Closed Expansion Vessel System; Automatic Thermostatic Mixer Valve (Optional); Heat Discharge Valve (Optional) - LA NORDICA TermoISOTTA DSA Instructions Pour L'installation, L'utilisation Et L'entretien

3.2.

CLOSED expansion VESSEL system

It is COMPULSORY that the CLOSED expansion Tank system is provided with:
1. A 3 bar SAFETY VALVE :
water column). Higher pressures can cause deformation and breakage of the boiler body
2. AUTOMATIC THERMOSTATIC MIXING VALVE – (see chapter 3.3)
3. HEAT DISCHARGE VALVE or HEAT SAFETY DISCHARGE (positive safety, therefore, this continues
discharge, should the valve be damaged )
4. CLOSED EXPANSION VESSEL
5. PUMP CONTROL THERMOSTAT
6. NOISE ALARM ACTIVATION THERMOSTAT
7. NOISE ALARM
8. TEMPERATURE INDICATOR
9. PRESSURE INDICATOR
10. PUMP SYSTEM
IMPORTANT : temperature safety sensors must be in place on the machine at a distance no greater than 30 cm from
the flow connection of the thermo-product. Whenever the thermo products lack a device, those missing can be
installed on the thermo product flow pipe, within a distance no greater than 1m from the thermo product.
IT IS MANDATORY that the thermo products for domestic heating inserted in CLOSED VESSEL heating systems,
must be internally equipped, with a cooling circuit, prepared by the unit manufacturer, which is activated by a thermal
safety valve (see chapter 3.4) which does not require auxiliary power and can guarantee that the standard set
temperature limit is not exceeded. Connection between the power supply unit and the valve must be free from
interceptions. Cooling circuit upstream pressure must be at least 1,5 bar.
3.3.

AUTOMATIC THERMOSTATIC MIXER VALVE (OPTIONAL)

The automatic thermostatic mixer valve finds applications in solid fuel heat generators as it prevents cold water return
in the exchanger.
Routes 1 and 3 are always open and, along with the pump installed on the return (Picture 2 R ), the guarantee water
circulation inside the biomass boiler exchanger ( CB ).
An elevated return temperature, allows efficiency improvement, reduces formation of smoke condensation and
prolongs the boiler life span.
Valves on the market have different calibrations. NORDICA advises use of model 55° c with 1" hydraulic connections.
Once the valve calibration temperature is reached, route 2 is opened and the boiler water is goes to the system via the
flow ( M ).
IMPORTANT lack of installation of the device voids the heat exchanger warranty
3.4.

HEAT DISCHARGE VALVE (OPTIONAL)

Solid fuel thermo products must be installed with safety devices determined by laws in vigour.
For this reason the thermo stove are equipped with a heat discharge coil.
The heat discharge coil must have one side connected to the water network (Picture 3 A ) and the other rot drainage
network( C ). When the safety temperature is reached, the heat discharge valve, the bulb of which is to be connected
to attachment B , enables the intake of cold water in the boiler coil, discharging the excess heat out of pipe C towards
a conveniently installed drain.
Cooling circuit upstream pressure must be at least 1,5 bar.
22
maximum operation pressure allowed for the system is 3 bar (equal to 30m of the
CB
55°
TERMOPRODOTTO
Termo ISOTTA – DSA
M
3
R
2
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7199701 Rev.05 – EN
Picture 2