Wega ALE Series Use And Maintenance Manual page 11

2.6.1 Boiler
The boiler is constructed in copper sheet metal (1), to
which the heat exchangers are assembled which in turn
are connected to the dispensing group. Water for coffee
dispensing is taken directly from the heat exchanger.
During dispensing, cold water is sent to the inside of the
exchanger by means of the motor pump. Inside the heat
exchanger, cold water and the pre-existing hot water
are mixed, thus obtaining optimal water temperature
for coffee infusion.
1
ELECTRIC HEATING
The water is heated in the boiler by means of an electrical
heating element that is immerged in the water (2).
GAS HEATING
Gas heating is obtained by supplying the flame of the
burner located under the boiler
ELECTRIC + GAS HEATING
In machines equipped with both systems, it is possible
to combine the heating types.
2.6.2 Overflow device
The cover installed on the pressure relief valve makes
it possible to collect any water and steam which may leak
from the boiler due to malfunction and channel it to the
drain pad, by means of a special hose.
TECHNICIANS manual
2.6.3 Pressure relief safety valve
The pressure relief safety valve has a
calibration of 1.9 bar in order to ensure
that the pressure in the boiler services does
not exceed the value of 2.1 bar. In case of
malfunction, the valve can eliminate all the
excess pressure from the boiler.
The safety valve should be checked regularly as indicated in
Chapter "8.3 Maintenance" on page 34 ".
On all machines with 4 groups, two safety valves are installed.
2.6.4 Expansion + non-return valve
This is a valve consisting of an expansion valve and
a non-return valve.
2
expansion valve (A):
the cold water sent from the exchanger pump to the
exchangers is heated. This heating causes an increase
in the volume of water. To limit
pressure increases in the hydraulic
circuit, the valve limits the maxi-
mum internal pressure of the cir-
cuit to 12 Bar.
non-return valve (B):
its function is that of preventing
the backflow of water from the
exchangers in the hydraulic circuit.
2.6.5 Negative pressure valve
The purpose of the negative pressure valve
is to prevent the backflow of liquids through the
steam nozzle when they are being heated. Fur-
thermore, the excess air is eliminated inside the
boiler during the heating phase of the machine.
2.6.6 Pressure switch
The pressure switch makes it possible to
control boiler pressure by activating or
bypassing the heating element in the boiler.
Any calibration of the pressure switch which
may be required can be carried out with the
machine in operation by means of the screw
6
( ) located on the body of the component.
A
B
6
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