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What is PEX?
PEX is cross-linked polyethylene. Through one
of several available processes, links between
polyethylene macro-molecules are formed to
create essentially one large molecule of polyethylene.
This three-dimensional molecule is
more resistant to temperature extremes, chemical
attack and creep deformation which makes
PEX ideal for use in hot water applications.
Typical cross-linking levels in pipe are 65%-
89%. For more than three decades, PEX (or
XLPE) has been used extensively in Europe for
hot water heating and plumbing applications.
How is PEX made?
The process starts with medium to high density
polyethylene (MDPE or HDPE) resin. In some of
the cross-linking methods, chemicals are added
to the base resin which, either during extrusion
or in a post-extrusion process, create the
molecular cross-links through chemical reaction.
These chemical methods can be compared
to the vulcanization of rubber. Another
method, radiation (nuclear or electron beam),
uses high energy irradiation of the extruded
pipe to form the molecular links. Finished properties
of cross-linked material from these commercial
methods are very similar.
What cross-linking method
is used to make CANPEX™?
Vanguard Pipe & Fittings Ltd. uses the silane method of chemical
cross-linking. This process uses HDPE resin with
additives that react when the extruded pipe is
exposed to heat and moisture. The chemical
reaction stops when cross-linking reaches
70-80%. Even with further exposure, no additional
reaction will take place. CANPEX™ is
tested to check the degree of cross-link before
it leaves the factory.
What about the chemicals
used in cross-linking
CANPEX™? Are they harmful?
All of the chemical additives used in making
CANPEX™ are depleted during the cross-linking
process. NSF International (formerly the
National Sanitation Foundation) has tested
CANPEX™ tubing to Standard 61 (Health Effects)
and found it safe for use in potable water
systems.
What sizes is CANPEX™ available
in?
CANPEX™ tubing is made in 1/4", 3/8", 1/2",
5/8”, 3/4" and 1" sizes. The tubing is copper tube
size, meaning that the actual outside diameter of the
PEX is the same nominal size of copper tubing. CANPEX™ has a wall thickness corresponding to SDR9
(Standard Dimension Ratio 9) meaning that the wall
thickness is 1/9th of the outside diameter and is proportionate
for each size maintaining the same pressure
ratings for all sizes.
What about freeze-break resistance?
CANPEX™ tubing will stretch slightly to accommodate the
expansion of frozen water, then return to its original
size when the water thaws. This memory is a feature
of cross-linked material, giving it thermo-elastic
behavior. Although freeze-break resistant, no pipe is
freeze-break proof under all circumstances. Insulation
of plumbing pipes as required by local codes is still
recommended.
What about flexibility and
fewer fittings for changes in
direction?
CANPEX™ is flexible and requires fewer fittings to install
since most changes in direction can be accomplished
without the need for elbows. CANPEX™ is simply curved
around obstructions unlike rigid piping materials.
Compared to branch and main plumbing systems
with rigid piping, a CANPEX™ plumbed system uses only about
half the fittings.
What about the use
temperatures and pressures
ratings?
CANPEX™ tubing is rated for 100 psi @ 180° F and 160 psi
@ 73° F. CANPEX™ tubing is manufactured, sampled,
tested, marked and third-party-listed in accordance
with ASTM standards F876 and F877, and CSA
(Canadian Standards Association) standard B137.5.
What approvals does CANPEX™ have?
CANPEX™ tubing was the first of a very limited number
of PEX tubing manufacturers to acquire a third
party certification listing with NSF International
for both chlorinated hot and cold potable water
plumbing systems, and chlorinated recirculating
hot water plumbing loops. CANPEX™ is also third
party listed for potable water plumbing use by:
NSF International, IAPMO (International
Association of Plumbing and Mechanical
Officials), ICBO (International Conference of Building
Officials) Evaluation Service and Warnock Hersey. Also,
the PEX material used in the manufacture of CANPEX™ is
listed by the PPI (Plastics Pipe Institute).
What about code approvals?
Is PEX referenced in the
plumbing codes?
Yes. Currently, PEX manufactured to ASTM
F876/F877 is listed in the BOCA National
Plumbing Code, the BOCA National Mechanical
Code, the Standard Plumbing Code (SBCCI), the
CABO One and Two Family Dwelling Code and
the International Plumbing Code (IPC) for use in
plumbing systems as well as many provincial and
local codes in Canada. Before installing CANPEX™ tubing, check
with your municipal or provincial plumbing official. Contact Vanguard Pipe & Fittings Ltd. for an up
to date list of approvals.
How can I be assured that
CANPEX™ tubing will hold up?
CANPEX™ tubing meets or exceeds all of the industry
standards established to ensure quality and
reliability. Through independent laboratory testing
of tens-of-hundreds of pipe samples, test
data is developed and analyzed to determine
that CANPEX™ tubing will perform. Continual monitoring
by Vanguard Pipe & Fittings Ltd. and several third-party test
agencies assures consistently high-quality.
What do the letters A, B and
C mean when used to
describe PEX?
The ABC letter designation system is used in
Europe to identify the process by which a
particular PEX tubing is cross-linked. It is NOT a
grading system, but simply an identification
system. PE-Xa is cross-linked with the peroxide
method, PE-Xb is cross-linked with the silane
method (CANPEX™ is silane method) and PE-Xc is
cross-linked by electron beam irradiation.
What about Brass Insert Fittings
systems?
The Brass Insert Fittings system is extremely
efficient and reliable. The system has a 25 year
history of performance in flexible plumbing systems.
The system is simple to assemble and requires no
glues, solders, torches or lubricants.
To make a Brass Insert Fitting connection, simply:
1) Position the crimp ring and insert the fitting into
the tubing
2) Crimp the ring in place with the correct size
crimp tool
Each size takes its own, specially sized crimp tool to ensure
consistent, properly made connections. Brass Insert Fitting system is a
gaugeable system allowing checking of the crimp connections
for proper crimp size.
All Brass Insert Fitting components and tools meet or exceed the
requirements of ASTM standard specification F1807. This
assures a consistent fit and compatibility with components
from other manufacturers also making fittings to F1807.
Can I use CANPEX™ tubing in
Hydronic Heating Systems?
Yes, CANPEX™ tubing is perfectly suited for hydronic heating
loops. An oxygen-barrier version of the tubing
and a complete line of heating system components
are also available.
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