User Guide
60 l uponorengineering.com
Ensure the piping layout,
including anchors, adequately
isolates joints, ttings and
connections from high-thrust
or bending forces.
Uponor ProPEX connections
have a very high resistance to
pull-out forces when compared
to other various joint types.
The best solution for absorbing
expansion and contraction in
Uponor PEX piping systems
is proper support and to build
in exibility. In applications
where long piping runs
may be exposed to large
temperature changes, the
resulting expansion and
contraction must be absorbed
by additional means such as
expansion loops, arms and
offsets or by restraining the
pipe in a continuous run of
PEX-a Pipe Support. Piping
runs between anchors and
expansion compensating
devices must be periodically
supported, at a spacing
dened by code, with hangers
or supports that allow for
movement of the piping. The
compensating device relieves
axial stress in a straight run
of piping by transferring it
into a moderate bending
stress, thereby absorbing the
expansion stress.
Above-ground and
suspended applications
In single-family and low-
rise residential applications,
thermal expansion is generally
not an issue due to the use
of smaller-diameter piping
that absorbs expansion and
contraction forces due to the
routing, supporting methods
and exible nature of Uponor
PEX piping. Smaller diameter
(⅜" to 1") pipe runs require an
extra ⅛" to
3
⁄16" of longitudinal
clearance per foot of run.
Do not allow piping to dip
excessively between supports
and do not pull piping tight
during installation.
Larger suspended commercial
systems are often designed to
include a number of changes
in direction. These directional
changes can be a benecial
aspect in the piping system by
creating a spring-like effect,
which safely absorbs and
controls thermal expansion
and contraction.
Controlling expansion
in hot-water systems
Best practice for controlling
expansion forces is to
continuously restrain the
pipe by installing Uponor
PEX-a Pipe Support.
Install PEX-a Pipe Support
in accordance with the
installation guidelines on
pages 68-72 in Chapter 6.
For best results, terminate
PEX-a Pipe Support segments
only at tting locations. Refer
to Table 6-6 on page 70 for
minimum distance to ttings.
Proper use of strapping
is critical when using this
technique. Strapping shall be:
• Nylon-coated stainless-steel
with a minimum tensile rating
of 300 lbs.
• Rated for operating
temperature ranges,
including high temperatures
• UV-resistant to withstand
expected life of the piping
system
To account for expansion, use
xed anchor points to restrict
piping movement. Fixed
anchor points shall be:
• Installed every 65 ft. (19.8m)
• Constructed with materials
that provide rigidity (see
Figure 5-6)
• Used with a pipe clamp that
will restrain piping material
• Installed within 18" of a re-
rated wall penetration (see
Figure 5-7)
Two hole open short angle
Steel strut
All-threaded rod
Two hole open short angle
Strut clamp
Uponor PEX pipe
Steel strut or other
approved device
Figure 5-6: Fixed anchor point