1.3.6.4. Flowmeter
The flowmeter installed on the EVD electronic machines,
measures the quantity of water sent to the brewing unit
for espresso brewing.
The flowmeter generates an electric impulse which is
sent to the electronic control unit.
This impulse is read by the control unit and memorized
during the programming of the dose.
The flashing of the LED (1) indicates that the electrical
impulse has been sent from the flowmeter to the control
unit.
1.3.6.5. Boiler temperature and pressure control
The flowmeter installed on the EVD electronic machines,
measures the quantity of water sent to the brewing unit
for espresso brewing.
The flowmeter generates an electric impulse which is
sent to the electronic control unit.
This impulse is read by the control unit and memorized
during the programming of the dose.
The flashing of the LED (1) indicates that the electrical
impulse has been sent from the flowmeter to the control
unit.
1.3.6.6. Pumping system
It is the component that feeds the machine, raising the
water pressure to 8-9 bars for coffee brewing and auto-
matic filling of the boiler.
To set the pressure rating, proceed as follows:
- select a coffee dispensing key;
- connect a pressure gauge, with bottom scale greater
than 9 bars, to the specific fitting on the water circuit
(see the hydraulic diagram);
- set the pressure by using the pressure adjusting screw
located in the pump (A) in such a way as to reach a
value between 8 and 9 bars: turning clockwise the
pressure increases, turning anticlockwise the pressure
decreases;
- check the pressure on the pressure gauge.
1.3.6.7. Valve group
The valves serve to ensure safety and proper machine
operation.
Safety valve
The safety valve serves to eliminate the air
in the boiler during the heating of the ma-
chine.
Pressure relief valve
The pressure relief valve ensures that the
pressure in the boiler doesn’t exceed 2.2
bars. In case of a malfunction, the capacity
of the valve is likely to eliminate all the ex-
cess pressure in the boiler.
Expansion – one-way valve
This device consists of an expansion valve and a one-
way valve.
Expansion valve: the cold water sent from the pump to
the heat exchangers is heated. This heating causes an
increase in the volume of the water. To limit pressure in-
creases in the hydraulic circuit, the valve limits the ma-
ximum internal pressure in the circuit to 12 bars.
one-way valve: its function is to prevent the backflow of
the water from the exchangers to the hydraulic circuit.
1
X
A
One-way
valve
Expansion
valve
Manual code 10066574 / Rel. 2.00 / February 2012
5
Maintenance manual for technical assistance
