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PAGE # 12
PF-50 Series Filter (ver. 4/5/05)
THEORY OF OPERATION
Influent (unfiltered) fluid is drawn via the pump into the filter piping, where it enters the overdrain (upper
internals). The influent fluid is dispersed over the filter media evenly. Suspended solids are trapped in the
pores formed between the media. The effluent (filtered) fluid then passes from the vessel through the
underdrain (lower internals) and is returned to the system.
As the trapped particles load the media the differential pressure increases. When the differential pressure
reaches 16 psi, a backwash cycle is required. The control valves are repositioned, reversing the flow and
the media is backwashed. The reverse flow lifts and churns the media causing a scouring action to release
the trapped debris. The trapped debris is then pushed up through the overdrain and flushed to drain. On
completion of the backwash cycle, the valves are repositioned and the filtration process continues.
OPERATION AND MAINTENANCE
The following information pertains to the procedures, operation and general maintenance of the PF-50 series
permanent media filter.
Please read this entire OPERATION and MAINTENANCE MANUAL thoroughly and understand all safety
related issues before attempting any work on the PF-50 series filters.
GENERAL MAINTENANCE PROCEDURES
Always follow the start-up and shut down procedures before and after any service or maintenance is done on
the filter unit. The PF-50 series filters are designed for low maintenance and minimal service. With proper
care the PF-50 series filters will provide trouble free service. The following is a list of maintenance check
points and schedules for standard units and includes optional components.
1. Visually inspect filter every 48 hours (minimum) for proper operation
(check for unusual noise and/or vibration).
2. Read pressure gauge (gauge reading should not exceed 45 psi).
3. Backwash filter every 48 hours (minimum).
4. Never allow differential pressure to increase above 16 psid.
5. Check media condition every 6 months (replace if needed).
6. Inspect filter internal assembly each media change.
7. Clean pump pre-strainer before blind-off occurs (check as often as environment dictates).
8. Gasket (filter and pre-strainer) each time the filter is serviced.
9. Check voltage and amperage draw on motor lead.
NOTE:
All recommendations are minimums. The environment/operating conditions in which the filter
unit is installed will dictate the frequency of scheduled maintenance. Maintaining your PF-50 Series
filter will assure a long trouble free life.
SECTION 2
