V250: 2 Different Standard Versions - Pentair V250 Manuel D'utilisation

V250: 2 DIFFERENT STANDARD
VERSIONS
Residential and Commercial usage: Standard version with By-pass valve
(untreated water by-pass during service depending on the differential
inlet/outlet pressure drop to ensure constant outlet flow rate)
The 250 valve can be equipped with a by-pass valve or with a backwash valve
activated by pilots during regeneration.
The by-pass valve is opened when the outlet pressure P2 is less than the inlet
pressure P1. The by-pass valve will be opened during the backwash phase, enabling
proper flushing within the valve (see flow diagrams). However, the by-pass valve can
also be open during service depending on the differential inlet/outlet pressure drop.
When the pressure at the outlet becomes lower than at the inlet, the by-pass valve
will open to equilibrate the outlet pressure with the inlet pressure ensuring so a
constant flow rate at the outlet but of course obtaining in that case an intermediate
hardness during part of the service cycle. This can be the case for instance when the
unit is producing high flow rate during a short period of time (shower time in hotels for
example), in which case the outlet water will then have an intermediate hardness
compared to the inlet water.
Industrial usage: Standard version with a Backwash valve (no untreated
water by-pass during service)
If it is not desired or desirable to have mixed outlet water during service, regardless of
the difference in pressure, it is necessary to use a backwash valve. This is driven directly
by the pilots and will remain closed during service, but will open during regeneration,
allowing the raw water to pass through the valve for backwash and also allowing to
have raw water at the outlet during backwash, brine draw and slow rinse. No
untreated water will be available during fast rinse however. If no untreated water by-
pass should occur during the regeneration, installation of an outlet shuf-off valve is
required.
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