User Guide

Installing PureFlow Systems
44
PG-PF 724998 0320 PureFlow System
Shower Valves
PEX lines should only be run to the
inlet connections of tub/shower valves
unless speci󶈵cally approved by the valve
manufacturer for other connections.
Electrical Grounding
Neither Viega PureFlow PEX nor FostaPEX
tubing may be used as an electrical
ground. Consult the NEC for recommended
grounding method when plastic pipe is used.
■ Install 󶈵xtures that are not water
hammer prone. As a general rule,
two-handle 󶈵xtures are less likely to
cause a hammer than single-handle
󶈵xtures. Single-handle shower valves,
which rotate to close and therefore
are di󶈷cult to close quickly, might be
good choices.
■ Clamping or strapping more frequently
may help prevent tubing noise. It is
important that the tubing not be in
contact with the wallboard, forced air
ducts, or other high-resonance articles.
Insu󶈷ciently or improperly clamped or
strapped tubing may move during 󶈵xture
operation and hit against these surfaces.
■ Install a water hammer arrester at
󶈵xtures where noise is a problem.
A water hammer arrester (AA sized)
installed as closely as possible to the
󶈵xture on the cold-water side only will
eliminate the source of the noise (the
pressure wave). It should be noted that
even with an arrester, tubing that is
clamped or strapped insu󶈷ciently may
still hit against something as it moves
slightly when the water 󶈶ow is stopped.
■ Avoid operating 󶈵xtures in such a
way that causes near instantaneous
shuto󶈴. Simply closing 󶈵xtures in a
less abrupt manner can eliminate
hammer noise.
Expanding Foams
When penetrations must be sealed for
air in󶈵ltration purposes, there are several
options available. Use a good grade of
silicone, acrylic, or siliconized acrylic
caulking. DO NOT use oil-based caulks.
Other materials may be used provided they
do not cause short- or long-term damage to
the PEX tubing.
WARNING!
When using expanding spray
foam to insulate walls in a
structure, there are several
options available. Viega suggests using
water-based or urethane-based open-cell
insulation only. Do not use closed-cell
spray foams. Both open-cell and closed-
cell spray foams have the potential to
generate high temperatures during their
expansion process, especially when not
applied properly, which can damage
PEX tubing. Therefore, Viega suggests
applying open-cell spray foam in layers
up to 1.5 inches thick and allowing
the insulation to cool before applying
additional layers. Additionally, Viega’s
PureFlow polymer 󶈵ttings and manifolds
should be wrapped with a protective
coating prior to the application of spray
foam to avoid damage. Protective
coatings can be either a polyethylene 󶈵lm
or aluminum wrap. Viega’s metallic 󶈵ttings
do not require additional protection from
open-cell spray foam. Always follow the
spray foam manufacturer’s installation
instructions and warnings.
Do not expose Viega products to any
foreign substance that includes but is
not limited to Volatile Organic Chemical
(VOC) compounds, paints, solvents,
glues, cleaners, and disinfectants. Viega
products that are exposed to these types of
substances are at risk of having failures (leaks).