User Guide

Installing PureFlow Systems
45
PG-PF 724998 0320 PureFlow System
Fire Stop Compounds
Most building codes require the use of
a 󶈵re-stopping compound when tubing
penetrates a 󶈵re-rated wall. There are
a number of 󶈵re-stopping compounds
identi󶈵ed as water based, acrylic, or latex
that have been listed for use with PEX
tubing that include but are not limited to
the following:
■ 3M Fire Protection – CP 25WB+ Caulk
■ Tremco, Inc – TREMstop
®
IA
■ Speci󶈵ed Technologies, Inc. –
SpecSeal
®
SSS 100 / SSS 102
■ Passive Fire Protection Partners – Fire
Stop
™
4800 DW / 4100 DW / 4100 NS /
3600 EX
It is the responsibility of the user to
determine the suitability of these or any
products for the intended application and
install the compounds in accordance with
the product’s installation instructions and
listing.
Tubing Expansion
Viega PureFlow PEX tubing, as with any
PEX tubing, expands and contracts with
temperature changes in the environment
or the 󶈶uid inside the tubing. The
longer the tubing run and the higher the
temperature change, the more linear
expansion the system will experience.
This expansion and contraction can a󶈴ect
the appearance as well as integrity of the
system by putting stress on the tubing,
󶈵ttings, valves, and fasteners.
Tubing fasteners perform two functions:
providing support for the tubing and
guiding the tubing during expansion
and contraction. It is important to keep
this in mind when installing fasteners.
An expansion compensator will not be
e󶈴ective if the fasteners prevent linear
movement of the piping system.
Tubing sizes smaller than ¾" generally do
not require expansion compensators with
󶈵ttings and can easily be bent into loops
and o󶈴sets to absorb linear expansion.
For tubing sizes 1" and larger, refer to
“Calculating Expansion Loops and O󶈴sets”
on page 46 for compensation options.
For unconstrained tubing runs (not
within the 󶈶oor) Viega recommends the
use of expansion o󶈴sets. This can be
accomplished at a corner or by using
o󶈴sets or loops on straight tubing runs.
Expansion compensators should be
installed at the midway point of tubing
runs and should be spaced no more than
50 feet apart.
Using a loop to
accommodate tubing
expansion
Offsets also provide
room for tubing
expansion.
Allow some slack in all runs to prevent damage
from tubing contraction.
⅛" to
3
/
16
"
slack per foot
Below is an example of required o󶈴sets
for a 100-foot tubing run. Note that the
expansion compensators are no more
than 50 feet apart.
100'
25'25' 50'
50' 50'