3
4
60T - 280T
COSMOGAS
particularly clogged. Then fill it with new treated water.
If the analysis of a sample of water that will be used to fill the
system shows the following values:
- Hardness from 12°F to 20°F
- 7,5 < pH < 9,5
then you can proceed with loading. If the characteristics are
different, an inhibitor must be used.
10.7.3 Treating water in heating systems
for civil use
Water must always be treated in heating systems for civil
use, both when replacing the generator and in the event of
a new system.
The design stage, based on the characteristics of the raw
water, must provide for all the treatment and chemical
conditioning systems needed to obtain water with the following
characteristics:
- Appearance: clear, colourless and non-foamy;
- pH: from 7,5 a 9,5;
- Hardness from 12°F to 20°F;
- Conditioners: present within the concentrations prescribed
by the
supplier.
If the water characteristics are unknown, there is a very high
probability of encountering the following typical setbacks:
a. SCALE BUILD-UP
30° fr = 300 mg/kg CaCO
3
In a system containing 1000 litres of water at 30°CF, the CaC0
3
content is equal to 300 g. If not appropriately treated, it will
deposit on the surface of the heat exchanger as that is the
hottest point of the system, creating concentrated increases
in temperature and leading to the heat exchanger breaking.
b. CORROSION
Corrosion is usually facilitated by the presence of oxygen,
by contact between different metals or by the presence of
chlorides.
c. DEPOSITS
SLUDGE, PROCESSING RESIDUES are organic and
inorganic insoluble substances.
10.8 - Draining the boiler heating circuit
In order to avoid constant water top-ups and subsequent
oxygen and scale, it is advisable to limit draining the heating
circuit as much as possible.
10.9 - Boiler low temperature
(or floor) systems
ATTENTION !!! If the boiler is installed in a floor
system built with plastic piping, all precautions against
corrosion due to water oxygenation must be taken:
make sure the system is built with plastic piping with an
oxygen permeability no greater than 0,1 g/m3 at 40°C.
Should the pipe not meet these features, the boiler radiant
panel circuit must be isolated using a plate heat exchanger
that can resist the corrosion caused by the oxygen
dissolved in the water.
10.10 - Manifold probe
The manifold probe (part 26 in figure 3-5 and 3-7) is factory
installed on the boiler manifold. However, that position may
not be correct in some systems where there is a hydraulic
separator or plate exchanger (see figures 10-1 and 10-2).
It is advisable to move the probe from the boiler manifold to
the hydraulic separator as shown in figures 10-1 and 10-2,
part “58”.
ATTENTION !!! For the system to work properly,
the manifold sensor must be positioned in a point
of the hydraulic separator/plate exchanger, able to
detect the correct supply temperature and able to
be influenced by the secondary circuit water flow
temperature
10 - INSTALLATION - Hydraulic connections - boiler
