Sanremo CAFE RACER CR2, Инструкция пользователя, Страница: 28 / 134

CAFÈ RACER
28
Connections
EN
2) Quality of Water.
Tight mechanical tolerances of components and
materials used for rotary vane pumps require a
very clean water, free from suspended particles.
Sand, deposits on connecting pipes or the resins
of the sweetener, when flowing through the pump,
may scratch graphite parts causing problems of
insufficient pressure and flow rate.
If a closed loop hydraulic circuit is not available
to guarantee a clean water and no sources of
contamination SANREMO recommend to install a
5-10 micron filter between the sweetener and the
pump.
Recommended filter: food approved polipropilene
wire cartridge.
Keep the filter clean.: an upstream dirty filter will
create cavitation and the pump will break shortly
(see section 4).
3) Dry operation
Rotary vane pumps may operate in dry condition
only for a very short time- few seconds!
Without a proper water cooling the temperature
of the mechanical seal will increase very quickly
with resulting breakage. The most likely impact is
a remarkable leak visible from the four drain holes
close to the motor clamp . For potential lack of
feed from city water line SANREMO recommend
the installation of a minimum pressure safety
switch upstream from the pump.
In case of feed from a tank install on the tank a
minimum level switch.
4) Cavitation
Cavitation shows when feed flow rate does
not match the pump design requirement: most
frequent causes are dirty filters, small diameter
pipes, more users on the same line.
Opening of the safety valve (generally installed
upstream from pump and filter) must happen
before the pump start up. This will avoid cavitation.
For the same reason closing of the safety valve
must be delayed after the pump shut down.
The most noticeable effect is an increase of noise.
If cavitation continues the impact is the same as of
dry operation.
5) Back Feed of Hot Water
If a non return valve between the pump and the
hot water vessel is defective the pump may come
in contact with hot water(194-212°F). Dimensional
variations of components will cause seizure of the
pump.
6) Wrong connections
Pumps connectors are 3/8”NPT(conical) or 3/8”
GAS(cylindrical).Connectors with thread different
from the recommended type are occasionally
used. Sealing is made with a glue or with teflon
tape. If the connector is forced it is possible to
create beards; if excess sealing glue is used the
extra quantity of glue may enter into the pump
body.
In both cases it is likely to create a damage.
7) Pressure strokes
To avoid pressure strokes opening of solenoid
valves installed downstream must happen before
the start of the pump. For the same reason closing
of the valve must be delayed after stopping of the
pump.
A pressure stroke may break graphite parts and
damage mechanical seal causing blockage of the
pump and leaks.
8) Handling
A crash on the floor may create deformations that
will jeopardize the tight mechanical tolerances of
the pump components. For the same reason be
very careful when clamping the pump to mount or
demount connectors.
9) Scale build up
Scale deposits will quickly show on inner
components when using hard water, not
sweetened with ion exchange resins. Scale
formation increases when the pressure relief
valve is used as flow rate regulator: the rate of
scale deposition increases with increasing of
closed loop circulation. Scale deposits cause an
increase of torque, occasional seizure of the pump
or a reduction of operating pressure because the
pressure relief valve cannot work properly.