UH211
UH211 Series
H I G H P R E S S U R E F I LT E R S
s e r v i c e
i n s t r u c t i o n s
3
Note: Painting of the filter housing is optional. The coating on
the filter housing is a suitable painting base. Cover the
differential pressure warning device and nameplate if painting
of the housing takes place.
4.8
Bleed the filter.
4.8.1
UH211C series (cover service): Bleed the filter
by opening the vent plug (7) at the top of filter
one and one half turns. Jog system and fill filter
until all air bleeds through the plug, then torque
tighten the vent plug to 12 ft/lb or 16 Nm.
4.8.2
UH211H series (head service): Bleed the filter
by opening the blanking plug (6b) one and
one-half turns. Jog system and fill filter until all
air bleeds through the plug, then torque
tighten the blanking plug to 40 ft/lb or 54 Nm.
Pressurize system fully and check for leaks; if leaks occur refer
to section 5.
5
Routine maintenance
5.1
Pall
filters do not normally require special attention
except for periodic monitoring of the differential pressure
warning device. Schedule replacement of filter element
every six months or sooner, and have ample supply of
spare elements available.
5.2
If external leakage is noted, replace O-ring at leak. If
leakage persists, check sealing surfaces for scratches
or cracks; replace any defective parts.
5.3
Differential pressure devices actuate when the element
needs changing or because of high fluid viscosity in
'cold start' conditions. If 'cold start' conditions exist,
see Section 6.2 and 6.3.
5.4
A dirty system can quickly plug a new filter element,
especially with
Pall
high efficiency filter media. It may
require one or two initial element changes to stabilize
element life. If filter element service life is short or
differential pressure is excessive, the filter may be
undersized; refer to the sizing and selection section of
the product literature or contact your local Pall
representative.
5.5
Make sure element change labels are clean and
undamaged. Replace illegible labels with the appropriate
new labels.
6
Differential pressure devices
Reference should be made to product literature for dimensions,
operating parameters, part numbering, ordering information
and specifications.
6.1
Differential pressure devices actuate when the element
needs changing or because of high fluid viscosity in
‘cold start’ conditions.
6.2
If visual indicator is fitted and actuates during ‘cold start’
(red button extends 5 mm, 3/16 "), reset by depressing
the button when the normal operating temperature is
reached. If indicator actuates after resetting, replace
element.
NOTE: Option ‘P’ visual indicator has thermal lockout and
manual reset. No signal below 0 °C (32 °F), signal above 29 °C
(80 °F).
6.3
If the electrical switch actuates (e.g. red light comes on)
during cold start, continue operating until the signal
(red light) goes out as system warms to normal
operating temperature. This feature can be used as
'warm up' indication in operating procedures. If the
warning signal (red light) remains or appears when
system is warm, replace the filter element.
ENGLISH
6.4
Use of both positive indication (green light) and negative
indication (red light for dirty element) is recommended to
effectively monitor filter element life.
Electrical connections and ratings for all differential
pressure switch options:
110 VAC
=
4A (inductive),
4A (resistive)
220 VAC
=
4A (inductive),
4A (resistive)
28 VDC
=
3A (inductive),
5A (resistive)
48 VDC
=
1A (inductive),
1.5A (resistive)
125 VDC
=
0.25A (inductive),
0.5A (resistive)
Maximum inrush - 24 amps.
Underwriter’s lab. Inc. listed ratings of pressure switch
(Microswitch) options are:
4 amps at 250 VAC
0.25 amp resistive at 220 VDC
0.50 amp resistive at 110 VDC
Electrical differential pressure switch operation:
When preset differential pressure is exceeded continuity
switches from 'C' - 'A' to 'C' - 'B'.
When differential pressure decreases below the pre-set value,
continuity returns to 'C' - 'A'.
Figure 1
- Switch Circuit Diagram
C
or black
or tag 2
CAUTION:
Failure to bleed the filter housing adequately will
increase the dissolved air content of the system fluid
which will shorten fluid life and may cause other
problems in the system.
A
or white
or tag 1
B
or red
or tag 3
LOW DIFFERENTIAL PRESSURE
HIGH DIFFERENTIAL PRESSURE
