Check valve with integral filter

Abstract

To provide a check valve.SOLUTION: A check valve may include an upper housing defining an inlet, a lower housing defining an outlet, and a cavity interposed between and defined by the upper and lower housings. The check valve may further include a flexible valve member mounted in the cavity to selectively permit fluid flow in a first direction, and prevent fluid backflow in a second direction opposite to the first direction. A filter member may be mounted in the upper housing, upstream of the flexible valve member. The filter member may have an elongated portion configured to maximize surface area thereof exposed to the fluid flow, and restrict passage of undesirable matter in fluid flowing through the check valve.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates generally to check valves, and more particularly to check valves having a filtration mechanism for filtering particulate matter in a fluid flowing through the check valve. [Background technology]

[0002] Patients are generally infused with IV solutions, which are initially provided in an IV reservoir (bottle or bag) and dripped into the patient's veins through an IV line. Typically, an injection port is provided along the IV line, adapted to work with a syringe, allowing the infusion fluid to be added to the IV solution. Also, a check valve is generally included in the IV line, allowing fluid flow only in the direction of the patient. This ensures that the infusion fluid flows downstream toward the patient and not upstream toward the IV reservoir. Summary of the Invention

[0003] An IV check valve is normally closed when there is no movement of fluid (e.g., infusion solution) through the IV set. For example, when there is no movement of fluid, the check valve is closed and does not allow fluid to pass through the inlet port. When fluid flows through the IV set, the IV check valve opens, allowing fluid to flow from one end of the IV check valve to the other. However, many valves are susceptible to lodged grit and particles. When reverse flow is applied while grit is lodged, the inlet port does not seal completely and creates small leaks that render the valve useless.

[0004] It would be advantageous to provide an IV check valve with an integral filter member that prevents grit retention that can lead to fluid leakage and backflow. Described herein is a check valve with an integral filter that achieves these desired functions and objectives.

[0005] The check valve includes an upper housing defining an inlet portion of the check valve; a lower housing defining an outlet portion of the check valve; and a cavity interposed between and defined by the upper and lower housings for fluidly connecting the inlet and outlet portions. The check valve further includes a flexible valve member mounted in the cavity selectively permitting fluid flow in a first direction and preventing backflow of fluid in a second direction opposite the first direction, and a filter member mounted in the upper housing upstream of the flexible valve member. The filter member has an elongated portion configured to maximize a surface area of ​​the filter member exposed to fluid flow and to limit the passage of undesirable materials in fluid flowing through the check valve.

[0006] The check valve includes an upper housing including an inlet portion of the check valve; a lower housing axially connected to the upper housing and including an outlet portion of the check valve; and a cavity cooperatively formed by the upper and lower housings to fluidly connect the inlet and outlet portions. The check valve further includes a flow passage extending between the inlet and outlet portions and in fluid communication with the cavity; a flexible valve member mounted in the cavity; and an elongated filter member mounted in the flow passage upstream of the flexible valve member. The flexible valve member selectively permits fluid flow in a first direction and prevents backflow of fluid in a second direction opposite the first direction. The elongated filter member maximizes its surface area exposed to the fluid flow and limits the passage of undesirable substances in the fluid flowing toward the flexible valve member.

[0007] The following figures are included to illustrate certain aspects of the embodiments and should not be viewed as exclusive embodiments. The disclosed subject matter is capable of considerable modification, substitutions, combinations, and equivalents in form and function, as will occur to those skilled in the art and having the benefit of this disclosure. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is an exploded view of a check valve according to some embodiments of the present disclosure. [Diagram 2] 1A-1C are diagrams illustrating a check valve in a closed state, in which the check valve restricts fluid flow in a reverse direction, according to some embodiments of the present disclosure. [Diagram 3] FIG. 1 illustrates a check valve in an open state when subjected to upstream pressure, in which the check valve allows fluid flow in a forward direction, according to some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The detailed description set forth below describes various configurations of the subject technology and is not intended to represent the only configurations in which the subject technology may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the subject technology. Thus, dimensions may be provided for certain embodiments as non-limiting examples. However, it will be apparent to those skilled in the art that the subject technology may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form to avoid obscuring concepts of the subject technology.

[0010] It should be understood that the present disclosure includes examples of the subject technology and does not limit the scope of the appended claims. Various aspects of the subject technology will now be disclosed according to specific, but non-limiting, examples. The various embodiments described in the present disclosure can be implemented in different ways and with modifications according to a desired application or implementation.

[0011] The present disclosure relates generally to check valves, and more specifically, for example and without limitation, to check valves having a filtering mechanism for filtering particulate matter in a fluid flowing therethrough. The present check valves described herein provide a filter mechanism having a cylindrical elongated portion that provides an extended and increased filtering surface area through which fluid flows, as compared to conventional filters. The increased surface area advantageously allows for improved and enhanced filtering of the fluid as it flows from an inlet portion to an outlet portion of the check valve. Additionally, because the filter mechanism is elongated in shape, the diameter of the filter mechanism, and thus the size of the corresponding check valve in which the filter mechanism is housed, may be minimized.

[0012] According to various embodiments, the filter mechanism may be formed from a porous material capable of withstanding back pressure resulting from reverse flow up to 200 KPa. Advantageously, the latter configuration may minimize the likelihood of the filter mechanism collapsing under back pressure resulting from reverse fluid flow. Moreover, the check valve may include at least one axially extending stop that functions to prevent the filter mechanism from being displaced upwardly into the inlet portion when excessive back pressure is experienced within the check valve. Due to the presence of the stop, the filter mechanism is prevented from being displaced upwardly into the inlet portion as a result of the force exerted by the deflected valve member. As such, the filter mechanism may advantageously act as a support or safeguard to protect the valve member from excessive bowing when excessive reverse flow pressure is experienced.

[0013] FIG. 1 is an exploded view of a check valve 100 according to some embodiments of the present disclosure. As shown, an upper portion of the check valve 100 (i.e., the upper housing 10) is displayed in a cross-sectional view to more clearly illustrate some of the features of the check valve 100. With reference to FIG. 1, the check valve 100 includes an axially extending body portion 101 that defines a central longitudinal axis X1. The body portion 101 can be a generally cylindrical (or tubular) structure and can include an upper housing 10 and a lower housing 15. The upper housing 10 can include a first end portion 12 and an axially opposite second end portion 14. As shown, the radial extension of the upper housing 10 at the second end portion 14 can be greater than its radial extension at the first end portion 12. The lower housing 15 may include an upstream inner surface 52, and the second end portion 14 and the upstream inner surface 52 of the lower housing 15 may axially contact one another and cooperate to form the cavity 30 of the check valve 100.

[0014] The upper housing 10 can include an inlet portion 20 of the check valve 100 at the first end 12, and the lower housing 15 can include an outlet portion 25 of the check valve 100. The body portion 101 can define an internal flow passage 85 that extends axially between and is in fluid communication with the inlet portion 20 and the outlet portion 25. As can be seen, the check valve 100 can allow fluid to flow from the inlet portion 20 to the outlet portion 25 (as shown by arrow A) and can minimize (or otherwise restrict) fluid flow from the outlet portion 25 to the inlet portion 20 (as shown by arrow B). As shown, the upper housing 10 and the lower housing 15 can define a cavity 30 for fluidly connecting the inlet portion 20 and the outlet portion 25. In the embodiment shown, a flexible valve member 35 may be mounted within the cavity 30 to selectively permit fluid flow in a first direction (indicated by arrow A) and prevent reverse fluid flow in a second direction (indicated by arrow B) opposite the first direction. The valve member 35 may be mounted on a support portion 50 of the lower housing 14. As shown in FIG. 1, the support portion 50 may be centrally disposed within the cavity 30, with a central axis X3 of the support portion coaxially aligned with a central longitudinal axis X1 of the body portion 101. The support portion 50 may be coupled to, integrally formed with, or otherwise protrude from an upstream inner surface 52 of the lower housing 15 and extend into the cavity 30. As discussed in more detail below, cavity 30 may form part of or may otherwise be fluidly connected to internal flow passage 85 such that fluid flowing from inlet portion 20 to outlet portion 25 may flow through cavity 30.

[0015] According to some embodiments, a filter member 40 defining a central longitudinal axis X2 may be mounted within the upper housing 10 at a location upstream of the flexible valve member 35. The filter member 40 may have an elongated shape configured to maximize the surface area of ​​the filter member 40 exposed to fluid flow. In this manner, the filter member may be configured to restrict and minimize the passage of undesirable substances in the fluid flowing through the check valve 100. For example, as shown, the filter member 40 may be formed in an inverted "T" shape or a top hat shape. To this effect, the filter member 40 may include an elongated stem portion 42 and a head portion 44. The above-described configuration is advantageous in that the elongated stem portion provides an extended and increased filtration surface area (through which fluid flows) compared to conventional filters. The increased surface area allows for improved and enhanced filtration of the fluid as it flows from the inlet portion 20 to the outlet portion 25.

[0016] In the embodiment shown, the filter member 40 may be mounted in a cavity defined by the internal flow passage 85 in the upper housing 10. As shown, and as will be described in further detail below with reference to FIG. 2, the filter member 40 may be press-fitted into the upper housing at a location upstream of the valve member 35. Press-fitting the filter member 40 into the upper housing eliminates the need to use conventional fastening and bonding techniques, which may require additional equipment and materials, thereby increasing the complexity of the assembly and associated costs. Thus, the above-described configuration provides a simple, cost-effective, and mechanically robust filter and check valve assembly.

[0017] In other embodiments, filter member 40 may be coupled or bonded to the interior walls of upper housing 10 within the cavity that defines interior flow passage 85. For example, filter member 40 may be bonded through any suitable method, including, but not limited to, ultrasonic welding, heat sealing, insert molding, adhesives, or other attachment methods. In some embodiments, at least head portion 44 of filter member 40 may be integrally formed with the interior walls of upper housing 10 as part of the molding process of upper housing 10.

[0018] According to various embodiments of the present disclosure, at least a portion of the filter member 40 can be devoid of material. For example, the filter member 40 can include a hollow central channel 72 that extends longitudinally through a central axis X2 of the filter member 40. As shown, the hollow central channel 72 can extend partially through the stem portion 42 and completely through the head portion 44. However, in other embodiments, the hollow central channel 72 can extend only partially through each of the stem portion 42 and the head portion 44. In operation, fluid flows from the inlet portion 20 into the internal flow passage 85, where the fluid is filtered by the filter member 40. As shown in more detail in FIG. 3, the fluid flows from the internal flow passage 85 into the filter member 40, through the top surface 58 and sidewall portion 68 of the stem portion 42, and through the head portion 74 of the filter member 40. In some embodiments, the fluid filtered in the stem portion 42 of the filter element 40 then travels into the central channel 72, passes through the valve element 35 (when in an open state), into the outlet portion 25, and exits the check valve 100.

[0019] The filter member 40 may be formed from a porous material that can prevent particulate matter of a certain size from passing through and potentially reaching and causing failure of the valve member 35. For example, the filter member 40 may be formed from a porous plastic material. Alternatively, the filter member 40 may be made from a non-woven casting material, a cork material, or any other porous fabric or material. The filter member 40 may be formed with a plurality of small holes, or it may be woven to provide pores of about 0.2 microns to 100.0 microns in size. In some embodiments, the filter member 40 may be a flexible material, such as a metal or polymeric material that can maintain an "inverted T" or "top hat" under fluid pressure. Additionally, the filter member 40 may be made from a non-swelling material to maintain a gap between the stem portion 42 and the interior wall or surface of the upper housing 10, as will be discussed in more detail below. In some embodiments, the filter element 40 may be formed from a material capable of withstanding or filtering a flow rate between 3 liters per hour and 8 liters per hour. Additionally, the filter element 40 may be formed from a porous material capable of withstanding back pressure resulting from reverse flow of up to 200 KPa. Advantageously, the latter configuration may minimize the likelihood of the filter element 40 collapsing under back pressure resulting from reverse fluid flow.

[0020] 2 and 3 are cross-sectional views of a check valve 100 according to some embodiments of the present disclosure. FIG. 2 illustrates the check valve 100 in a closed state, in which the check valve 100 restricts fluid flow in a reverse direction, according to some embodiments of the present disclosure. As shown, the upper housing 10 can include an interior surface 55 that extends along an interior length of the upper housing 10 and defines a flow passage 85 (illustrated in FIG. 1). The upper housing 10 can further include an exterior surface 60 that defines an exterior of the body portion 101. The interior surface 55 can include an upstream interior surface 57 and a downstream interior surface 59. The cavity 30 can be at least partially defined by the downstream interior surface 59 of the upper housing 102. In the embodiment shown, the downstream interior surface 59 extends radially outward from the upstream interior surface 57. The downstream inner surface 59 can include a protrusion 65 that extends circularly about the central longitudinal axis X1 of the body 101 and into the cavity 30. In some embodiments, the protrusion 65 defines a sealing surface 70 at its distal end. The protrusion 65, and thus the sealing surface 70, can be arranged as a ring above the valve member 35. In a normally closed state of the check valve 100, the valve member 35 contacts the sealing surface 70. With the valve member 35 contacting the sealing surface 70, fluid flow in the reverse direction (illustrated by arrow B) from the outlet 25 to the inlet 20 is prevented.

[0021] During operation, when downstream pressure (i.e., pressure applied by fluid flowing from outlet port 25 to inlet port 20 (indicated by arrow B)) is applied to valve member 35, the valve member can deflect toward sealing surface 70 and block fluid communication between inlet port 20 and cavity 30, thereby restricting the backflow of fluid from outlet port 25 to inlet port 20. Preventing the backflow of fluid is advantageous in that it limits undesirable particulate matter (e.g., contained in drug dispensed from a secondary pathway) from flowing back through the check valve (thereby preventing a patient from receiving the correct drug dosage concentration or timely delivery of the drug).

[0022] According to some embodiments, the valve member 35 may be formed from a flexible, resilient material that is fluid impermeable. For example, the valve member 35 may be made from a silicone material. However, in other embodiments, the valve member 35 may be formed from any non-sticky, resilient material, such as natural or synthetic rubber or plastic, etc. The valve member may be formed from a material having a Shore hardness of 70 or less.

[0023] In the embodiment shown, the valve member 35 can have a generally circular disk shape that corresponds to the generally cylindrical shape of the check valve body 101. However, various embodiments of the present disclosure are not limited to the above configuration. In some embodiments, the valve member 35 can have a non-circular shape, such as a square, rectangular, polygonal, or any other shape that can span an area sufficient to cover and encase the sealing surface 70.

[0024] In some embodiments, the valve member 35 is not limited to any particular shape or size. However, in the embodiment shown, the size of the valve member 35 may be limited based on the desired flexure / bending characteristics of the valve member when subjected to either upstream or downstream forces. For example, the valve member 35 may be sized and shaped to flex or bend under fluid pressure to permit forward flow of fluid (from the inlet portion 20 to the outlet portion 25) into the cavity 30 through the flow passage 85 and restrict fluid flow in the reverse direction. In some embodiments, the valve member 35 can be a curved flexible disk mounted on the support portion 50 of the lower housing 15.

[0025] As shown, the valve member 35 may be centrally mounted within the cavity 30. To this end, the downstream inner surface 59 may include a number of ribs 80 formed thereon to centrally align the valve member 35 within the cavity 30. As shown, the number of ribs 80 may be disposed within the cavity 30 in a manner that projects radially inwardly from the downstream inner surface 59. The above-described configuration is advantageous in that the number of ribs 80 act as guide members for accurate centering of the valve member 35 during assembly. Thus, the ribs 80 prevent the valve member 35 from being assembled in a distorted or otherwise misaligned manner that is undesirable. This ensures that a maximum surface area is present for filtration, and that the filter cannot become restrictive even if it contacts the inner wall.

[0026] During assembly, the valve member 35 may be mounted on the support portion 50 and then the upper housing 10 may be lowered onto the lower housing 15. The valve member 35 may be disposed to contact the sealing surface 70 with the peripheral edge of the valve member 35 overlying the sealing surface 70. When assembled, the valve member 35 may have a slight upward bend at the peripheral edge, which creates a normally closed state of the check valve 100. The filter member 40 may be assembled into the upper housing by being forced into and aligned within the cavity defining the flow passage 85. In some embodiments, the head portion 44 of the filter member 40 is aligned with and press-fit into a lower portion of the cavity defined in the flow passage 85. As shown in FIG. 1, the head portion 44 may be formed with a diameter D2 that is slightly larger than the diameter of the interior surface 55 that defines the flow passage 85 (in which the filter member 40 is positioned). Thus, during assembly, the head portion 44 may be pressed into the interior surface 55 to form a tight interference fit therewith. In some embodiments, the diameter D1 of the stem portion 42 of the valve member 40 may be smaller than the diameter D2 of the head portion. Thus, when the valve member 40 is assembled into the flow passage 85, a gap 56 may be formed between the stem portion 42 and the interior surface 55. Thus, fluid entering the check valve 100 may flow into the flow passage 85, through the filter member 40 (where the fluid is filtered and traps undesirable particulate matter), and into the cavity 30, as will be described below.

[0027] According to some embodiments, the upper housing 10 can include at least one axially extending stop 75 that projects radially inward from the upstream inner surface 57. The at least one stop 75 can be configured as a protruding surface disposed immediately above or upstream of the stem portion 42 of the filter element 40. The stop 75 can project radially inward from the upstream inner surface 57 a distance greater than the size of the gap 56 between the inner surface 55 and the outer surface of the sidewall 68 of the stem portion 42. By projecting radially inward a distance greater than the size of the gap 56, the stop 75 functions to prevent the filter element 40 from being displaced upward into the inlet portion 20 when excessive back pressure is experienced within the check valve 100. For example, excessive back pressure exerted on valve member 35 may cause the valve member to flex or bend to such an extent that the valve member abuts head portion 44 and exerts an upward force on valve member 40. Due to the presence of stop 75, filter member 40 is prevented from being displaced upwardly into inlet portion 20 as a result of the force exerted by the deflected valve member 40. As such, filter member 40 can advantageously act as a support or safeguard to protect valve member 35 from excessive bowing when excessive reverse flow pressure is experienced. Additionally, stop 75 also prevents the filter from "bottoming out," which would cut off flow to the cylindrical wall of filter member 40.

[0028] 3 illustrates a check valve 100 in an open state when subjected to upstream pressure, where the check valve 100 allows fluid flow in a forward direction, according to some embodiments of the present disclosure. As shown, during operation, fluid may enter the check valve 100 via the inlet portion 20, flow into the flow passage 85, flow through the top wall 46 of the filter element 40, and flow into the cavity 30. As previously discussed, the diameter D1 of the stem portion 42 of the valve element 40 may be smaller than the diameter D2 of the head portion, such that a gap 56 may be formed between the stem portion 42 and the interior surface 55. Thus, fluid entering the check valve 100 may flow into the flow passage 85, flow through the top wall 46 and side wall of the filter element 40 (where the fluid is filtered and traps undesirable particulate matter), and flow into the cavity 30. Any grit or other undesirable particulate matter larger in size than the pores of the filter member 40 may be trapped within the filter member 40 and prevented from passing downstream to the valve member 35 .

[0029] Upstream pressure applied to the valve member 35 (i.e., pressure applied by fluid flowing from the inlet portion 20 to the outlet portion 25 (indicated by arrow A)) causes the valve member 35 to bow or bend downward at its outer edge and deflect away from the sealing surface 70. The check valve is thus shifted from a closed state (illustrated in FIG. 2) to an open state (illustrated in FIG. 3) in which the inlet portion 20, the cavity 30, and the outlet portion 25 are in fluid communication. In the open state, a gap 95 is created between the sealing surface 70 and the upper surface of the valve member 35, allowing the filtered fluid to flow therethrough. The filtered fluid 90 can then flow through the gap 95 into the cavity 30 and exit the check valve 100 via the outlet portion 25 in the lower housing 15, as indicated by the arrows.

[0030] The above-described configuration is advantageous in that the elongated shape of the stem portion 42 of the valve member 40 provides a maximized surface area for filtration of fluid traveling through the flow passage 85. Additionally, the configuration in which the filter member 40 is positioned upstream of the valve member 35 is advantageous in that it prevents the passage of undesirable particulate matter to the valve member 35 that could otherwise cause damage or wear to the valve member. The above-described configuration also prevents undesirable particulate matter from becoming potentially lodged between the valve member 40 and the sealing surface 70 (thereby preventing the valve member 35 from fully closing and sealing against reverse flow).

[0031] In contrast, in conventional check valve configurations that do not include an integral filter member, during low flow conditions, the pressure exerted on the check valve as a result of fluid flow may not be sufficient to fully open the check valve (e.g., deflect the valve member 35) to allow grit (or other undesirable particulate matter) to pass through gap 95. In such conditions, grit may become lodged in gap 95 and the valve may not fully close. Undesirably, this can cause the check valve to "leak," allowing fluid to flow through the valve in the reverse direction, thereby rendering the check valve ineffective.

[0032] The present disclosure is provided to enable any person skilled in the art to practice the various aspects described herein. The present disclosure provides various examples of the subject technology, and the subject technology is not limited to these examples. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects.

[0033] Reference to an element in the singular is not intended to mean "one and only one" unless specifically so stated, but rather "one or more." The term "some" refers to one or more, unless specifically stated otherwise. Masculine pronouns (e.g., his) include the feminine and neuter genders (e.g., "her" and "it"), and vice versa. Headings and subheadings, if present, are used for convenience only and do not limit the invention.

[0034] The word "exemplary" is used herein to mean "serving as an example or illustration." Any aspect or design described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects or designs. In one aspect, various alternative configurations and operations described herein may be considered at least equivalent.

[0035] As used herein, the phrase "at least one of" preceding a list of items (with the term "or" separating any of the items) modifies the list as a whole rather than each item in the list. The phrase "at least one of" does not require the selection of at least one item. Rather, the phrase allows the meaning to include at least one of any one of the items, and / or at least one of any combination of the items, and / or at least one of each of the items. By way of example, the phrase "at least one of A, B, or C" can refer to only A, only B, or only C; or any combination of A, B, and C.

[0036] A phrase such as "aspect" does not imply that such aspect is essential to the subject technology or that such aspect applies to all configurations of the subject technology. Disclosure of an aspect may apply to all configurations, or to one or more configurations. An aspect may provide one or more examples. A phrase such as an aspect may refer to one or more aspects, and vice versa. A phrase such as "embodiment" does not imply that such embodiment is essential to the subject technology or that such embodiment applies to all configurations of the subject technology. Disclosure of an embodiment may apply to all embodiments, or to one or more embodiments. An embodiment may provide one or more examples. A phrase such as an embodiment may refer to one or more embodiments, and vice versa. A phrase such as "configuration" does not imply that such configuration is essential to the subject technology or that such configuration applies to all configurations of the subject technology. Disclosure of an embodiment may apply to all configurations, or to one or more configurations. A configuration may provide one or more examples. A phrase such as a configuration may refer to one or more configurations, and vice versa.

[0037] In one aspect, unless otherwise stated, all measurements, values, ratings, positions, dimensions, sizes, and other specifications set forth in this specification (including the claims which follow) are approximate and not precise, and are intended to have a reasonable range consistent with the function to which they relate and with that customary in the art to which they pertain.

[0038] It is understood that the specific order or hierarchy of steps or operations in the disclosed processes or methods is an illustration of example approaches. It is understood that based on implementation preferences or scenarios, the specific order or hierarchy of steps, operations, or processes may be rearranged. Some of the steps, operations, or processes may be performed simultaneously. In some implementation preferences or scenarios, certain operations may or may not be performed. Some or all of the steps, operations, or processes may be performed automatically, without user intervention. The accompanying method claims present elements of the various steps, operations, or processes in a sample order, and are not meant to be limited to the specific order or hierarchy presented.

[0039] All structural and functional equivalents (known or later known to those skilled in the art) to the elements of the various embodiments described throughout this disclosure are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be made available to the public, regardless of whether such disclosure is expressly recited in the claims. No element of a claim is to be construed under the provisions of 35 U.S.C. 112(f) unless the element is expressly recited using the phrase "means for" or, in the case of a method claim, unless the element is recited using the phrase "step for". Moreover, to the extent terms such as "include" or "having" are used, such terms are intended to be inclusive in a manner similar to the term "comprise" when "comprise" is interpreted when used as a transitional phrase in a claim.

[0040] The title, background, brief description of the drawings, and abstract of this disclosure are hereby incorporated into this disclosure and are provided as examples for illustrative purposes of the disclosure, and are not provided as limiting descriptions. They are submitted with the understanding that they will not be used to limit the scope or meaning of the claims. In addition, in the detailed description, it can be seen that the description provides examples for illustrative purposes, and that various features have been grouped together in various embodiments for the purpose of streamlining the disclosure. This method of disclosure should not be interpreted as reflecting an intention that the claimed subject matter requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed structure or operation. The following claims are hereby incorporated into the detailed description, with each claim standing on its own as separately claimed subject matter.

[0041] The claims are not intended to be limited to the embodiments described herein, but are to be accorded the full scope consistent with the language of the claims and include all legal equivalents. Nonetheless, none of the claims are intended to, and should not be construed to, cover subject matter that does not meet the requirements of 35 U.S.C. §§ 101, 102, or 103.

Claims

1. A check valve, comprising: a lower housing including an outlet portion of the check valve, an upper housing including an inlet portion of the check valve and a protrusion, and a cavity formed between the upper housing and the lower housing, the protrusion including a distal end portion that extends into the cavity toward the lower housing and forms a sealing surface; The check valve is a flexible valve member positioned within the cavity along a fluid pathway between the inlet and outlet of the check valve, the flexible valve member configured to permit fluid flow along the fluid pathway in a first direction from the inlet of the check valve to the outlet of the check valve and configured to resist fluid flow along the fluid pathway in a second direction from the outlet of the check valve to the inlet of the check valve; an elongated filter member positioned along the fluid pathway upstream of the flexible valve member, the elongated filter member maximizing a surface area of ​​the elongated filter member exposed to the fluid flow and limiting the passage of undesirable materials in the fluid flow through the check valve; and 4. A check valve comprising:

2. 2. The check valve of claim 1, wherein the upper housing includes an interior surface that defines a flow passage, and the elongated filter member is positioned within the flow passage of a cylindrical body portion of the upper housing.

3. The check valve of claim 2 , wherein an outer surface of the elongated filter member is spaced apart from the inner surface.

4. The check valve of claim 1 , wherein a portion of the elongated filter member is mounted within the upper housing by an interference fit.

5. 2. The check valve of claim 1, wherein the elongated filter member includes a stem portion and a head portion, an outer surface of the stem portion including a first diameter and an outer surface of the head portion including a second diameter, the second diameter being larger than the first diameter.

6. 6. The check valve of claim 5, wherein the head portion of the elongated filter member is positioned adjacent to the flexible valve member with the stem portion of the elongated filter member between the head portion and the inlet portion of the check valve.

7. 10. The check valve of claim 1, wherein the elongated filter member comprises a porous material selected from the group consisting of a plastic material, a cork material, a woven material, and a non-woven material.

8. 2. The check valve of claim 1, wherein the lower housing includes a support portion extending toward the cavity, and the flexible valve member is positioned between the support portion of the lower housing and the protrusion of the upper housing.

9. The check valve according to claim 1 , wherein the protrusion extends in a circular shape around a central axis of the upper housing.

10. when an upstream pressure is applied to the flexible valve member, the flexible valve member is configured to deflect away from the sealing surface to permit fluid flow along the fluid path in the first direction; 2. The check valve of claim 1, wherein when a downstream pressure is applied to the flexible valve member, the flexible valve member is configured to engage against the sealing surface and resist fluid flow along the fluid path in the second direction.

11. 2. The check valve of claim 1, wherein the upper housing includes a stop extending radially inward from an inner surface of the upper housing such that movement of the elongated filter member toward the inlet portion of the check valve is resisted by engagement of the elongated filter member with the stop.

12. 2. The check valve of claim 1, wherein the lower housing includes a plurality of ribs extending into the cavity and configured to engage a peripheral surface of the flexible valve member to resist radial movement of the flexible valve member.

13. 2. The check valve of claim 1, wherein the elongated filter member includes a hollow central channel, the hollow central channel extending longitudinally through an axial center of the elongated filter member.

14. 14. The check valve of claim 13, wherein the inlet portion of the check valve, the hollow central channel, and the outlet portion of the check valve are aligned along a central longitudinal axis of the check valve.

15. The check valve of claim 13 , wherein the fluid pathway extends through the hollow central channel of the elongated filter member.

16. 1. A method of providing a check valve, the method comprising: providing a housing including an upper portion, a lower portion, and a cavity formed between the upper and lower portions of the housing, the upper portion of the housing including an inlet portion of the check valve and a projection extending into the cavity, the lower portion of the housing including an outlet portion of the check valve, a fluid path extending through the inlet portion, the outlet portion, and the cavity; positioning a flexible valve member within the cavity along the fluid pathway, the flexible valve member engaged against the protrusions to permit fluid flow along the fluid pathway in a first direction from the inlet to the outlet and to resist fluid flow along the fluid pathway in a second direction from the outlet to the inlet; positioning an elongated filter member along the fluid pathway upstream of the flexible valve member to maximize a surface area of ​​the elongated filter member exposed to the fluid flow and to resist migration of undesirable materials toward the flexible valve member; A method comprising:

17. 17. The method of claim 16, further comprising positioning a portion of the elongated filter member having an elongated shape in a flow passage of the upper portion of the housing.

18. 17. The method of claim 16, wherein positioning the flexible valve member within the cavity includes biasing the flexible valve member between the protrusion and a support portion of the lower portion of the housing.

19. 17. The method of claim 16, wherein positioning the flexible valve member within the cavity includes engaging a peripheral surface of the flexible valve member against a plurality of ribs extending from the lower portion of the housing into the cavity.

20. 17. The method of claim 16, wherein positioning the elongated filter member along the fluid pathway includes engaging an outer surface of the elongated filter member against a stop extending radially inward from an inner surface of the upper portion of the housing.

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