Check valve

Abstract

The check valve (100) includes a valve element (130) and a valve body having a body housing (120), an annular valve seat insert (160), a bushing (140), and a biasing member (145). The body housing includes an outer peripheral wall (113) that extends between an inlet port (111) and an outlet port (112) and defines a valve cavity (115) therebetween. The valve seat insert is mounted within a body seating surface (124) that surrounds the inlet port. A bushing is disposed within the valve cavity and defines a central bore, the bushing including an outer end surface (142) axially matable with the valve seat insert. The biasing member is disposed between a bearing portion (126) of the body housing and an inner end (143) of the bushing to permit axial movement of the bushing relative to the body seating surface. The valve element extends through the central bore of the bushing and is movable between a closed position and an open position.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to and the benefit of all U.S. Provisional Patent Application No. 63 / 280,346 (filed November 17, 2021) entitled "CHECK VALVE," the entire disclosure of which is incorporated herein by reference. [Background technology]

[0002] Check valves are used to allow flow in one direction but block flow in the opposite direction to prevent undesirable backflow in piping systems. The valve element (e.g., poppet) of a check valve is typically acted upon by two primary forces: a closing force, which may be generated by a spring, magnet, or gravity, and an opening force, which may be generated by the upstream fluid. Valve chatter can occur when the forces are balanced (i.e., canceling) and when there are instabilities in the flow of the system medium. It is often advantageous for the force acting to open the poppet to be measurably greater than the force acting to close the valve; however, this is usually achieved by trading off the full stroke of the valve element and a reduction in the overall flow capacity. Summary of the Invention

[0003] According to one or more embodiments of the inventions presented in this disclosure, a check valve includes a valve element and a valve body having a body housing, an annular valve seat insert, a bushing, and a biasing member. The body housing includes an outer peripheral wall extending between an inlet port and an outlet port to define a valve cavity therebetween. The valve seat insert is mounted within a body seating surface surrounding the inlet port. The bushing is disposed within the valve cavity and defines a central bore, the bushing including an outer end surface axially mateable with the valve seat insert. The biasing member is disposed between a bearing portion of the body housing and an inner end of the bushing to permit axial movement of the bushing relative to the body seating surface. The valve element extends through the central bore of the bushing and is movable between a closed position in which the valve element seals against the valve seat insert to prevent flow between the inlet port and the outlet port, and an open position in which fluid flow is permitted from the inlet port to the outlet port.

[0004] In accordance with one or more further embodiments of the inventions presented in this disclosure, a check valve includes a valve element and a valve body having a body housing, an annular valve seat insert, and a bushing. The body housing includes an outer peripheral wall extending between an inlet port and an outlet port to define a valve cavity therebetween. The valve seat insert is mounted within the body seating surface surrounding the inlet port. The bushing is disposed within the valve cavity and defines a central bore, the bushing including an outer end face that axially mates with the valve seat insert. The valve element extends through the central bore of the bushing and is movable between a closed position in which a head portion of the valve element seals against the valve seat insert to prevent flow between the inlet port and the outlet port, and an open position in which fluid flow is permitted from the inlet port into the central bore of the bushing and through an internal flow passage in the valve element to the outlet port. The bushing further includes a tapered flow guiding surface opposite the outer end face that is angled to substantially match the angled conical surface of the valve element head portion and to guide flow toward the valve element flow path when the valve element is in the open position.

[0005] According to one or more further embodiments of the inventions presented in this disclosure, a check valve includes a valve element and a valve body having a body housing, an annular valve seat insert, and a bushing. The body housing includes an outer peripheral wall extending between an inlet port and an outlet port to define a valve cavity therebetween. The valve seat insert is mounted within the body seating surface surrounding the inlet port. The bushing is disposed within the valve cavity and defines a central bore, the bushing including an outer end surface that axially mates with the valve seat insert. The valve element extends through the central bore of the bushing and is movable between a closed position in which the valve element seals against the valve seat insert to prevent flow between the inlet port and the outlet port, and an open position in which fluid flow is permitted from the inlet port to the outlet port. The body seating surface includes a concave surface sized to retain the valve seat insert and an annular inner wall portion extending axially inward from the concave surface, the annular inner wall portion sized to limit compression of the valve seat insert by the valve element to a predetermined percentage of the uncompressed thickness of the valve seat insert.

[0006] In accordance with one or more further embodiments of the inventions presented in this disclosure, a check valve includes a valve element and a valve body having a body housing, an annular valve seat insert, and a bushing. The body housing includes an outer peripheral wall extending between an inlet port and an outlet port to define a valve cavity therebetween. The valve seat insert is mounted within the body seating surface surrounding the inlet port. The bushing is disposed within the valve cavity and defines a central bore, the bushing including an outer end surface that axially mates with the valve seat insert. The valve element extends through the central bore of the bushing and is movable between a closed position in which a head portion of the valve element seals against the valve seat insert to prevent flow between the inlet port and the outlet port, and an open position in which fluid flow is permitted from the inlet port to the outlet port. The body seating surface includes a secondary sealing surface positioned to sealingly mate with an outer peripheral sealing surface of a valve element head portion radially inward of the valve seat insert when the valve element is exposed to a backpressure exceeding a threshold backpressure.

[0007] According to one or more further embodiments of the inventions presented in this disclosure, a check valve includes a valve element and a valve body having a body housing, an annular valve seat insert, and a bushing. The body housing includes a first body housing member including an inlet port, a body seating surface surrounding the inlet port, and an outer circumferential wall extending to a female threaded end, and a second body housing member including an outlet port and a male threaded end thread assembled with the female threaded end. The valve seat insert is mounted within the body seating surface surrounding the inlet port. The bushing is disposed within the valve cavity and defines a central bore, the bushing including an outer end surface that axially mates with the valve seat insert and an inner end that is engaged by a bearing portion of the male threaded end thread to transmit an axial compressive force from the second body housing member to the valve seat insert. The valve element extends through the central bore of the bushing and is movable between a closed position in which the valve element seals against the valve seat insert to prevent flow between the inlet port and the outlet port, and an open position in which fluid flow is permitted from the inlet port to the outlet port.

[0008] According to one or more further embodiments of the inventions presented in this disclosure, a check valve includes a valve element and a valve body having a body housing, an annular valve seat insert, and a bushing. The body housing includes an outer peripheral wall extending between an inlet port and an outlet port to define a valve cavity therebetween. The valve seat insert is mounted within the body seating surface surrounding the inlet port. The bushing is disposed within the valve cavity and defines a central bore, the bushing including an outer end surface that axially mates with the valve seat insert. The valve element extends through the central bore of the bushing and is movable between a closed position in which the valve element seals against the valve seat insert to prevent flow between the inlet port and the outlet port, and an open position in which fluid flow is permitted from the inlet port into the central bore of the bushing and through an internal flow passage in the valve element to the outlet port. The body seating surface and the bushing outer end surface together define an annular seal cavity sized to hold the valve seat insert. The bushing further includes at least one peripheral recess extending to the outer end face to intersect with the annular seal cavity, the at least one peripheral recess including a vent passage that intersects with the central bore of the bushing.

[0009] Further advantages and merits will become apparent to those skilled in the art from a consideration of the following description and appended claims in conjunction with the accompanying drawings. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a cross-sectional schematic diagram of a check valve according to an exemplary embodiment of the present disclosure. [Diagram 2] FIG. 2 is a cross-sectional view of a check valve in accordance with another exemplary embodiment of the present disclosure, shown with the poppet in an open position; [Diagram 3] FIG. 3 is a cross-sectional view of the check valve of FIG. 2 shown with the poppet in a closed position. [Figure 4]FIG. 3 is an enlarged partial cross-sectional view of the poppet seal portion of the check valve of FIG. 2, shown with the poppet in a closed, secondary sealing position. [Diagram 5] FIG. 3 is a perspective view of a poppet of the check valve of FIG. [Figure 6] FIG. 3 is a perspective view of a bushing of the check valve of FIG. 2. [Figure 7] FIG. 3 is an enlarged partial cross-sectional view of the valve seal and vent arrangement of the check valve of FIG. 2. [Figure 8] FIG. 2 is a cross-sectional view of a check valve in accordance with another exemplary embodiment of the present disclosure, shown with the poppet in an open position; [Figure 8A] FIG. 9 is an enlarged partial cross-sectional view of the poppet and body seal portion of the check valve of FIG. 8, shown with the poppet in an open position. [Figure 9] FIG. 9 is a cross-sectional side view of the check valve of FIG. 8 shown with the poppet in a closed position. [Figure 9A] FIG. 9 is an enlarged partial cross-sectional view of the poppet and body seal portion of the check valve of FIG. 8, shown with the poppet in a closed position. [Figure 10] FIG. 9 is a perspective view of a bushing of the check valve of FIG. 8. [Figure 11] FIG. 9 is another cross-sectional side view of the check valve of FIG. 8 showing the bushing vent path. [Figure 11A] FIG. 9 is an enlarged partial cross-sectional view of the poppet and body seal portion of the check valve of FIG. 8, showing the bushing ventilation path. [Figure 12] FIG. 13 is a cross-sectional view of a check valve in accordance with another exemplary embodiment of the present disclosure. [Figure 12A] FIG. 13 is an enlarged partial cross-sectional view of the poppet and body seal portion of the check valve of FIG. 12 shown with the poppet in a closed position. [Figure 12B] FIG. 2 is an enlarged partial cross-sectional view of a poppet and body sealing portion of a check valve in accordance with another exemplary embodiment of the present disclosure, shown with the poppet in a closed position; [Figure 12C]FIG. 2 is an enlarged partial cross-sectional view of a poppet and body sealing portion of a check valve in accordance with another exemplary embodiment of the present disclosure, shown with the poppet in a closed position; [Figure 13] FIG. 13 is a cross-sectional view of a check valve in accordance with another exemplary embodiment of the present disclosure. [Figure 13A] FIG. 14 is an enlarged partial cross-sectional view of the poppet and body seal portion of the check valve of FIG. [Figure 13B] FIG. 14 is a perspective view of the inlet end threads of the check valve of FIG. [Figure 13C] FIG. 14 is a perspective view of a bushing of the check valve of FIG. 13. [Figure 14] FIG. 13 is a cross-sectional view of a check valve in accordance with another exemplary embodiment of the present disclosure. [Figure 14A] FIG. 16 is an enlarged partial cross-sectional view of the poppet and body seal portion of the check valve of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Although various inventive aspects, concepts, and features of the present invention may be described and illustrated herein as embodied in combination in exemplary embodiments, these various aspects, concepts, and features may be used individually or in various combinations and subcombinations thereof in many alternative embodiments. All such combinations and subcombinations are intended to be within the scope of the present invention, unless expressly excluded otherwise herein. Furthermore, although various alternative embodiments of various aspects, concepts, and features of the present invention (e.g., alternative materials, structures, configurations, methods, circuits, devices and components, software, hardware, control logic, alternatives (in terms of formation, fit, and function), etc.) may be described herein, such descriptions are not intended to be a complete or exhaustive list of available alternative embodiments, whether currently known or later developed. Those skilled in the art may readily adopt one or more of the inventive aspects, concepts, or features into further embodiments and uses within the scope of the present invention, even if such embodiments are not expressly disclosed herein. Furthermore, while some features, concepts, or aspects of the invention may be described herein as preferred arrangements or methods, it is not intended that such description imply that such features are required or necessary, unless expressly so stated. Furthermore, while typical or representative values ​​and ranges may be included to aid in the understanding of the present disclosure, such values ​​and ranges should not be construed in a limiting sense, and are intended to be critical values ​​or ranges only if so expressly stated. A parameter identified as "about" or "approximately" a particular value is intended to include both the particular value and values ​​within 10% of the particular value, unless otherwise specified. Furthermore, it should be understood that the drawings accompanying this disclosure may, but are not necessarily, to scale, and thus may be understood as teaching various ratios and proportions apparent in the drawings.Moreover, while various aspects, features, and concepts may be expressly identified herein as being inventive or forming part of the invention, such identification is not intended to be exclusive; rather, there may be aspects, concepts, and features of the invention fully described herein without being expressly identified as such or as part of a particular invention, and the invention is instead set forth in the appended claims as currently described or as may be modified or added to in the future. Descriptions of exemplary methods or processes are not limited to the inclusion of every step as being necessary in all cases, nor should the order in which steps are presented be construed as necessary or essential unless expressly so stated.

[0012] In an exemplary embodiment of the present disclosure, as shown generally in FIG. 1, a check valve 10 includes a valve body 11 defining inlet and outlet ports 21, 22, an outer circumferential wall 23, and a valve seat 60 disposed within an annular seating surface 14 surrounding the inlet port 21. A valve element or poppet 30 is retained within a cavity 15 within the valve body 11 and is movable within an internal guide path (e.g., defined by an internal bushing 40, as described below) between a first closed position in which a sealing forward end 31 of the valve element seals against the valve seat 60 to, for example, prevent backflow into or low pressure flow from the inlet port 21, and a second open position in which fluid flow is permitted through one or more passages 33 in the poppet 30 between the inlet port 21 and the outlet port 22. A biasing member 50 located within the valve cavity 15 may exert a biasing force on the valve element 30 to urge the valve element toward the closed position.

[0013] The bushing 40 may include an outer end surface 42 extending opposite the seating surface 14 to further define an annular seating cavity 16 within the valve body 10, for example, to further surround and retain a valve seat 60 within the seating cavity.

[0014] According to aspects of the disclosure, the check valve 10 may include a valve seat formed from an annular valve seat insert 60 (e.g., an elastomeric O-ring or gasket, or a plastic gland) secured to the seating surface 14 of the valve body 11 by a sleeve or bushing 40 installed within the valve body 11. In some such embodiments, the bushing 40 may be sized and positioned for a controlled compression fit of the valve seat insert 60 to provide a seal between the body seating surface 14 and the valve seat insert, for example, to seal with the valve element 30 at the inner diameter of the valve seat insert 60 and to prevent over-compression of the valve seat insert. In other embodiments, the bushing may provide seat insert containment without compressing or even contacting the seat insert, at least under some conditions (e.g., in the closed position of the valve).

[0015] As shown, the bushing 40 may further provide a guide path for the valve element 30, for example, directing fluid flow past the sealed forward end 31 of the valve element and into a central passage 33 within the valve element.

[0016] Other exemplary embodiments of check valves having a poppet carrier that applies a compressive or retaining force to a seat sealing element are described in co-pending PCT Publication No. WO2020 / 236853, the entire disclosure of which is incorporated herein by reference.

[0017] Various configurations may be utilized to provide a check valve with a valve seat insert held in compression and a valve element guide passage for a poppet having an internal flow passage.

[0018] 2-7 illustrate an exemplary embodiment of a check valve 100 including a valve body 110, a poppet 130, a biasing spring 150, and a valve seat insert 160. The valve body 110 includes a first or inlet port 111, a second or outlet port 112, and a peripheral wall 113 extending between the inlet and outlet ports and defining an internal valve cavity 115 in which the poppet 130 and biasing spring 150 are retained. The biasing spring 150 surrounds a tail portion 135 of the poppet 130 and is compressed between a head portion 131 of the poppet and a bearing portion 126 of the body housing 120. The valve seat insert 160 is supported by a body seating surface 124 (e.g., a concave surface or a counterbore) that surrounds the inlet port 111. The inlet and outlet ports 111, 112 may be provided with end connections 101, 102 (eg, tube fitting connections) for assembling the check valve 100 into a fluid system.

[0019] A typical valve body 110 includes a body housing 120 including first and second body housing members 120-1, 120-2 assembled (e.g., threaded assembly) to define an internal valve cavity 115, with the inlet port 111 disposed on the first body housing member 120-1 and the outlet port 112 disposed on the second body housing member 120-2. A body seating surface 124 is disposed within (e.g., integrally formed with) the first body housing member 120-1. While the body housing members may be provided in a variety of structural arrangements, in the illustrated embodiment, the first body housing member 120-1 includes a substantially tubular body or enclosure structure defining the circumferential wall 113 and the internal valve cavity 115, and the second body housing member 120-2 includes an end thread structure having a male threaded inner end 123 that is threadedly assembled with the female threaded inner end 128 of the first body housing member.

[0020] A body seal gasket 119 (e.g., with one or more backup rings 119a as shown) may be provided in an annular groove in the inner end 123 of the second body housing member to provide a body seal between the valve cavity 115 and the threaded mating portions 2 of the body housing members 120-1, 120-2, for example, thereby eliminating wetted threads. In other embodiments, as illustrated in the embodiment of FIG. 14, for example, the check valve 400 may include a body seal gasket 419 that is axially compressed between a counterbore surface 421 of the inlet enclosure housing member 420-1 and a shoulder surface 422 of the outlet end threaded housing member 420-2, thereby isolating the mating threads from the wetted portions of the valve. In some embodiments, the body seal gasket 419 may be metallic (e.g., stainless steel, nickel alloy, brass, bronze, aluminum), for example, to provide a leak-tight seal over a wider temperature range (e.g., from about -60°C to about 300°C). The body gasket seal may be coated or lubricated to enhance the seal.

[0021] A variety of valve seats and valve seat mounting arrangements may be utilized, including, for example, plastic or elastomeric valve seats. In an exemplary embodiment, the valve seat may be provided as an annular elastomeric seal (e.g., an O-ring or other similar gasket), for example, for use in non-cryogenic (e.g., temperatures above -40°C) systems requiring enhanced sealing capabilities. Exemplary elastomeric materials include, without limitation, fluoroelastomers (e.g., FKM), ethylene propylene diene monomer (EPDM), hydrogenated nitrile rubber (HNBR), and nitrile rubber. In the illustrated embodiment of Figures 2-7, the valve seat insert 160 includes a gasket seal, and the body seating surface 124 is provided as a counterbored hole formed (e.g., machined) in the first body housing member 120-1 surrounding the inlet port 111, into which the gasket seal 160 is mounted. The gasket seal 160 is positioned to radially align with the head portion 131 of the poppet 130 for sealing engagement with the poppet head portion when the poppet is in the closed position. In an exemplary embodiment, the circumferential sealing edge 132 of the poppet head portion 131 mates with the inner periphery 162 of the gasket seal 160. The circumferential sealing edge 132 may be provided with a rounded surface sized to optimize the contact pressures and stresses within the gasket seal 160 while compressed under higher back pressure. In an exemplary embodiment, the circumferential sealing edge 132 is provided with a contact surface having a radius that is about 10% to about 30% of the cross-sectional thickness of the gasket seal. In other embodiments, the poppet may be provided with a frusto-conical tapered sealing surface similar to the embodiment of Figures 8-12C described in detail below.

[0022] The poppet 130 includes a central bore 133 and one or more intersecting side channels 134 that define a poppet flow path that extends from the head portion 131 (inside the sealing edge) to the poppet's inner tail portion 135. The poppet's side channels 134 may extend at an angle selected to optimize flow from the inlet port 111 to the poppet's central bore 133 (e.g., about 55° relative to the valve center axis). When the poppet 130 is in the open position (e.g., with sufficient inlet fluid pressure to overcome the biasing force of the spring 150), fluid from the inlet port 111 passes between the gasket seal 160 and the poppet head portion 131, through the side channel(s) 134 and the central bore 133 to the outlet port 112. The poppet head portion 131 may be provided with an angled (e.g., about 30°-60°, or about 40°-45°, or about 45° relative to the valve central axis) conical surface 136 to direct flow past the gasket seal 160 and toward the end of the poppet's side channel 134. As shown, the tail portion 135 of the poppet 130 is received within the counterbore 125 of the outlet port 112 to, for example, substantially isolate the biasing spring 150 (disposed radially between the tail portion of the poppet and the bushing 140) from the system fluid. The counterbore 125 of the outlet port may be positioned to limit the open position of the poppet 130 by abutting the tail portion 135 of the poppet, for example, to limit the compression of the biasing spring 150 to a desired functional range.

[0023] In some embodiments, the minimum flow area of ​​the inlet and outlet ports 111, 112 may be less than or equal to the flow area through the side channel 134 and central hole 133 of the poppet 130. In other embodiments, the flow area through the side channel 134 and central hole 133 of the poppet 130 may be configured to be less than the flow area of ​​the inlet and outlet ports 111, 112, for example, to bias the poppet 130 to an open position with minimal vibration when the differential pressure across the check valve is equalized.

[0024] An axial compressive force may be applied to the gasket seal to provide a consistent seal between the poppet head portion 131 and the gasket seal 160, and between the gasket seal and the body seating surface 124 in the closed position. In the illustrated embodiment, the valve body 110 includes a tubular bushing 140 mounted within the valve cavity 115 around the poppet 130 and biasing spring 150 to apply a compressive force against the gasket seal 160. The bushing 140 includes a central bore 141 within which the poppet 130 is closely received and guided between the closed and open positions. An inner end 143 of the bushing 140 is indirectly engaged by the valve body housing 120 (e.g., by the inner end surface or bearing portion 126 of the second body housing member 120-2) to provide a compressive and sealing engagement between the outer end surface 142 of the bushing 140 and the intermediate peripheral portion 163 of the valve seat insert 160. In the illustrated embodiment, the outer end surface 142 of the bushing 140 mates with a shoulder 129 of the first body housing member 120-1 to limit compression of the gasket seal 160 (e.g., to prevent damage to the gasket seal). While any suitable material may be used, in an exemplary embodiment, the bushing may be provided in a material (e.g., one of stainless steel, nickel alloy, brass, bronze, aluminum, and PEEK) different from the body housing material (e.g., a different one of stainless steel, nickel alloy, brass, bronze, aluminum, and PEEK) to, for example, minimize wear or abrasion of the contacting surfaces or to provide particular desired material properties for one or both of the bushing and body housing. In other embodiments, the same material may be used for both the bushing and body housing.

[0025] The valve seat gasket seal 160 may be radially retained against the body seating surface 124 by an annular inner wall portion 127 that extends axially inward from the concave body seating surface toward the bushing 140. When pressurized fluid is applied to the inlet port 111, the inner wall portion 127 blocks the flow from direct contact with the gasket seal inner periphery 162, e.g., to protect the relatively soft gasket seal 160 from abrasive high velocity flow. The concave surface 124, the inner wall portion 127, and the bushing end face 142 together define an annular seal cavity 116 that retains the valve seat gasket seal 160 (e.g., within the inner periphery portion of the seal cavity). The seal cavity 116 includes an inner periphery gap 117 defined by the inner wall portion 127 and the bushing end face 142. The inner circumferential gap 117 exposes an inner circumferential sealing portion 162 of the valve seat gasket seal 160 which is radially aligned with the outer circumferential sealing edge 132 of the poppet head portion 131 to provide a fluid-tight seal when the poppet 130 is in the closed position.

[0026] In some applications, the body seating surface may include a secondary sealing surface that is engaged by the poppet head when the poppet is subjected to substantial backpressure (e.g., greater than 25 psi, greater than 50 psi, or greater than 100 psi) to, for example, limit or prevent damage to the gasket seal. In the illustrated embodiment, the inner wall portion 127 provides a secondary metal-to-metal sealing surface 127a that can mate with the outer circumferential sealing surface 137 of the radially inner poppet head portion 131 of the gasket seal 160 when, for example, the poppet is subjected to a backpressure that exceeds a threshold backpressure such that the poppet compresses the gasket seal inner periphery 162. In such an arrangement, the height h of the inner wall portion 127 may be selected to prevent overcompression of the gasket seal. For example, the height h of the inner wall portion may be selected such that the distance d between the sealing surface 137 and the body seat surface 124 (which may, but need not, correspond to the height h) is limited to a predetermined percentage of the cross-sectional thickness of the gasket seal (e.g., about 35% to about 65%, or about 40% to about 55%) to limit compression of the gasket seal by a corresponding percentage of the cross-sectional thickness of the gasket seal (e.g., about 65% to about 35%, or about 60% to about 45%).

[0027] The thickness t of the inner wall portion 127 may be selected, for example, to provide sufficient strength to withstand bearing engagement by the poppet 130 under substantial back pressure loads, to provide a desired gasket seal inner diameter fit clearance, to provide a desired bore diameter to accommodate a desired flow rate, and / or to provide a sufficient sealing surface to mate with the peripheral sealing surface 137 of the poppet head portion 131.

[0028] The outer end of the bushing 140 may be provided with a tapered flow guide surface 144 disposed opposite the end face 142 at an angle θ1 (e.g., about 30°-60°, or about 40°-45°, or about 40° relative to the valve center axis) to complement or substantially match the angle θ2 of the conical surface 136 of the poppet head portion 131 (e.g., taper angle within about 5°) to guide flow toward the poppet's side channel 134, e.g., to reduce turbulence and optimize flow performance.

[0029] In some applications, the gasket seal valve seat may expand in size or volume during use of the valve due to, for example, chemical reactivity or pressure or temperature changes within the valve. In accordance with another aspect of the present disclosure, a biasing member may be provided between the bushing and the valve body housing to transmit an axial compressive force from the valve body housing to the bushing. In applications where the gasket seal expands, the compressibility of the biasing member allows the bushing to move axially away from the body seating surface, avoiding damage to the gasket seal.

[0030] In the illustrated embodiment, one or more Belleville washers 145 (or other suitable biasing members) may be disposed between the inner end 143 of the bushing 140 and the inner end face or bearing portion 126 of the second body housing member 120-2 to allow axial movement of the bushing 140 relative to the body seating surface 124, for example to accommodate variations in size of the gasket seal 160 or other dimensional tolerances of the valve components. In the illustrated embodiment, a spring bearing 146 is provided between the biasing member 145 and the bushing 140, for example to provide a stable seating surface for the biasing member 145. As shown, the spring bearing 146 may also provide a seating surface for the biasing spring 150. In other embodiments (not shown), the bushing may be provided with a bearing portion integrally formed with the inner end of the bushing to provide a bearing surface for the biasing member and / or the biasing spring.

[0031] According to another aspect of the present application, the annular seal cavity 116 may be provided with one or more vent passages (e.g., intersecting an outer periphery of the seal cavity) to provide fluid pressure to activate a seal against the outer periphery of the valve seat gasket seal 160 when the poppet 130 is in a closed position, and to provide a vent for pressurized fluid from the seal cavity 116 when the poppet is in an open position. This vent when the valve 100 is open may prevent the valve seat gasket seal 160 from being forced through the inner periphery gap 117 due to an increase in pressure within the seal cavity 116. As illustrated in Figures 6 and 7, the outer end 142 of the bushing 140 may be provided with one or more vent paths extending from the annular seal cavity 116 to a central bore 141 of the bushing. While many different vent paths may be provided, in the illustrated embodiment, the outer end 142 includes one or more vent holes 147 that extend from the bushing bore 141 to a recessed (e.g., flat) outer portion 148 of the outer end 142. When the valve 100 is opened (by sufficient positive fluid pressure being applied to the poppet head portion 131 to overcome the force of the biasing spring 150), pressure around the outer periphery of the seal cavity 116 is exhausted through the vent hole(s) 147 into the center bore flow passage. When the valve 100 is closed (by the force of the biasing spring 150 overcoming any upstream fluid pressure), pressurized downstream fluid is allowed to pass through the vent hole(s) 147 into the outer periphery of the seal cavity 116, pressurizing or activating the valve seat gasket seal 160. This promotes a sealing fit between the inner periphery 162 of the gasket seal 160 and the poppet head portion 131.

[0032] In another embodiment, according to another exemplary aspect of the present disclosure, a check valve may be provided with a body seating surface of the body housing and a bushing end surface that together define an undercut or dovetail groove shaped annular seal cavity that is sized and oriented to provide an inner circumferential sealing surface against a valve element (e.g., a poppet) while retaining a gasket seal against extrusion through an inner circumferential gap in the dovetail groove.

[0033] 8-11A illustrate another exemplary embodiment of a check valve 200. The check valve 200 may be similar to the check valve 100 of FIGS. 2-7 (corresponding components are numbered accordingly) and includes a valve body 210 including a body housing 220, a valve seat insert or gasket seal 260, and a bushing 240 having an end face 242. The end face 242 extends adjacent a body seating surface 224 in a body housing (e.g., first threaded body housing member 220-1 as shown) to form a dovetail groove shaped annular seal cavity 216. The annular seal cavity 216 is sized to retain a gasket seal 260 and expose an inner peripheral sealing portion 262 of the gasket seal 260 for sealing engagement with a valve element or poppet 230. As shown, the bushing end face 242 may, but need not be, be molded to extend outwardly beyond the bushing mating shoulder 229 of the body housing 220 .

[0034] The body seating surface 224 and the bushing end face 242 may be provided with various surface contours to form a variety of different undercut or dovetail groove shaped annular seal cavity 216, with a rear seating surface 216-1 defined by a concave or groove portion 225 of the body seating surface, an inner side 216-2 defined by an inner wall portion 227 of the body seating surface, and an outer side 216-3 defined by the bushing end face 242. In the illustrated example, the rear seating surface 216-1 of the groove 225 is inwardly tapered (e.g., at an angle of about 40° to about 80°, or about 66° relative to the valve central axis) and the dovetail groove sides 216-2, 216-3 are angled relative to the seating surface (e.g., forming an included angle α of about 40° to about 80°) to form a conical dovetail groove. The dovetail groove has an inner circumferential gap or neck portion 217 (eg, having a width of about 55% to about 85% of the nominal gasket seal cross section) to expose an inner circumferential seal portion 262 of the gasket seal 260, for example.

[0035] While the sides 216-2, 216-3 may be positioned to compress the gasket seal 260 against the rear seating surface 216-1 to provide a seal with the seating surface (similar to the check valve 100 of FIGS. 2-7), in some embodiments the sides 216-2, 216-3 may be effective to simply retain the retention gasket seal 260 within the annular seal cavity 216 when the poppet 230 is in the open position, and the poppet head portion 231 compresses the gasket seal against the rear seating surface 216-1 to provide a seal with the seating surface when in the closed position. While the sides of the seal cavity are shown as flat surfaces, in some embodiments the surfaces of the seal cavity may be contoured (e.g., concave) surfaces, for example, to more closely correspond to the geometry of the gasket seal cross-section.

[0036] In the illustrated embodiment, an outer step 249 of the bushing 240 mates with a shoulder 229 of the first body housing member 220-1 to consistently position the bushing end face 242 (and outer side 216-3) against the rear seating surface 216-1 and inner side 216-2 of the annular cavity 216. While any suitable material may be used, in an exemplary embodiment, the bushing 240 may be provided in a different (e.g., softer) material (e.g., one of stainless steel, nickel alloy, brass, bronze, and aluminum) than the body housing material (e.g., a different one of stainless steel, nickel alloy, brass, bronze, and aluminum) to, for example, minimize wear or abrasion of contacting surfaces, limit wear to less critical, less expensive, or more easily replaced components, or provide particular desired material properties for one or both of the bushing and body housing.

[0037] In a typical embodiment, the circumferential sealing edge 232 of the poppet head portion 231 mates with the inner periphery 262 of the gasket seal 260. The circumferential sealing edge 232 may be provided with a tapered (e.g., frustoconical) surface sized to optimize contact pressures and stresses within the gasket seal 260 while compressed under higher back pressure. For example, the seal edge surface may be sized to extend along a width of about 40% to about 80% of the nominal gasket seal cross section. In a typical embodiment, the angle β1 of the tapered seal edge surface 232 may be substantially matched (e.g., within about 5° to about 15°) with the angle β2 of the rear seating surface 216-1 to obtain, for example, a substantially uniform compression of the gasket seal 260 between the seal edge surface and the rear seating surface when the poppet is in the closed position. In other embodiments, the tapered circumferential sealing edge may be replaced with a rounded seal edge or shoulder, similar to the poppet 130 of FIGS. 2-7.

[0038] 2-7, the inner wall portion 227 may provide a secondary metal-to-metal seal surface 227a that may mate with the outer circumferential seal surface 237 of the radially inner poppet head portion 231 of the gasket seal 260, for example, when the poppet 230 is subjected to a backpressure exceeding a threshold backpressure, causing the poppet to compress the gasket seal inner periphery 262 to a greater extent (e.g., compared to the gasket seal compression resulting from the closing force of the biasing spring 250). In such an arrangement, the height h of the inner wall portion 227 may be selected to prevent overcompression of the gasket seal. For example, the height h of the inner wall portion may be selected to limit the distance d between the sealing edge surface 232 and the opposing seating surface 216-1 to a predetermined percentage (e.g., about 65% to about 95%) of the cross-sectional thickness of the gasket seal, thereby limiting compression of the gasket seal by a corresponding percentage (e.g., about 35% to about 5%) of the cross-sectional thickness of the gasket seal.

[0039] The thickness t of the inner wall portion 227 may be selected, for example, to provide sufficient strength to withstand bearing engagement by the poppet 230 under substantial back pressure loads, to provide a desired gasket seal inner diameter fit clearance, to provide a desired bore diameter to accommodate a desired flow rate, and / or to provide a sufficient sealing surface to mate with the peripheral sealing surface 237 of the poppet head portion 231.

[0040] The outer end of the bushing 240 may be provided with a tapered flow guide surface 244, angled (e.g., about 35°-65°, or about 40°-45°, or about 40° relative to the valve center axis) opposite the end face 242 to complement or substantially match (e.g., within about 15° or within about 5°) the angled conical surface 236 of the poppet head portion 231 to guide flow toward the poppet's side channel 234, e.g., to reduce turbulence and optimize flow performance.

[0041] Similar to the check valve 100 of FIGS. 2-7, one or more Belleville washers 245 (or other suitable biasing members) may be disposed between the inner end 243 of the bushing 240 and the inner end face or bearing portion 226 of the second body housing member 220-2 to allow axial movement of the bushing 240 relative to the body seating surface 224, for example to accommodate variations in size of the gasket seal 260 or other dimensional tolerances in the valve components. In the illustrated embodiment, a spring bearing 246 is provided between the biasing member 245 and the bushing 240, for example to provide a stable seating surface for the biasing member 245. As shown, the spring bearing 246 may also provide a seating surface for the biasing spring 250. In other embodiments (not shown), the bushing may be provided with a bearing portion integrally formed with the inner end of the bushing to provide a bearing surface for the biasing member and / or the biasing spring.

[0042] 2-7, the annular seal cavity 216 may be provided with one or more vent passages (e.g., intersecting an outer periphery of the seal cavity) to provide fluid pressure to activate a seal against the outer periphery of the valve seat gasket seal 260 when the poppet 230 is in a closed position, and to provide a vent for pressurized fluid from the seal cavity 216 when the poppet is in an open position. This vent when the valve 200 is open may prevent the valve seat gasket seal 260 from being forced out through the inner periphery gap or dovetail neck portion 217 due to an increase in pressure within the seal cavity 216. As illustrated in FIGS. 10, 11, and 11A, the outer end 242 of the bushing 240 may be provided with one or more vent paths extending from the annular seal cavity 216 to a central bore 241 of the bushing. While many different vent paths may be provided, in the illustrated embodiment, the outer end 242 includes one or more vent holes 247 that extend from the bushing hole 241 to a recessed (e.g., chamfered) outer portion 248 of the outer end 242. When the valve 200 is opened (sufficient positive fluid pressure is applied to the poppet head portion 231 to overcome the force of the biasing spring 250), pressure around the outer periphery of the seal cavity 216 is exhausted through the vent hole(s) 247 into the center bore flow path. When the valve 200 is closed (by the force of the biasing spring 250 overcoming any upstream fluid pressure), pressurized downstream fluid passes through the vent hole(s) 247 into the outer periphery of the seal cavity 216, pressurizing or energizing the valve seat gasket seal 260. This promotes a sealing fit between the inner periphery 262 of the gasket seal 260 and the poppet head portion 231.

[0043] Other seat seal groove configurations may be utilized. In the exemplary embodiment of Figures 12 and 12A, inner wall portion 227' may be provided with a tapered outer surface 227b' to provide a desired included angle α (with bushing end face 242') with dovetail groove cavity 216', e.g., between about 40° and about 80°, e.g., to provide a desired retention of gasket seal 260. Although the sides of the seal cavity are shown as flat surfaces, in some embodiments the surfaces of the seal cavity may be contoured (e.g., concave) surfaces, e.g., to more closely correspond to the geometry of the gasket seal cross section.

[0044] In the exemplary embodiment of FIG. 12B, the annular seal cavity 216'' includes a tapered seating surface 224a'' opposite a peripheral seal edge 232'' of the poppet head portion 231'', which may, but need not be, angled to substantially coincide with the peripheral seal edge 232'' (e.g., within about 15° or within about 5°), and a radial seating surface 224b'' opposite a radial bushing end face 242'' which may, but need not be, substantially parallel to coincide with the bushing end face 242'' (e.g., within about 15° or within about 5°). As shown, the inner wall portion 227'' may include an axially extending outer surface 227b'' that further defines the seal cavity 216'', resulting in a four sided (e.g., trapezoidal) seal cavity for the gasket seal 260''. This configuration may be simpler to manufacture or machine than, for example, the dovetail groove configurations of Figures 8-11 and 12-12A. Although the sides of the seal cavity are shown as flat surfaces, in some embodiments the surfaces of the seal cavity may be contoured (e.g., concave) surfaces, for example, to more closely correspond to the geometry of a gasket seal cross section.

[0045] In the exemplary embodiment of FIG. 12C , the annular seal cavity 216′″ includes a first tapered seating surface 224a′″ opposite the peripheral seal edge 232′″ of the poppet head portion 231′″, which may, but is not required to be, angled to substantially coincide with the peripheral seal edge 232′″ (e.g., within about 15° or within about 5°), and a second tapered seating surface 224b′″ opposite the tapered bushing end face 242′″, which may, but is not required to be angled to substantially coincide with the bushing end face 242′″ (e.g., within about 15° or within about 5°). In some embodiments, the tapered surface of sealing edge 232''' may be disposed at an angle β1 greater than the angle β2 of first tapered seating surface 224a''' (e.g., about 10° greater) to, for example, reduce pinching of gasket seal 260''' due to poppet closing. As shown, axially extending outer surface 227b''' of inner wall portion 227''' and axially extending inner circumferential surface 224c''' of body seat recess 224''' may, but are not required to, be provided to further define seal cavity 216''', resulting in a six-sided seal cavity for gasket seal 260'''. This configuration may, for example, be sized and shaped to more closely match the geometry of gasket seal 260''', resulting in balancing strains and stresses on the gasket seal trapped under poppet loads and / or fluid pressures. This design, like other embodiments disclosed herein, utilizes pressure loading and deformation on the gasket seal 260''' while utilizing a lower initial compression of the gasket seal by the poppet head sealing edge 232''' to still produce a seal at high back pressures. The first and second tapered seating surfaces 224a'''', 224b''' may be joined by fully rounded surfaces or by one or more transition planes.Although the sides of the seal cavity are shown as flat surfaces, in some embodiments the surfaces of the seal cavity may be contoured (e.g., concave) surfaces, e.g., to more closely correspond to the geometry of the gasket seal cross-section.

[0046] In the embodiment of Figures 2-12A, the check valve body housing is formed from a female threaded enclosure defining the inlet port, the body seating surface, and the outer circumferential wall defining the valve cavity, and a male threaded end thread defining the outlet port and the poppet counterbore, with an end portion of the end thread defining the bearing portion of the biasing member. In other embodiments, the check valve may be provided with a body housing formed from a male threaded end thread defining the inlet port, with an end portion of the end thread defining the body seating surface, and the female threaded enclosure defining the outlet port, the outer circumferential wall, and the poppet counterbore. Such an arrangement may facilitate machining of the body seating surface, for example, by providing the body seating surface on the endmost surface of the male threaded end thread rather than in a recessed cavity within a tubular body housing member.

[0047] 13 and 13A illustrate an exemplary embodiment of a check valve 300. The check valve 300 may be similar to the check valves 100, 200 of FIGS. 2-7 and 8-12A (corresponding components are numbered accordingly) and may include any one or more of the features described above. That is, the valve body 310 includes a body housing 320, a valve seat insert or gasket seal 360, and a bushing 340 having an end face 342. The end face 342 extends adjacent a body seating surface 324 on a body housing (e.g., first threaded body housing member 320-1 as shown) to form an annular seal cavity 316. The annular seal cavity 316 is sized to retain the gasket seal 360 and expose an inner peripheral sealing portion 362 of the gasket seal 360 for sealing engagement with the valve element or poppet 330.

[0048] A typical body housing 320 includes first and second body housing members 320-1, 320-2 assembled (e.g., threaded assembly) to define an internal valve cavity 315, with an inlet port 311 disposed on the first body housing member 320-1 and an outlet port 312 disposed on the second body housing member 320-2. A body seating surface 324 is disposed on (e.g., integrally formed with) the first body housing member 320-1. The first body housing member 320-1 includes an end thread structure having an externally threaded inner end 323 that defines the body seating surface 324. The second body housing member 320-2 includes a substantially tubular enclosure structure that defines an outer peripheral wall 313 and an internal valve cavity 315, with an internally threaded portion 328 that is threadedly assembled with the externally threaded inner end 323 of the first body housing member 320-1. A body seal gasket 319 (e.g., with one or more back-up rings 319a as shown) may be provided in an annular groove in the inner end 323 of the first body housing member to provide a body seal, for example, between the valve cavity 315 and the threaded engagement of the body housing members 320-1, 320-2, thereby eliminating wetted threads. In other embodiments, the check valve may include a body seal gasket (e.g., a metal gasket) that is axially compressed between a counterbore surface of the outlet enclosure housing member and a shoulder surface of the inlet end threaded housing member, similar to the embodiment of FIG. 14 described herein.

[0049] The body seating surface 324 and the bushing end face 342 may be provided with various surface features for forming a variety of different annular seal cavities 316. In the illustrated example, the body seating surface 324 includes a concave surface defined by a flat radially extending outer end surface 324a and an annular inner wall portion 327 extending axially inwardly of the concave surface, and the bushing end face 342 includes a flat radially extending inner end surface 342a and an annular outer wall portion 342b extending axially to mate with the concave surface of the body seating surface. In other embodiments, the end faces and annular wall portions may be contoured to provide differently shaped annular cavities (e.g., the dovetail groove cavities described herein).

[0050] The outer end of the bushing 340 may be provided with a tapered flow guide surface 344, angled (e.g., about 35°-65°, or about 40°-45°, or about 40° relative to the valve center axis) opposite the end face 342 to complement or substantially match (e.g., within about 15°, or within about 5°) the angled conical surface 336 of the poppet head portion 331 to guide flow toward the poppet's side channel 334, e.g., to reduce turbulence and optimize flow performance.

[0051] Similar to the check valve 100 of FIGS. 2-7, one or more Belleville washers 345 (or other suitable biasing members) may be disposed between the inner end 343 of the bushing 340 and the inner end face or bearing portion 326 of the second body housing member 320-2 to allow axial movement of the bushing 340 relative to the body seating surface 324, for example to accommodate variations in the size of the gasket seal 360 or other dimensional tolerances in the valve components. In the illustrated embodiment, a spring bearing 346 is provided between the biasing member 345 and the bushing 340, for example to provide a stable seating surface for the biasing member 345. As shown, the spring bearing 346 may also provide a seating surface for the biasing spring 350. In other embodiments (not shown), the bushing may be provided with a bearing portion integrally formed with the inner end of the bushing to provide a bearing surface for the biasing member and / or the biasing spring.

[0052] While any suitable material may be used, in an exemplary embodiment, the bushing 340 may be provided from a different (e.g., softer) material (e.g., one of stainless steel, nickel alloy, brass, bronze, and aluminum) than the body housing material (e.g., a different one of stainless steel, nickel alloy, brass, bronze, and aluminum), for example, to minimize wear or abrasion at the contacting surfaces, limit wear to less critical, less expensive, or more easily replaced components, or to provide particular desired material properties for one or both of the bushing and body housing.

[0053] Similar to the check valves 100, 200, 200′ of FIGS. 2-12A, the annular seal cavity 316 may be provided with one or more vent passages (e.g., intersecting an outer periphery of the seal cavity) to provide fluid pressure to activate a seal against the outer periphery of the valve seat gasket seal 360 when the poppet 330 is in a closed position, and to provide a vent for pressurized fluid from the seal cavity 316 when the poppet is in an open position. This venting when the valve 300 is open may prevent the valve seat gasket seal 360 from being forced through the inner periphery gap due to an increase in pressure within the seal cavity 316. As illustrated in FIG. 13B, the outer end 342 of the bushing 340 may be provided with one or more vent paths extending from the annular seal cavity 316 to the central bore 341 of the bushing. While many different vent paths may be provided, in the illustrated embodiment, the outer end 342 includes one or more vent holes 347 and a notched end portion 348 in the outer end 342. When the valve 300 is opened (sufficient positive fluid pressure is applied to the poppet head portion 331 to overcome the force of the biasing spring 350), pressure around the outer periphery of the seal cavity 316 is exhausted through the vent(s) 347 into the center bore flow passage. When the valve 300 is closed (by the force of the biasing spring 350 overcoming any upstream fluid pressure), pressurized downstream fluid enters through the vent(s) 347 into the outer periphery of the seal cavity 316, pressurizing or energizing the valve seat gasket seal 360. This promotes a sealing fit between the inner periphery of the gasket seal and the poppet head portion 331.

[0054] In the embodiment of Figures 2-13A, the valve seat insert 160, 260, 260', 360 is an elastomeric gasket seal mounted in an annular groove or seal cavity 116, 216, 216', 316 in the body housing 120, 220, 220', 320. In other embodiments, the valve seat insert may be provided as a plastic gland or ring installed in the body housing. Depending on the application, the plastic valve seat material may be selected based on chemical compatibility, temperature rating, wear resistance, or other such factors. Exemplary plastic materials include, without limitation, polytetrafluoroethylene (PTFE), polyetheretherketone (PEEK), and ultra-high molecular weight polyethylene (UHMWPE).

[0055] 14 and 14A illustrate an exemplary embodiment of a check valve 400. The check valve 400 may be similar to the check valve of FIGS. 2-13A (with corresponding components numbered accordingly) and may include any one or more of the features described above. That is, the check valve 400 has a valve body 410 including a body housing 420 formed from an inlet enclosure 420-1 and an outlet end thread 420-2 (e.g., similar to the body housing members 120-1, 120-2 of the check valve of FIGS. 2-7), a valve seat insert (e.g., a plastic gland) 460, and a bushing 440 having an end face 442. The end face 442 extends adjacent a body seating surface 424 on the body housing (e.g., in the inlet enclosure 420-1 as shown) to form an annular seal cavity 416. The annular seal cavity 416 is sized to hold a valve seat insert 460 and expose an inner peripheral sealing portion 462 of the seat insert 460 for sealing engagement with the valve element or poppet 430 .

[0056] An axial compressive force may be applied to the seat insert to provide a consistent seal between the poppet head portion 431 and the seat insert 460, and between the seat insert and the body seating surface 424 in the closed position. In the illustrated embodiment, a tubular bushing 440 installed in the valve cavity 415 is sized and positioned to apply a compressive force against the seat insert 460. The bushing 440 includes a central bore 441 within which the poppet 430 is closely received and guided between the closed and open positions. An inner end 443 of the bushing 440 is indirectly engaged by the valve body housing 420 (e.g., by the inner end surface or bearing portion 426 of the second body housing member 420-2) to provide a compressive and sealing engagement between an outer end surface 442 of the bushing 440 and an intermediate portion 463 of the valve seat insert 460. In the illustrated embodiment, the outer end surface 442 of the bushing 440 mates with the shoulder 429 of the first body housing member 420-1 to limit compression of the valve seat insert 460 (e.g., prevent damage to the seat insert). The outer end surface 442 of the bushing 440 may be contoured (e.g., tapered axially outward and radially inward) to provide a desired amount of compression of the seat insert 460 when the bushing abuts the shoulder 429.

[0057] While any suitable material may be used, in an exemplary embodiment, the bushing 440 may be provided in a material (e.g., one of stainless steel, nickel alloy, brass, bronze, aluminum, and PEEK) that is different from the body housing material (e.g., a different one of stainless steel, nickel alloy, brass, bronze, aluminum, and PEEK), for example, to minimize wear or abrasion of the contacting surfaces or to provide particular desired material properties for either or both of the bushing and body housing. In other embodiments, the same material may be used for both the bushing and body housing.

[0058] The valve seat insert 460 may be radially protected or aligned against the body seating surface 424 by an annular inner wall portion 427 that extends axially inward from the concave body seating surface toward the bushing 440. When pressurized fluid is applied to the inlet port 411, the inner wall portion 427 blocks the flow from direct contact with the gasket seal inner periphery 462, e.g., to protect the seat insert 427 from abrasive high velocity flow. The concave surface 424, the inner wall portion 427, and the bushing end face 442 together define an annular seal cavity 416 that retains the valve seat gasket seal 160 (e.g., within the inner periphery of the seal cavity). The seal cavity 416 includes an inner periphery gap 417 defined by the inner wall portion 427 and the bushing end face 442. Inner circumferential gap 417 exposes an inner circumferential sealing portion 462 of valve seat insert 460 which is radially aligned with an outer circumferential sealing edge 432 of poppet head portion 431 to provide a fluid-tight seal when poppet 430 is in the closed position.

[0059] The seat insert 460 may be loosely fitted or press-fit into the body seat surface 424, but in some embodiments, the inner wall portion 427 may be crimped or crimped radially outward prior to assembly of the check valve body 420 to secure the seat insert to the inlet enclosure 420-1.

[0060] In some applications, the inner wall portion 427 may provide a secondary metal-to-metal sealing surface that is matable with a peripheral sealing surface of a poppet head portion, as described in more detail above with respect to the embodiment of Figures 2-13C.

[0061] The outer end of the bushing 440 may be provided with a tapered flow guide surface 444, angled (e.g., about 30°-60°, or about 40°-45°, or about 40° relative to the valve center axis) opposite the end face 442 to complement or substantially match (e.g., within about 15°, or within about 5°) the angled conical surface 436 of the poppet head portion 431 to guide flow toward the poppet's side channel 434, e.g., to reduce turbulence and optimize flow performance.

[0062] In some applications, the valve seat insert may expand in size or volume during use of the valve due to, for example, chemical reactivity or pressure or temperature changes within the valve. In accordance with another aspect of the present disclosure, a biasing member may be provided between the bushing and the valve body housing to transmit an axial compressive force from the valve body housing to the bushing. In applications where the gasket seal expands, the compressibility of the biasing member allows the bushing to move axially away from the body seating surface, avoiding damage to the gasket seal.

[0063] In the illustrated embodiment, one or more Belleville washers 445 (or other suitable biasing members) may be disposed between the inner end 443 of the bushing 440 and the inner end face or bearing portion 426 of the second body housing member 420-2 to allow axial movement of the bushing 440 relative to the body seating surface 424, for example to accommodate variations in size of the gasket seal 460 or other dimensional tolerances in the valve components. In the illustrated embodiment, a spring bearing 446 is provided between the biasing member 445 and the bushing 440, for example to provide a stable seating surface for the biasing member 445. As shown, the spring bearing 446 may also provide a seating surface for the biasing spring 450. In other embodiments (not shown), the bushing may be provided with a bearing portion integrally formed with the inner end of the bushing to provide a bearing surface for the biasing member and / or the biasing spring.

[0064] In accordance with another aspect of the present application, the annular seal cavity 416 may be provided with one or more vent passages (e.g., intersecting an outer circumferential portion of the seal cavity) to provide fluid pressure to activate a seal against the outer circumferential surface of the valve seat insert 460 when the poppet 430 is in a closed position, and to provide a vent for pressurized fluid from the seal cavity 416 when the poppet is in an open position. This vent when the valve 400 is open may prevent the valve seat insert 460 from being forced through the inner circumferential gap 417 due to an increase in pressure within the seal cavity 416. While many different vent paths may be provided, in the illustrated embodiment, the outer end 442 includes one or more vent holes 447 that extend from the bushing hole 441 to a recessed (e.g., flat) outer portion 448 of the outer end 442. When the valve 400 is opened (sufficient positive fluid pressure is applied to the poppet head portion 431 to overcome the force of the biasing spring 450), pressure around the outer periphery of the seal cavity 416 is exhausted through the vent(s) 447 into the center bore flow passage. When the valve 400 is closed (by the force of the biasing spring 450 overcoming any upstream fluid pressure), pressurized downstream fluid enters through the vent(s) 447 into the outer periphery of the seal cavity 416 and pressurizes or activates the valve seat insert 460. This promotes a sealing fit between the inner periphery 462 of the valve seat insert and the poppet head portion 431.

[0065] Aspects of the invention have been described with reference to exemplary embodiments. Modifications and alterations will occur to others upon reading and understanding this specification. It is intended to include all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims

1. A check valve, A valve body, a body housing including an outer peripheral wall extending between an inlet port and an outlet port to define a valve cavity therebetween; a stationary annular valve seat insert mounted within a body seating surface surrounding the inlet port; a bushing disposed within the valve cavity and defining a central bore, the bushing including an outer end surface that axially mates with the valve seat insert; a biasing member disposed between the bearing portion of the main housing and the inner end of the bushing, the biasing member transmitting an axial compressive force from the main housing member to the bushing; a valve body including: a valve element extending through a central bore of the bushing, the valve element movable between a closed position that seals against the valve seat insert to prevent flow between the inlet port and the outlet port and an open position that allows fluid flow from the inlet port to the outlet port; A check valve.

2. 10. The check valve of claim 1, wherein the biasing member comprises at least one Belleville washer.

3. 2. The check valve of claim 1, further comprising a bearing member disposed between the biasing member and the inner end of the bushing.

4. 4. The check valve of claim 3, further comprising a biasing spring disposed between said valve element and said bearing member for biasing said valve element toward said closed position.

5. 5. The check valve of claim 4, wherein the biasing spring is radially disposed between the valve element and the bushing.

6. 2. The check valve of claim 1, wherein the body housing comprises a first body housing member threadably assembled with a second body housing member.

7. 7. The check valve of claim 6, wherein the first body housing member includes the inlet port, the body seat, and the outer periphery wall, and the second body housing member includes the body housing bearing portion and the outlet port.

8. 7. The check valve of claim 6, wherein said second body housing member includes externally threaded end threads, and said body housing bearing portion is disposed on an end face of said end threads.

9. 7. The check valve of claim 6, wherein the first body housing member includes the inlet port and the body seat, and the second body housing member includes the outer circumferential wall, the body housing bearing portion, and the outlet port.

10. 10. The check valve of claim 9, wherein said first body housing member includes externally threaded end threads, said body seat disposed on an end face of said end threads.

11. 7. The check valve of claim 6, further comprising a body seal gasket disposed between opposing surfaces of said first and second body housing members to provide a seal between said valve cavity and mating threads of said first and second body housing members.

12. 7. The check valve of claim 6, wherein the valve element comprises a poppet having an outer head portion and an inner tail portion.

13. 13. The check valve of claim 12, wherein the tail portion of the poppet is received within a counterbore of the outlet port.

14. 13. The check valve of claim 12, wherein the bushing further comprises a tapered flow guide surface opposite the outer end face and substantially matching the angled conical surface of the poppet head portion, the tapered flow guide surface being angled to guide flow toward the poppet's internal flow passage when the valve element is in the open position.

15. 2. The check valve of claim 1, wherein the body seating surface and the bushing outer end surface together define an annular seal cavity sized to retain the valve seat insert.

16. 16. The check valve of claim 15, wherein the bushing further comprises at least one circumferential recess extending to the outer end face so as to intersect the annular seal cavity, the at least one circumferential recess including a vent path intersecting the central bore of the bushing.

17. 16. The check valve of claim 15, wherein the annular seal cavity comprises a dovetail groove having a rear seating surface, a first side defined by the body seating surface, and a second side defined by the bushing outer end face.

18. 18. The check valve of claim 17, wherein the dovetail groove comprises a conical dovetail groove having a rear seating surface that extends at an angle of between about 40 degrees and about 80 degrees relative to a central axis of the valve.

19. 18. The check valve of claim 17, wherein the first side and second side of the dovetail groove form an included angle of between about 40 degrees and about 80 degrees.

20. 16. The check valve of claim 15, wherein the annular seal cavity is defined in part by a tapered portion of the body seating surface opposite a tapered peripheral seal surface of the valve element and a radial portion of the body seating surface opposite the bushing outer end face.

21. 21. The check valve of claim 20, wherein the tapered portion of the body seating surface extends substantially parallel to the tapered peripheral sealing surface of the valve element.

22. 21. The check valve of claim 20, wherein the annular seal cavity is further defined by an axially extending outer surface of an inner wall portion.

23. 16. The check valve of claim 15, wherein the annular seal cavity is defined in part by a first tapered portion of the body seating surface opposite a tapered peripheral seal surface of the valve element and a second tapered portion of the body seating surface opposite the bushing outer end face.

24. 24. The check valve of claim 23, wherein the first tapered portion of the body seating surface extends substantially parallel to the tapered peripheral sealing surface of the valve element.

25. 24. The check valve of claim 23, wherein the second tapered portion of the body seating surface extends substantially parallel to the bushing outer end face.

26. 24. The check valve of claim 23, wherein the annular seal cavity is further defined by an axially extending outer surface of an inner wall portion and an axially extending inner periphery portion of the body seat.

27. 10. The check valve of claim 1, wherein the valve seat insert comprises an elastomeric gasket seal.

28. 10. The check valve of claim 1, wherein the valve seat insert comprises a plastic gland.

29. 30. The check valve of claim 28, wherein the body seating surface comprises a concave surface sized to retain the plastic gland and an annular inner wall portion extending axially inward from the concave surface.

30. 30. The check valve of claim 29, wherein said annular inner wall portion is crimped radially outward to retain said plastic gland within said recessed surface.

31. A check valve, A valve body, a body housing including an outer peripheral wall extending between an inlet port and an outlet port to define a valve cavity therebetween; a stationary annular valve seat insert mounted within a body seating surface surrounding the inlet port; a bushing disposed within the valve cavity and defining a central bore, the bushing including an outer end surface that axially mates with the valve seat insert; a biasing member disposed between the bearing portion of the main housing and the inner end of the bushing, the biasing member transmitting an axial compressive force from the main housing member to the bushing; a valve body including: a valve element extending through a central bore of the bushing, the valve element movable between a closed position that seals against the valve seat insert to prevent flow between the inlet port and the outlet port and an open position that allows fluid flow from the inlet port to the outlet port; A check valve comprising: the body seat surface includes a concave surface sized to retain the valve seat insert and an annular inner wall portion extending axially inward from the concave surface, the annular inner wall portion sized to abut the valve element when the valve element is subjected to a backpressure above a threshold backpressure to limit compression of the valve seat insert by the valve element to a predetermined percentage of the uncompressed thickness of the valve seat insert.

32. 32. The check valve of claim 31, wherein the valve seat insert comprises an elastomeric gasket seal.

33. 32. The check valve of claim 31, wherein the annular inner wall portion defines a secondary sealing surface positioned radially inward of the valve seat insert for sealing engagement with a peripheral sealing surface of the valve element when the valve element is subjected to a backpressure above a threshold backpressure.

34. A check valve, A valve body, a body housing having a first body housing member including an inlet port, a body seating surface surrounding the inlet port, and an outer periphery wall extending to an internally threaded end; and a second body housing member including an outlet port and an externally threaded end screw assembled with the internally threaded end; a stationary annular valve seat insert mounted within a body seating surface surrounding the inlet port; a bushing disposed within the valve cavity and defining a central bore, the bushing including an outer end surface axially mateable with the valve seat insert; a biasing member disposed between a bearing portion of the male end thread and an inner end of the bushing, the biasing member transmitting an axial compressive force from the second body housing member to the valve seat insert; a valve body including: a valve element extending through a central bore of the bushing, the valve element movable between a closed position that seals against the valve seat insert to prevent flow between the inlet port and the outlet port and an open position that allows fluid flow from the inlet port to the outlet port; A check valve.

35. 35. The check valve of claim 34, wherein the valve element comprises a poppet having an outer head portion, an inner tail portion, and an internal passage extending from the head portion to the tail portion.

36. 36. The check valve of claim 35, wherein the tail portion of the poppet is received within a counterbore of the outlet port.

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