Note: Descriptions are shown in the official language in which they were submitted.
CA 02348115 2001-05-16
DvIF-198-B =SBO 1
FLUID FILTER WITH PRESSURE RELIEF VALVE
Field of the Invention
[0001 ] The present invention relates to fluid filters, and more particularlv,
a fluid filter
havin- a pressure relief valve to provide an accurate visual indicator as to
the remaining life of
a filter element.
Background of the Invention
[000?] It is well known to utilize fuel filter assemblies to filter fuel for a
combustible
encqne of a motor vehicle. Such fuel filter assemblies comprise a varietv of
different
orientations of the fuel filter assembly. For example, it is known to utilize
sidewavs,
downwardly, and upwardly mounted canisters having a paper filter media
enclosed in the
canister. With respect to upwardly mounted fuel assembiies, prior art
filtration devices have
been known to. draw fuel into the filter assembly by use of a pump on the
outlet side of the
filter assembly. The fuel is directed downward into a lower chamber of the
filter assembly
wherein the fuel flow proceeds upward into an upper filter chamber of the
filter assembly. The
fisel may then be contained and sealed 'oy a transparent filter cover or
closure and a filter
mount which may separate the lower chamber from the upper chamber.
[0003] Within the filter cnamber of the filter assembly, the filter assembly
may provide
a filter canister comprised of a filt-Ir media circlincT a central filter tube
that is contained by
filter end caps at the top and bottom of the filter media. The end caps are
sealed to the edaes
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D.NIF-198-B 5B01
or'the filter media to preclude anv possible leak paths at the ends of the
filter canister. The
f,lter media typically comprises a porous paper material that may be pleated
or concentrically
wound so as to direct the tluid throuQh the filtzr media. The filter media
removes and retains
undesirable contaminants within and on the media.
[0004] As fluid enters the tilter chamber, the fuel level rises and passes
through from
the outside to the inside of the filter media. The fuel then flows downward
into a central
passage located along the central axis of the canister. The central passaQeway
is in
communication with a fuel outlet wherein the fuel passes outwardly from the
filter assembly.
[0005] During the filtering process, the fuel is either drawn into the filter
chamber by a
vacuum or pushed into the filter chamber by pressure until the fuel finds a
path throuahhthe
filter media. As the fuel flows through the filter, dirt and other
contaminants laro-er than the
porous openings in the filter media, are trapped and retained by the filter
media. These
contaminants plug or clog the porous holes in the filter media and restrict or
close the paths
used by the flowing fuel. The fuel is then forced to seek other open and less
restrictive flow
openin-s which are available above the level of the fuel by climbing the
height of the filter and
accessinQ the clean areas of the filter media. This process of cloajing and
climbing continues
until the filter media is completely immersed in the flowina fuel.
[0006] Even though the filter media may be completely immersed in the flowing
fluid,
the incominc, fuel continues to pass throuQh the filter media. It is not until
the filter media
becomes greatly clogged that the filter media needs to be replaced. This is a
problem since the
user aenerally views the height of the fuel in the filter chamber to see if
the filter media is
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DNLF-l98-B 26B01
clogQed. If the filter media is completely immersed in fuel, the user
Qenerally believes that the
filter media needs to be replaced. Therefore, this type of system may lead to
premature
replacement of the filter media.
[0007] It would be desirable to provide a fuel filter assembLy that provides
an accurate
indication as to the remaininc, usefulness of the filter media.
Summary of the Invention
[0008] The present invention provides a fluid filter assemblv that provides an
accurate
indication of the remaining usefulness of a filter element. The present
invention provides a
vertical, transparent housinc, havinc, a fuel inlet for communicating fluid
into the housinor and a
fluid outlet for communicating fluid downstream of said housinQ. A filter
element is disposed
within the housing between the lluid inlet and the tiuid outlet for filtering
the fluid. A means
for maintainin- and relieving a predetermined tevel of pressure across the
filter element
provides an accurate visual indicator as to whether the filter element needs
replacement.
[0009] Preferably, the maintaining and relieving means provides a divider that
is
connected to the filter element and extends between a housinc, wall and an
unfiltered side of
the filter element. The divider divides the housing into an outer region and
an inner region,
wherein the outer and inner regions are in communication at a lower portion of
the housinc,.
A relief valve is in communication with a filtered side and the unfiltered
side of the filter
element and is located in the top of the filter element in the outer region of
the housing. The
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relief valve opens when the pressure across the filter element exceeds the
predetermined
pressure level thereby raising the level of fluid in the outer region of the
housing and
indicating that the filter element needs replacement. A segment of filter
media may be
adjacently mounted to the relief valve to filter any unfiltered fluid that
passes through the
relief valve to the filtered side of the filter element.
[0010] Alternatively, the maintaining and relieving means may provide a
restrictive filter media integrally connected to the filter element. The
restrictive filter
media prevents the flow of fluid through the restrictive filter media until
the pressure
across the filter element reaches the predetermined pressure level thereby
causing the
fluid in the housing to rise and indicating that the filter element needs
replacement.
[0010a] Accordingly, in one aspect of the present invention there is provided
a
fluid filter assembly comprising:
a vertical housing having a fluid inlet for communicating a fluid into said
housing and a fluid outlet for communicating said fluid downstream of said
housing,
wherein at least a portion of said housing is substantially transparent;
a filter element disposed within said housing between said fluid inlet and
said fluid outlet for filtering said fluid;
means for maintaining and relieving a predetermined level of pressure
across said filter element to provide an accurate visual indicator as to
whether said filter
element needs replacement; and
a divider connected to said filter element and extending between a
housing wall and an unfiltered side of said filter element to divide said
housing into an
outer region and an inner region, wherein said outer and inner regions are in
communication at a lower portion of said housing.
[0010b] According to another aspect of the present invention there is provided
a
fluid filter assembly for filtering a fluid, comprising:
a vertical housing having a fluid inlet for communicating said fluid into
said housing and a fluid outlet for communicating said fluid downstream of
said housing,
wherein at least a portion of said housing is substantially transparent;
a filter element disposed within said housing between said fluid inlet and
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said fluid outlet for filtering said fluid, and said filter element having a
bottom and a top
wherein fluid flows from said bottom to said top of said filter element;
a pressure reliever in communication with a filtered side and an unfiltered
side of said filter element, and said pressure reliever allowing said fluid
and/or air/vapor
to pass through said pressure reliever when the pressure across said filter
element reaches
a predetermined level, wherein the release of said pressure allows the level
of said fluid to
rise within said housing thereby providing a visual indicator that said filter
element needs
replacing; and
a divider connected to said top of said filter element and extending
downward between a housing wall and said filter element toward said bottom of
said
filter element, and said divider dividing said housing into an outer portion
and an inner
portion wherein said outer and inner portions communicate at a bottom of said
housing.
[0010c] According to yet another aspect of the present invention there is
provided
a fluid filter assembly for filtering fluid, comprising:
a vertical housing having a fluid inlet for communicating said fluid into
said housing and a fluid outlet for communicating said fluid downstream of
said housing,
wherein said housing has a transparent outer cover for viewing the level of
fluid in said
housing;
a concentrically tubular filter element disposed within said housing
between said fluid inlet and said fluid outlet for filtering said fluid, and
said filter element
having a top and a bottom wherein said fluid flows from said bottom to said
top of said
filter element;
a pressure reliever mounted in the top of said filter element and in
communication with a filtered side and an unfiltered side of said filter
element, and said
pressure reliever allowing said fluid and/or air/vapor to pass through said
pressure
reliever when the pressure across said filter element reaches a predetermined
level
wherein the release of said pressure reliever raises the level of said fluid
within said
housing thereby providing a visual indicator that said filter element needs
replacement;
and
4a
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a divider connected to said top of said filter element and extending
downward between a wall of said housing and said unfiltered side of said
filter element
toward a bottom of said housing wherein said divider divides the space between
said
outer wall of said housing and said unfiltered side of said filter element
into an outer
portion and inner portion of said housing wherein said inner and outer
portions are in
communication at said bottom of said housing.
Brief Description of the Drawings
[0011] The description herein makes reference to the accompanying drawings
wherein like referenced numerals refer to like parts throughout several views
and
wherein:
[0012] Fig. 1 is a schematic drawing showing the fluid flow path and the
normal
rising fluid path of a prior art fuel filter assembly.
[0013] Fig. 2 is a schematic drawing showing the rising fluid level in the
fluid
filter assembly of the present invention.
[0014] Fig. 3 is a schematic drawing showing a segment of filter media being
utilized above a relief valve of the present invention.
4b
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DMF-198-B 26B01
[00151 Fia. 4 is a schematic drawing showing a secment of ;ilter media beinQ
utilized
underneath the relief valve of the present invention.
[0016] Fig. 5 is a schematic drawing of a hanc, down fluid filter assembly of
the present
invention.
[0017/] Fi-. 6 is a schematic drawin= showin- a restrictive media being
utilized as a
relief valve in the fluid filter assembly of the present invention.
[0018] Fiz. 7 is a bottom view of the filter element of the present invention.
[0019] Fig. 8 is a sectional view of the filter element of the present
invention taken in
the direction of arrows 9-9 in Fig. 8.
[0020] Fi;. 9 is an exploded view of the relief valve shown in the top of the
filter
element of the present invention.
[0021 ] Fig. 10 is a sectioned perspective view of the relief valve shown in
the top of
the filter element of the present invention.
Description of the Preferred Embodiment
[0021] Referrina to the drawings, the present invention will now be described
in detail
with reference to the preferred embodiment.
[00?3] Fia. 2 shows a fluid filter assembly 10 of the present invention in its
preferred
form. The fluid filter assembly 10 is best suited for ulterincy and processing
diesel fuel, but the
fluid filter assembly 10 may also be utilized with other fluids, such as
gasoline, oil, water,
CA 02348115 2008-10-16
antifreeze, etc. The fluid filter assembly 10 is mounted vertically upright
and provides a
closed housing 12 having a lower fluid storage chamber 16, and an upper filter
chamber
17, the outer housing of which is preferably made of transparent plastic. A
fluid inlet 14
is in communication with the lower fluid storage chamber 16, which is in
communication
with the upper chamber 17 through a passageway 15. A filter element 20 is
housed
within the upper chamber 17 of the housing 12 for filtering a fluid 19 to a
fluid outlet 18.
The fluid inlet 14 delivers fluid 19 into the housing 12 so that the fluid 19
may pass
through the filter element 20 and out the fluid outlet 18. A relief valve 38
mounted in the
top of the filter element 20 opens when the pressure level across the filter
element 20
reaches a predetermined level. A relief valve filter 40 filters fluid 19 that
passes through
the relief valve 38. Preferably, the relief valve filter 40 is mounted below
the relief valve
38, as shown in Fig. 4, but alternatively, the relief valve filter may be
mounted above the
relief valve 38, as shown in Fig 3.
[0024] To filter contaminants from the fluid 19, the filter element 20 is
fabricated
from a pleated porous paper material. The filter element 20 encircles a
central filter tube
22 and is contained by a top and bottom end cap 24, 26, respectively, as seen
in Figs. 2
and 7-11. The top and bottom end caps, 24, 26 are sealed to the edges of the
filter
element 20 to preclude any possible leak paths at the ends of the filter
element 20. A
flexible seal 28 is provided on the bottom end cap 26 of the filter element 20
to create a
seal between the central filter tube 22 and an inner core 43 of the filter
element 20 and
ensure that unfiltered fluid 19 does not leak into or escape through the fluid
outlet 18.
The filter element 20 is preferably pleated or concentrically wound but may
also be
arranged in any of the ways known to one familiar with
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DNIF-19S-B 15b01
filtration construction so as to direct the fluid 19 throu,h the filter
etement 20. In addition, . ttie
filter element 20 may be fabricated from a hydrophobic filter material to
filter out water from
the fluid 19.
[0025] The portion of the housing 12 between the filter element 20 and an
outer wall
37 of the upper filter chamber 17 of the housin- 12 is preferably divided bv a
substantiallv
frusto-conical divider 30. The divider 30 has a top portion 32 that is either
intearally or
sealedly connected to the top end cap 24 of the filter element 20. The divider
30 also has a
bottom portion 33 that extends downward toward the bottom of the filter
element 20, while
also tapering or flaring outward away from the filter element 20. It should be
noted that the
present invention is not limited to a frusto-conical divider 30, but rather,
the divider may also
be substantially cylindrical wherein the bottom portion of the divider may
extend downward
substantially parallel to the filter element 20. In both embodiments, the
divider 30 essentially
divides the upper chamber 17 of the housinc, 12 into an inner portion or
regioin 34 and an
outer portion or region 36. The inner portion 34 is the space contained
between the outside or
unfiltered side of the filter element 20 and the inner surface of the divider
30. The outer
portion 36 is the space contained between the outer surface of the divider 30
and the inner
surface of the outer wall 37 of the upper chamber 17 of the housinc, 12. The
inner and outer
portions 34, 36 remain in fluid corn.munication at the bottom portion of the
upper filter
chamber 17 of the housinc, 12.
[D 025] In order to maintain and relieve the pressure in the upper chamber 17
of the
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DiV1F-198-B 26B01
housinc, 12, a relief valve 38 is mounted in the tep end cap 24 of the filter
element 20. The top
end cap 24 is fabricated from a thin metallic material having a shape
complementary to the top
of the filter element 20. The top end cap 24 has a substantiallv circular
configuration with
sidewalls 39 that extend downward from its peripherv to sealingly connect to
and cover the
top of the-filter element 20. The top end cap 24 also has a centrally located
recessed portion
41 which is received by and complementarily envages the inner core 43 of the
filter element
20.
[0027] The recessed portion 41 of the top end cap 2=1 is formed by two layers
of thin
metallic material. A first inner layer 45 is integrally connected to the
sidewalls 39 and the
portion of the top end cap 24 that extends over the top of the filter element
20. A second
outer layer of the recessed portion 41 is formed by a substantially
cylindrical cup that is
connected to and complementarily engages the inner layer 45 of the recessed
portion 41. The
inner layer 45 of the recessed portion 41 has a raised portion 49 relative to
the outer layer 47.
The outer laver 47 has four apertures 51 that extend therethrough and ali~n
directly under the
raised portion 49 of the inner layer 45 of the recessed portion 41. A sheet of
filter media 53
lies between the inner layer 4:5 and the outer layer 47 of the recessed
portion 41 so as to
cover the four apertures 51 extending through the outer layer 47.
[0028] The raised portion 41 of the inner layer 45 provides two apertures 55,
57
extending therethrough. The larger of the two apertures 55 .receives a
fle;cibte valve mernber
58 having an inverted mushroom-shaped connauration. The stem portion 39 of the
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D-NiF-198-B =5B01
mushroom-shaped confi-uration is disposed within the larger aperture -55. The
head portion
61 of the flexible member 58 extends across the underside of the raised
portion 49 of the inner
layer 33 such that the head portion 61 of the flexible member 58 covers the
smaller aperture
5', . The smaller aperture 37 acts as a port such that when the pressure level
across the filter
element 20 reaches a predetermined level, the head portion 61 of the flexible
member 58 flexes
away from the smaller aperture 5- thereby allowing .1uid 19 and/or air/vapor
from the
unfiltered side of the filter element 20 to pass through the smaller aperture
5,7. Fluid 19 will
only pass through the smaller aperture 57 after all of the air/vapor has first
passed through the
smaller aperture 57. The fluid 19 and/or air/vapor passes through the sheet of
filter media 53
and through the four apertures 51 in the outer layer 47 of the recessed
portion 41 to the
filtered side of the filter element 20. Although the patentable subject matter
may be limited to
a relief valve 38 having the structure defined above, Applicants consider the
invention to
include any relief valve 38 having a structure that provides for the release
of fluid 19 and/or
air/vapor at a predetermined pressure level.
[0029] The relief valve 38 is normally closed until the pressure level across
the filter
element 20 exceeds a predetermined level. When the relief valve 38 is closed,
the air/vapor
within the outer portion 36 of the housing 12 is trapped thereby forcing the
fluid level in the
outer portion 36 to be lower than the fluid level in the inner portion 34.
This occurs because
as long as the filter element 20 is aot clogged, airivapor and fluid 19 within
the inner portion
34 will pass through the filter element 20 at a pressure less than the
pressure level in which the
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DNEF-198-B ? B01
relief valve 38 is to open. Once the pressure across the filter element 20
exceeds the
predeter,nined leve'. due to the filter element beina sutTiciently clogged,
the relief valve 38
opens and allows air/vapor and/or fluid 19 to pass from the outer portion 36
of the housing 12
to the inner core 43 of the filter element 20.
[0030] In a secondary embodiment of the fluid filter assembly 10', a
restrictive filter
media section 42 of the filter media 20' is either integrally formed on the
top of the filter media
20' or is attached to the upper portion of the filter media 20', as shown in
Fi2 6. The
restrictive section 42 of the filter media 20' acts in the same manner as the
relief valve 38 and
the relief valve filter 40 of the preferred embodiment, but the secondary
embodiment does not
require the divider 30. The restrictive section 42 of the filter media 20'
only allows air/vapor
and/or fluid 19 to pass throuQh the restrictive section 42 once the pressure
level across the
filter element 20 exceeds a predetermined level. This ensures that the fluid
level within the
housing 12 will remain at a level below the restrictive filter media 42. Once
the predetermined
pressure level is reached, air/vapor and/or fluid is allowed to pass through
the restrictive filter
media 42 thereby raising the tluid level and providing a visual indicator that
the filter element
20' needs replacement.
[0031] In yet another embodiment of the present invention, a divider 30" and a
relief
vaive 38" may be utilized in conjunction with a hang down fluid filter
assembly 10", as shown
in Fij. 5. The structure in this embodiment is simiiar to that of the
preferred embodiment in
that the divider 30" is sealedly connected to a top end cap 24". The divider
30" extends
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DtiIF-198-B 26B0 i
downward alonc, the bottom portion of the filter element 20 while flaring
outward from the
filter element 20. A relief valve filter (althou-h not shown in Fi2. ~ but
similar to that shown
in Fias. 3and 4) is mounted in a portion of the central filter tube 22. The
relief valve filter is
incorporated with the relief valve 38" to prevent any unfiltered fluid 19 from
enterinc" fluid
outlet 18". The relief valve 38" in the hana down fluid filter assembly 10"
works in the same
manner as the preferred embodiment. The divider 30" forms an outer portion 34"
and an
inner portion 32" of the housing 12" wherein the trapped air in the outer
portion 34" forces
the fluid level in the outer portion 34" to be lower than the fluid level in
the inner portion
32". This allows the filter element 20 to become completely clogged before
reaching the
predetermined pressure level that will open the relief valve 38". Once the
relief valve 38"
opens, air/vapor passes through the relief valve 38" thereby allowing the
fluid level in the
outer portion 34" to rise and provide a visual indicator that the filter
element 20 needs
replacement.
[00321 In operation, the prior art device functions as depicted in Figs. 1.
Fluid 19
enters the fluid inlet 14 of the fluid filter assembly 10 and accumulates
within the lower
chamber 16 of the housing 12. Fluid flows throucrh the passageway 15 leadinc,
to the upper
filter chamber 17 wherein an unfiltered fluid level is established within the
upper filter chamber
17. The fluid 19 is drawn into the filter chamber 17 by vacuum (as most
commonly occurs in
diesel fuel filters) or forced by low pressure (as seea in oil, antifreeze or
many other filters)
until it finds a path through the filter element 20. As the filter eiement 1-0
becomes partially
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Dti1F-19S-B ^6B01
clo~ged, the restriction increases temporarily overcoming the surface tension
of fluid covering
the unused pores of the filter 20 element and causing, a temporary flow of
air,'vapor throuzh
the filter element 20, As the airivapor passes, it creates a void on the
outside of the filter
element 20, and the fluid level rises to fill the void. The new fluid level
allows flow throuCrh
clean and unused pores of the filter eierr.ent 20, and the restriction through
the filter element
20 reestablishes itself at a fluid level as previously described. Once the
fluid level establishes
itself, the surface tension of the fluid 19 across the remaininc, pores of the
filter media 20
prevents the flow of air/vapor through the filter element 20 uniil, once
again, the restriction
increases to a level in which air/vapor is forced through the filter element
20. This process
continues as dirt and other contamina.nts in the fluid 19, lar,er than the
openings in the filter
element 20, are trapped and retained by the filter element 20 as the fluid 19
passes through the
filter element 20. These contaminants plug or clol- the holes in the filter
media 20 and restrict
and/or close the paths used by the flcwina fluid 19. The tluid 19 is forced to
seek other open
and less restrictive fluid openings that are above the level of the fluid 19,
and therefore, the
fluid 19 climbs up the heiQht of the filter element 20 and uses the clean
areas of the filter
element 20. The process of cloaging and climbing continues until the filter
element 20 is
completely immersed in the flowing fluid 19. When the fluid level reaches the
top of the upper
filter chamber 17, this has generally been a visible indication to the user to
change the filter
element 20. The problem with changing the filter element 20 at this point is
that the filter
element 20 still allows for the passa'e of fluid 19 through the filter element
20 even when the
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DNIF-198-B 26B01
tluid level has risen to the top of the filter chamber 17. Therefore, if the
tilter element 20 is
changed immediately upon the fluid level rising to the top of the filter
cham.ber 17 1, then the
filter element 20 is being replaced prematurely.
[0033 ] During the operation of the preferred embodiment of the present
invention,
fiuid 19 enters the tluid filter assembly 10 and the upper filter chamber 17
in the same way as
described in the prior art. However, bv employin- the divider 30 and
incorporatinc, the preset
relief valve 38 in the top end cap 24, the fluid level can be made to rise
approximately in
proportion to the plugaing rate of the fuel element 20. This gives an accurate
visual indicator
as to the remaining life of the filter element 20. In so doing, the incoming
fluid 19 and
air/vapor initially behave as similarlv described in the prior art. When the
fluid level
approaches the bottom of the divider 30, the fluid 19 continues to rise
between the filter
element 20 and the inside surface of the divider 30, which was previously
defined as the inner
portion of the housing 12, but the fluid 19 does not rise between the outer
surface of the
divider 30 and the outer wall of the housinlg 12, which was previously defined
as the outer
portion of the housinc, 12. This is because the trapped air/vapor in the outer
portion 36 of the
housing 12 prevents the rise of fluid 19 into the outer portion of the housin,
12.
[0034] As to the inner portion 34 of the housinlg 12, tluid 19 and air/vapor
move
through the filter element 20 in a usual manner. The fluid level continues to
rise between the
filter element 20 and the inside surface of the divider 30 as the filter
element 20 becomes more
clo~-ed. This continues until the fluid 19 has risen to the full or nearly
full height of the filter
13
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element 20, as previously described. Once the filter element 20 is completely
saturated, the
pressure differential across the filter element 20 begins to increase with the
increased cloaQina
of the filter element 20. Once this pr-Issure differer.tial reaches a
predetermined level,
preferabi.y 5" Ha, the relief valve 38 mav open, and vapor/air may flow
throuah the relief valve
38 while fluid flows throuyh the filter element 20 since both present the same
amount of
resistance to fiow. As the pressure differeatial across the filter media 22
begins to exceed the
5" HQ point, the relief valve 38 becomes the preferred tlow path since its
pressure differential
is fixed at 5" Ho. Since air;'vapor is ctosest to the relief valve 38, the
air/vapor flows through
the relief valve 38 first, and the fluid 19 follows. The fluid level begins to
rise in the outer
portion 36 of the housing 12, thereby providing a visual indicator to the
operator that the filter
element 22 is piugQed. The relief valve filter 40 provided in the fluid path
of the relief valve
38 ensures that the tluid 19 that passes through the relief valve 38 is
filtered. Once the user
sees that the fluid level in the outer portion 36 of the housing 12 has risen
to the top of the
upper filter chamber 17, the user k.nows to replace the filter element 20.
In operation, the secondary emboditr.ent, as depicted in Fig. 4, works in a
similar manner as described in the preferred embodiment. The fluid level rises
within the filter
chamber 1, , until it reaches the restrictive filter media 42 on the filter
media 20. When the
fluid level reaches the restrictive media 42, the pressure differential across
the filter media 20'
must rise to a preferred level of 5" HI, in order for the aidvapor and fluid
19 to pass through
the restrictive media 42. The fluid level stops at a point just below the
restrictive media 42
14
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level. At that point, air/vapor and fluid 19 pass throulgh the restrictive
media 42, thus
allowing the fluid level to rise within the filter chamber 17 of the fluid
filter assembly 10' . The
user may then use the risen fluid level as an indicator that the filter media
20' needs to be
replaced.
~0036] In operation, the alternative embodiment depicted in Fig. 5 works in
exactly the
same manner as described in the preferred embodiment. The only difference in
the
embodiment depicted in Fig. 5 is that the housing, 12" is upside down, but the
fluid level
responds in the same manner as described in the preferred embodiment.
[0037] While the invention has been described in connection with what is
presently
considered to be the most,practical and preferred embodiment, it is to be
understood that the
invention is not to be limited to the disclosed embodiments, but on the
contrary, it is intended
to cover various modifications and equivalent arrangements included within the
spirit and
scope of the appended claims, the scope is to be accorded the broadest
interpretatiori so as to
encompass all such modifications and equivalent structures as is permitted
under the law.
[0038]
