Installation & Operation Manual
SAF-X
01.2022
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001301
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910101
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9.
Description of Filter Operation
Introduction:
The SAF-X Series is sophisticated yet easy-to-operate family of automatic filters, with a self-cleaning mechanism driven by
an electric motor.
The SAF-X is designed to work with various types of screens in filtration degrees from 10 to 800 micron.
There are three models in the series, 4500, 3000 and 1500. Each model is available in three different inlet/outlet diameters.
Filtering process:
Feed water enters from the filter inlet, passes through the coarse screen from outside in, and through the fine screen
from inside out. Filtered water flows through the filter outlet.
The gradual dirt buildup on the inner screens surface causes an increase of the pressure differential across the filter. The
self-cleaning process begins when the pressure differential reached a pre-set value.
The coarse screen is designed to protect the cleaning mechanism from large objects.
Usually, it does not accumulate large quantities of suspended solids and therefore it is not cleaned automatically.
Self-cleaning process:
The SAF-X initiates the self-cleaning process when either the pressure differential across the fine screen reaches a pre-
set value or the flush timer reaches its preset timed interval.
The exhaust valve opens, creating high velocity suction force at the scanner’s n
ozzles' edges which "vacuums" the filter
cake from the screen's surface.
A 2-way (fwd/rev) drive unit that is connected to the scanner by a threaded shaft rotates the scanner and provides the
spiral path movement.
The exhaust valve is activated for the duration of the cleaning cycle by a 3-way solenoid. During the 20 seconds self-
cleaning process, filtered water continues to flow downstream.
Cleaning Cycle Stages
•
Exhaust valve opens to atmosphere.
•
3 seconds’ delay.
•
Motor starts rotating the suction scanner outward (CCW) until reach the outer limit switch (TLS).
•
Motor stops and the exhaust valve closes.
•
The filter is ready for the next flushing cycle.
In the next flush cycle, the motor will rotate the scanner inward (CW) until reach the inner limit switch (BLS).
Cross Section illustration
INLET
OUTLET
FLUSH VALVE
FLUSHING CHAMBER
VALVE`
COARSE SCREEN
SUCTION SCANNER
DRIVE UNIT
