La Marzocco LEVA X, Manual

Page: 26 / 98

EN
26
You just need to lower the lever by a few
degrees for water loading and then pre-
infusion to start.
The longer the lever stroke, the more water
is loaded and the higher the resulting
delivery pressure. If you move the lever by
a full half-turn (180°), the following will
occur:
• The delivery pressure reaches its
maximum value.
• The maximum dose is delivered.
10.2) Releasing the lever
Before releasing the lever gently move
it upward until you feel the resistance
exerted by the system. Then disconnect
the main lever from the secondary one
and if desired move them back to the rest
position.
WARNING: When using the lever we
recommend that you do not exceed 12 bar
as the delivery pressure value. Exceeding
this value might result in damages to some
machine parts, like filters.
In order to warn the operator that
the recommended pressure has been
exceeded, the corresponding areas are
marked in red on the display of both
analogue and digital pressure gauges.
WARNING: Never release the lever if the
coffee panel isn’t exerting an appropriate
back pressure on the piston. In particular,
never release the lever in any of the
following cases:
• Portafilter not properly installed on the
group.
• Portafilter installed but containing no
coffee.
• No water in the machine.
Failing to comply with this provision
may result in structural damages to the
machine.
10.4) Dose adjustment
If you fully raise the piston, and then wait
until the system has loaded all the water
and the coffee panel has absorbed the
relevant amount, the machine will be able
to deliver the maximum dose.
Its value depends on many factors,
including the coffee type, the amount of
powder in the portafilter, the grinding grade
and the force exerted when it was pressed.
Under normal conditions, however, the
machine is designed to deliver a dose of
about 50cc.
Raising the piston partially will result in
the delivery of a proportionally smaller
dose.
10.5) Force to be exerted on the lever
The force the barista has to exert on the
lever in order to fully raise the piston
depends on the spring preload. The higher
the preload the greater the force the
barista will have to exert.
In the following condition:
• pre-infusion pressure: 3bar
• spring set to generate a maximum
pressure of: 12bar
the barista will have to exert on the lever a
force of about 8kg.
WARNING: We recommend that you set
the spring preload and the pre-infusion
pressure in such a way as to ensure that
the delivery pressure doesn’t exceed 12
bar. Exceeding this value might result
in damages to some machine parts, like
filters.
10.6) Safety precaution
While raising the piston we recommend
that you pay particular attention to the
following:
• Do not accidentally release the lever.