La Marzocco LEVA X, Manual

Page: 10 / 98

EN
10
1) General Description
The machine is built in 2 and 3 coffee
group versions and is essentially composed
of the following parts:
• Steam Boiler (produces steam and hot
water);
• Coffee (“saturated”) boiler;
• Brewing groups;
• Exterior Cover;
• Water pump (if present).
2) Description of the various parts
• Steam Boiler
The Steam Boiler consists of a cylindrical
tank, of varying length according to the
number of coffee groups, which is made
of AISI 300 series stainless steel. Each
unit is subjected to a hydraulic test, at a
pressure of 6 bar, and has an operating
pressure of 1.3-1.5 bar. The following
is a list of effective volumes and power
ratings according to the number of groups
installed:
2 groups 8,2 liters 3000 Watts
3 groups 11,8 liters 4000 Watts
Covers are welded at either end of the
cylindrical tank and on one of them there
is a housing for the water heating element,
which allows the steam boiler to reach
operating pressure within approximately 25
minutes. Operating pressure is maintained
by temperature probe and PID controller.
The steam boiler has various fittings used
for safety devices, for supplying hot water
and steam, and for the heating element.
It consists of AISI 300 stainless steel
tubes. Heating is accomplished through an
immersion-type plated heating element.
•
Operating pressure of 1.3-1.5
bar, controlled automatically through a
pressure switch or a temperature probe,
adjusted to open the heating element
supply circuit at 1.5 bar and close it at
1.3 bar.
•
The pressure is displayed by
means of a pressure gauge with a scale of
0 to 2 bar.
•
Safety device, based on an
expansion type mechanical valve, with
counter-acting spring adjusted to 1.8 bar.
•
Testing: hydraulic test at 4.5 bar
performed on ready-to-use small boilers,
at our factory.
• Coffee Boiler
The Coffee Boiler consists of a cylindrical
tank made of AISI 300 series stainless
steel. One each group (hot water generator
for brewing coffee).
Each unit is subject to a hydraulic test, at
a pressure of 18 bar, and thus is suitable
to operate with pressures of up to 6 bar,
the calibration value of the expansion
valve. The following is a list of effective
volume and power ratings according to the
number of groups installed:
LEVA X:
2 groups 2 x 1,3 liters 2 x 800 Watt
3 groups 3 x 1,3 liters 3 x 800 Watt
LEVA S:
2 groups 1 x 3,4 liters 1 x 1400 Watt
3 groups 1 x 5,0 liters 1 x 1900 Watt
Covers are installed at either end of the
cylindrical tank and on one of them
there is housing for the water heating
elements. A further electrical resistances,
in addition, are installed at the top of the
group and the bayonet ring. The coffee
boiler temperature is kept constant by an
electronic PID temperature control unit,
with a precision of 0.2°C. The brewing
groups are installed on the boile.
It consists of AISI 300 stainless steel
tubes. Heating is accomplished through an
immersion-type plated heating element.
• Operating temperature 95°C (adjustable),
controlled automatically by an electronic
temperature controller with an accuracy of
0,2°C. Pressure inside the boiler depends
on the setting of the pressure reducer - see
page 27. In any case, its value is limited