Patent Description:
Filter systems are used to remove impurities from fluids. The filter system often includes a replaceable filter element that can be replaced once the filter element has reached the end of its serviceable life.

In some filter systems, the filter system will include a filter head that has a dirty fluid inlet and a clean fluid outlet. The filter element will have a tube of filter media through which the fluid flows in a radial direction as it is being filtered. The flow of fluid may be either radially inward or radially outward depending on how the filter element interacts with the dirty fluid inlet and clean fluid outlet.

One such situation where filter systems are used is for filtering fuel where particulates as well as entrained water is often removed from the fuel prior to flowing to a downstream system such as an internal combustion engine. The filter element often uses a tube of filter media and as the fluid flows through the filter media particulates are removed.

Water may be removed from the fuel either being stripped from the fuel prior to the fuel passing through the filter media or coalesced after flowing through the filter media. Typically, the removed water will then flow to a water bowl where it is stored until the maintenance interval and/or it is evacuated from the filter system, such as back to the fuel storage tank.

Because stripping and coalescing result in the removed water being on opposite sides of the filter media (e.g. upstream - stripping or downstream - coalescing), it is often not possible to switch between a stripping filter element and a coalescing filter element because the removed water will end up on opposite sides of the filter media with all else being equal. Instead, it may be necessary to reverse the flow of fluid through the filter media when switching between the different water removal options.

In addition to changes in water removal techniques, there may be other reasons for switching the direction of fluid flow through a filter element when using a same filter head.

For example, modern diesel fuel filtration applications require different mechanisms for water removal depending on fuel quality and flow rate. For fuels with higher IFT (interfacial tension) and low flow rates, water stripping filter designs work adequately. For lower IFT and higher flow rates, coalescing filter designs must be used.

In order to design a fuel filtration system for multiple applications, it may also be necessary to change the direction of the fuel flowing through the filter from outside-in to inside-out, or vise-versa. This allows for water stripping or coalescing by simply changing the element used. The head, housing and bowl can be used regardless of the flow of fluid through the filter element.

Attempts have been made to redirect flow through a tube of filter media using modular endcaps. This has resulted in complex structures for assembly. Some examples of such attempts to change the direction of flow include <CIT> and <CIT>.

<CIT> describes a filter assembly with vented filter element, the filter element including a ring of filtration media, first and second end caps, and a vent orifice formed in the first end cap into a central cavity of the media ring.

Filter systems and filter elements are provided as defined in the appended claims.

The filter element of the invention includes a tube of filter media, top and bottom end caps, a standpipe, an axial flow tube, and a radial flow conduit is provided. The tube of filter media circumscribes a central axis and defines a central chamber. The tube of filter media extends along the central axis between a top end and a bottom end. The top end cap is secured to the top end of the tube of filter media and has a first opening. The bottom end cap is secured to the bottom end of the tube of filter media. The standpipe is located within the tube of filter media and defines a standpipe flow path having a standpipe port proximate the top end cap. A fluid chamber is formed between an exterior of the standpipe and an interior of the tube of filter media. The fluid chamber forms part of the central chamber. A fluid chamber port is defined between the top end cap and the standpipe. The axial flow tube has a first flow tube port positioned fluidly exteriorly of the central chamber. The axial flow tube defines a flow tube flow path extending from the first flow tube port axially towards the bottom end cap for fluid flow generally parallel to the central axis. Flow can be either towards or away from the bottom end cap depending on the configuration of the element and/or filter system in which it is utilized. The radial flow conduit defines a radial flow path radially fluidly connecting the flow tube flow path with the standpipe flow path at a location closer to the bottom end cap than the top end cap.

In one example, the first flow tube port is positioned axially closer to the top end of the tube of filter media than the bottom end of the tube of filter media.

In one example, a filter element flow path is defined from the fluid chamber port to the stand pipe port, the filter element flow path extends from the fluid chamber port, into the fluid chamber, radially through the filter media to the exterior of the tube of filter media, into the first flow tube port, through the flow tube flow path towards the bottom end cap, radially through the radial flow path, into the standpipe flow path, and axially towards the top end cap to the standpipe port.

In one example, the stand pipe extends axially through the first opening of the top end cap such that the standpipe port is external of the central chamber of the tube of filter media and axially offset from the tube of filter media.

In one example, the standpipe port has a standpipe port diameter that is larger than a first opening diameter of the first opening of the top end cap. As such, fluid flowing from the fluid chamber port to the fluid chamber flows radially toward the central axis and fluid flowing from the fluid chamber toward the fluid chamber port flows radially away from the central axis.

In one example, the tube of filter media comprises a ring of pleated filter media, the exterior axial flow tube is located between adjacent pleats of the tube of filter media.

In one example, the tube of filter media generally comprises a section of pleated filter media folded around the central axis to form the tube of filter media such that opposed first and second sides of the section of pleated filter media are proximate one another. The axial flow tube is positioned angularly between the opposed first and second sides of the section of pleated filter media to form the tube of filter media.

The section of pleated filter media could be in the form of a flat panel of filter media that is subsequently folded around the central axis.

In one example, the first and second sides of the section of pleated filter media are secured to the axial flow tube.

In one example, the axial flow tube includes first and second clips on opposed sides of the axial flow tube. The first clip engages a first pleat panel of the pleated filter media proximate the first side of the section of filter media. The second clip engages a second pleat panel of the pleated filter media proximate the second side of the section of filter media.

In one example, the axial flow tube is an elongated wedge shape. The wedge shape tapers outwardly from a narrower radial inner end toward a broader radially outer end. The radially inner end is closer to the central axis than the radially outer end.

In one example, the axial flow tube has a molded body defining the flow tube flow path. The first and second clips each have a portion embedded in the molded body and a tab portion extending outward from the molded body. The tab portion of each clip engaging the filter media.

In one example, the bottom end cap is adhesively secured to the tube of filter media, the axial flow tube and the standpipe.

In one example, the tube of filter media is formed from pleated filter media. Adjacent pleat panels form voids therebetween. A cross-sectional area of the flow tube flow path orthogonal to the central axis is greater than a cross-sectional area of the voids orthogonal to the central axis.

In some examples, the cross-sectional area of the voids could be substantially nonexistent if the adjacent plate panels are angularly pressed against one another.

In one example, the radial flow conduit and the axial flow tube are formed from a single continuous body and a seal member seals the radial flow conduit to the standpipe.

In one example, the continuous body defining the radial flow conduit and the axial flow tube includes an annular member that extends around an outer periphery of the standpipe proximate the bottom end cap.

In one example, the standpipe, radial flow conduit and the axial flow tube are formed from a single continuous body.

In one example, the bottom end cap bounds, at least in part, the radial flow conduit as the radial flow conduit extends radially between the standpipe and the axial flow tube.

In one example, fluid flow between an exterior of the tube of filter media and the standpipe does not pass through the filter media of the tube of filter media.

In example, a filter system including a filter head, a filter element housing, and a filter element as outlined above. The filter head defines a dirty fluid inlet and a clean fluid outlet. The filter head has a filter element mounting arrangement. The filter element is within the filter element housing. The filter element and filter element housing are mounted to the filter head with the fluid chamber port fluidly connected to the dirty fluid inlet or the clean fluid outlet and the standpipe port fluidly connected to the other one of the clean fluid outlet or the dirty fluid inlet. The filter element housing and an exterior of the tube of filter media define a second fluid chamber exterior of the tube of filter media in direct fluid communication with the axial first flow tube port.

In one example, both dirty fluid flowing from the filter head flowing through the dirty fluid inlet and clean fluid flowing into the filter head from the filter element pass through the first opening in the filter element.

In one example, dirty fluid within the central chamber of the tube of filter media is separated from clean fluid within the central chamber by the standpipe.

In one example, the dirty fluid inlet is connected to the fluid chamber port upstream of the filter media and the clean fluid outlet is connected to the standpipe port downstream from the filter media such that dirty fluid flows into the fluid chamber prior to passing through the filter media and clean fluid flows into the standpipe after flowing through the second fluid chamber, axial flow tube, and the radial flow conduit.

In one embodiment, the dirty fluid inlet circumscribes the clean fluid outlet.

In an example, a filter system including a filter head, a filter element housing and a filter element is provided. The filter head defines a first port and a second port. The filter head has a filter element mounting arrangement, which could be threading, catches, latches, tabs, etc. The filter element is located within the filter element housing. The filter element and filter element housing are mounted to the filter head with the fluid chamber port fluidly connected to the first or second port and the standpipe port fluidly connected to the other one of the first or second port. The filter element housing and an exterior of the tube of filter media define a second fluid chamber exterior of the tube of filter media in direct fluid communication with the axial first flow tube port.

<FIG> illustrates a filter system <NUM> that includes a filter head <NUM>, a filter housing <NUM> and a filter element <NUM>. The filter element <NUM> is located within the filter housing <NUM>. The filter element <NUM> and filter housing <NUM> are removably attachable to the filter head <NUM>.

The filter head <NUM> has a dirty fluid inlet <NUM> and a clean fluid outlet <NUM> that are fluidly separated from one another. Dirty fluid <NUM> (represented by arrows <NUM>) enters the filter system <NUM> through the dirty fluid inlet <NUM>, flows through the filter element <NUM> where it is filtered and then exits the filter system <NUM> through the clean fluid outlet <NUM> as clean fluid <NUM> (represented by arrows <NUM>). Dirty fluid <NUM> may also be referred to as "wet" fluid while clean fluid <NUM> may also be referred to as "dry" fluid.

In this example, the filter housing <NUM> is reusable such that at maintenance intervals only the filter element <NUM> is replaced. However, in other examples, the filter housing <NUM> and filter element <NUM> can be a one-time use assembly where the filter element <NUM> is permanently secured within the filter housing <NUM>. In such an example, both the filter housing <NUM> and the filter element <NUM> are replaced at maintenance intervals. The enter assembly would be removable as a single unit from the filter head <NUM>.

The filter housing <NUM> is attached to the filter head <NUM> with the filter element <NUM> secured within a cavity <NUM> of the filter housing <NUM>. Mounting structure, such as cooperating threads, secures the filter housing <NUM> to the filter head <NUM>. While not illustrated, a seal may be provided between the filter housing <NUM> and filter head <NUM> to avoid fluid leakage therebetween. In the illustrated configuration, this would prevent leakage of dirty fluid <NUM>.

The filter head <NUM> includes an inner annular wall <NUM> that forms part of or is otherwise connected to the clean fluid outlet <NUM>. The filter head also includes an outer annular wall <NUM>. A chamber <NUM> formed between the inner annular wall <NUM> and the outer annular wall <NUM> forms part of or is otherwise connected to the dirty fluid inlet <NUM>. The inner annular wall <NUM> fluidly separates the clean fluid flow <NUM> therethrough from the chamber <NUM> and the associated dirty fluid flow <NUM>.

With additional reference to <FIG>, filter element <NUM> includes a tube of filter media <NUM> that extends around central axis <NUM> to form a central chamber <NUM>. The tube of filter media <NUM> extends axially along the central axis <NUM> between a top end <NUM> and a bottom end <NUM>.

A top end cap <NUM> is secured to the top end <NUM>. This may be done by way of adhesive, welding the tube of filter media <NUM> to the top end cap <NUM>, embedding of the tube of filter media <NUM> into the top end cap <NUM> or other known means. In this example, the top end cap <NUM> forms an annular well <NUM> that receives the top end <NUM> and an adhesive such as a potting material to secure the tube of filter media <NUM> to the top end cap <NUM>. Further, the potting material may also seal the top end <NUM> of the tube of filter media <NUM>, such as if the tube of filter media <NUM> is formed from pleated filter media.

The top end cap <NUM> carries a housing seal illustrated in the form of o-ring <NUM> that seals the filter element <NUM> within the filter housing <NUM> and particularly an outer region of the top end cap <NUM>. Other sealing arrangements are contemplated.

The top end cap <NUM> includes a first opening <NUM> extending therethrough. As such, when the top end cap <NUM> is secured to the tube of filter media <NUM>, access to the central chamber <NUM> of the tube of filter media <NUM> is permissible through the top end cap <NUM>.

A standpipe <NUM> extends into the central chamber <NUM> of the tube of filter media <NUM>. The standpipe <NUM> is generally tubular and defines a standpipe flow path <NUM>.

A first end <NUM> of the standpipe <NUM> defines a standpipe port <NUM>. As illustrated in <FIG>, the standpipe port <NUM> sealingly engages the inner annular wall <NUM> to sealingly connect the standpipe <NUM> and the standpipe flow path <NUM> with the clean fluid outlet <NUM>. A gasket such as o-ring <NUM> may be used to seal the standpipe <NUM> to the inner annular wall <NUM>. In this example, the standpipe port <NUM> engages an outer surface of the inner annular wall <NUM>, but it could engage an inner surface depending on the configuration.

In this example, the standpipe port <NUM> has a diameter that is larger than the diameter of the opening <NUM> of the top end cap <NUM>.

The standpipe <NUM> extends into the central chamber <NUM> defined by the inner periphery <NUM> of the tube of filter media <NUM>.

In this example, the stand pipe <NUM> extends axially through the central opening <NUM> and axially out of the tube of filter media <NUM>. The standpipe <NUM> is sized and configured to provide a clearance between an outer periphery thereof and the top end cap <NUM>. This clearance provides a fluid chamber port <NUM> that provides fluid communication to the central chamber <NUM> and particularly a fluid chamber <NUM> formed between inner periphery <NUM> of the tube of filter media <NUM> and an outer periphery <NUM> of the standpipe <NUM>. Fluid chamber <NUM> is part of central chamber <NUM>. Notably, the clearance need not be entirely around the standpipe. Instead, one or more clearance channels may be formed if the standpipe <NUM> contacts the top end cap <NUM> in various locations.

The fluid chamber port <NUM> is operably sealingly communicated with the dirty fluid inlet <NUM>. This is done by seals between the standpipe <NUM> and the inner annular wall <NUM> and the end cap <NUM> and the housing <NUM>. In this embodiment, this is accomplished, at least in part, by o-ring <NUM> and o-ring <NUM>. However, other sealing arrangements are contemplated as long as fluid bypass or leakage is not permitted.

The standpipe <NUM> in this example has an enlarged head portion <NUM> at the first end <NUM> that has an outer diameter that is greater than the inner diameter of the first opening <NUM> through the top end cap <NUM>. The enlarged head portion <NUM> thus extends radially outward in overlap with a portion of the top end cap <NUM>. Further, enlarged head portion <NUM> is axially outward from the filter media <NUM> as compared to the adjacent portion of the top end cap <NUM>. This causes the fluid chamber port <NUM> to direct dirty fluid radially inward towards central axis <NUM> in operation.

However, other configurations are contemplated, e.g. where head portion <NUM> is not larger in diameter than first opening <NUM>. Further, a radially outward directed seal could be provided as compared to the radially inward directed seal in the current example.

A bottom end cap <NUM> is attached to the bottom end <NUM> of the tube of filter media <NUM>. In this example, the bottom end cap <NUM> is a closed end cap and free of any apertures therethrough. The bottom end cap <NUM> can be secured to the bottom end <NUM> in the same way as the top end cap <NUM> (e.g. adhesive, welding, embedding, etc.).

In a preferred example, adhesive, e.g. potting material, secures the bottom end cap <NUM> to the tube of filter media <NUM>. The potting material can also be used to secure a second end <NUM> of the standpipe <NUM> to the bottom end cap <NUM> and consequently the rest of the filter element <NUM>, e.g. the top end cap <NUM> and the tube of filter media <NUM>.

The bottom end cap <NUM> also closes off the bottom end <NUM> of the central chamber <NUM>. Further, in some examples, the bottom end cap <NUM> and/or any adhesive closes any pleats if the filter media is pleated filter media.

In the current arrangement of the filter system <NUM>, dirty fluid <NUM> flows into central chamber <NUM> into the fluid chamber <NUM> formed radially outward of standpipe <NUM> and then flows radially outward through the tube of filter media <NUM> to remove particulates. Further, the tube of filter media <NUM> is configured to cause coalescing of entrained water, illustrated by droplets <NUM>. These droplets <NUM> are formed exteriorly of the tube of filter media <NUM>.

The clean fluid <NUM> and droplets <NUM> are located in a second fluid chamber <NUM> formed between the exterior of the filter element <NUM> and an interior surface of the filter housing <NUM>. The droplets <NUM> are sized such that they will flow downward toward a water collection region <NUM> of the filter system <NUM>. The water collection region <NUM> may be a water collection bowl, sump or other region for collection of the coalesced water.

A stripper <NUM> (<FIG>) may be included to help strip the coalesced water droplets <NUM> from the flow of clean fluid <NUM>. The stripper may be attached to an outer periphery of support frame <NUM>.

Because the clean fluid outlet <NUM> and inner annular wall <NUM> associated therewith are generally centered on axis <NUM>, the clean fluid must get back to the central axis <NUM> from the second fluid chamber <NUM> (i.e. external of the filter element) without mixing with the incoming dirty fluid <NUM>.

To allow for this, a radially directed flow path from the second fluid chamber <NUM> to standpipe <NUM> and particularly the standpipe flow path <NUM> is provided.

An axial flow tube <NUM> and a radial flow conduit <NUM> provide this flow path. In this embodiment, at least a portion of the axial flow tube <NUM> and at least a portion of the radial flow conduit <NUM> are formed as a single continuous body of material.

In one example, the axial flow tube <NUM> and radial flow conduit <NUM> are formed from molded material, such as molded plastic.

The axial flow tube <NUM> has an inlet port <NUM> in which cleaned fluid <NUM> within the second fluid chamber <NUM> enters the axial flow tube <NUM> and a flow tube flow path <NUM> provided thereby.

To reduce inadvertently drawing coalesced water droplets <NUM> or other separated water into the inlet port <NUM>, the inlet port <NUM> is preferably closer to the top end cap <NUM> than the bottom end cap <NUM>. More particularly, as the water droplets <NUM> flow downward towards the bottom end cap <NUM>, the concentration of water is typically greater closer to the bottom end cap <NUM> than the top end cap <NUM>. However, other examples are contemplated to have the inlet port <NUM> closer to the bottom end cap <NUM> than the top end cap <NUM>.

In the illustrated example, the radial flow conduit <NUM> includes an annular collar <NUM> (see e.g. <FIG>). The second end <NUM> of the standpipe <NUM> is axially received into the annular collar <NUM>.

An o-ring <NUM> seals the radial flow conduit <NUM> to the standpipe <NUM>. In this example, the stand pipe <NUM> includes a plurality of ports <NUM> in the sidewall <NUM> of the standpipe <NUM> that provides fluid communication between the radial flow conduit <NUM> and the standpipe flow path <NUM>.

Thus, the radial flow conduit <NUM> allows for radially inward directed flow from the exterior of the tube of filter media <NUM> to the standpipe flow path <NUM> that is positioned within the central chamber <NUM> formed by the tube of filter media <NUM>.

While the body that forms the axial flow tube <NUM> and radial flow conduit <NUM> is a separate component than standpipe <NUM>, it is contemplated that in other examples these components could all be formed in a single body. It is also contemplated that the radial flow conduit <NUM> could be formed from its own independent body. It is further contemplated that the axial flow tube <NUM>, radial flow conduit <NUM> and standpipe <NUM> could be formed from a single continuous body, e.g. molded or machined as a single component.

In this example, the bottom end cap <NUM> closes off or otherwise forms part of the flow path formed, at least in part, by the axial flow tube <NUM>, the radial flow conduit <NUM> and the standpipe <NUM>.

In this configuration, clean fluid <NUM> that is external to the tube of filter media but within the axial flow tube <NUM><NUM> flows axially away from the top end cap <NUM> and towards the second end cap <NUM>. The clean fluid <NUM> flows radially inward through the radial flow conduit <NUM> and then axially towards, and ultimately through, the top end cap <NUM> within the standpipe <NUM>.

In many instances, this filter head <NUM> would have been used with a radially inward directed flow filter element. In such an arrangement, water removal would have occurred using a water stripping technique where water is removed from the dirty fluid flow prior to the dirty fluid flowing through filter media of the filter element. However, if a coalescing element were used, the removed coalesced water would undesirably end up on the inside of the tube of filter media due to coalescing media having the removed water downstream of the media, rather than upstream.

The inclusion of the flow path defined by the axial flow tube <NUM>, radial flow conduit <NUM> and standpipe <NUM> allow for such a filter head, as illustrated in <FIG>, by allowing for a flow reversal through the filter media of the tube of filter media <NUM> of filter element <NUM>.

In an example, the tube of filter media <NUM> is provided by pleated filter media.

With reference to <FIG>, the axial flow tube <NUM> is located angularly between opposed sides <NUM>, <NUM> of the tube of filter media <NUM>. Typically, the tube of filter media <NUM> is formed from a flat section of filter media that is folded around central axis <NUM>. If pleated media is used, the folds would be oriented generally vertically/parallel to central axis <NUM>. The folds could be at a slight angle to central axis <NUM> if the filter element <NUM> was frustoconical in shape, but the folds would typically extend more parallel to axis <NUM> than perpendicular thereto.

The axial flow tube <NUM> is generally wedge shaped in cross-section in a plane orthogonal to central axis <NUM>. As best illustrated in <FIG>, the axial flow tube <NUM> tapers such that the cross-section gets wider when moving radially outward away from central axis <NUM>.

The axial flow tube <NUM> is sealed to opposed sides <NUM>, <NUM> of the filter media forming the tube of filter media <NUM>. In view of <FIG>, the tube of filter media <NUM> need not extend a complete <NUM> degrees about central axis <NUM>.

To secure the opposed sides <NUM>, <NUM> to opposed sides of the axial flow tube <NUM>, first and second clips <NUM>, <NUM> are provided that clip portions of the tube of filter media <NUM> to the axial flow tube <NUM>. In this example, the clips <NUM>, <NUM> are folded over one or more pleat panels of the tube of filter media <NUM> proximate the opposed sides <NUM>, <NUM> of the tube of filter media.

An adhesive may be provided in the alternative or in combination with the clips <NUM>, <NUM> to help seal the filter media to the axial flow tube <NUM>. In some embodiments, the filter media may be welded to the body of the axial flow tube <NUM>, such as by heat or ultrasonic welding.

In this example, clips <NUM>, <NUM> are flexible metal components that have a first leg that is embedded in the body forming axial flow tube <NUM> and a second leg exterior of the axial flow tube <NUM> that is folded at bend <NUM> to pinch the portion of the filter media against adjacent sides of the axial flow tube <NUM>.

In one example, the clips <NUM>, <NUM> are molded into the axial flow tube <NUM>.

In other examples, the clips <NUM>, <NUM> could be flange portions integrally formed with the axial flow tube <NUM>.

In some examples, a combination of one or more of welding, adhesives, mechanical clips, etc. may be used to secure and/or seal the opposed sides <NUM>, <NUM> of the tube of filter media to the axial flow tube <NUM>.

Further yet, in some embodiments, the tube of filter media <NUM> may extend entirely around the central axis <NUM> and the axial flow tube <NUM> is located between adjacent pleat panels, but fluidly exterior of the tube of filter media <NUM>.

When pleated media is used to form the tube of filter media <NUM>, adjacent pleat panels form voids <NUM> therebetween on the external side of the tube of filter media <NUM>. In an example, a cross-sectional area of the flow tube flow path <NUM> when viewed orthogonal to the central axis is greater than a cross-sectional area of the voids <NUM> when viewed orthogonal to the central axis.

In examples, the cross-sectional area of the flow tube flow path <NUM> may be at least one and a half times, at least two times, at least two and a half times and at least three times the area of voids <NUM>.

The support frame <NUM> surrounds the tube of filter media <NUM> and provides radial support thereto as well as axial strength to the filter element <NUM>. In one example, the support frame <NUM> is preformed prior to assembly of the filter element <NUM>.

With reference to <FIG>, the support frame <NUM> is keyed to the axial flow tube <NUM>. More particularly, the support frame <NUM> includes a rectangular window <NUM> that is sized and configured to mate with a corresponding rectangular portion <NUM> of the axial flow tube <NUM>. Notably, the window <NUM> and rectangular portion <NUM> need not include a portion proximate top end <NUM> of the tube of filter media <NUM>. This mating relationship can assist in assembly of the filter element by allowing for proper location of the relative components.

While not illustrated, in some embodiments, a stripping element can extend across the rectangular portion <NUM> of the axial flow tube <NUM> to further prevent water from entering into the axial flow tube <NUM>.

Claim 1:
A filter element (<NUM>) comprising:
a tube of filter media (<NUM>) circumscribing a central axis (<NUM>) and defining a central chamber (<NUM>), the tube of filter media (<NUM>) extending between a top end (<NUM>) and a bottom end (<NUM>);
a top end cap (<NUM>) secured to the top end (<NUM>) of the tube of filter media having a first opening (<NUM>);
a bottom end cap (<NUM>) secured to the bottom end (<NUM>) of the tube of filter media;
a standpipe (<NUM>) located within the tube of filter media defining a standpipe flow path (<NUM>) having a standpipe port (<NUM>) proximate the top end cap (<NUM>), a fluid chamber (<NUM>) being formed between an exterior (<NUM>) of the standpipe and an interior (<NUM>) of the tube of filter media, the fluid chamber (<NUM>) forming part of the central chamber (<NUM>), a fluid chamber port (<NUM>) being defined between the top end cap (<NUM>) and the standpipe (<NUM>);
an exterior axial flow tube (<NUM>) having a first flow tube port (<NUM>) positioned fluidly exteriorly of the central chamber (<NUM>), the axial flow tube (<NUM>) defining a flow tube flow path (<NUM>) extending from the first flow tube port (<NUM>) axially towards the bottom end cap (<NUM>) for fluid flow generally parallel to the central axis (<NUM>); and said filter element being characterized in that it further comprises
a radial flow conduit (<NUM>) defining a radial flow path radially fluidly connecting the flow tube flow path (<NUM>) with the standpipe flow path (<NUM>) at a location closer to the bottom end cap (<NUM>) than the top end cap (<NUM>).