Patent Description:
Liquid filter systems are known for filter various fluids such as gas, oil, diesel fuel, etc. to remove contaminants from these fluids. In some cases, the filter is in fluid communication with pumps, engines, or other similar devices that may create pulses in the fluid to be filtered that may reach the filter. It has been shown that pressure pulses can reduce the efficiency of filters in actual use depending on the environment in which the filters operate.

<CIT> discloses a pulsation reducing apparatus that includes a piston that is displaced in a valve chamber due to an increase in a fuel pressure in an upstream fuel passage caused by a pressure pulse. The fluid communication between the valve chamber and a downstream fuel passage is blocked, and fluid communication between the valve chamber and a return passage is unblocked, allowing a bypass flow of fluid. The pressure pulse is thus conducted into the return passage and dampened by a pulsation reducing mechanism including a plurality of flow restricting orifices. The fuel, once it has passed through the orifices, is returned to the upstream fuel passage through the return passage.

As can be seen, the '<NUM> patent requires an extra mechanism outside of the filter to provide pressure pulse protection. This extra mechanism increases the overall cost of the system and may need maintenance itself. <CIT>, <CIT>, <CIT>, <CIT> and <CIT> show other relevant prior art documents.

Accordingly, it desirable to develop a pressure pulse protection mechanism that is less complicated, less costly, and easier to maintain.

According to an embodiment of the present disclosure, there is provided a pulse dampening interface between a filter and a filter base configured to mitigate pulses, the interface comprising: a housing bolt; a base; and a replaceable filter element that includes at least a partially cylindrical configuration and that defines a longitudinal axis, and a radial direction. The filter element comprises an annular filter media defining a central passage, a center tube that is disposed in the central passage of the annular filter media that defines a central reservoir, and the annular filter media surrounds the center tube and the central reservoir, a top open end joined to the center tube disposed along the longitudinal axis, the top open end including an opening allowing fluid to flow from the central reservoir to the outside of the filter element, a bottom open end joined to the center tube opposite the top open end disposed along the longitudinal axis; and a filter pulsation dampening device. The filter pulsation dampening device includes a flexible valve that defines a valve free end that is disposed in the central reservoir of the center tube; a first baffle extending from the housing bolt and terminating at a first baffle free end and the flexible valve of the filter element which is disposed radially inwardly and longitudinally above the first baffle free end, defining a shut-off gap distance between the first baffle valve free end and the flexible valve, wherein the flexible valve opens and closes on the first baffle and opens when there is no pressure pulsation downstream, allowing a normal flow of filtered fluid.

Reference will now be made in detail to embodiments of the disclosure, examples of which are illustrated in the accompanying drawings. In some cases, a reference number will be indicated in this specification and the drawings will show the reference number followed by a letter for example, 100a, 100b or a prime indicator such as <NUM>', <NUM>" etc. It is to be understood that the use of letters or primes immediately after a reference number indicates that these features are similarly shaped and have similar function as is often the case when geometry is mirrored about a plane of symmetry. For ease of explanation in this specification, letters or primes will often not be included herein but may be shown in the drawings to indicate duplications of features discussed within this written specification.

First, a filter system will now be described to give the reader the proper context for understanding how various embodiments of the present disclosure are used. It is to be understood that this description is given as exemplary and not in any limiting sense. Any embodiment of an apparatus or method described herein may be used in conjunction with any filter system.

Then, a filter element that may include a pulsation dampening device according to various embodiments will be discussed. The device may include an assortment of baffles, baffles and/or valves, etc. that are attached to various components of the filter element, the center tube, the top end cap, the base, etc..

<FIG> illustrate a canister filter system <NUM>, <NUM>' that may use a filter element <NUM>, <NUM>' according to various embodiments of the present disclosure. This system may also be referred to as a pulse dampening interface between a filter and a filter base that is configured to mitigate pulses.

Starting with <FIG> and <FIG>, the canister filter system <NUM>, <NUM>' may include having a base <NUM>, a canister <NUM>, and a filter element <NUM>, <NUM>'. The canister filter system <NUM> may be used to filter fluids such as diesel or gasoline or other liquid fuels, lubrication oil, hydraulic fluid for hydraulic power systems, transmission fluid, or even possibly intake air for an engine. The canister filter system <NUM> may also be used as a fuel/water separator filter. The canister filter system <NUM> with the features described herein could be adapted by those of ordinary skill in this art to serve many different purposes and suit many other applications.

The base <NUM> includes an inlet channel <NUM> for fluid to enter into the canister filter system <NUM>, and an outlet channel <NUM> for fluid to exit from the canister filter system <NUM>. The base <NUM> also includes base threads <NUM>. Other attachment structure than threads may be used.

The canister <NUM> includes a top open end <NUM> and a bottom closed end <NUM>. Adjacent the top open end <NUM> are bolt threads <NUM> which can be engaged with base threads <NUM> to hold the canister <NUM> to base <NUM>. Threads are one example of engagement structures which may be included on the base <NUM> and bolt <NUM>, <NUM>' to form a releasable engagement. Other engagement structures may be used as will be recognized by those of ordinary skill in this art.

The filter element <NUM>, <NUM>' may take many different forms to suit a particular application. In the illustrated embodiment, the filter element <NUM>, <NUM>' is well suited for filtering fuel or lubrication oil. The filter element <NUM>, <NUM>' may include annular filter media <NUM> circumferentially surrounding a central reservoir <NUM> defined by a center tube <NUM>. Axial ends of annular filter media <NUM> are shown to be sealed by end caps.

A top end cap <NUM> may define an axial open end of filter element <NUM>. The top end cap <NUM> is termed "open" because it includes an opening <NUM> for allowing passage of fluid to outlet channel <NUM> from the central reservoir <NUM> defined by center tube <NUM>.

On the other hand, the bottom end cap <NUM> defines an axial closed end of filter element <NUM>. The bottom end cap <NUM> is termed "closed" because it prevents any fluid outside the filter element <NUM> adjacent the axial end of the annular filter media <NUM> from flowing unfiltered into center tube <NUM>. The bottom end cap <NUM> may be closed by mating with a housing bolt <NUM>, <NUM>' that in turn mates with the center tube <NUM>. This may not be the case for other embodiments of the present disclosure.

The top end cap <NUM> and the bottom end cap <NUM> may each be joined to the center tube <NUM> via welding, adhesives, etc. Alternatively, several or all of center tube <NUM>, the top end cap <NUM>, and the bottom end cap <NUM> may be constructed as unitary components. Other configurations are possible.

In operation, fluid to be filtered enters from the inlet channel <NUM> and flows to the annular cavity <NUM> between canister <NUM> and the annular filter media <NUM>. The fluid then passes into and through filter media <NUM>, then into the center tube <NUM> through the perforations <NUM> shown therein in <FIG> and <FIG>.

Then, the fluid exits center tube <NUM> through the top end cap <NUM> and opening <NUM> into the outlet channel <NUM>. The sealed construction at the bottom of the filter element <NUM>, <NUM>' helps to define the fluid channels into and out of the annular filter media <NUM>, preventing any fluid from flowing directly to outlet channel <NUM> and bypassing the annular filter media <NUM>. To the same end, baffles, baffles and valves, etc. may be provided at the top of the canister filter system <NUM>, <NUM>' that will be discussed in detail later herein that prevent provide a similar seal and may also provide a pulsation dampening device according to various embodiments of the present disclosure.

Referring now to <FIG> and <FIG>, a canister filter system <NUM> according to various embodiments of the present disclosure that provides a pulsation dampening device will now be discussed.

The canister filter system <NUM> may comprise a filter element <NUM> that includes at least partially a cylindrical configuration and that defines a longitudinal axis <NUM>, and a radial direction <NUM>. The filter element <NUM> may comprise an annular filter media <NUM> defining a central passage <NUM> and a center tube <NUM> that is disposed in the central passage <NUM> of the annular filter media <NUM> that defines a central reservoir <NUM>. Thus, the annular filter media <NUM> surrounds the center tube <NUM>, and the central reservoir <NUM>.

As best seen in <FIG>, the filter element <NUM> may further include a top open end <NUM> joined to the center tube <NUM> disposed along the longitudinal axis <NUM>. The top open end <NUM> includes an opening <NUM> that allows fluid to flow from the central reservoir <NUM> to the outside of the filter element <NUM>.

Similarly, referring again to <FIG>, the filter element <NUM> may include a bottom open end <NUM> joined to the center tube <NUM> opposite the top open end <NUM> that is also disposed along the longitudinal axis <NUM>. Thus the bottom open end <NUM> allows insertion of the housing bolt <NUM>.

The canister filter system <NUM> may also include a canister <NUM> that includes a top open end <NUM> (see <FIG>), and a bottom closed end <NUM> relative to the longitudinal axis <NUM> (as previously described herein, see <FIG> and <FIG>), and a housing bolt <NUM> that may penetrates through the bottom closed end <NUM> of the canister <NUM> (providing a seal(s)) or side on top of the bottom closed end <NUM> as shown in <FIG> and <FIG>. This may be referred to as a stud style bolt that rests on the bottom closed end of the canister such that is shoulder portion or its head is trapped between the filter element and the canister, etc..

Looking at <FIG> and <FIG>, a pulsation dampening device <NUM> may include a first baffle <NUM> extending from the housing bolt <NUM>, and a second baffle <NUM> extending either from the base <NUM> or the filter element <NUM> that is disposed proximate to the first baffle <NUM>, defining a flow passage <NUM> with a minimum distance <NUM> between the first baffle <NUM> and the second baffle <NUM>. In certain embodiments of the present disclosure, the minimum distance <NUM> ranges from <NUM> to <NUM>.

As a result of this construction, a pressure pulsation(s) <NUM> downstream from the annular filter media <NUM> may be greatly reduced before they reach the annular filter media <NUM>. In turn, this might reduce any degradation of the performance of the filter element <NUM> such as its output to an engine or another downstream device. The minimum distance <NUM> may be varied to achieve the desired effect, and may be different than the range just mentioned in other embodiments of the present disclosure. As will be described momentarily, the configurations of the first baffle <NUM>, and the second baffle <NUM> may be reversed in other embodiments of the present disclosure.

As shown in <FIG> and <FIG>, the first baffle <NUM> may extend radially outwardly and longitudinally upwardly from the housing bolt <NUM> past the top open end <NUM> (e.g. top end cap <NUM>) of the filter element <NUM>. The second baffle <NUM> may be attached to the base <NUM> and extends longitudinally downwardly and radially inwardly from the base <NUM> past the top open end <NUM> (e.g. top end cap <NUM>) of the filter element <NUM>.

The second baffle <NUM> may define a S-shaped portion <NUM>. A third baffle <NUM> may extend purely longitudinally from the S-shaped portion <NUM> of the second baffle <NUM> to the top open end <NUM> (e.g. top end cap <NUM>) or to the center tube <NUM>, forming a downward facing V-shaped region <NUM> with the second baffle <NUM>. The first baffle <NUM> may be disposed between the second baffle <NUM>, and the third baffle <NUM>, defining a serpentine shaped flow passage <NUM> (may have a consistent minimum distance <NUM> or not). Other configurations are possible in other embodiments. For example, the second baffle may have other configurations such as a straight shape, etc..

In some embodiments of present disclosure, such as shown in <FIG>, the second baffle <NUM> is attached to the base <NUM>, the first baffle <NUM> is attached to the housing bolt <NUM>, and the third baffle <NUM> is attached to the filter element <NUM> (the third baffle <NUM> may be attached to the top open end <NUM> (e.g. the top end cap <NUM>) or to the center tube <NUM>, etc.). During assembly, the housing bolt <NUM> may be attached to canister <NUM> and the filter element <NUM>, forming a subassembly. Then, the canister <NUM>, the filter element <NUM>, and the housing bolt <NUM> are attached to the base <NUM>. The third baffle <NUM> then contacts the second baffle <NUM>, forming a seal therebetween, and the second baffle <NUM> fits between the first baffle <NUM>, and the second baffle <NUM> to form the serpentine flow passage <NUM>.

In other embodiments, the second baffle <NUM> and the third baffle <NUM> may be unitary and may be attached to the filter element <NUM> so that these baffles contact the base <NUM>. Other variations are possible.

The first baffle <NUM>, the second baffle <NUM>, and the third baffle <NUM> may all comprise a thermoplastic material (e.g. Polyurethane, nylon, etc.). Other materials such as metal may be used in other embodiments, and the materials of the various baffles may be different from each other, etc. The first baffle <NUM>, the second baffle <NUM>, and the third baffle <NUM> may all have the same thickness <NUM> (minimum dimension) ranging from <NUM> to <NUM> in certain embodiments. Other thicknesses and ranges may be used in other embodiments of the present disclosure.

The first baffle <NUM>, the second baffle <NUM>, and the third baffle <NUM> may be concentric about the longitudinal axis <NUM> (e.g. may be geometrically formed by rotating the cross-section shown in <FIG> about the longitudinal axis). Similarly, the filter element <NUM> may concentric with the canister <NUM>, and with the housing bolt <NUM>. Other configurations are possible in other embodiments of the present disclosure. The housing bolt <NUM> may be attached to the canister <NUM> or the base <NUM>, fixing the position of the housing bolt <NUM> relative to the canister <NUM> and/or the base <NUM>.

A filter element <NUM> that may be provided as a replacement part according to an embodiment of the present disclosure that may be used with the canister filter system <NUM> just described will now be discussed with reference to <FIG> and <FIG>. The filter element <NUM> may include a filter pulsation dampening device <NUM> that has a filter element baffle <NUM>' extending longitudinally upwardly from the top open end <NUM> (e.g. top end cap <NUM>) or from the center tube <NUM> of the filter element <NUM>.

The filter element <NUM> may further comprising a housing bolt <NUM> with a bolt baffle <NUM>' extending radially outwardly and longitudinally upwardly from the housing bolt <NUM> past the top open end <NUM> (e.g. top end cap <NUM>) of the filter element <NUM>, terminating at a bolt baffle free end <NUM> in close but spaced apart relation to the filter element baffle <NUM>', defining a flow passage <NUM> having a minimum distance <NUM> between the filter element baffle <NUM>' and the bolt baffle <NUM>'. The minimum distance <NUM> may range from <NUM> to <NUM>. This distance may be varied as previously described.

In the embodiment shown in <FIG> and <FIG>, the filter element baffle <NUM>' may be attached to the top open end <NUM> (e.g. top end cap <NUM>) of the filter element <NUM>, to the center tube <NUM>, or both. The bolt baffle <NUM>' may be joined to the housing bolt <NUM> at a point <NUM> disposed longitudinally below the top open end <NUM> (e.g. top end cap <NUM>) of the filter element <NUM>.

As alluded to earlier herein, the filter element baffle <NUM>', and the bolt baffle <NUM>' comprise a thermoplastic material, and have the same thickness ranging from <NUM> to <NUM>. Other variations are possible as previously described herein.

Similarly, the filter element baffle <NUM>', and the bolt baffle <NUM>' may be concentric about the longitudinal axis <NUM> (e.g. may be formed by rotating the cross-sectional geometry in <FIG> about the longitudinal axis <NUM>).

The center tube <NUM> and the housing bolt <NUM> may be separate components or they may be formed as an unitary component.

Next, the housing bolt <NUM> will be described in further detail with continued reference to <FIG> and <FIG>.

The housing bolt may comprise an at least partially cylindrical body <NUM> defining a cylindrical axis <NUM> and a radial direction <NUM>. The housing bolt <NUM> may have a head <NUM> defining a head diameter <NUM>, and a shaft portion <NUM> extending axially from the head <NUM>. The shaft portion <NUM> defining a shaft portion diameter <NUM> that is less than the head diameter <NUM>, forming a support surface <NUM> configured to contact a portion of the filter element <NUM>. A first baffle <NUM> (as previously discussed herein) may extend from the shaft portion <NUM>. More specifically, the first baffle <NUM> may extend from the side of the shaft portion <NUM>, axially away from the head <NUM>, and radially away from the shaft portion <NUM>.

The first baffle <NUM> may extend from the shaft portion <NUM> at an attachment point <NUM> that is spaced axially away from the head <NUM> an attachment point axial distance <NUM> ranging from <NUM>% to <NUM>% of the length of the filter. The first baffle <NUM> may define a first baffle thickness <NUM>' ranging from <NUM> to <NUM>. Other configurations and dimensional ranges are possible in other embodiments of the present disclosure.

The first baffle <NUM> may terminate at a free end <NUM>' that is also spaced axially away from the head <NUM> a free end axial distance <NUM> ranging from <NUM>% to <NUM>% of the length of the filter. The free end <NUM>' may also being spaced radially away from the shaft portion <NUM> a free end radial distance <NUM> ranging from <NUM>% to <NUM>% of the inner diameter of the center tube. Again, other configurations and dimensional ranges are possible in other embodiments of the present disclosure.

Referring now to <FIG> and <FIG>, canister filter system <NUM>' (similar to canister filter system <NUM>) that uses a filter pulsation dampening device <NUM>' according to other embodiments of the present disclosure will now be discussed.

The filtration pulsation dampening device <NUM>' may include a first baffle <NUM>" extending from the housing bolt <NUM>', and terminating at a first baffle free end <NUM>'', and a flexible valve <NUM> extending from the filter element <NUM>' that defines a valve free end <NUM> that is disposed radially inwardly and longitudinally above the first baffle free end <NUM>". This construction defines a shut-off gap distance <NUM> between the first baffle valve free end <NUM>" and the flexible valve <NUM>. The shut-off gap distance <NUM> may range from <NUM> to <NUM>.

As a result of this construction, a pressure pulsation(s) <NUM> downstream from the annular filter media <NUM> may be greatly reduced before they reach the annular filter media <NUM>. In turn, this might reduce any degradation of the performance of the filter element <NUM>' such as its output to an engine or another downstream device. The shut-off gap distance <NUM> may be varied to achieve the desired effect to be different than the range just mentioned in other embodiments of the present disclosure. The flexible valve <NUM> opens when there is no pressure pulsation downstream, allowing a normal flow of filtered fluid.

This arrangement of the flexible valve and the first baffle may be reversed in other embodiments of the present disclosure. In <FIG> and <FIG>, the flexible valve <NUM> (e.g. a diaphragm, a flap, etc.) extends radially inwardly and longitudinally downwardly from the center tube <NUM> or the top open end <NUM> (e.g. the top end cap <NUM>) of the filter element <NUM>''. In certain embodiments, the flexible valve <NUM> extends from the center tube <NUM> and terminates in the central reservoir <NUM> of the filter element <NUM>'.

The pulsation dampening device <NUM>' may also have a support baffle <NUM> extending from either the top open end <NUM> (e.g. the top end cap <NUM>) or the center tube <NUM> of the filter element <NUM>' longitudinally below and parallel with the flexible valve <NUM>.

The first baffle <NUM>'', and the support baffle <NUM> may comprise the same material (similar to what has been described earlier herein), and may have the same thickness <NUM>''. The support baffle <NUM> terminates at a support baffle free end <NUM> that is disposed radially outward and longitudinally above the valve free end <NUM>. The support baffle <NUM> may help support the flexible valve <NUM> so that it does not tear, overly deform, or otherwise become ineffective as the flexible valve <NUM> opens and closes on the first baffle <NUM>.

A second baffle <NUM>' including a serpentine shape (e.g. a S-shaped curve, undulating curve, etc.) that extends longitudinally below the top open end <NUM> (e.g. the top end cap <NUM>) of the filter element <NUM>', terminating in a second baffle free end <NUM> that is disposed longitudinally above the valve free end <NUM>. The second baffle <NUM>' may extend all the way from the base <NUM> or it may be split into two pieces including a bottom piece extending from the top end cap and a top piece extending from the base to the filter element, creating a seal between these components, etc. The support baffle and the second baffle may also be integrated into an unitary baffle that extends from the filter element and contacts the base. Other configurations are possible in other embodiments of the present disclosure.

The second baffle <NUM>' may limit the upward movement of the flexible valve <NUM> as it opens so that it does not tear, overly deform or otherwise become ineffective as the flexible valve <NUM> opens and closes.

Similar to what has been previously described herein, the first baffle <NUM>", the second baffle <NUM>', the support baffle <NUM>, and the flexible valve <NUM> are concentric about the longitudinal axis <NUM>. That is to say, these components may be created by rotating the cross-sectional geometry about the longitudinal axis <NUM>. Likewise, the filter element <NUM>' may be concentric with the canister <NUM>, and with the housing bolt <NUM>'. The housing bolt <NUM>' may be attached to the canister <NUM> or the base <NUM>, fixing the position of the housing bolt <NUM>' relative to the canister <NUM> and/or the base <NUM>. Other constructions are possible in other embodiments of the present disclosure.

Now, a filter element <NUM>' that may be provided as a replacement part according to an embodiment of the present disclosure that may be used with the canister filter system <NUM>' just described will now be discussed with reference to <FIG> and <FIG>. The filter element <NUM>' includes a filter pulsation dampening device <NUM>' having a flexible valve <NUM> that defines a valve free end <NUM> that is disposed in the central reservoir <NUM> of the center tube <NUM>. The flexible valve <NUM> extends radially inwardly and longitudinally downwardly from the center tube <NUM> or the top open end <NUM> (e.g. the top end cap <NUM>) of the filter element <NUM>'. As shown in <FIG> and <FIG>, the flexible valve <NUM> actually extends from the center tube <NUM> in the embodiment shown.

The pulsation dampening device <NUM>' may include a radially outer baffle <NUM> extending from the center tube <NUM> that is disposed longitudinally below the flexible valve <NUM>. The radially outer baffle <NUM> extends longitudinally downwardly and radially inwardly from the center tube <NUM>. The radially outer baffle <NUM> terminates at an outer baffle free end <NUM> that is spaced longitudinally above and radially outwardly away from the valve free end <NUM>.

The radially outer baffle <NUM> may comprise a thermoplastic material or other suitable material as discussed earlier herein. The radially outer baffle <NUM> has an outer baffle thickness <NUM> ranging from <NUM> to <NUM>. The flexible valve <NUM> may comprise a rubber material or other suitable material. The flexible valve <NUM> has a valve thickness <NUM> ranging from <NUM> to <NUM> (may be made from an elastomer such as used in seals, and the range may be more particularly from <NUM> to <NUM>, etc.). These dimensional ranges may be different in other embodiments of the present disclosure.

The flexible valve <NUM> and the radially inner baffle <NUM> may be concentric about the longitudinal axis <NUM> as previously alluded to herein. This may not be the case for other embodiments.

The housing bolt <NUM>' may have a radially inner baffle <NUM> extending longitudinally upwardly and radially outwardly from housing bolt <NUM>', terminating at an inner baffle free end <NUM>. The inner baffle free end <NUM> may be disposed radially outward and longitudinally below the valve free end <NUM>, defining a gap <NUM> with a minimum gap distance <NUM> from ranging <NUM> to <NUM>. The range for this distance may be different in other embodiments of the present disclosure.

Next, the housing bolt <NUM>' will be described in further detail with continued reference to <FIG> and <FIG>. The housing bolt <NUM>' may be similarly constructed as discussed earlier herein with respect to <FIG>. Furthermore, the housing bolt <NUM>' may include a first baffle <NUM>" extending from the shaft portion <NUM>. The first baffle <NUM>'' may extend axially away from the head <NUM>, and radially away from the shaft portion <NUM>.

More specifically, the first baffle <NUM>'' may extend from the shaft portion <NUM> at an attachment point <NUM>' that is spaced axially away from the head <NUM> an attachment point axial distance <NUM>' ranging from <NUM>% to <NUM>% of the length of the filter, and the first baffle <NUM>'' defines a first baffle thickness <NUM>' ranging from <NUM> to <NUM>. These dimensional ranges may be different in other embodiments of the present disclosure.

Also, the first baffle <NUM>'' may terminate at a free end <NUM>''' that is spaced axially away from the head <NUM> a free end axial distance <NUM>' ranging from <NUM> to <NUM>. The free end <NUM>''' may also be spaced radially away from the shaft portion <NUM> a free end radial distance <NUM>' ranging from <NUM> to <NUM>.

Any of the aforementioned dimensions and configurations may be different than what has been specifically set forth herein. Moreover, the materials of the various components discussed above may be different than those specifically mentioned.

In practice, a filter element, a housing bolt, or a canister filter system may be obtained or provided in an OEM (original equipment manufacturer) or aftermarket context according to various embodiments of the present disclosure.

The center tube and the housing bolt may be made from any suitable material including plastic, metal, etc. It may be desirable to choose materials that are chemically compatible with the fluids being filtered.

Various parameters may be measured to determine the efficacy of any of the embodiments discussed herein for a particular application. For example, at point A in <FIG> and <FIG>, the magnitude of the pressure pulsation <NUM> may be monitored, the pressure and the flow rate of the outgoing fluid may be monitored. Also, at point B in <FIG> and <FIG>, base line pressures of the pressure pulses may be monitored, and the pressure of the fluid may be measured. So, the pressure drop of the fluid may be determined as well as the flow rate as a function opposing pressure pulsations. The geometry of the pulsation dampening mechanism may be adjusted to achieve the desired outgoing fluid flow and/or the desired pulsation pressure exerted on the filter media, etc..

Claim 1:
A pulse dampening interface between a filter and a filter base configured to mitigate pulses, the interface comprising:
a housing bolt (<NUM>');
a base (<NUM>);
and a replaceable filter element (<NUM>') that includes at least a partially cylindrical configuration and that defines a longitudinal axis (<NUM>), and a radial direction (<NUM>), the filter element (<NUM>') comprising:
an annular filter media (<NUM>) defining a central passage (<NUM>);
a center tube (<NUM>) that is disposed in the central passage (<NUM>) of the annular filter media (<NUM>) that defines a central reservoir (<NUM>), and the annular filter media (<NUM>) surrounds the center tube (<NUM>) and the central reservoir (<NUM>);
a top open end (<NUM>) joined to the center tube (<NUM>) disposed along the longitudinal axis (<NUM>), the top open end (<NUM>) including an opening (<NUM>) allowing fluid to flow from the central reservoir (<NUM>) to the outside of the filter element (<NUM>');
a bottom open end (<NUM>) joined to the center tube (<NUM>) opposite the top open end (<NUM>) disposed along the longitudinal axis (<NUM>); and
a filter pulsation dampening device
characterised in that the filter pulsation dampening device including a movable flexible valve (<NUM>) extending from the filter element (<NUM>') having a valve free end (<NUM>) that is disposed in the central reservoir (<NUM>) of the center tube (<NUM>);
a first baffle (<NUM>") extending from the housing bolt (<NUM>') and terminating at a first baffle free end (<NUM>") and the flexible valve (<NUM>) of the filter element (<NUM>') which is disposed radially inwardly and longitudinally above the first baffle free end (<NUM>''), defining a shut-off gap distance (<NUM>) between the first baffle valve free end (<NUM>) and the flexible valve (<NUM>), wherein the flexible valve (<NUM>) opens and closes on the first baffle (<NUM>") and opens when there is no pressure pulsation downstream, allowing a normal flow of filtered fluid.