Patent Description:
Metal seated valves usually cost more than the soft seated variety, but can leak more than a soft seated valve. Soft seated valves have sealing surfaces made out of non-metallic, thermoplastic materials like PTFE, Delrin, Nylon, and PEEK. They work in medium- or low-pressure environments and are suitable for working temperatures below <NUM> (<NUM>°F). In the right conditions, soft seated valves can offer a fairly high level of sealing through their lifespan, typically more than a metal seated valve.

However, conventional soft seated valves might not withstand the same pressures as metal seated valves. It may thus be desirable to configure a soft seal valve with features that enhance the life of the soft seal used in the valve. This way, the valve is configured with the enhanced sealing ability of a soft seal, while having enhanced life for the soft seal.

Examples of valves are described in <CIT>, <CIT>, <CIT>, <CIT> and <CIT>, which may provide a useful background to the present disclosure.

The present disclosure describes implementations that relate to a valve having a poppet with a soft seal and features enhancing life of the soft seal. Optional features are defined in the dependent claims.

In a first example implementation, the present disclosure describes a valve. The valve includes: a valve body having a first port and a second port; a poppet movable within the valve body, wherein the poppet comprises: (i) a first conical surface having a first angle and a second conical surface having a second angle, such that the first angle is greater than the second angle, (ii) an exterior cylindrical surface, and (iii) an annular groove; and a seal disposed in the annular groove of the poppet. The poppet is movable between at least (i) a seated position in which the seal contacts an interior surface of the valve body to block fluid flow from the first port to the second port, and (ii) a partially-unseated position in which the poppet moves to form a flow area allowing fluid flow from the first port to the second port, wherein the exterior cylindrical surface of the poppet forms a diametrical clearance restriction with the interior surface of the valve body downstream from the flow area, wherein the first conical surface is configured to direct fluid toward the interior surface of the valve body, away from the seal, and wherein the diametrical clearance restriction generates back-pressure around the seal to reduce velocity of fluid around the seal.

In a second example implementation, the present disclosure describes a method. The method includes: positioning a poppet of a valve in a seated position, wherein the valve comprises a valve body having a first port and a second port, wherein the poppet is movable within the valve body, wherein the poppet comprises an annular groove, and wherein the valve further comprises a seal disposed in the annular groove of the poppet, wherein when the poppet is positioned in the seated position, the seal contacts an interior surface of the valve body to block fluid flow from the first port to the second port; moving the poppet to a partially-unseated position in which a flow area is formed between the poppet and the interior surface of the valve body, allowing fluid flow from the first port to the second port, wherein in the partially-unseated position a flow restriction is formed downstream from the flow area; directing fluid toward the interior surface of the valve body, away from the seal, when the poppet is in the partially-unseated position; and generating, by the flow restriction, back-pressure around the seal to reduce velocity of fluid around the seal.

In addition to the illustrative aspects, implementations, and features described above, further aspects, implementations, and features will become apparent by reference to the figures and the following detailed description.

The novel features believed characteristic of the illustrative examples are set forth in the appended claims. The illustrative examples, however, as well as a preferred mode of use, further objectives and descriptions thereof, will best be understood by reference to the following detailed description of an illustrative example of the present disclosure when read in conjunction with the accompanying Figures.

The present disclosure relates to valve having a poppet with features that protect a soft seal mounted to the poppet during operation so as to enhance the life of the soft seal. Particularly, the valve is configured such that as the poppet moves off its seat, flow rate is reduced as opposed to allowing fluid at high flow rate to suddenly rush through the valve. Also, the fluid is directed away from the soft seal as the poppet moves off the seat. Further, the valve has features to create a back-pressure at the soft seal to reduce velocity of fluid and have an enhanced pressure gradient (e.g., a substantially consistent pressure level) around the soft seal, thereby enhancing its life.

The term "soft seal" is used herein to indicate a seal made of non-metallic materials (e.g., rubber, elastomers, polymers, thermoplastic materials, etc.). In this disclosure, a check valve is used as an example to illustrate the features of the valve. However, it should be understood that other types of valves (e.g., a shuttle valve) can be configured with the same features. Further, the valve (e.g., the check valve) can be a standalone valve, or can be integrated into another valve assembly such as a sectional valve.

<FIG> illustrates a perspective view of a valve <NUM>, <FIG> illustrates a side view of the valve <NUM>, <FIG> illustrates a cross-sectional side view of the valve <NUM> as labelled in <FIG>, and <FIG> illustrates an enlarged partial cross-sectional view of the valve of <FIG>, in accordance with an example implementation. <FIG> are described together.

The valve <NUM> includes a valve body <NUM> including a first port <NUM> and a second port <NUM>. The valve body <NUM> also defines a longitudinal cavity <NUM> therein. The longitudinal cavity <NUM> is aligned with the first port <NUM> and is perpendicular to the second port <NUM>.

The valve <NUM> also includes a poppet <NUM> movable in the longitudinal cavity <NUM> within the valve body <NUM>. The first port <NUM> is disposed longitudinally at a nose of the poppet <NUM>, whereas the second port <NUM> is lateral to the poppet <NUM>.

The valve <NUM> further includes a biasing element such as a spring <NUM> disposed in a cavity <NUM> formed within the poppet <NUM>. As shown, the valve <NUM> includes a plug <NUM> threaded into the valve body <NUM>. A proximal end of the spring <NUM> rests against the plug <NUM>, whereas the distal end of the spring <NUM> rests against a respective interior surface of the poppet <NUM>. The plug <NUM> is fixed (e.g., screwed into the valve body <NUM>), and thus the spring <NUM> biases the poppet <NUM> toward the seated position shown in <FIG> where the poppet is seated against the interior surface of the valve body <NUM> to block fluid flow between the first port <NUM> and the second port <NUM>. The term "block" is used herein to indicate substantially preventing fluid flow except for minimal or leakage flow of drops per minute, for example.

Additionally, in some examples, fluid from the second port <NUM> can flow through a cross-hole <NUM> and a blind channel <NUM> formed in the poppet <NUM> to the cavity <NUM>. As such, the cross-hole <NUM> and the blind channel <NUM> form an internal fluid path that communicates fluid from the second port <NUM> to the cavity <NUM>. In this example, the diameter of the poppet <NUM> at its back (proximal) end can be made slightly larger than its respective diameter at its front (distal) end. As a result of such differential area, fluid in the cavity <NUM> may apply a fluid force on the poppet <NUM> in the distal direction to bias the poppet <NUM> in the distal direction toward a seated position.

<FIG> illustrates a perspective view of the poppet <NUM>, in accordance with an example implementation. Referring to <FIG> together, the poppet <NUM> has an annular groove <NUM> formed in a distal end or distal end face <NUM> of the poppet <NUM>, and the annular groove <NUM> defines or is bounded by three surfaces and accommodate a seal <NUM>. The seal <NUM> can be a face seal configured as a soft seal that can be made of a rubber, elastomer, polymer, or thermoplastic material. For example, the seal <NUM> can be a Viton® O-ring. The seal <NUM> can be bonded with an adhesive material to the three surfaces bounding the annular groove <NUM>.

In the closed or seated position shown in <FIG>, the seal <NUM> seals against an interior inclined surface <NUM> of the valve body <NUM>, which operates as a seat for the poppet <NUM>. Due to the seal <NUM> being made of a soft material, as the seal <NUM> is pressed against the hard interior surface of the valve body <NUM>, the seal <NUM> deforms and conforms to the microstructure of the valve body <NUM> interacting therewith. Thus, the interior surface of the valve body <NUM> and the seal <NUM> form a bond at their contact area, thereby sealing the first port <NUM> from the second port <NUM>.

In the cross-sectional view of <FIG>, each inclined surface of the valve body <NUM> or the poppet <NUM> is a conical surface as illustrated in the perspective view of <FIG>. Similarly, each horizontal line of the poppet <NUM> or the valve body <NUM> in the cross-sectional view of <FIG> represents a cylindrical surface, and each point in poppet <NUM> or the valve body <NUM> represents a circular line.

As shown in <FIG>, the poppet <NUM> has an exterior cylindrical surface <NUM> disposed opposite or facing an interior cylindrical surface <NUM> of the valve body <NUM> proximate the second port <NUM>. The outer diameter of the poppet <NUM> at the exterior cylindrical surface <NUM> is smaller than an inner diameter of the valve body <NUM> at the interior cylindrical surface <NUM> such that a first diametrical clearance restriction <NUM> (e.g., a gap) is formed therebetween.

Similarly, the poppet <NUM> has an exterior cylindrical surface <NUM> (at the nose of the poppet <NUM>) disposed opposite or facing an interior cylindrical surface <NUM> of the valve body <NUM> proximate the first port <NUM>. The outer diameter of the poppet <NUM> at the exterior cylindrical surface <NUM> is smaller than an inner diameter of the valve body <NUM> at the interior cylindrical surface <NUM> such that a second diametrical clearance restriction <NUM> is formed therebetween.

The poppet <NUM> has several conical surfaces between the two exterior cylindrical surfaces <NUM>, <NUM>. However, the conical surfaces do not have a consistent angle, but rather has several different taper angles. Particularly, tracing the exterior surface of the poppet <NUM> from its distal end in a proximal direction, the poppet <NUM> includes an annular groove <NUM> adjacent the exterior cylindrical surface <NUM>. The annular groove <NUM> then leads to a first conical surface <NUM> having a steep angle (see angle θ<NUM> in <FIG> between the first conical surface <NUM> with a horizontal or longitudinal line in <FIG>).

The first conical surface <NUM> then connects with a second conical surface <NUM> at seat contact line <NUM> at the intersection between the first conical surface <NUM> and the second conical surface <NUM>. The second conical surface <NUM> has an angle (see angle θ<NUM> between the second conical surface <NUM> with a horizontal or longitudinal line in <FIG>) that is smaller than the respective angle of the first conical surface <NUM>. As examples for illustration, the angle of the first conical surface <NUM> can be about <NUM> degrees, whereas the angle of the second conical surface <NUM> can be about <NUM> degrees.

In an example, the angle of the interior inclined surface <NUM> of the valve body <NUM> (i.e., the angle that the line representing the interior inclined surface <NUM> makes with a horizontal line) can be an angle that is greater than the angle of the second conical surface <NUM> but smaller than the angle of the first conical surface <NUM>. For instance, if the angle of the second conical surface <NUM> is about <NUM> degrees and the angle of the first conical surface <NUM> is about <NUM> degrees, the angle of the interior inclined surface <NUM> can be about <NUM> degrees.

With this difference in angle, the first conical surface <NUM> and the second conical surface <NUM> meet at a corner or the seat contact line <NUM> that is configured as a protrusion in the distal end face <NUM> of the poppet <NUM>.

The seat contact line <NUM> is shown as a point (e.g., a corner) that connects the first conical surface <NUM> with the second conical surface <NUM>; however, it should be understood that the seat contact line <NUM> of the poppet <NUM> is a circular line that contacts or sits at the interior inclined surface <NUM> of the valve body <NUM> to form a metal-to-metal seal when the valve <NUM> is in a closed position. The metal-to-metal seal between the seat contact line <NUM> and the valve body <NUM> may provide sealing functionality. However, the primary sealing function may be performed by the seal <NUM> disposed in the annular groove <NUM> formed in the distal end face <NUM> of the poppet <NUM>.

The second conical surface <NUM> then leads to the annular groove <NUM> that receives the seal <NUM>. The annular groove <NUM> is then followed by an annular face <NUM> (represented as a vertical line in <FIG>). The annular face <NUM> then connects with a third conical surface <NUM> having an angle (see angle θ<NUM> between the third conical surface <NUM> with a horizontal or longitudinal line in <FIG>) that may be the same as or less than the angle of the second conical surface <NUM>. As an example, the angle of the third conical surface <NUM> can be about <NUM> degrees. The seal <NUM> is disposed between or straddled by, the second conical surface <NUM> and the third conical surface <NUM>.

The third conical surface <NUM> is followed by a cylindrical surface <NUM>, which then leads to an annular face <NUM> (vertical line in <FIG>). The annular face <NUM> then leads to the exterior cylindrical surface <NUM> of the poppet <NUM>.

This configuration of the poppet <NUM> and the valve body <NUM> protects the seal <NUM> and enhances its life compared to conventional soft seal valve configurations. Particularly, assuming high pressure fluid is provided to the first port <NUM>, as the pressurized fluid pushes the poppet <NUM> in the proximal direction to move it to an unseated position, the features of the poppet <NUM> and the valve body <NUM> reduce the velocity of fluid around the seal <NUM>. Further, the inlet fluid jet is directed toward the interior inclined surface <NUM> of the valve body <NUM> rather than the seal <NUM> to protect the seal <NUM> from the fluid jet.

<FIG> illustrates an enlarged partial cross-sectional view of the valve of <FIG> with arrows representing fluid flow through the valve <NUM> when the poppet <NUM> is partially-unseated, and <FIG> illustrates an enlarged partial cross-sectional view of the poppet <NUM> partially-unseated from the valve body <NUM>, in accordance with an example implementation. In other words, <FIG> illustrates the poppet <NUM> in a partial stroke position between a closed or seated position and a fully-shifted or fully-unseated position (see <FIG>). The terms "fully-shifted," "fully-open," and "fully-unseated" can be used interchangeably herein.

The term "seated" position indicates a position of the poppet <NUM> where the seat contact line <NUM> and/or the seal <NUM> contact the inner surface (e.g., the interior inclined surface <NUM>) of the valve body <NUM>, which operates as a seat for the poppet <NUM>. "Unseated" position, indicates that the poppet <NUM> has moved off the seat, thereby allowing fluid flow between the first port <NUM> and the second port <NUM>.

When pressurized fluid is provided to the first port <NUM>, pressure level can increase at the distal end of the poppet <NUM> until it is sufficient to overcome the biasing force of the spring <NUM>, thereby causing the poppet <NUM> to be unseated (i.e., moves in the proximal direction to the right in <FIG>). Once the poppet <NUM> "cracks" open, fluid starts to flow from the first port <NUM> through the second diametrical clearance restriction <NUM>.

Referring to <FIG>, fluid then flows through a flow area <NUM> (i.e., space formed between poppet <NUM> and the interior surface of the valve body <NUM> as the poppet <NUM> is unseated). Due to the angle θ<NUM> of the first conical surface <NUM> being greater than the angle θ<NUM> of the second conical surface <NUM>, fluid is directed by the first conical surface <NUM> toward the interior inclined surface <NUM> of the valve body <NUM> as represented by arrow <NUM>, rather than toward the seal <NUM>. As such, the configuration of the poppet <NUM> protects the seal <NUM> from the initial gush of fluid that flows through the valve <NUM>, and fluid is directed away from the seal <NUM>. As mentioned above, as an illustrative example, θ<NUM> can be about <NUM> degrees, θ<NUM> can be about <NUM> degrees, and the angle of the interior inclined surface <NUM> of the valve body <NUM> can be about <NUM> degrees. These angles are example for illustration only and other angles that maintains the relationship between the angles θ<NUM> and θ<NUM> could be used.

Fluid then continues through a flow area zone <NUM> around the seal <NUM> toward the first diametrical clearance restriction <NUM>, then toward the second port <NUM>. The first diametrical clearance restriction <NUM> is configured to operate as an orifice or flow restriction downstream of the flow area zone <NUM>. As a result of the first diametrical clearance restriction <NUM> restricting fluid flow downstream of the flow area zone <NUM>, back-pressure (e.g., an increased pressure level) is generated at the flow area zone <NUM> around the seal <NUM>.

As such, the flow area zone <NUM> operate as a dampening chamber. Particularly, the first diametrical clearance restriction <NUM> restricts fluid flow therethrough, and therefore generates an increased bulk static pressure at the flow area zone <NUM>. In other words, as fluid flows through the flow area zone <NUM>, fluid decelerates converting excess kinetic energy into pressure as the fluid slows. As such, fluid slows down around the seal <NUM> while pressure level increases. As a result of such increased bulk static pressure at the flow area zone <NUM>: the likelihood of formation of cavitation bubbles in the flow area <NUM> generally, and the flow area zone <NUM> particularly, may be reduced, and (ii) the velocity of fluid flowing through the flow area zone <NUM> is reduced, thereby reducing the likelihood of damaging (i.e., "nibbling" away) the seal <NUM>.

In examples, additionally, the valve <NUM> can be configured to have the second diametrical clearance restriction <NUM> upstream of the flow area zone <NUM>, which restricts fluid flow rate from the first port <NUM> when the poppet <NUM> is unseated. Such limiting of flow rate may protect the seal <NUM> from a sudden gush of fluid flow as the poppet <NUM> is unseated. However, without the second diametrical clearance restriction <NUM>, the configuration of the poppet <NUM> with the dual-angle surface (i.e., the angle of the first conical surface <NUM> being different from the angle of the second conical surface <NUM>) directing fluid away from the seal <NUM>, and the first diametrical clearance restriction <NUM> generating a back-pressure in the flow area zone <NUM> around the seal <NUM> may sufficiently protect the seal <NUM> and enhance its life.

The poppet <NUM> can continue moving in the proximal direction under pressure from the fluid at the first port <NUM>. <FIG> illustrates a cross-sectional side view of the valve <NUM> with the poppet <NUM> in a fully-unseated position, and <FIG> illustrates an enlarged partial cross-sectional view of the poppet <NUM> in the fully-unseated position, in accordance with an example implementation. As shown in <FIG>, the poppet <NUM> is fully shifted and the flow area <NUM> is enlarged. In this position, the proximal end of the poppet <NUM> may contact the plug <NUM>.

In this position, fluid can flow freely past the poppet <NUM>, and the seal <NUM> is largely out of the way. Also, notably, the poppet <NUM> shifted such that the diametrical clearance restrictions <NUM>, <NUM> are no longer formed between the poppet <NUM> and the valve body <NUM>, and there is no restriction of the fluid flow. Particularly, the exterior cylindrical surface <NUM> disengages from (i.e., no longer overlaps) the interior cylindrical surface <NUM>, and the exterior cylindrical surface <NUM> disengages from (i.e., no longer overlaps) the interior cylindrical surface <NUM> such that the diametrical clearance restrictions <NUM>, <NUM> are no longer formed.

In examples, the valve <NUM> can be configured to be bidirectional, allowing fluid flow from the first port <NUM> to the second port <NUM> as described above, and also allowing fluid flow from the second port <NUM> to the first port <NUM>. In this example, the valve <NUM> may be configured to fluidly couple the cavity <NUM> to a fluid reservoir to reduce pressure level in the cavity <NUM>. For example, the cavity <NUM> may be fluidly coupled to the fluid reservoir via a normally-closed solenoid-operated valve. When the solenoid-operated valve is actuated, it opens, thereby allowing fluid in the cavity <NUM> to be relieved to the fluid reservoir, reducing pressure level in the cavity <NUM>.

Once pressure level in the cavity <NUM> is reduced, pressurized fluid at the second port <NUM> can push the poppet <NUM> in the proximal direction against the spring <NUM>, unseating the poppet <NUM>. As a result, fluid can flow from the second port <NUM> to the first port <NUM>. The valve <NUM> is configured with features that protect the seal <NUM> when fluid flows from the second port <NUM> to the first port <NUM>, similar to the features that protect the seal <NUM> when fluid flows from the first port <NUM> to the second port <NUM>.

<FIG> illustrates an enlarged partial cross-sectional view of the valve of <FIG> with arrows representing fluid flow from the second port <NUM> to the first port <NUM> when the poppet <NUM> is unseated, in accordance with an example implementation. Once the poppet <NUM> "cracks" open, fluid starts to flow from the second port <NUM> through the first diametrical clearance restriction <NUM>. Fluid then flows through a flow area <NUM> (i.e., space formed between poppet <NUM> and the interior surface of the valve body <NUM> as the poppet <NUM> is unseated). Due to the angle θ<NUM> (e.g., an angle of <NUM> degrees) of the third conical surface <NUM>, fluid is directed by the third conical surface <NUM> toward the interior surface of the valve body <NUM> as represented by arrow <NUM>, rather than toward the seal <NUM>. As such, the configuration of the poppet <NUM> protects the seal <NUM> from the initial gush of fluid that flows through the valve <NUM>, and fluid is directed away from the seal <NUM>.

Fluid then continues through a flow area zone <NUM> around the seal <NUM> toward the second diametrical clearance restriction <NUM>, then toward the first port <NUM>. The second diametrical clearance restriction <NUM> is configured to operate as an orifice or flow restriction downstream of the flow area zone <NUM>. As a result of the second diametrical clearance restriction <NUM> restricting fluid flow downstream of the flow area zone <NUM>, back-pressure (e.g., an increased pressure level) is generated at the flow area zone <NUM> around the seal <NUM>.

Thus, the second diametrical clearance restriction <NUM> restricts fluid flow therethrough, and therefore generates an increased bulk static pressure at the flow area zone <NUM>. In other words, as fluid flows through the flow area zone <NUM>, fluid decelerates converting excess kinetic energy into pressure as the fluid slows. As such, fluid slows down around the seal <NUM> while pressure level increases. As a result of such increased bulk static pressure at the flow area zone <NUM>: the likelihood of formation of cavitation bubbles in the flow area <NUM> generally, and the flow area zone <NUM> particularly may be reduced, and (ii) the velocity of fluid flowing through the flow area zone <NUM> is reduced, thereby reducing the likelihood of damaging (i.e., "nibbling" away) the seal <NUM>.

<FIG> is a flowchart of a method <NUM> for operating a valve, in accordance with an example implementation. The method <NUM> can be used for operating the valve <NUM>, for example.

The method <NUM> may include one or more operations, functions, or actions as illustrated by one or more of blocks <NUM>-<NUM>. Although the blocks are illustrated in a sequential order, these blocks may also be performed in parallel, and/or in a different order than those described herein. Also, the various blocks may be combined into fewer blocks, divided into additional blocks, and/or removed based upon the desired implementation. It should be understood that for this and other processes and methods disclosed herein, flowcharts show functionality and operation of one possible implementation of present examples. Alternative implementations are included within the scope of the examples of the present disclosure in which functions may be executed out of order from that shown or discussed, including substantially concurrent or in reverse order, depending on the functionality involved, as would be understood by those reasonably skilled in the art.

At block <NUM>, the method <NUM> includes positioning a poppet (e.g., the poppet <NUM>) of a valve (e.g., the valve <NUM>) in a seated position (see <FIG>), wherein the valve comprises a valve body (e.g., the valve body <NUM>) having a first port (e.g., the first port <NUM>) and a second port (e.g., the second port <NUM>), wherein the poppet is movable within the valve body, wherein the poppet comprises an annular groove (e.g., the annular groove <NUM>), and wherein the valve further comprises a seal (e.g., the seal <NUM>) disposed in the annular groove of the poppet, wherein when the poppet is positioned in the seated position, the seal contacts an interior surface (e.g., the interior inclined surface <NUM>) of the valve body to block fluid flow from the first port to the second port.

At block <NUM>, the method <NUM> includes moving the poppet to a partially-unseated position (see <FIG>) in which a flow area (e.g., the flow area <NUM> and/or the flow area zone <NUM>) is formed between the poppet and the interior surface of the valve body, allowing fluid flow from the first port to the second port, wherein in the partially-unseated position a flow restriction (e.g., the first diametrical clearance restriction <NUM>) is formed downstream from the flow area.

At block <NUM>, the method <NUM> includes directing fluid toward the interior surface of the valve body, away from the seal, when the poppet is in the partially-unseated position. As described above, the first conical surface <NUM> directs fluid toward the interior inclined surface <NUM> of the valve body <NUM> (see the arrow <NUM>), away from the seal <NUM>.

At block <NUM>, the method <NUM> includes generating, by the flow restriction, back-pressure around the seal to reduce velocity of fluid around the seal. As described above, the first diametrical clearance restriction <NUM> causes or generates back-pressure at the flow area zone <NUM>, thereby causing velocity of fluid to be reduced around the seal <NUM>.

The method <NUM> can further include other steps described herein such as restricting fluid flow via the second diametrical clearance restriction <NUM> upstream of the flow area <NUM>.

Additionally, the first diametrical clearance restriction <NUM> upstream of the flow area zone <NUM> restricts fluid flow rate from the second port <NUM> when the poppet <NUM> is unseated. Such limiting of flow rate may protect the seal <NUM> from a sudden gush of fluid flow as the poppet <NUM> is unseated.

The detailed description above describes various features and operations of the disclosed systems with reference to the accompanying figures. The illustrative implementations described herein are not meant to be limiting. Certain aspects of the disclosed systems can be arranged and combined in a wide variety of different configurations, all of which are contemplated herein.

Thus, the figures should be generally viewed as component aspects of one or more overall implementations, with the understanding that not all illustrated features are necessary for each implementation.

Further, devices or systems may be used or configured to perform functions presented in the figures. In some instances, components of the devices and/or systems may be configured to perform the functions such that the components are actually configured and structured (with hardware and/or software) to enable such performance. In other examples, components of the devices and/or systems may be arranged to be adapted to, capable of, or suited for performing the functions, such as when operated in a specific manner.

By the term "substantially" it is meant that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.

The arrangements described herein are for purposes of example only. As such, those skilled in the art will appreciate that other arrangements and other elements (e.g., machines, interfaces, operations, orders, and groupings of operations, etc.) can be used instead, and some elements may be omitted altogether according to the desired results. Further, many of the elements that are described are functional entities that may be implemented as discrete or distributed components or in conjunction with other components, in any suitable combination and location.

Claim 1:
A valve (<NUM>) comprising:
a valve body (<NUM>) having a first port (<NUM>) and a second port (<NUM>);
a poppet (<NUM>) movable within the valve body (<NUM>), wherein the poppet (<NUM>) comprises: (i) a first conical surface (<NUM>) having a first angle and a second conical surface (<NUM>) having a second angle, such that the first angle is greater than the second angle, (ii) an exterior cylindrical surface (<NUM>), and (iii) an annular groove (<NUM>); and
a seal (<NUM>) disposed in the annular groove (<NUM>) of the poppet (<NUM>), wherein the poppet (<NUM>) is movable between at least (i) a seated position in which the seal (<NUM>) contacts an interior surface (<NUM>) of the valve body (<NUM>) to block fluid flow from the first port (<NUM>) to the second port (<NUM>), and (ii) a partially-unseated position in which the poppet (<NUM>) moves to form a flow area zone (<NUM>) around the seal (<NUM>) allowing fluid flow from the first port (<NUM>) to the second port (<NUM>), wherein the exterior cylindrical surface (<NUM>) of the poppet (<NUM>) forms a diametrical clearance restriction (<NUM>) with the interior surface (<NUM>) of the valve body (<NUM>) downstream from the flow area zone (<NUM>), wherein the first conical surface (<NUM>) is configured to direct fluid toward the interior surface of the valve body (<NUM>), away from the seal (<NUM>), characterised in that
the diametrical clearance restriction (<NUM>) generates back-pressure around the seal (<NUM>) to reduce velocity of fluid around the seal (<NUM>), wherein the interior surface of the valve body (<NUM>) comprises an interior inclined surface (<NUM>), wherein the first conical surface (<NUM>) of the poppet (<NUM>) connects with the second conical surface (<NUM>) at a seat contact line (<NUM>) configured to contact the interior inclined surface (<NUM>) of the valve body (<NUM>) when the poppet (<NUM>) is in the seated position to form a metal-to-metal seal.