until it clears the pipe ends.
5.1.1 The polyethylene encasement shall prevent contact
between the pipe and the surrounding backfill and bedding 5.2.1.2 Lower the pipe into the trench and make up the pipe
joint with the preceding section of pipe. A shallow bell hole
material but is not intended to be a completely airtight or
watertight enclosure. All lumps of clay, mud, cinders, etc. must be made at joints to facilitate installation of the polyeth-
ylene tube.
which may be on the pipe surface shall be removed prior to
installation of the polyethylene encasement. During installa- 5.2.1.3 After assembling the pipe joint, make the overlap of
tion, care shall be exercised to prevent soil or embedment the polyethylene tube. Pull the bunched polyethylene from the
material from becoming entrapped between the pipe and the preceding length of pipe, slip it over the end of the new length
polyethylene. of pipe, and secure in place. Then slip the end of the
5.1.2 The polyethylene film shall be fitted to the contour of polyethylenefromthenewpipesectionovertheendofthefirst
the pipe to effect a snug, but not tight, encasement with wrap until it overlaps the joint at the end of the preceding
minimum space between the polyethylene and the pipe. Suffi- length of pipe. Secure the overlap in place. Take up the slack
A674
FIG. 1 Method A
width at the top of the pipe as shown in Fig. 2, to make a snug, polyethylene around the pipe so that it overlaps circumferen-
but not tight, fit along the barrel of the pipe, securing the fold tially over the top quadrant of the pipe. Secure the cut edge of
at quarter points. polyethylene sheet at approximately 3-ft (0.9-m) intervals
5.2.1.4 Repair any rips, punctures, or other damage to the along the pipe length.
polyethylene with adhesive tape or with a short length of 5.2.3.3 Lowerthewrappedpipeintothetrenchandmakeup
polyethylene tube cut open, wrapped around the pipe, and the pipe joint with the preceding section of pipe.Ashallow bell
secured in place. Proceed with installation of the next section hole must be made at joints to facilitate installation of the
of pipe in the same manner. polyethylene. After completing the joint, make the overlap as
5.2.2 Method B (see Fig. 3): described in 5.2.1.
5.2.2.1 Cut the polyethylene tube to a length approximately 5.2.3.4 Repair any rips, punctures, or other damage to the
1 ft (0.3 m) shorter than the length of the pipe section. Slip the polyethylene as described in 5.2.1. Proceed with installation of
tube around the pipe, centering it to provide 6 in. (150 mm) of the next section of pipe in the same manner.
bare pipe at each end. Make the polyethylene snug, but not 5.3 Pipe-Shaped Appurtenances—Bends, reducers, offsets,
tight, as shown in Fig. 2; secure ends as described in 5.2.1. and other pipe-shaped appurtenances shall be covered with
5.2.2.2 Before making up a joint, slip a 3-ft (0.9-m) length polyethylene in the same manner as the pipe.
ofpolyethylenetubeovertheendoftheprecedingpipesection, 5.4 Odd-Shaped Appurtenances—Wrap valves, tees,
bunching it accordion fashion lengthwise. Alternatively, place crosses, and other odd-shaped pieces which cannot practically
a 3-ft (0.9 m) length of polyethylene sheet in the trench under be wrapped in a tube, with a flat sheet or split length of
the joint to be made. After completing the joint, pull the 3-ft polyethylene tube. Pass the sheet under the appurtenance and
lengthofpolyethyleneoveroraroundthejoint,overlappingthe bring up around the body. Make seams by bringing the edges
previously installed on each adjacent section of pipe by at least together, folding over twice, and taping down. Handle slack
1 ft (0.3 m); make snug and secure each end as described in width and overlaps at joints as described in 5.2.1. Tape
5.2.1. A shallow bell hole must be made at joints to facilitate polyethylene securely in place at valve stem and other penetra-
installation of the polyethylene tube or sheet. tions.
5.2.2.3 Repair any rips, punctures, or other damage to the 5.5 Repairs—Repair any cuts, tears, punctures, or damage
polyethylene as described in 5.2.1. Proceed with installation of to polyethylene with adhesive tape or with a short length of
the next section of pipe in the same manner. polyethylene tube cut open, wrapped around the pipe covering
5.2.3 Method C (see Fig. 4): the damaged area, and secured in place.
5.2.3.1 Flat sheet polyethylene shall have a minimum width 5.6 Openings in Encasement—Make openings for branches,
twice the flat tube width shown in Table 3. service taps, blow-offs, air valves, and similar appurtenances,
5.2.3.2 Cutthepolyethylenesheettoalengthapproximately by making an X-shaped cut in the polyethylene and tempo-
2 ft (0.6 m) longer than the length of pipe section. Center the rarily folding the film back.After the appurtenance is installed,
cut length to provide a 1-ft (0.3-m) overlap on each adjacent tape the slack securely to the appurtenance and repair the cut,
pipe section, bunching it until it clears the pipe ends. Wrap the as well as any other damaged areas in the polyethylene, with
FIG. 2 Slack Reduction Procedure—Methods A and B
A674
FIG. 3 Method B
FIG. 4 Method C
tape. Direct service taps may also be made through the 5.7 Junctions Between Wrapped and Unwrapped Pipe—
polyethylene, with any resulting damage areas being repaired Where polyethylene wrapped pipe joins a pipe that is not
asdescribedpreviously.Thepreferredmethodofmakingdirect wrapped, extend the polyethylene tube to cover the unwrapped
servicetapsconsistsofapplyingtwoorthreewrapsofadhesive pipe a distance of at least 3 ft (0.9 m). Secure the end with
tape completely around the polyethylene encased pipe to cover circumferential turns of adhesive tape. Service lines of dissimi-
the area where the tapping machine and chain will be mounted. lar metals shall be wrapped with polyethylene or a suitable
This method minimizes possible damage to the polyethylene dielectric tape for a minimum clear distance of 3 ft (0.9 m)
during the direct tapping procedure.After the tapping machine away from the ductile-iron pipe.
is mounted, the corporation stop is installed directly through 5.8 Backfill for Polyethylene Wrapped Pipe—Backfill ma-
the tape and polyethylene as shown in Fig. 5. Experience has terial shall be the same as specified for pipe without polyeth-
shown that this method is very effective in elim
...
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