CMA Technical Manual - Love Coffee Machines
CMA Technical Manual - Love Coffee Machines
CMA Technical Manual - Love Coffee Machines
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18 - English<br />
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11. VALVE GROUP<br />
espresso coffee machine - instructions for technician<br />
9. ANTI-FLOODING DEVICE<br />
The cover installed on the pressure modulating switch makes it possible, by means<br />
of the special tube, to collect and carry to the drain tub any water which may exit<br />
the boiler to due any malfunction of the machine.<br />
10. PUMPING SYSTEM<br />
This is a component that serves the purpose of feeding the machine, raising the<br />
water pressure to 8-9 bar for the delivery of the coffee and for automatic filling<br />
of the boiler.<br />
The valves are devices whose purpose is to ensure the safety and proper operation<br />
of the machine.<br />
11.1 NEGATIVE PRESSURE VALVE<br />
The purpose of the negative pressure valve is to prevent the backflow of liquids<br />
through the steam nozzle when they are being heated. Furthermore, the excess<br />
air is eliminated inside the boiler during the heating phase of the machine.<br />
11.2 SAFETY OR PRESSURE RELIEF VALVE<br />
The pressure relief valve guarantees that the pressure in the boiler does not go<br />
above 2 bar. If there is a malfunction, the capacity of the valve is such that it can<br />
eliminate all of the excess pressure in the valve.<br />
11.3 EXPANSION VALVE - NON-RETURN VALVE<br />
This is a valve consisting of an expansion valve and a non-return valve.<br />
• Expansion valve valve: the cold water sent from the pump to the heat exchangers<br />
is heated. This heating causes an increase in the volume of water. To limit<br />
increases of pressure in the hydraulic circuit, the valve limits the maximum<br />
internal pressure of the circuit to 12 bar.<br />
• non-return valve: Its function is that of preventing the back flow of water<br />
from the exchangers in the hydraulic circuit.<br />
NOTE<br />
On all machines with four groups, two pressure relief valves are installed.<br />
valve<br />
EXPANSION<br />
valve<br />
NON-RETURN