Astoria SABRINA SAE DISPLAY Use And Maintenance Manual page 48

Sabrina
9.3.3 Dispensing group maintenance
Replace the dispensing
group's shower screen (2) and
group gasket (4) on a quarterly
basis (it is recommended to use
original spare parts only), by
proceeding as follows:
Unscrew the screw (1);
Remove the shower screen
containment ring (3);
Replace the group shower
screen (2) and the rubber
group gasket (4);
Reassemble the compo-
nents.
9.3.4 SAFETY VALVE check
The pressure relief valve is one of the main compo-
nents for machine safety. Therefore, it is important to
carry out the following checks:
First check:
Remove the machine's upper grille;
Use pliers to pull the valve pin (3) upwards;
If the pin will not budge, it probably means
that the valve is encrusted with limestone
and must be replaced.
Second check:
Turn the machine off;
Close off the pressure switch contacts;
Turn the machine back on and wait for the pres-
sure in the heating unit to rise.
Check that the valve is working correctly at the
maximum pressure of 1.9 bar.
If any malfunctions are detected, the valve must be replaced. Only
use the Manufacturer's original Safety Valves.
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9.3.5 NEGATIVE PRESSURE VALVE check
First check:
Remove the machine's upper grille;
Use pliers to push the valve pin (5) downwards;
If the pin will not budge, it probably means that
the valve is encrusted with limestone
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and must be replaced.
Second check:
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Turn the machine off;
Open the steam valves and release all
2
the pressure from inside the heating
unit;
Turn the machine back on and check
1
that the valve is closing normally.
If any malfunctions are detected, the valve must be replaced.
9.3.6 NON-RETURN DRAIN VALVE check
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The non-return drain valve is an important compo-
nent for the correct operation of the machine. Perform
the check as follows:
Activate the dispensing groups for about 30 seconds;
Attach a filter holder (4) with a pressure gauge (avail-
able on request) to the dispensing group;
Activate the dispensing group, and use the pressure
gauge (5) to monitor the pressure as it increases up
to 8-9 bar;
Check that the pressure is increasing due to the
heated water expanding until it reaches approxi-
mately 12 bar: when this value is reached, it confirms
that the valve is working correctly and the seals and
solenoid valves are tight;
Stop dispensing;
Repeat the check on the other dis-
pensing groups.
If any malfunctions are detected, the valve must be replaced.
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