User Guide

84 l uponorengineering.com
Uponor PEX piping
Undisturbed soil
Excavation level
Uponor PEX piping
Undisturbed soil
Fill level
Excavation level
Trench bottom preparation
To achieve a satisfactory installation, it is essential that the soil provides stable and continuous support for the piping.
Figure 6-46: Good soil conditions — If the trench is dug
smoothly, install the piping directly on the prepared bottom.
The bottom must be at with no hollows, lumps or rocks.
Figure 6-47: Poor soil conditions — With rocky, clay, muddy
or other poor soil conditions, it may be necessary to prepare
the trench bottom using granular material of such size and
grading to provide a stable base. See local code for additional
requirements.
Piping embedment
Proper soil selection,
placement and compaction are
essential in the area around
the piping. Backll around the
piping with sand or gravel that
has a maximum particle size
of ¾".
Compact the initial backll
around the piping to provide
adequate piping support
and prevent settling. It is
particularly important to
adequately compact the soil
around the tap connection.
Uponor recommends
pressurizing the piping prior
to backlling to reveal any
damage. In heavy vehicular
trafc areas, compact backll
to 90 percent of maximum soil
density.
Do not use highly plastic clays,
silts, organic materials, or
sharp or large rocks as backll
in the immediate vicinity of the
piping. Compact the backll
from the subgrade to a level
per local code that will cover
the piping 4" to 6" to provide
protection around the piping
and to prevent settling that
puts stress on the ttings and
the piping.
For additional information
about the proper installation
practices of PEX piping in
water-service applications,
refer to AWWA C904.
Installation
Install Uponor AquaPEX piping
underground in a manner
that ensures external loads
will not subsequently cause
a decrease in the vertical
dimension of the cross section
of the piping that exceeds
5 percent of the outside
diameter. Install Uponor
AquaPEX piping in a snaking
pattern with sufcient slack in
the line to allow for contraction
of the line due to temperature
change prior to backlling.
The linear expansion rate for
Uponor AquaPEX piping is
approximately 1.1" per 10ºF
temperature change per 100
ft. of piping (27.94mm per
5.56ºC temperature change
per 30.48m of piping).
Note: Do not use blocking to
support the piping or change
the piping grade. Do not install
potable-water service piping
in, under or above cesspools,
septic tanks, septic-tank
drainage elds or pits.
Caution: Do not install
Uponor AquaPEX
piping in soil environments
contaminated with solvents,
fuels, organic compounds,
pesticides or other detrimental
materials that may cause
permeation, corrosion,
degradation or structural
failure of the piping. In areas
where such conditions are
suspected, perform a chemical
analysis of the soil or
groundwater to ascertain the
acceptability of Uponor
AquaPEX piping for the
specic installation. Check
local codes for additional
requirements.
Handling and repairs
Although Uponor AquaPEX
piping is highly resistant to
kinking and abrasion, take
care while handling and
installing the piping to prevent
damage and possible failure of
the piping. If damage occurs
during installation, cut out
the damaged area and repair
before backlling.
To reform kinked piping, see
“Reforming kinked piping”
on page 64. If the piping is
damaged beyond its thermal-
memory capacity, use a
ProPEX coupling. Do not
reuse or reclaim EP ttings.