User Guide

Installing PureFlow Systems
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PG-PF 724998 0320 PureFlow System
The properties of Viega PureFlow PEX
tubing make it easy to work with and
install in most types of construction. Some
care must be taken to prevent damage to
the tubing before and during installation:
■ Use care to protect both Viega PureFlow
PEX and FostaPEX tubing from physical
damage during storage and installation.
Keep the tubing away from sharp
objects, open 󶈶ames, etc., and do not
place heavy objects on the tubing.
■ Damaged sections of tubing should be
cut out and discarded.
■ Do not expose Viega PureFlow PEX
tubing to sunlight or any UV
source for extended periods of
time exceeding six months.
■ FostaPEX, with its aluminum layer, is
resistant to UV light, but long-term
exposure should still be avoided.
■ Do not store Viega PureFlow PEX or
FostaPEX tubing outdoors where it
may be exposed to UV light.
Uncoiling PureFlow PEX Tubing
An uncoiler should be used to prevent
twisting when removing tubing from ⅜"
to 1" coils. Roll coils out and use care to
avoid twisting 1¼", 1½", and 2" coils or
when an uncoiler is unavailable.
Bending PureFlow PEX Tubing
Viega PureFlow PEX tubing can be free
bent (unsupported bend) to a minimum
radius of eight times the tubing O.D. and
󶈵ve times the tubing O.D. with the use of
a Viega-approved bend support. Viega
FostaPEX tubing can be free bent to a
minimum radius of eight times the tubing
O.D. and 3.5 times the tubing O.D. with
the use of a Viega tubing bender. For
situations requiring tighter bends, use
elbow 󶈵ttings. If bending against a PEX
coil bend direction, the bending radius is
24 times the tubing O.D. Viega does not
allow the practice of “hot bending” Viega
PureFlow PEX tubing to make a tighter
bend radius.
Handling Viega PureFlow PEX Tubing
Viega
PureFlow
PEX
Minimum Radius
Nominal Size*
Free Bend
(8 x O.D.)
Supported
(5 x O.D.)
⅜" 4" 2.5"
½" 5" 3.1"
¾" 7" 4.4"
1" 9" 5.6"
1¼" 11" 6.75"
1½" 13" 8.1"
2" 17" 10.6"
*Viega PureFlow PEX bend radius values were
calculated using standard CTS O.D. dimensions,
which are ⅛" larger than the nominal tube size listed.
Viega
FostaPEX
Minimum Radius
Nominal
Size**
Free Bend
(8 x O.D.)
Supported
(3.5 x O.D.)
½" 5.6" 2.4"
¾" 7.5" 3.3"
1" 9.6" 4.2"
** FostaPEX bend radius values were calculated
using the actual O.D. dimensions, which include the
additional aluminum and PE layers.