6
3.0 Maintenance
A. When to Replace Filter Element
NOTE: Grades C, D, E, F, G, - complete element is
replaced.
1. Grade D (dry desiccant afterfilter)
Initial drop: 1 psi (0.07 kgf/cm
2
). Pressure drop
increases as element loads with solid particles.
Replace when pressure drop reaches 6 psi (0.42 kgf/
cm
2
) (indicator in red area) or annually, whichever
occurs first. Reference page 7, Figure 3.2 for gauge
scale detail.
2. Grade A (mechanical separator)
Element should not require replacement unless
physically damaged. If sludge accumulates, element
can be removed and cleaned with soap and water.
3. Grades B, C, E, F
a. Initial (dry) pressure drop: 1 psi (0.07 kgf/cm
2
) to 2
psi (0.14 kgf/cm
2
)
b. Operating pressure drop: As filter becomes liquid
loaded (wetted), pressure drop will increase to 2 to
4 psi (0.14 to 0.28 kgf/cm
2
). Further pressure drop
occurs as element loads with solid particles.
c. FOR MAXIMUM FILTRATION EFFICIENCY, REPLACE
ELEMENT WHEN PRESSURE DROP REACHES 6
PSI (0.42 KGF/CM
2
) (INDICATOR IN RED AREA) OR
ANNUALLY, WHICHEVER OCCURS FIRST. Reference
page 7, Figure 3.2 for gauge scale detail.
NOTE: Pressure drop may temporarily increase when flow
is resumed after flow stoppage. Pressure drop should
return to normal within one hour.
NOTE: Grades E and F - During normal operation bottom
of foam sleeve will have a band of oil. Spotting above the
band indicates that liquids are accumulating faster than
they can be drained and that prefiltration is required.
4. Grade G (activated carbon filters)
a. Adsorption capacity - 1000 hours at rated capacity.
Element life is exhausted when odor can be
detected downstream of the filter.
B. Procedure for Element Replacement
THIS FILTER IS A PRESSURE CONTAINING
DEVICE. DEPRESSURIZE BEFORE SERVICING. If filter has not
been depressurized before disassembly, an audible alarm
will sound when the bowl begins to be removed from the
head. If this occurs, stop disassembly, isolate and com
-
pletely depressurize filter before proceeding.
1. Isolate filter (close inlet and outlet valves if installed)
or shut off air supply.
2. Depressurize filter by slowly opening manual drain
valve.
3. Remove bowl
a. For models 12 through 20 - bayonet mount -
push bowl up, turn bowl 1/8th turn to your left,
and pull bowl straight down
b. For models 22 through 30 - threaded bowls -
unscrew bowl from head using hand, strap wrench
or C spanner.
4. Clean filter bowl
5. Replace element
a. Replacing complete element
1) Pull off old element and discard.
2) Make certain o-ring inside top of replacement
element is in place and push element onto
filter head. For Housing sizes 40 to 48, place
element in bowl and secure with centering
device.
NOTE: Grades E, F, and G - Do not handle elements by
outside foam cover. Handle by bottom end cap only.
6. After making certain that o-ring inside top of bowl
(and on bayonet mount heads, wave spring) are in
place, reassemble bowl to head.
NOTE: Make certain o-ring is generously lubricated.
NOTE: Wave spring ends should be pointed down
to prevent the wave spring from interfering with
reassembly.
NOTE: Threaded bowl to head connection, generously
lubricate threads with a high grade/temperature lubricant
good for 150°F, 66°C.
C. Auto Drain Mechanism
It is recommended that drain mechanism be replaced
annually.
