User Guide

Plumbing Design Assistance Manual l Chapter 6 – Installation methods l 85
Horizontal directional
drilling (HDD)
Horizontal directional drilling
is used when trenching or
excavation is not practical.
A surface-launched drilling
rig provides a steerable,
trenchless method of installing
underground pipes along
a shallow arc bore path,
resulting in minimal impact
to surrounding areas. It is
suitable for a variety of soil
conditions.
HDD is further categorized into
the following types:
• Mini-HDD
- Distances less than 600 ft.
- Depths up to 15 ft.
- Pipe diameters up to 12"
• Equipment pullback
capability of up to 20,000
lbs. and torque less than 950
ft-lbs.
• Maxi-HDD
- Distances greater than
600 ft.
- Depths up to 200 ft.
- Pipe diameters up to 48"
- Equipment pullback
capability of up to 100,000
lbs. and torque up to
80,000 ft-lbs.
Criteria for Uponor PEX
piping in HDD applications
• Use Uponor PEX only as the
follow pipe.
• Take precautionary steps to
ensure piping does not come
in contact with sharp objects.
• Do not exceed minimum
bend radius of 6 times the
O.D. of the piping
• Pressure test installed piping
after installation to ensure
the integrity of the piping has
not been compromised.
For HDD applications using
Uponor PEX piping, reference
PPI TR-46 Guidelines for Use
of Mini-Horizontal Directional
Drilling for Placement of High
Density Polyethylene Pipe.
Joining methods and ttings
Use ProPEX or approved
compression ttings to
connect piping to itself or
to the corporation and curb
stops. Approved manufactures
are Ford Meter Box Company,
Mueller Company, A.Y.
McDonald Mfg. Co. and
Philmac.
When using compression
ttings with Uponor AquaPEX
piping, a plastic or stainless-
steel insert stiffener is required
on the inside of the piping
at the connection.
For applications requiring
direct burial, use Uponor
ProPEX EP or LF brass ttings
for large-dimension Uponor
AquaPEX piping up to 3".
H-20 load
Deepest point of road bed 0 2083 pounds p.s.f.
10" native soil
6" sand (min.)
Service pipe
4" sandbed
Bicycles
Pedestrians
SDR9 Uponor PEX 12-hour pull
Nominal
pipe size
Tensile yield design
(safety) factor
Allowable tensile load
at 73°F/22.8°C - lbs (N)
½" 0.4 128 (569)
¾" 0.4 248 (1,103)
1" 0.4 411 (1,828)
1¼" 0.4 615 (2,735)
1½" 0.4 859 (3,821)
2" 0.4 1,465 (6,516)
2½" 0.4 2,239 (9,960)
3" 0.4 3,169 (14,096)
H-20 loads
When installing Uponor AquaPEX under a roadway, follow the same procedures as previously indicated with the following exception:
Ensure the top of the piping is 16" below the bottom of the roadbed material as specied. You can also use a suitable steel or
structural conduit to sleeve the Uponor AquaPEX pipe.
Figure 6-48: Trafc loads
Table 6-9: Safe pull force
Note: The method set forth in ASTM F1804 determines the
allowable tensile load.