8.1
Standards and guidelines
EDGE
TM
system for water services must be planned,
calculated, installed and operated according to AS/
NZS 3500 and other relevant standards.
8.2
Operating parameters
For continuous operation, the following parameters must
not be exceeded.
Application:
Hot water supply at 60ºC / 1 MPa (10 bar)
or 70 C / 800 kPa (8 bar)
(Application class 1-2 acc. ISO 10508)
The above continuous operating parameters are based on
a life span of 50 years and allow for short periods of higher
temperatures as listed in the following table:
Tab. 8-1 Operating parameters according to DIN EN
806-2, DIN 1988-200 and ISO 10508 (Application classes 1
and 2)
8.3
Hot water circulation
EDGE
TM
pipes and fittings are suitable for installation
in hot water circulation (ring main) applications, with or
without copper pipes installed in the same line, provided
the temperature does not exceed 70ºC and the operating
pressure is limited to 8 bar (800 kPa). The maximum
permissible water velocity under those conditions is 3.0
m/s. Note - AS/NZS 3500.4 limits the maximum
permissible velocity to 2.0 m/s.
Refer to Chapter 8.6.4 for maximum allowable levels of
disinfectants.
In buildings with in-house water treatment (ie. water
softening, disinfection) and hospitals we recommend
confirming the water chemistry parameters with REHAU
prior to installing EDGE
TM
system in hot water circulation
(ring main) applications.
8.4
Drinking water requirements
The drinking water must comply with the currently valid
limits of the following standards:
• Australian Drinking Water Guidelines
• Drinking-water standards for New Zealand
Nonetheless, no material exists that can be used for every
application.
In some specific cases, even drinking water qualities within
the permitted range of the drinking water guideline and
standards have properties that may negatively aect DZR
brass fittings and lead to corrosion.
The maximum disinfection agent concentration mentioned
in above guidelines shall only be applied during temporary
disinfection and not continuously. Refer to chapter 9.4.
In locations with highly corrosive water composition, e.g.
in volcanic areas, installations using bore/well water etc.,
the suitability of EDGE
TM
pipe system must be checked
with REHAU. In some cases, the available water quality
may void the REHAU warranty unless appropriate water
treatment is provided.
8.5
Water chemistry limitations
High levels of chloride content combined with low levels
of hydrogen carbonate content may negatively influence
the corrosiveness of the drinking water and lead to
dezincification of DZR brass materials.
To avoid corrosion of EDGE
TM
MX Brass fittings in drinking
water application, the following limits shall not be
exceeded:
• Chloride contents (Cl-) ≤ 200 mg/l
• Sulphate content (SO42-) ≤ 240 mg/l
• Calculated calcite solubility capacity ≤ 5 mg/l
(achieved as soon as pH value ≥ 7.7)
Treated drinking water (e.g. softened water) may
be corrosive to EDGE
TM
components.
•
Verify supplied water from the treatment
plant suits to all materials used in EDGE
TM
water installation system.
• REHAU explicitly recommends to consult
an expert or the system manufacturer for an
assessment of the individual situation and to
ensure correct design, installation and operation
of water treatment plants. It is the responsibility
of the system designer to ensure that the above-
mentioned factors and parameters are taken into
account to prevent corrosion and scaling. If the
drinking water quality is outside the limits of the
drinking water guidelines or above limits, or if
previous experience indicates corrosive tendencies
of the supplied water, consult REHAU before using
EDGE
TM
system.
Design Temperature T
D
/ Time T
D
70ºC / 49 years
Short-term maximum
temperature T
max
/ Time T
max
+ 80ºC / 1 year
Short-term malfunction
temperature T
mal
/ Time T
mal
+ 95ºC / 100 h
Total = 50 years
08 Water quality - Specific guidelines for
water application
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