User Guide

Installing PureFlow Systems
52
PG-PF 724998 0320 PureFlow System
Sealants
The space between corrugated sleeving
and opening of a building envelope, wall,
󶈶oor, or ceiling assembly penetrated by
a pipe shall be sealed in an approved
manner with caulking material, foam
sealant, or gasketing system tested in
accordance with ASTM E814 or UL 1479.
Use of a silicone, acrylic, or siliconized
acrylic caulk may be necessary to seal
any voids between PEX tubing and the
sleeving material. Most canned expanding
foams and open- or closed-cell pipe
insulation are also good sealing materials
and may be used in direct contact with
PEX tubing. DO NOT use oil-based caulks
or closed-cell spray foams!
If the use of 󶈵ttings buried in concrete is
necessary for repairs, all such 󶈵ttings must
be wrapped with insulation, noncorrosive
tape (no adhesives) or sleeved to prevent
corrosion. The wrap shall be a self-fusing,
formaldehyde-free, fully cured silicone tape
with a minimum of 0.020" thickness. The
wrap is available from Viega (part number
15320). Contact a Viega representative
for additional information on approved
wrapping materials.
Heat Tape
It is an acceptable practice to use heat
tape on PEX tubing as long as it is a
self-limiting type not controlled by an
external thermostat. Below is a list of
manufacturers that o󶈴er heat tapes
meeting these requirements:
■ EasyHeat
®
/10800 series
■ Heaterzone.com
■ WRAP-ON / PIPE-GUARD
™
■ BriskHeat
®
Freeze Repair
The 󶈶exibility of Viega PureFlow PEX
tubing makes it resistant to damage from
freezing. PEX tubing systems should not
be intentionally subjected to freezing.
Installing PEX Under a Slab
When installing Viega PureFlow PEX or
FostaPEX tubing in the ground under
the slab, the tubing should be snaked
from side to side in the prepared
trench to provide for contraction due
to temperature change. The trench
bottom should be smooth and free of
rocks and debris. Lay the tubing directly
on the trench bottom. Tubing must be
continuously supported by the trench
bottom. Best practice dictates that
only continuous runs of tubing should
be placed under slabs. Viega does not
recommend the installation of 󶈵ttings
under a slab as part of a design. Any
connections must be outside the slab or
in an access box.
However, if freezing occurs, there are
several methods to thaw PEX tubing.
■ Hot water
■ Wet, hot towels
■ Hand-held hair dryer
■ Low-wattage electric heating tape (self
limiting)
■ A commercial system that pumps
heated water through a tube to the ice
blockage and returns the cooled water
for reheating
WARNING!
Heat must be applied directly
to the frozen tubing section.
Temperatures on tubing shall
not exceed 180°F.
WARNING!
Do not use open torch or excessive
heat to thaw PEX tubing. Tubing
failure or damage can result.
Condensation Control
As a general practice, anywhere
metal piping requires insulation for
condensation control, plastic piping will
too. Always check code for necessary
insulation requirements.