Install Instructions

Product Information
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IM-PF 724596 1021 PureFlow Water System (EN)
2.3 PEX
PEX is a material made up of molecules of high density (HDPE) that are
permanently linked to each other by a process called crosslinking. This
process allows PEX to withstand higher temperatures and pressures
compared to standard HDPE tubing, making it ideal for hot and cold
potable water applications as well as hydronic radiant heating and cooling
systems. There are three common methods of crosslinking polyethylene,
two of which are a chemical method and one that is physical.
■ Peroxide - Pressure/heat/chemical
■ Silane - Moisture cure
■ Radiation - Electron beam
Each method induces links between single strands of PE to form a more
dense network. The number of links between these strands determines
the crosslink density and is an important factor in determining the
physical properties of the material. The minimum percent crosslinking for
each method is speci󶈵ed in the ASTM F876 standard. These methods are
also known as PEX-a, PEX-b and PEX-c, respectively, but are not related
to any type of a quality rating system.
The ASTM F876 manufacturing standard incorporates a material
designation number that is a rating scale for chlorine resistance, UV
resistance and material strength. This designation consists of the tubing
material type “PEX” followed by a four-digit number. These four digits
break down as follows:
$IMPSJOFSFTJTUBODF
67SFTJTUBODF
)%4!d'QTJ
)
%4!d'QTJ