WATER SUPPLIES
21
SATURATION INDEX
The satur
ation index is used as a measure of the water’s corrosive or scaling
properties. The saturation index figures stated are calculated using a water
temperature of 80°C.
In a corrosive water supply, the water can attack copper parts and cause them
to fail. Where the saturation index is less than
–1.0, the water is very corrosive
and the Aquamax warranty does not apply to a copper sheathed heating unit. A
corrosion resistant heating unit must be used for the Aquamax warranty to apply
to the heating unit.
In a scaling water supply calcium carbonate is deposited out of the water onto
any hot metallic surface. Where the saturation index e0.40, the water is
very scaling. An expansion control valve must be fitted on the cold water line
after the non-return valve to protect and for the Aquamax warranty to apply to
the temperature pressure relief valve and water heater cylinder.
Where the saturation index exceeds +0.80, the Aquamax warranty does not
apply to a standard watts density heating unit. A low watts density heating unit
must be used for the Aquamax warranty to apply to the heating unit.
Water which is scaling may be treated with a water softening device to reduce
the saturation index of the water.
Refer to the
on page 21. Refer to the
35 for the position of the expansion control valve.
Contact Aquamax Service if a replacement heating unit is required.
+0.4
+0.8
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-1.0
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SATURATION INDEX (SI)
ELECTRIC WATER HEATERS
WITHIN WARRANTY
SPECIFICATION
SATURATION INDEX
(calculated @ 80°C water temperature)
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very corrosive
very scaling
scaling
corrosive
