HERZ laying system

Pipes
HERZ plastic and aluminium
composite pipe, PE-RT
Polyethylene is a versatile plastic and can
be recycled after being separated from the
aluminum, for example, as an oil substitute
in combustion plants. Plastic and aluminium
composite pipes consist of five layers with
a middle layer made of aluminium. This
aluminum layer gives the pipe rigidity,
100 % watertightness and an oxygen
barrier.
The inner tube is made of a special PE-RT
(Polyethylene – Resistant Temperature) with
increased temperature resistance according
to DIN 16833. PE-RT is an ethylene-octanecopolymer.
Its molecular structure with
linear ethylene main cells and octane side
cells results in a high viscosity and flexibility
with long-term stability.
Advantages:
• 100 % oxygen and steam impermeable
• Laser butt-welded aluminium tube
0.20 mm/0.25 mm
• Extensive guarantee
Application
The HERZ- pipe is an ideal plastic multilayer
pipe for both underfloor heating and
radiator connections having a maximum
operating temperature of 95 °C (short-time
resistance up to 110 °C) and a maximum
operating pressure of 12 bar.
Technical data:
• Outside diameter: 10 – 63 mm
• Pipe tolerances for the thickness
of the tube wall:
Pipe outside diameter + 0.2 mm
Pipe inner diameter + 0.2 mm
• Standard pipe length: 200 mm,
other lengths upon request
• Pipe colour: white, other colours
upon request
Maximum operating temperature 95 °C
Maximum operating pressure 10 bar
Durability at 70 °C / 10 bar minimum
440,000 (50 years)
Breakdown temperature /
pressure 110 °C, 15 bar
Internal surface roughness 0.007 mm
Heat conductivity 0.5 W/m x °K
Linear expansion coefficient, 0.024 mm/m °K
Colour – white
Oxygen diffusion < 0.005mg/l d
Minimum bending radius without tools 5 d
Minimum bending radius with tools 3 d
Creep behaviour of HERZ pipe
Creep behaviour of the pipe interior
Aluminium composite pipe, PE-RT, 26 x 3 mm
Test pressure in bar
The creep behaviour indicates what
maximum pipe wall stress (pipe internal
pressure) is permissible under constant
operating temperatures, in order to achieve
a certain operating time. The hoop stress
resistance, particularly due to the creep
strength of the relatively thick aluminium
layer, is proven in HERZ pipes.
The creep behaviour of HERZ pipes is far
above the temperatures relevant to the
housing market for heating and domestic
water installations. The HERZ pipe consists
of various layers of materials, the individual
contributions of which add to the creep
strength of the whole pipe. An appropriate
creep diagram can therefore be drawn for
each individual pipe size.
The creep behaviour is indicated by
testing the pipe over 10,000 hours, with a
temperature 40 °C higher than the maximum
operating temperature. Afterwards, these
results are extrapolated to 50 years with
a safety factor of 1.5. In accordance with
the standards, the pipes are dimensioned
for 50-year durability. A decrease in the
durability must be calculated where higher
temperatures or pressures are used.
The pipes are supplied in straight lengths
or coils and are connected using HERZ
press fittings or HERZ screw connections.
HERZ pipe and HERZ connection fittings
are tested for conformity to standards and
accredited by externally recognised testing
centres in many European countries. The
system is registered as HERZ PipeFix.
HERZ pipes have good electrical
conductivity due to the “continuous”
aluminium layer. “Lateral” to the pipe shaft,
the polyethylene layer works as an electrical
insulator up to a voltage of around 35,000 V.
It is not possible to earth the piping.
Extraposition 20 °C
Extraposition 60 °C
Extraposition 70 °C
Extraposition 95 °C
Extraposition 110 °C
Regvest DVGW (70 °C / 15 bar / 50 Jahre)
Standzeit in Jahren
Starting time in hours
Example: DN 16 mm pipe
Diagrams are available on request for other dimensions or tools
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