ASTM F690-86(2003)

Standard Practice for Underground Installation of Thermoplastic Pressure Piping Irrigation Systems

SCOPE
1.1 This practice covers general and basic procedures related to the proper installation of thermoplastic, flexible, pressure piping, 36 in. nominal size and smaller, for underground irrigation systems. Because there is considerable variability in end-use requirements, soil conditions, and thermoplastic piping characteristics, it is the intent of this practice to outline general objectives and basics of proper installation and to provide pertinent references, rather than to prescribe detailed installation procedures.  
1.2 This practice should not be used for installing thermoplastic underground sewer, drain, potable water, conduit or gas service piping.  
1.3 The values stated in inch-pound units are to be regarded as the standard. Values in parentheses are given for information only.  
1.4 This standard does not purport to address all of the safety problems, 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.

General Information

• Status: Historical
• Publication Date: 09-Aug-2003
• Technical Committee: F17 - Plastic Piping Systems
• Drafting Committee: F17.61 - Water

Relations

• Replaces: ASTM F690-86(1994) - Standard Practice for Underground Installation of Thermoplastic Pressure Piping Irrigation Systems
• Effective Date: 10-Aug-2003
• Replaced By: ASTM F690-86(2003)e1 - Standard Practice for Underground Installation of Thermoplastic Pressure Piping Irrigation Systems
• Effective Date: 10-Aug-2003
• Referred By: ASTM F1668-16(2022) - Standard Guide for Construction Procedures for Buried Plastic Pipe
• Effective Date: 10-Aug-2003

Standards Content (Sample)

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
An American National Standard
Designation: F 690 – 86 (Reapproved 2003)
Standard Practice for
Underground Installation of Thermoplastic Pressure Piping
Irrigation Systems
This standard is issued under the fixed designation F 690; 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 3.2 All joining materials shall be of composition that will
not damage the pipe and shall be recommended for use at the
1.1 This practice covers general and basic procedures re-
design pressure for the pipeline. Consult the manufacturer for
lated to the proper installation of thermoplastic, flexible,
design and installation recommendations and refer to Practice
pressure piping, 36 in. nominal size and smaller, for under-
F 402.
ground irrigation systems. Because there is considerable vari-
3.3 When steel or other metallic joining materials, subject to
ability in end-use requirements, soil conditions, and thermo-
corrosion, are used in the line, they shall be adequately
plastic piping characteristics, it is the intent of this practice to
protected by wrapping or coating with high quality corrosion
outline general objectives and basics of proper installation and
preventatives. Wrapping or coatings that are applied on metal-
to provide pertinent references, rather than to prescribe detailed
lic surfaces should not be applied on plastic pipes and fittings
installation procedures.
unless it is first established by consulting the piping manufac-
1.2 This practice should not be used for installing thermo-
turer that they have no detrimental effect on the plastic.
plastic underground sewer, drain, potable water, conduit, or gas
3.4 Joining specifications are listed under 2.1.3.
service piping.
3.5 Manufacturers of joining materials should be consulted
1.3 The values stated in inch-pound units are to be regarded
for specific assembly instructions not covered by existing
as the standard. Values in parentheses are given for information
specifications. When requesting information, the intended ser-
only.
vice application should be defined.
1.4 This standard does not purport to address all of the
safety problems, if any, associated with its use. It is the
4. Trench Preparation
responsibility of the user of this standard to establish appro-
4.1 Trench Depth—In stable granular soils, which tend to be
priate safety and health practices and determine the applica-
relatively smooth and free of all rocks and debris larger than ⁄2
bility of regulatory limitations prior to use.
in. (13 mm) in sizes, excavation may proceed directly to final
2. Referenced Documents grade. Where rocks of other protrusions are encountered which
may cause point loading on the pipe, the trench bottom should
2.1 ASTM Standards:
be overexcavated to permit installation of proper bedding (see
D 2487 Test Method for Classification of Soils for Engi-
Section 5).
neering Purposes (Unified Soil Classification System)
4.2 Trench Width—The width of the trench at any point
D 2488 Practice for Description and Identification of Soils
below the top of the pipe should be established with attention
(Visual-Manual Procedure)
given to these considerations:
F 402 Practice for Safe Handling of Solvent Cements,
4.2.1 The wider the trench at the top of the pipe, the greater
Primers, and Cleaners Used for Joining Thermoplastic Pipe
3 the earth load imposed on the pipe until the prism load has been
and Fittings
achieved.
3. Joints and Connections 4.2.2 Trench width should allow sufficient and safe working
room for proper alignment and assembly of the joints. Gener-
3.1 Joints and connections shall be assembled to withstand
ally, a trench width at the top of the pipe of about 2 ft (600 mm)
the design working pressure for the pipeline without leakage,
wider than the pipe diameter is adequate. However, for pipe
internal restriction or obstruction, which could reduce line
with an 18-in. (457-mm) diameter and larger in a vertical-
capacity below design requirements.
walled trench, a clearance of 3 ft (1 m) wider than the nominal
pipe size may be needed. For sloped trenches, a minimum of an
This practice is under the jurisdiction of ASTM Committee F17 on Plastic
18-in. (457-mm) greater trench bottom width than the pipe
Piping Systems and is the direct responsibility of Subcommittee F17.61 on Water.
diameter allows sufficient width. If a wider trench becomes
Current edition approved Aug. 10, 2003. Published September 2003. Originally
necessary, the enlargement should be restricted as much as
approved in 1980. Last previous edition approved in 1994 as F 690 – 84 (1994).
Annual Book of ASTM Standards, Vol 04.08.
possible to only that section above the top of the pipe.
Annual Book of ASTM Standards, Vol 08.04.
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NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
F 690 – 86 (2003)
4.2.3 Trench width should allow adequate room for snaking be injurious to the piping. With elastomeric seal joints, take
when recommended by the manufacturer or as may be required care to avoid joint displacement and pull out. Allow heat-fused
to accommodate thermal expansion or contraction. joints to cool or solvent-cemented joints to cure for the
4.2.4 Narrower trench widths may be utilized by joining the minimum prescribed time before moving the pipe. While
pipe above ground and lowering it into the trench, provided moving larger diameter pipe lines, care should be taken to
enough room is available in the trench for proper haunching. avoid excessive stressing of the joints.
Precautions outlined in 5.2 shall be followed.
5.3 Ensure that elastomeric seal joints are not installed so
4.3 Trench Depth—The trench depth shall be established
they remain excessively deflected. Consult the pipe manufac-
with consideration given to requirements imposed by founda- turer for maximum permissible joint deflection limits.
tion, bedding, pipe size, and cover.
5.4 Changes in the grade and line of direction of the pipe
4.4 Foundation—An adequate and stable foundation should
shall be limited and shall be gradual enough so that the bending
be present, or provided, for proper support at the total trench
of the pipe will develop neither excessive diametrical expan-
load.
sion nor excessive bending stresses. At no time should the pipe
4.4.1 Foundation preparation is not necessary when smooth
be blocked or braced to hold a bend. Excess curvature can
stable trench bottoms are encountered.
create stresses which could induce pipe failure under pressure.
4.4.2 Foundation preparation is necessary when unstable
Consult the pipe manufacturer for recommended minimum
trench bottom conditions are encountered. The designer should
pipe bending radius.
specify the stabilizing method and materials which will satis-
5.5 When installing pipe with elastomeric seal, flanged
factorily stabilize the encountered condition and provide ad-
joints, or with any connector which protrudes beyond the pipe
equate and permanent support.
diameter, bell holes should be excavated in the bedding
4.5 Bedding—The bedding material should consist of
material or trench bottom to permit the pipe to be continuously
gravel, sand, silty sand, silty gravel, or clayey sand in granular
supported. After pipe assembly and placement in the trench,
form and having a maximum particle size of ⁄4 in. (19 mm).
each bell hole should be filled with bedding material and
4.5.1 Bedding shall be provided whenever rock, hard pan,
compacted if necessary to attain the same general density as the
boulders, or other materials that might damage the pipe are
rest of the bedding.
encountered in the trench bottom at the established pipe grade.
5.6 It is advisable to permit newly installed pipe to cool to
4.5.2 When bedding is used, it shall be kept as nearly
approximately ground temperature prior to backfilling. This
uniform in depth as possible to minimize differential settle-
will minimize the development of contraction stresses on the
ment.
joints and, in the case of solvent-cemented connections, it will
4.6 Minimum Earth Cover—Protection from traffic loading
prevent the possibility of joint separation due to contraction
or frost penetration, or both should be considered when
forces acting on an incompletely cured bond. Typically, pipe
establishing minimum earth cover requirements.
will cool adequately soon after being placed on a shaded-trench
4.6.1 For installations exposed to normal farm vehicle
bottom.
traffic, the minimum total cover should not be less than:
5.7 Where differential settlement could create concentrated
Pipe1to2 ⁄2 in. in diameter: 18 in. (450 mm)
loading on a pipe or joint, for example, at a point of connection
Pipe 3 to 4 in. in diameter: 24 in. (600 mm)
of a buried pipe to a rigid structure, such as a manhole,
Pipe 5 in. and larger in diameter: 30 in. (750 mm)
manufacturer’s recommendations should be followed to pre-
Pipe 5 to 18 in. in diameter: 30 in. (750 mm)
Pipe 18 in. and larger in diameter: 36 in. (900 mm)
vent, or to properly relieve, damaging and shearing forces. One
technique is to use extra care when compacting the foundation
4.6.2 The pipe line should be installed at sufficient depths to
and bedding under a rigid structure. Other techniques might
provide protection from traffic crossing, farming operations,
include construction of a supporting structure underneath the
and soil cracking. Load-bearing capabilities of installed pipe
joint and the pipe of about three diameters in cross section or
vary with type of pipe, type of backfill, soil conditions, and
the utilization of a flexible joint.
installation procedures. Consult the manufacturer for informa-
5.8 Special Installation—With certain pipes and in some
tion on product response to expected maximum earth loading.
soil conditions it is possible to install long lengths of pipe by
4.6.3 The trench depth shall be sufficient to ensure place-
the plowing-in technique. Consult the manufacturer for recom-
ment of the top of the pipe at least 10 in. (250 mm) below the
mendations.
known frost line. When conditions and design requirements
prevent satisfaction of this requirement, system design and
6. Thrust Blocking
installation must ensure proper drainage in the low portions of
the line.
6.1 When installing piping systems that include joints that
are not self restraining (for example, elastomeric seal type)
5. Pipe Assembly and Installation
thrust blocking may be necessary at certain points in the
5.1 Preparation of Joints—Joint assembly shall be done in system, such as changes in direction, in order to prevent
possible disengagement of the fitting from the pipe.
accordance with specifications listed under 2.1.3.
5.2 If the pipe is to be assembled above ground, it should be 6.2 Thrust blocking is required where line shift or joint
lowered into the trench, taking care not to drop it or damage it separation at system operating pressure can be anticipated, that
against the trench walls, nor to subject it or its joints to is, pump discharge, directional changes, reducers, and dead
treatment, such as, dragging or excessive bending which could ends. Thrust blocking is essential to the proper performance of
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
F 690 – 86 (2003)
high pressure irrigation piping when the system includes 7.2.2 With valves at ends and high points open, the pipelines
non-self-restraining joints. (See Fig. 1.) should be slowly filled with water, limiting the flow velocity to
6.3 Thrust Block Construction: 1 ft/s (0.3 m/s) to prevent surge, or water hammer, and air
entrapment.
6.3.1 The thrust block should be constructed of concrete
having a compression strength of 2000 psi (14 MPa) or more. 7.2.3 Ensure that all entrapped air is released from the line
Wood blocking, or stone blocking with wood wedges, are not while filling. The system should include appropriate air and
acceptable. vacuum relief valves for proper function during operation after
6.3.2 The thrust block acts as an anchor between pipe or installation.
fitting and the solid trench wall. The size of the thrust block 7.2.4 The pipeline should be filled but not pressurized until
should be adequate to prevent pipe movement at the point of
the engineer is ready to witness or conduct the pressure test.
thrust. Consult the system designer.
7.3 Inspection and Repairs—The line should be pressurized
6.3.3 The thrust block cavity should be hand dug into
to 125 % of the system’s design operating pressure, for the
undisturbed soil and framed with soil or wood to hold freshly
time necessary to check all joints but not to exceed 1 h. While
poured concrete. The earth-bearing surfaces should be undis-
under pressure, inspect all joints for leaks. Any leaks found
turbed.
should be repaired, and the line recharged and retested.
6.3.4 Before pressurizing the line, ensure that adequate time
is allowed for the concrete thrust blocks to set.
8. Backfilling Procedures
8.1 Haunching and Initial Backfill—This practice covers
7. Line Charging and Testing
those thermoplastic piping products which may be deflected
7.1 If possible, the pipeline should be thoroughly inspected
considerably, without structural damage. The flexibility of the
and tested for leaks before backfilling. When so testing, it is
pipe enables it to utilize the passive resistance of the soil to
advisable to anchor the pipe by placing haunching and initial
support loads externally applied to the pipe. The resistance of
backfill up to about 6 in. (150 mm) over the pipe, taking care
the soil is affected by the type of soil, its density and moisture
to leave all joints and fittings exposed for inspection.
content. Therefore, the higher the soil resistance, the less the
7.2 Line Charging: pipe will deflect. Proper techniques for pipe embedment are
7.2.1 Before filling and proceeding to test, sufficient time necessary to ensure that the passive soil resistance required to
should be allowed for solvent-cemented joints to cure or prevent excessive pipe deflection will be developed and
heat-fused joints to cool. maintained. The designer will determine the minimum material
FIG. 1 Types of Thrust Blocking
NOTICE: This
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