Push-type fuel tank isolation valve

Abstract

A fuel tank isolation valve assembly for controlling vapor flow between a fuel tank and a vapor recovery canister is provided. The assembly includes a valve housing defining an inlet in fluid communication with the fuel tank, an outlet in fluid communication with the vapor recovery canister, and a chamber therebetween. A valve seat surrounds an aperture within the chamber. An actuating assembly is coupled to the valve housing and includes a push-type mechanism for selectively extending an push rod into the chamber to open the valve. An overpressure relief (OPR) seal assembly is biased toward the valve seat by an OPR spring, and an over-vacuum relief (OVR) seal assembly is biased toward the OPR seal assembly by an OVR spring. When actuated, the push rod extends through the aperture to mechanically displace the OPR seal assembly from the valve seat, thereby permitting a controlled fluid flow path between the inlet and outlet. The configuration enables reliable venting of pressure or vacuum conditions within the fuel tank while providing active control of vapor flow for evaporative emissions management.

Description

ATTORNEY DOCKET PATENT APPLICATION 006976.23331 of 25Push-Type Fuel Tank Isolation ValveTECHNICAL FIELD

[0001] This disclosure generally relates to a valve assembly for a fuel tank, and particularly relates to a valve assembly configured with push-type actuation architecture.BACKGROUND

[0002] Fuel tank isolation valves are critical components in hybrid vehicles, designed to manage the flow of fuel vapor between the fuel tank and the vehicle’ s evaporative emissions system. Unlike conventional vehicles, hybrid powertrains often operate with extended engine- off periods, which can cause pressure fluctuations in the fuel tank due to temperature changes and vapor accumulation. The isolation valve helps regulate these conditions by sealing the tank when necessary to prevent vapor escape and by venting through the evaporative emissions control system under controlled conditions. This functionality ensures compliance with stringent emissions regulations, maintains system integrity, and enhances safety by preventing over-pressurization or vacuum conditions in the tank. Additionally, because hybrid vehicles experience unique operating cycles, isolation valves are often designed with advanced control logic and robust sealing technologies to ensure reliable performance across a wide range of operating environments. As such, they play a vital role in reducing environmental impact while supporting the efficiency and safety of modern hybrid vehicle designs.SUMMARY OF PARTICULAR EMBODIMENTS

[0003] Conventional fuel tank isolation valve assemblies generally rely on solenoid-driven actuation to regulate vapor communication between a fuel tank and a vapor recovery canister. In such designs, the solenoid lifts valve components upward to transition the valve from a closed position to an open position. While effective, this upward-lift configuration requires the solenoid to generate substantial magnetic force to overcome the combined weight of the valve components and the operating pressures acting within the fuel tank. As a result, large amounts of copper windings are needed to achieve the necessary actuation force, leading to increased material costs, higher overall assembly expense, and reduced efficiency in operation.ACTIVE 513286736.1ATTORNEY DOCKET PATENT APPLICATION 006976.23332 of 25

[0004] The present disclosure provides a solution to address these limitations by providing a fuel tank isolation valve assembly configured for push-type actuation. Rather than lifting valve components upward against load forces, the assembly employs a solenoid-driven mechanism that selectively extends an armature downward to displace a seal assembly away from a valve seat. By opening the valve through a downward pushing action, the effective load on the solenoid is significantly reduced. This architecture allows for the use of a smaller and less costly solenoid while maintaining reliable performance under varying pressure and vacuum conditions, thereby improving efficiency and reducing manufacturing costs compared to conventional designs.

[0005] The clauses below summarize various embodiments described herein.

[0006] Clause 1. A valve assembly comprising: a valve housing defining an inlet, an outlet, and a chamber between the inlet and the outlet; a valve seat disposed within the chamber and surrounding an aperture, the aperture being positioned along a fluid flow path between the inlet and the outlet of the valve housing, the valve seat having an inlet side facing the inlet and an outlet side facing the outlet; an actuating assembly coupled to the valve housing, the actuating assembly including an armature rod, the actuating assembly being configured such that, when actuated, the armature rod extends axially toward the aperture; a push rod disposed within the chamber and operatively coupled to a distal end of the armature rod such that the push rod is displaced in response to movement of the armature rod, the push rod having a retracted position and an extended position, wherein the push rod at least partially extends through the aperture in the extended position; an over-pressure relief (OPR) seal assembly disposed between the outlet side of the valve seat and the outlet, wherein the push rod is operatively coupled to the OPR seal assembly; and an OPR spring configured to bias the OPR seal assembly toward the outlet side of the valve seat; wherein the OPR seal assembly has a first closed position and a first open position, wherein in the first closed position, the OPR seal assembly forms a seal with the outlet side of the valve seat, and wherein in the first open position, the OPR seal assembly is separated from the outlet side of the valve seat.

[0007] Clause 2. The valve assembly of clause 1, wherein the push rod includes a hollow cavity and side walls surrounding an opening to the hollow cavity.

[0008] Clause 3. The valve assembly of clause 2, wherein distal ends of the side walls of the push rod are configured to mechanically engage the OPR seal assembly.

[0009] Clause 4. The valve assembly of any one of the preceding clauses, wherein the OPR seal assembly is configured to switch from the first closed position to the first open positionACTIVE 513286736.1ATTORNEY DOCKET PATENT APPLICATION 006976.23333 of 25 when the actuating assembly extends the armature rod, thereby causing the push rod to mechanically displace the OPR seal assembly and separating the OPR seal assembly from the valve seat.

[0010] Clause 5. The valve assembly of any one of the preceding clauses, wherein the OPR seal assembly is configured to switch from the first closed position to the first open position when a pressure from the inlet overcomes a spring force of the OPR spring, independently of whether the actuating assembly extends the armature rod.

[0011] Clause 6. The valve assembly of any one of the preceding clauses, further comprising: an over- vacuum relief (OVR) seal assembly disposed between the push rod and the OPR seal assembly, the OVR seal assembly having a stem that extends into the hollow cavity and a base that is surrounded by the side walls of the push rod; and an OVR spring disposed within the hollow cavity, the OVR spring configured to bias the OVR seal assembly toward the OPR seal assembly; wherein when the OVR seal assembly is in a second closed position, the base of the OVR seal assembly seals one or more through openings in the OPR seal assembly, and when the OVR seal assembly is in a second open position, the base of the OVR seal assembly is separated from the one or more through openings in the OPR seal assembly.

[0012] Clause 7. The valve assembly of any one of the preceding clauses, wherein the base of the OVR seal assembly has a seal, and the OPR seal assembly has a recess for mating with the seal of the OVR seal assembly.

[0013] Clause 8. The valve assembly of any one of the preceding clauses, wherein the OVR seal assembly is configured to switch from the second closed position to the second open position when a vacuum pressure from the inlet overcomes a spring force of the OVR spring.

[0014] Clause 9. The valve assembly of any one of the preceding clauses, wherein the base of the OVR seal assembly has a thickness smaller than a permissible travel distance between the distal end of the side walls of the push rod and the opening to the hollow cavity to permit the OVR seal assembly to translate relative to the push rod along an axis of the push rod.

[0015] Clause 10. The valve assembly of any one of the preceding clauses, wherein the side walls of the push rod have one or more through openings to permit fluid flow from the outlet to the inlet when the OVR seal assembly is in the second open position.

[0016] Clause 11. The valve assembly of any one of the preceding clauses, wherein the inlet is configured to be coupled to a fuel tank of a vehicle, and the outlet is configured to be coupled to a vapor recovery canister.ACTIVE 513286736.1ATTORNEY DOCKET PATENT APPLICATION 006976.23334 of 25

[0017] Clause 12. The valve assembly of any one of the preceding clauses, wherein the fluid flow path is blocked when the aperture is closed, and the fluid flow path is permitted when the aperture is open.

[0018] Clause 13. The valve assembly of any one of the preceding clauses, further comprising a seal housing disposed within the chamber, the seal housing defining the valve seat and the aperture.

[0019] Clause 14. The valve assembly of any one of the preceding clauses, wherein the seal housing includes one or more windows to facilitate fluid flow through the seal housing.

[0020] Clause 15. The valve assembly of any one of the preceding clauses, wherein at least a portion of the seal housing corresponding to where the one or more windows are disposed is separated from an interior surface of the valve housing by a gap, the gap facilitating fluid flow around the seal housing.

[0021] Clause 16. The valve assembly of any one of the preceding clauses, further comprising a first O-ring disposed between an upper portion of the seal housing and a first interior surface of the valve housing above the inlet, and a second O-ring disposed between a lower portion of the seal housing and a second interior surface of the valve housing below the inlet.

[0022] Clause 17. A fuel system of a vehicle, comprising: a fuel tank; a vapor recovery canister; and a valve assembly comprising: a valve housing defining an inlet coupled to the fuel tank, an outlet coupled to the vapor recovery canister, and a chamber between the inlet and the outlet; a valve seat disposed within the chamber and surrounding an aperture; an actuating assembly coupled to the valve housing, the actuating assembly configured to selectively extend a push rod disposed within the chamber; an over-pressure relief (OPR) seal assembly disposed between the valve seat and the outlet; an OPR spring disposed between the OPR seal assembly and the outlet and configured to bias the OPR seal assembly toward the valve seat; an overvacuum relief (OVR) seal assembly disposed between the push rod and the OPR seal assembly; and an OVR spring disposed between the push rod and the OVR seal assembly and configured to bias the OVR seal assembly toward the OPR seal assembly; wherein the actuating assembly is configured to selectively extend the push rod through the aperture to mechanically engage the OPR seal assembly and separate the OPR seal assembly from the valve seat, thereby opening a fluid flow path between the inlet and the outlet.

[0023] Clause 18. The fuel system of clause 17, wherein: the push rod includes a hollow cavity and side walls surrounding an opening to the hollow cavity, and the OVR seal assemblyACTIVE 513286736.1ATTORNEY DOCKET PATENT APPLICATION 006976.23335 of 25 has a stem that extends into the hollow cavity and a base that is surrounded by the side walls of the push rod.

[0024] Clause 19. The fuel system of any one of clauses 17-18, wherein when the OVR seal assembly is in a closed position, the OVR seal assembly seals one or more through openings in the OPR seal assembly, and when the OVR seal assembly is in an open position, the OVR seal assembly is separated from the one or more through openings in the OPR seal assembly.

[0025] Clause 20. The fuel system of any one of clauses 17-19, wherein: the OPR seal assembly is configured to switch from a first closed position to a first open position when a pressure from the fuel tank overcomes a spring force of the OPR spring, independently of whether the actuating assembly extends the push rod, and the OVR seal assembly is configured to switch from a second closed position to a second open position when a vacuum pressure from the fuel tank overcomes a spring force of the OVR spring.BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings.

[0027] FIG. 1 illustrates a fuel tank isolation valve assembly 100 in a closed position, according to an embodiment of this disclosure.

[0028] FIG. 2 illustrates an exploded view of the valve assembly 100 shown in FIG. 1.

[0029] FIG. 3 illustrates a close-up view of the valve assembly 100 in a closed position.

[0030] FIG. 4 illustrates a schematic view of the valve assembly 100 in the closed position, specifically showing various forces acting on various valve components of the valve assembly.

[0031] FIGS. 5-6 illustrate the valve assembly 100, particularly depicting its fluid flow paths when the valve is in an open state for pressure relief — whether actively opened by an actuation assembly or passively opened through the overpressure release mechanism..

[0032] FIGS. 7-9 illustrate the valve assembly 100, specifically showing its fluid flow paths when it is in a open state for vacuum pressure relief.DESCRIPTION OF EXAMPLE EMBODIMENTS

[0033] A fuel tank isolation valve assembly are typically used to regulate fuel vapor communication between a fuel tank and other components of a vehicle fueling system, such asACTIVE 513286736.1ATTORNEY DOCKET PATENT APPLICATION 006976.23336 of 25 a vapor recovery canister. In some implementations, the fuel tank isolation valve assembly selectively isolates the fuel tank from the vehicle engine and / or controls venting of vapors from the fuel tank to the vapor recovery canister to allow periodic purging of the canister. The valve assembly may also manage fuel tank pressure by releasing fuel vapor to the canister in response to control commands from a vehicle controller. For example, in a hybrid vehicle operating in electric-driving mode, the fuel tank may remain isolated from the engine, which may cause pressure to accumulate in the fuel tank. To relieve this pressure, the vehicle controller may open the valve assembly under particular operating conditions or in response to particular pressure build ups. For example, during refueling, air and fuel vapor within the fuel tank may need to be vented. So when the vehicle operator opens the fuel tank cover, the vehicle’s control system may instruct the valve assembly to open so as to release tank pressure in preparation for the refueling process.

[0034] Conventional fuel tank isolation valve assemblies typically employ a solenoid actuator to control valve operation. In such assemblies, valve components are supported by a solenoid that, when energized, lifts or displaces the valve components toward the solenoid to transition the valve from a closed position to an open position. The solenoid-driven actuation allows the valve assembly to regulate tank pressure under both static and dynamic conditions.

[0035] Conventional solenoid-actuated fuel tank isolation valve assemblies present challenges in terms of cost and efficiency. In such assemblies, the solenoid is typically the most expensive component, largely due to the amount of copper wire required in its construction. The solenoid must be designed to generate sufficient magnetic force to support and lift the valve components against the weight of the valve components and the operating pressures acting on them. As a result, significant copper windings are needed, which increases material costs and contributes to the overall expense and complexity of the assembly.

[0036] Embodiments of the fuel tank isolation valve assembly described herein is designed based on the recognition that in conventional solenoid-actuated valve assemblies, where the solenoid opens the valve by lifting the valve components upward, the solenoid must overcome substantial forces. Such forces can be decreased in an alternative valve assembly architecture, as described in the present application, which supports solenoid actuation through a downward pushing action. By opening the valve in a downward direction away from the solenoid, the assembly reduces the effective forces that must be overcome during actuation. As a result, the solenoid is subject to significantly lower load demands, enabling the use of a smaller, lessACTIVE 513286736.1ATTORNEY DOCKET PATENT APPLICATION 006976.23337 of 25 costly solenoid while still achieving reliable valve operation under varying fuel tank pressure conditions

[0037] FIG. 1 illustrates a fuel tank isolation valve assembly 100 with an architecture that supports a solenoid with a push-down actuation mechanism, and FIG. 2 illustrates an exploded view of the same valve assembly 100. The fuel tank isolation valve assembly 100 is configured to regulate fluid communication between a vehicle fuel tank and a vapor recovery canister, thereby maintaining tank pressure within a desired operational window. The relative positions of the components shown in FIG. 1 is when the valve assembly 100 is in the closed position.

[0038] The valve assembly 100 includes a valve housing 102 having an inlet 104, an outlet 106, and a chamber 160 between the inlet 104 and the outlet 106. In one embodiment, the housing 102 is formed as a 90-degree structure in which the inlet 104 and outlet 106 are generally perpendicular to one another, with the inlet 104 connected to the fuel tank and the outlet 106 connected to the vapor recovery canister. The chamber 160 is the portion of the interior of the valve housing 102 that bridges the inlet 104 and the outlet 106. In alternative embodiments, the housing may be formed as a 180-degree structure in which the inlet and outlet are aligned in a generally parallel configuration, allowing flexibility in packaging within different vehicle architecture. For example, instead of extending downward, the outlet may bend to the left, facing the opposite direction as the inlet. An internal portion of such a valve housing also includes a chamber that bridges the inlet and the outlet. As will be described in further detail below, various valve components for opening and closing a fluid flow path between the inlet and the outlet are disposed within the chamber of either a 90-degere or a 180- degree housing structure.

[0039] The valve assembly 100 may incorporate integrated over pressure relief (OPR) and / or over vacuum relief (OVR) functionalities in an in-line arrangement. During an OPR event where pressure within the fuel tank exceeds a certain threshold, the pressure causes the valve assembly 100 to mechanically open, thereby permitting the fuel tank to depressurize as fluid / vapor flows from the fuel tank into the inlet 104 and out of the outlet 106. This depressurization allows the fuel tank to release excess pressure to the vapor recovery canister, helping keep pressure within the fuel tank at a safe level, even when the solenoid is not energized or malfunctioning. Conversely, during an OVR event where pressure inside the fuel tank is below ambient pressure, the valve assembly 100 mechanically opens to allow reverse flow from the outlet 106 to the inlet 104, thereby relieving the vacuum condition by drawing air or vapor back toward the fuel tank. By consolidating OPR and OVR functions into a singleACTIVE 513286736.1ATTORNEY DOCKET PATENT APPLICATION 006976.23338 of 25 housing, the valve assembly 100 reduces the need for separate relief devices, improving system efficiency and simplifying integration. The resulting system ensures that the pressure within the fuel tank remains within a safe and controlled range, protecting tank integrity, supporting evaporative emissions control, and promoting reliable operation under a variety of environmental and driving conditions.

[0040] In particular embodiments, the valve assembly 100 may include an actuating assembly 108, such as a solenoid assembly or another suitable electromagnetic actuation mechanism, operatively coupled to the valve housing 102. The actuating assembly 108 may, for example, be mounted to an upper portion of the housing 102 and configured to interact with internal valve components to control fluid communication between the inlet 104 and outlet 106. The actuating assembly 108 is adapted to receive electrical power and to be triggered and modulated by an electrical control signal originating from the vehicle’s electronic control unit (ECU) or another suitable controller.

[0041] In certain embodiments, the actuating assembly 108 may include a coil 112 and an armature coupled to an armature rod 110 arranged along a longitudinal axis of the housing 102. When energized, the coil 112 generates an electromagnetic field that drives the armature and the armature rod 110 in a downward direction, causing the armature rod 110 to extend axially out of the actuating assembly 108 and toward the valve chamber 160 or, as will be described in further detail below, an aperture 162 (see FIG. 6) disposed within the chamber 160. The stroke or range of motion of the armature and the armature rod 110 is restricted by a ceiling within the actuating assembly 108 and a bottom seat for the armature. When energized, the armature moves toward the bottom seat until it is stopped by the bottom seat. When deenergized, the armature may retract upward until it is stopped by the ceiling. This upward motion may be assisted by an OPR spring 124 (described in further detail below) that exerts an upward spring force configured to urge the armature upward via the armature rod 110 and push rod 114. The armature rod 110 and push rod 114 may be configured to engage a sealing element, diaphragm, or other valve closure member positioned within the housing 102, thereby selectively opening or closing the valve passage between the inlet 104 and outlet 106.

[0042] As will be explained in further detail below, by employing a push-type actuation architecture — where the armature rod 110 applies force in a downward direction to open the valve — embodiments disclosed herein reduce the actuation force required during operation, particularly under over pressure relief (OPR) conditions. For example, when the valve opens to relieve excess pressure from the fuel tank to the vapor recovery canister, the direction ofACTIVE 513286736.1ATTORNEY DOCKET PATENT APPLICATION 006976.23339 of 25 tank pressure assists rather than resists the downward actuation stroke, which is in contrast to conventional fuel tank isolation valves with pull-type actuation assemblies. This push-type arrangement not only decreases the electrical energy demand of the coil 112 but also improves response time and durability of the solenoid assembly 108, thereby improving component costs and supporting more efficient pressure management within the fuel system.

[0043] In particular embodiments, the valve assembly 100 may include an internal seal housing 128 that is positioned within a chamber 160 of the valve housing 102. The seal housing 128 may be configured as a generally cylindrical or sleeve-like component that fits coaxially within the chamber 160 and provides structural support for valve components that provide sealing and flow control functions. In certain embodiments, the seal housing 128 may be fixed in place by press-fitting, welding, adhesive bonding, or other suitable joining techniques to ensure stable positioning during operation. The seal housing 128 may have openings on both ends, with the top opening configured to receive the solenoid’s armature rod 110, and the bottom opening configured to surrounding the opening to the outlet 106.

[0044] The exterior surface of the seal housing 128 may include an upper groove 140 and a lower groove 141. Each groove may be annular and dimensioned to retain an O-ring, such as O-ring 130 in the upper groove 140 and O-ring 131 in the lower groove 141. When the seal housing 128 is installed within the valve housing 102, the upper groove 140 is positioned above the opening to the inlet 104, while the lower groove 141 is positioned below the opening. In this arrangement, the O-rings 130, 131 seal the annular gap between the external surface of the seal housing 128 and the internal surface of the valve housing 102, thereby preventing leakage or bypass flow around the seal housing 128 and ensuring that fluid communication occurs only through designated flow paths.

[0045] In addition to its sealing features, the seal housing 128 may further include one or more windows 150 formed in its wall. These window(s) 150 may be circumferentially spaced and sized to permit controlled passage of vapor or fluid between the inlet 104 and outlet 106 through the seal housing 128. For example, the window(s) 150 allow vapor to enter the interior of the seal housing 128 from the inlet 104 and exit toward the bottom opening of the seal housing 128 and into the outlet 106 during normal venting or pressure relief events. The number, size, and distribution of the windows may be selected to balance flow capacity with structural integrity, ensuring reliable operation under varying fuel tank pressure conditions.

[0046] In particular embodiments, at least one of the windows 150 may be aligned with the inlet 104 so that vapor and gas may flow directly to / from the inlet 104 and into the seal housingACTIVE 513286736.1ATTORNEY DOCKET PATENT APPLICATION 006976.233310 of 25128. In an optional configuration, one or more additional windows 150 may be formed along the wall of the seal housing 128, for example, at a location circumferentially offset from the inlet 104 (e.g., positioned on the opposite side of the inlet 104). The portion of the exterior surface of the seal housing 128 where the additional windows 150 are located may be radially spaced apart from the corresponding internal surface of the valve housing 102, thereby defining an annular gap or clearance region between the two surfaces. In this arrangement, vapor or gas entering the chamber 160 through the inlet 104 may flow into the annular gap, travel circumferentially around the exterior of the seal housing 128, and access the one or more additional windows 150 even if they are not directly aligned with the inlet 104. This configuration promotes more uniform distribution of flow into the seal housing 128, reduces localized flow restriction, and can improve pressure equalization across the valve assembly during venting or relief events.

[0047] An optional cap of the actuating assembly 108 may be fitted to the upper end of the seal housing 128 to couple the actuating assembly 108 to the seal housing 128 in a fixed and sealed manner. In certain embodiments, the cap may include an annular lip configured to seat within a corresponding recess of the actuating assembly 108. The annular lip may transition into a cylindrical portion that extends outward through an aperture in the actuating assembly 108. Because the annular lip has a larger diameter than the aperture, the cap is securely retained in place and prevented from disengaging from the actuating assembly 108. When assembled, the cylindrical portion of the cap may extend into and be received by the top opening of the seal housing 128, which is itself positioned within the chamber 160 of the valve housing 102. In particular embodiments, the cap may further include an annular groove formed around the exterior of the cylindrical portion. The groove may be dimensioned to receive an O-ring, which provides a radial seal between the outer surface of the cylindrical portion of the cap and the corresponding internal surface of the seal housing 128. This arrangement ensures that any potential leakage path between the actuating assembly 108 and the seal housing 128 is blocked, thereby maintaining controlled flow through the designated valve passages.

[0048] In particular embodiments, a push rod 114 may be positioned within the seal housing 128 to receive actuation force from the actuating assembly 108. The push rod 114 may be operatively coupled to the lower end of the armature rod 110 such that the push rod 114 displaces in response to movement of the armature rod 110 when actuated by the coil 112 of the actuating assembly 108. The coupling between the armature rod 110 and the push rod 114 may be implemented using any suitable interface. For example, and without limitation, theACTIVE 513286736.1ATTORNEY DOCKET PATENT APPLICATION 006976.233311 of 25 upper end of the push rod 114 may define a pocket or recess configured to receive the lower end of the armature rod 110. Because the actuation stroke of the armature rod 110 is directed downward toward the push rod 114, the pocket provides alignment, guidance, and sufficient surface area to transmit actuation force from the armature rod 110 to the push rod 114. In this configuration, the armature rod 110 is not rigidly affixed to the push rod 114; thus, when the armature rod 110 retracts upward into the actuating assembly 108, the push rod 114 is not directly pulled along with it. Instead, as will be described in further detail below, spring elements within the assembly bias the push rod 114 toward the armature rod 110, causing the push rod 114 to follow the retracting motion of the armature rod while maintaining compliance. In alternative embodiments, the push rod 114 may be rigidly coupled to the armature rod 110, such as by press-fit engagement, welding, adhesive bonding, or other fastening techniques. In this arrangement, both the downward extension and upward retraction of the armature rod 110 directly displace the push rod 114, providing a fixed mechanical linkage between the two components.

[0049] In certain embodiments, the axial length of the push rod 114 is dimensioned to define its range of motion. For instance, when the armature rod 110 is fully retracted, the upper end of the push rod 114 may abut a ceiling (e.g., the bottom surface of the actuating assembly 108). At this position, the push rod 114 allows the OPR seal assembly 120 to fully close the aperture 162. As the actuating assembly 108 extends the armature rod 110, the push rod 114 is correspondingly extended, such that the stroke of the armature rod 110 is translated through the push rod 114 to open the OPR seal assembly 120.

[0050] In particular embodiments, the lower end of the push rod 114 opposite to the armature rod 110 may be operatively coupled to an over-vacuum relief (OVR) seal assembly 116. By way of example, the lower end of the push rod 114 may be formed with a hollow cavity 117 or inner space dimensioned to receive and house at least a portion of the OVR seal assembly 116. In an optional embodiment, the push rod 114 may have a side wall 119 or prongs surrounding the opening of the hollow cavity 117. The side wall 119 may optionally have one or more through-openings, which are more clearly shown in FIG. 2 and 6. These openings provide fluid communication into and out of the inner space, thereby allowing vapor or gas to flow through the push rod 114 as needed during valve operation. The side wall 119 of the push rod 114 may have a dimension smaller than a sealable aperture 162 (see FIG. 6) in the seal housing 128, thereby allowing the push rod 114 to extend through the sealable aperture 162. This sealable aperture 162 may be defined and surrounded by a valve seat 161 formed on theACTIVE 513286736.1ATTORNEY DOCKET PATENT APPLICATION 006976.233312 of 25 internal surface of the seal housing 128 placed in the chamber 160. The valve seat 161 may be positioned along a fluid flow path between the inlet 104 and the outlet 106 of the valve housing. The valve seat 161 may have an inlet side (e.g., top side in FIG. 1) facing the inlet 104 and an outlet side (bottom side in FIG. 1) facing the outlet 106.

[0051] The OVR seal assembly 116 may include a base and an axially extending stem coupled thereto. For example, the base may be a disk, and the stem may be a narrower rod that extend from a center of the disk. A seal 122 may be secured to the lower surface of the base to provide a sealing interface. The seal 122 may generally have an annular rim around its perimeter, surrounding a substantially flat region. In particular embodiments, the seal 122 may be formed of an elastomeric or otherwise resilient material such as rubber, silicone, or other fuel-compatible polymer, which is deformable under pressure to form a tight seal against a corresponding seat surface. The seal 122 may be attached to the base of the OVR seal assembly 116 by over- molding, adhesive bonding, or other suitable coupling techniques that ensure durability under repeated cycling.

[0052] An OVR spring 118 may be contained within the cavity 117 or inner space of the push rod 114 and operatively coupled to the stem of the OVR seal assembly 116. For example, the stem of the OVR seal assembly 116 may be inserted within the spring axis to retain OVR spring 118, and the OVR spring 118 may be seated on top of the base portion of the OVR seal assembly. The OVR spring 118 may be configured to apply a downward biasing force on the OVR seal assembly 116, urging it downward towards the over-pressure relief (OPR) seal assembly 120 in a normally closed, sealed position. This spring-loaded arrangement ensures that under standard conditions (i.e., the actuation assembly is in a retracted state, and the pressure and vacuum within the fuel tank are insufficient to overcome the OPR spring and OVR spring, respectively), the OVR seal assembly 116 remains seated to prevent unintended flow. As shown in FIG. 1 , at the closed position, the OVR spring 118 urges the OVR seal assembly 116 against the OPR seal assembly 120, which is resting against and sealing the aperture 162 within the seal housing 128, thereby preventing vapor for flowing through the aperture 162. This effectively seals fluid passage between the inlet 104 and outlet 106.

[0053] As shown in FIG. 1, the disk portion of the OVR seal assembly 116 fits within the space surrounded by the side wall at the bottom distal end of the push rod 114. The thickness of the disk is configured to be thinner than a permissible travel distance between the distal end of the wall 119 of the push rod 114 and the opening to the cavity 117. This geometry allows the OVR seal assembly 116 to travel up and down relative to the push rod 114. For example,ACTIVE 513286736.1ATTORNEY DOCKET PATENT APPLICATION 006976.233313 of 25 in the position shown in FIG. 1, the OVR seal assembly 116 is at the distal end of its travel. When sufficient vacuum differential arises within the fuel tank system that overcomes the spring force of the OVR spring 118, the OVR seal assembly 116 will be urged upward relative to the push rod 114, thereby allowing vapor to flow through the opening.

[0054] In particular embodiments, the over-pressure relief (OPR) seal assembly 120 may be positioned below and directly interface with the over- vacuum relief (OVR) seal assembly 116 within the valve assembly 100. As illustrated, the OPR seal assembly 120 may be configured as a hat-shaped valve body, with a base (e.g., a disk) and a tapered stem. The base portion of the OPR seal assembly 120 faces upward against the OVR seal assembly 116, and the stem portion faces downward in the opposite direction. The upper surface of the OPR seal assembly 120 may define a central recess 704 dimensioned to receive the OVR seal assembly 116 or the seal 122 attached thereto. One or more through openings 802 may be formed within the recessed portion to allow selective fluid passage through the OPR seal assembly 120 when the OVR seal assembly 116 is lifted by a vacuum condition in the fuel tank (see, e.g., FIGS. 8- 9). When the valve assembly 100 is in a closed condition, as shown in FIG. 1, the seal 122 on the OVR seal assembly 116 may be pressed downward into sealing engagement with the recess of the OPR seal assembly 120. In this arrangement, the seal 122 may seat snugly within the recess 704, thereby forming a fluid-tight interface that blocks fluid flow via the through openings 802 and into the inner space of the OVR seal assembly 116.

[0055] The base or disk portion of the OPR seal assembly 120 may have a dimension that is larger than the aperture 162 within the seal housing 128, so that the OPR seal assembly 120 cannot pass through the aperture 162. The OPR seal assembly 120 may further include a seal 126 positioned near the outer perimeter of its upper surface, radially outside the central recess. The seal 126 may be configured to press upward against the valve seat 161 around the aperture 162 in the seal housing 128. The seal 126 may be formed of an elastomeric or other resilient sealing material, such as rubber or a fuel-compatible polymer, which can elastically deform under pressure to provide a reliable sealing function. The seal 126 may be coupled to the body of the OPR seal assembly 120 by over- molding, adhesive bonding, or other suitable attachment techniques.

[0056] In particular embodiments, the OPR seal assembly 120 may be biased into its sealing position by an OPR spring 124. For example, the upper end of the OPR spring 124 may press upward against the underside of the OPR seal assembly 120, urging its seal 126 into sealing engagement with the valve seat 161 around the aperture 162 of the seal housing 128.ACTIVE 513286736.1ATTORNEY DOCKET PATENT APPLICATION 006976.233314 of 25In some embodiments, the OPR spring 124 may be conical in geometry, which provides greater stability and resistance to lateral displacement compared to a cylindrical spring design, while also accommodating more compact packaging within the chamber 160. The spring force of the OPR spring 124 may be greater than that of the OVR spring 118, so that absent any other forces, the OPR spring 124 will overcome the spring force of the OVR spring 118, thereby allowing the OPR seal assembly 120 to close.

[0057] FIGS. 3-4 illustrate the valve assembly 100 in the closed state, with FIG. 3 showing a close-up view of the valve assembly 100 and FIG. 4 schematically showing various forces acting on the components. In the closed condition, both the OVR seal assembly 116 and the OPR seal assembly 120 are sealed such that no vapor is permitted to pass through the valve assembly 100 from the inlet 104 to the outlet 106 or vice versa. Specifically, in this configuration, the seal 122 of the OVR seal assembly 116 is pressed down against the OPR seal assembly 120 into its recess under the spring force PS2 exerted by the OVR spring 118. Meanwhile, the seal 126 of the OPR seal assembly 120 is pushed upward to seal against the valve seat 161 around the aperture 162 of the seal housing 128 under the spring force Psifrom the OPR spring 124. In this configuration, the aperture 162 is sealed, since the seal 122 of the OVR seal assembly 116 seals the opening in the recess portion of the OPR seal assembly 120, and the seal 126 of the OPR seal assembly 120 prevents vapor from passing through the outer edge where the seal 126 interfaces with the valve seat 161 around the aperture 162 in the seal housing 128.

[0058] FIG. 4 further illustrates the forces acting on the valve components, demonstrating the amount of force needed by the actuating assembly 108 to open the valve assembly 100. As previously mentioned, spring force Psifrom OPR spring 124 is exerted upward against the OPR seal assembly 120. On the opposite end, OVR spring 118 exerts a spring force PS2 in the opposite downward direction on the OVR seal assembly 116. In addition, fluid vapor pressure from the inlet 104 may act down on the OPR seal assembly 120 (Pvi) and the OVR seal assembly 116 (PV2) as fuel tank pressure builds up. Lastly, the actuating assembly 108 may exert a downward force Psoion the OVR seal assembly 116 when actuated. Thus, a contact force N2 exerted on the OVR seal assembly 116 may be expressed as N2 = PS2 + Pv2 + Psoi. Whether the OPR seal assembly 120 opens depends on whether the OPR spring force Psi is overcome by the forces applied to the OVR seal assembly 116 (N2) and the vapor pressure on the OPR seal assembly 120 (Pvi). For example, when the valve is closed, Ni is greater than 0, indicating that the spring force Psi is greater than the combination of Pviand N2. During anACTIVE 513286736.1ATTORNEY DOCKET PATENT APPLICATION 006976.233315 of 25OPR event, the combined forces from Pviand N2 overcomes the spring force Psi, thereby pushing the OPR seal assembly 120 downward to open the valve assembly 100. During an OVR event, the vapor pressures Pviand Pv2 are negative and overcomes the spring force PS2 of the OVR spring 118, thereby causing the OVR seal assembly 116 to open upward.

[0059] When depressurization is actively needed, the actuating assembly 108 may be activated to push down the armature rod 110, exerting a downward force Psoiin order to push open the OPR seal assembly 120. In this case, since the fluid pressure Pviand PV2 (as well as spring force PS2 from the OVR spring 118) are acting in the same direction as the actuating assembly 108, the required Psoifrom the actuating assembly 108 to open the OPR seal assembly 120 is significantly reduced, since Psoionly needs to be greater than Psi- Pvi - Pv2 - Ps2 to overcome Psi. Thus, using a push-type actuating assembly 108 allows for a decrease in the number of coil turns (since actuation force is usually proportional to the coil turns) or other solenoid requirements, consequently lowering the product cost. This contrasts with traditional pull-type valve assemblies where fluid pressure acts against the solenoid actuation force during OPR operation, thus requiring a significant amount of actuation force from the solenoid.

[0060] FIGS. 5-6 illustrate the valve assembly 100 in an open state, triggered either actively by the actuation assembly 108 or passively via the OPR mechanism. When active actuation is desired, the actuation assembly 108 may be energized, causing the armature rod 110 to extend. Specifically, when deemed necessary, the vehicle controller may energize the actuating assembly 108, actuating the armature rod 110 to move it downward, consequently pushing down the push rod 114. In doing so, the push rod 114 presses down on the OPR seal assembly 120, overcoming the upward force by the OPR spring 124. This causes the seal 126 of the OPR seal assembly 120 to separate from the valve seat 161 around the aperture 162 of the seal housing 128, thereby opening a pathway therebetween. When this occurs, the OVR seal assembly 116 may continue to be pressed downward against the OPR seal assembly 120, as the OVR spring 118 continues to exert downward spring force.

[0061] In this configuration with the OPR seal assembly 120 pressed down to the open position, vapor may flow from the inlet 104 into the seal housing 128 through its windows 150, flow through the push rod 114 (e.g., via its through openings 602 in or between the side walls) along the passage formed between the OPR seal assembly 120 and the seal housing 128, and finally escape toward the outlet 106. This is schematically depicted by a flow path 502. As discussed, during this process, since fluid pressure is acting in the same direction as the valve actuation force by the actuating assembly 108, contributing to opening up the OPR sealACTIVE 513286736.1ATTORNEY DOCKET PATENT APPLICATION 006976.233316 of 25 assembly 120, the amount of force required from actuating assembly 108 is significantly reduced, thereby lowering coil requirement and optimizing force balancing issues.

[0062] As mentioned, the open state shown in FIGS. 5 and 6 may alternatively be achieved passively via an OPR mechanism. When pressure built up in the tank reaches a specific level, the OPR seal assembly 120 may be pressed down to the open position by the pressure force acting against the force of the OPR spring 124, leading to over-pressure relief with the vapor flow path 502 shown in FIGS. 5 and 6. Specifically, even without the actuating assembly 108 extending the armature rod 110 and the push rod 114, pressure from the inlet 104 may gradually build up in the chamber, pressing against the OPR seal assembly 120. The OPR seal assembly 120 would remain closed until the pressure is sufficient to overcome the upward spring force of the OPR spring 124, resulting in the OPR seal assembly 120 being displaced downward. This causes the seal 126 of the OPR seal assembly 120 to separate from the valve seat 161 around the aperture 162 of the seal housing 128, thereby opening a pathway therebetween. When this occurs, the OVR seal assembly 116 may continue to be pressed downward against the OPR seal assembly 120, as the OVR spring 118 continues to exert downward spring force.

[0063] In this configuration with the OPR seal assembly 120 pressed down to the open position, vapor may flow from the inlet 104 into the seal housing 128 through its windows 150, continue to flow through the push rod 114 (e.g., via its through openings 602 in or between the side walls) along the passage formed between the OPR seal assembly 120 and the seal housing 128, and finally escape toward the outlet 106. This is schematically depicted by a flow path 502.

[0064] FIGS. 7-9 illustrate the valve assembly 100 during vacuum relief when the actuating assembly 108 is not energized and the armature rod 110 remains still in its retracted position. When vacuum is accumulated in the fuel tank, pressure difference between the inlet 104 and the outlet 106 may overcome the downward spring force of the OVR spring 118, lifting up the OVR seal assembly 116 from the OPR seal assembly 120. Specifically, when this happens, the seal 122 is moved up away from the recess 704 of the OPR seal assembly 120, thus unblocking the through openings 802 in the recess of the OPR seal assembly 120. In other words, the OVR seal assembly 116 may be actuated passively in response to the upward pressure difference exceeding a certain limit. Therefore, a fluid path 702 is opened, allowing fluid to be drawn from the outlet 106, passing through the OPR seal assembly 120 via its through openings 802, then through and around the push rod 114 and its opening 602, and finally out of the seal housing 128 and towards the inlet 104. As depicted, in particularACTIVE 513286736.1ATTORNEY DOCKET PATENT APPLICATION 006976.233317 of 25 embodiments, the lip of the seal 122 of the OVR seal assembly 116 may be slanted toward the center, and the recess 704 may be correspondingly slanted to mate with the seal 122. This may help guide movement and proper alignment of the OVR seal assembly 116 as it is released down when the pressure is balanced, ensuring that the seal 122 always lands snugly within the recess 704, thus forming a vapor-tight seal.

[0065] Accordingly, embodiments disclosed herein provide a fuel tank isolation valve assembly that incorporates a push-type actuating assembly 108 architecture. This configuration enables the valve assembly to 100 continue to support active venting control, over-pressure relief (OPR), and over-vacuum relief (OVR), while significantly reducing the actuation force required from the actuating assembly 108. Because the armature rod 110 is driven in the same direction as the pressure bias acting within the valve, the actuation stroke benefits from pressure assistance rather than resistance. As a result, the actuating assembly 108 may be designed with a smaller, lower-power coil and associated components, thereby lowering manufacturing cost, reducing electrical energy consumption, and improving durability over extended use. Thus, the disclosed architecture achieves full functional performance of an isolation valve assembly while providing enhanced efficiency, cost-effectiveness, and system reliability.

[0066] In the embodiment shown and described, the chamber 160 within the valve housing 102 includes a seal housing 128, within which the aforementioned valve components are disposed (e.g., the push rod 114, OVR spring 118, OVR valve assembly 116, OPR valve assembly 120, OPR spring 124, etc.). In an alternative embodiment, the structural support features of the seal housing 128 may be built into the chamber of the valve housing 102. For example, on an interior surface within the chamber between the inlet and outlet, there may be an annular protrusion that serve as a valve seat, similar to the functionality of the valve seat 161 in the seal housing 128. The OPR valve assembly 120 may be disposed between the outlet and the valve seat formed directly within the chamber. In a similar manner previously described, the OPR valve assembly 120 may be urged upward by an OPR spring underneath it toward the valve seat. The OVR valve assembly 116 may be disposed above the OPR valve assembly 120 and urged by an OVR spring 118 downward, so that under normal conditions where vacuum pressure remains below a certain threshold, the OVR spring 118 would cause the OVR valve assembly 116 to close the through holes in the OPR valve assembly 120. When either the OPR valve assembly 120 or OVR valve assembly 116 is in an open state, a fluid flow path would permit vapor pressure to flow through the aperture defined by the valve seat.ACTIVE 513286736.1ATTORNEY DOCKET PATENT APPLICATION 006976.233318 of 25

[0067] In another alternative embodiment, a valve assembly may only have an OPR valve assembly without an OVR valve assembly. Such an embodiment is substantially similar to the embodiments described above, but certain features for OVR can be omitted. For example, such a valve assembly would not have an OVR valve assembly. Since the push rod no longer needs to accommodate the operations of the OVR valve assembly, the push rod may have a different form (e.g., without the hollow cavity or walls for receiving the OVR valve assembly), so long as it can translate the downward actuation motion from the actuating assembly (e.g. solenoid) to the OPR valve assembly. The OPR valve assembly, similar to the descriptions above, may be disposed below a valve seat defined on an interior surface of a seal housing or the valve housing, and the OPR valve assembly may be biased upward against the valve seat by an OPR spring. Since there is no OVR functionality in this embodiment, the top base portion of the OPR valve assembly may be solid, without any through openings. The OPR valve assembly can be opened by the actuating assembly or in response to pressure build up in the fuel tank, similar to what was previously described.

[0068] Herein, “or” is inclusive and not exclusive, unless expressly indicated otherwise or indicated otherwise by context. Therefore, herein, “A or B” means “A, B, or both,” unless expressly indicated otherwise or indicated otherwise by context. Moreover, “and” is both joint and several, unless expressly indicated otherwise or indicated otherwise by context. Therefore, herein, “A and B” means “A and B, jointly or severally,” unless expressly indicated otherwise or indicated otherwise by context.

[0069] The scope of this disclosure encompasses all changes, substitutions, variations, alterations, and modifications to the example embodiments described or illustrated herein that a person having ordinary skill in the art would comprehend. The scope of this disclosure is not limited to the example embodiments described or illustrated herein. Moreover, although this disclosure describes and illustrates respective embodiments herein as including particular components, elements, feature, functions, operations, or steps, any of these embodiments may include any combination or permutation of any of the components, elements, features, functions, operations, or steps described or illustrated anywhere herein that a person having ordinary skill in the art would comprehend. Furthermore, reference in the appended claims to an apparatus or system or a component of an apparatus or system being adapted to, arranged to, capable of, configured to, enabled to, operable to, or operative to perform a particular function encompasses that apparatus, system, component, whether or not it or that particular function is activated, turned on, or unlocked, as long as that apparatus, system, or componentACTIVE 513286736.1ATTORNEY DOCKET PATENT APPLICATION 006976.233319 of 25 is so adapted, arranged, capable, configured, enabled, operable, or operative. Additionally, although this disclosure describes or illustrates particular embodiments as providing particular advantages, particular embodiments may provide none, some, or all of these advantages.ACTIVE 513286736.1

Claims

1. ATTORNEY DOCKET PATENT APPLICATION 006976.233320 of 25CLAIMSWhat is claimed is:

1. A valve assembly comprising: a valve housing defining an inlet, an outlet, and a chamber between the inlet and the outlet; a valve seat disposed within the chamber and surrounding an aperture, the aperture being positioned along a fluid flow path between the inlet and the outlet of the valve housing, the valve seat having an inlet side facing the inlet and an outlet side facing the outlet; an actuating assembly coupled to the valve housing, the actuating assembly including an armature rod, the actuating assembly being configured such that, when actuated, the armature rod extends axially toward the aperture; a push rod disposed within the chamber and operatively coupled to a distal end of the armature rod such that the push rod is displaced in response to movement of the armature rod, the push rod having a retracted position and an extended position, wherein the push rod at least partially extends through the aperture in the extended position; an over-pressure relief (OPR) seal assembly disposed between the outlet side of the valve seat and the outlet, wherein the push rod is operatively coupled to the OPR seal assembly; and an OPR spring configured to bias the OPR seal assembly toward the outlet side of the valve seat; wherein the OPR seal assembly has a first closed position and a first open position, wherein in the first closed position, the OPR seal assembly forms a seal with the outlet side of the valve seat, and wherein in the first open position, the OPR seal assembly is separated from the outlet side of the valve seat.

2. The valve assembly of claim 1, wherein the push rod includes a hollow cavity and side walls surrounding an opening to the hollow cavity.

3. The valve assembly of claim 2, wherein distal ends of the side walls of the push rod are configured to mechanically engage the OPR seal assembly.ACTIVE 513286736.1ATTORNEY DOCKET PATENT APPLICATION 006976.233321 of 254. The valve assembly of claim 1, wherein the OPR seal assembly is configured to switch from the first closed position to the first open position when the actuating assembly extends the armature rod, thereby causing the push rod to mechanically displace the OPR seal assembly and separating the OPR seal assembly from the valve seat.

5. The valve assembly of claim 1, wherein the OPR seal assembly is configured to switch from the first closed position to the first open position when a pressure from the inlet overcomes a spring force of the OPR spring, independently of whether the actuating assembly extends the armature rod.

6. The valve assembly of claim 2, further comprising: an over-vacuum relief (OVR) seal assembly disposed between the push rod and the OPR seal assembly, the OVR seal assembly having a stem that extends into the hollow cavity and a base that is surrounded by the side walls of the push rod; and an OVR spring disposed within the hollow cavity, the OVR spring configured to bias the OVR seal assembly toward the OPR seal assembly; wherein when the OVR seal assembly is in a second closed position, the base of the OVR seal assembly seals one or more through openings in the OPR seal assembly, and when the OVR seal assembly is in a second open position, the base of the OVR seal assembly is separated from the one or more through openings in the OPR seal assembly.

7. The valve assembly of claim 6, wherein the base of the OVR seal assembly has a seal, and the OPR seal assembly has a recess for mating with the seal of the OVR seal assembly.

8. The valve assembly of claim 6, wherein the OVR seal assembly is configured to switch from the second closed position to the second open position when a vacuum pressure from the inlet overcomes a spring force of the OVR spring.

9. The valve assembly of claim 6, wherein the base of the OVR seal assembly has a thickness smaller than a permissible travel distance between the distal end of the side walls ofACTIVE 513286736.1ATTORNEY DOCKET PATENT APPLICATION 006976.233322 of 25 the push rod and the opening to the hollow cavity to permit the OVR seal assembly to translate relative to the push rod along an axis of the push rod.

10. The valve assembly of claim 6, wherein the side walls of the push rod have one or more through openings to permit fluid flow from the outlet to the inlet when the OVR seal assembly is in the second open position.

11. The valve assembly of any one of claims 1-10, wherein the inlet is configured to be coupled to a fuel tank of a vehicle, and the outlet is configured to be coupled to a vapor recovery canister.

12. The valve assembly of any one of claims 1-10, wherein the fluid flow path is blocked when the aperture is closed, and the fluid flow path is permitted when the aperture is open.

13. The valve assembly of any one of claims 1-10, further comprising a seal housing disposed within the chamber, the seal housing defining the valve seat and the aperture.

14. The valve assembly of claim 13, wherein the seal housing includes one or more windows to facilitate fluid flow through the seal housing.

15. The valve assembly of claim 14, wherein at least a portion of the seal housing corresponding to where the one or more windows are disposed is separated from an interior surface of the valve housing by a gap, the gap facilitating fluid flow around the seal housing.

16. The valve assembly of claim 13, further comprising a first O-ring disposed between an upper portion of the seal housing and a first interior surface of the valve housing above the inlet, and a second O-ring disposed between a lower portion of the seal housing and a second interior surface of the valve housing below the inlet.

17. A fuel system of a vehicle, comprising: a fuel tank; a vapor recovery canister; andACTIVE 513286736.1ATTORNEY DOCKET PATENT APPLICATION 006976.233323 of 25 a valve assembly comprising: a valve housing defining an inlet coupled to the fuel tank, an outlet coupled to the vapor recovery canister, and a chamber between the inlet and the outlet; a valve seat disposed within the chamber and surrounding an aperture; an actuating assembly coupled to the valve housing, the actuating assembly configured to selectively extend a push rod disposed within the chamber; an over-pressure relief (OPR) seal assembly disposed between the valve seat and the outlet; an OPR spring disposed between the OPR seal assembly and the outlet and configured to bias the OPR seal assembly toward the valve seat; an over- vacuum relief (OVR) seal assembly disposed between the push rod and the OPR seal assembly; and an OVR spring disposed between the push rod and the OVR seal assembly and configured to bias the OVR seal assembly toward the OPR seal assembly; wherein the actuating assembly is configured to selectively extend the push rod through the aperture to mechanically engage the OPR seal assembly and separate the OPR seal assembly from the valve seat, thereby opening a fluid flow path between the inlet and the outlet.

18. The fuel system of claim 17, wherein: the push rod includes a hollow cavity and side walls surrounding an opening to the hollow cavity, and the OVR seal assembly has a stem that extends into the hollow cavity and a base that is surrounded by the side walls of the push rod.

19. The fuel system of claim 17, wherein when the OVR seal assembly is in a closed position, the OVR seal assembly seals one or more through openings in the OPR seal assembly, and when the OVR seal assembly is in an open position, the OVR seal assembly is separated from the one or more through openings in the OPR seal assembly.

20. The fuel system of claim 17, wherein: the OPR seal assembly is configured to switch from a first closed position to a first open position when a pressure from the fuel tank overcomes a spring force of the OPR spring, independently of whether the actuating assembly extends the push rod, andACTIVE 513286736.1ATTORNEY DOCKET PATENT APPLICATION 006976.233324 of 25 the OVR seal assembly is configured to switch from a second closed position to a second open position when a vacuum pressure from the fuel tank overcomes a spring force of the OVR spring.ACTIVE 513286736.1

Images