Recirculating Pump Requirements; Initial Backwash Requirement; Start The Filter; Section 5. Maintenance - Jandy SFHT3461 Installation And Operation Manual

ENGLISH
4.5

Recirculating Pump Requirements

• Undersized or worn-out pumps may not generate
sufficient flow and/or pressure to meet the
facility's design flow rate or the required filter
system backwash flow rate.
• If adequate flow is not available from the
recirculation pump, the filter system will not
function properly in either the filtration or
backwash modes of operation.
• Typically, recirculation pumps must generate the
designed/required flow rate in gallons per minute
at a discharge head of 60 feet minimum.
4.6

Initial Backwash Requirement

• As the recirculating pump picks up prime, the
filter's influent gauge will indicate a high reading
and the effluent gauge a low reading. This is
because the new media (sand) in the filter may
contain very fine sand particles restricting flow.
NOTE: Fines must be thoroughly backwashed to waste
before the gauges will settle to their normal
operating pressures.
• The filter system should exhibit between 3.5
and 8.0 psi (depending on the model) differential
or head loss when employing #20 sand and
operating at 15 gallons per minute (gpm) per
square foot of filter area.
• Once the filter system is operational the inlet
pressure should be between 12 to 15 PSIG and
the outlet will be 6 to 8 PSIG.
• Backwash time of 8 to 10 minutes is usually
sufficient for removing these silica media fines.
Figure 6. Flow During Normal Filter Operation
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Jandy Commercial Horizontal Sand Filter | Installation & Operation Manual
®
Figure 7. Flow During Backwash Operation
4.7

Start the Filter

The operating valves, other than Multiport Valve, of
this system require slight flow restriction to produce
back pressure (1 to 2 pounds of back pressure) to
assure proper operation of the filtration System.
• Partial closure of the operating valves will aid
in the initial startup and the setup of the filter
system.
• Following the initial start-up procedure, the valves
will be adjusted to assure proper flow, slight back
pressure and operation.

Section 5. Maintenance

WARNING
Before performing any maintenance on the filter system, shut OFF
all electrical power and close all valves between the source water
and the filter system and employ LOCK OUT/TAG OUT procedures as
required by local codes.
WARNING
To avoid an electrical shock hazard, which can result in serious injury
or death, ensure that all electrical power to the system is turned off
before approaching, inspecting or troubleshooting any leaking valves
or plumbing that may have caused other electrical devices in the
surrounding area to get wet.