Scale Build Up - Sanremo MILANO S Instruction Booklet

ENGLISH
MILANO S
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(90-100°C). 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 ope- rating pressure because the pressure relief valve cannot work
properly.
To minimize this problem Fluid-o-Tech suggest to use pumps with flow rate
matching the hydraulic circuit features.
In some circuits it is advisable to periodically remove scale with a chemical
treatment.
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