Patent Description:
Pressure regulating valves are valves that are designed to adjust the pressure of a fluid or gas within a system to a desired working pressure. In some examples, pressure regulating valves receive a fluid or gas at a high pressure and the pressure regulating valve is configured to lower the output pressure of the fluid or gas before the fluid or gas flows downstream to other components of the system. Traditional pressure regulating valves include an inlet, an outlet, and a metering device positioned between the inlet and the outlet to adjust the pressure of the fluid or gas. At high pressures and temperatures, the metering device may not be capable of lowering the fluid or gas pressure to the desired working pressure and the metering device can completely close, causing a pressure spike within the valve. The pressure spike can impact the accuracy of the pressure regulating valve and cause damage to the overall system. As such, it is desirable to prevent a pressure spike within the pressure regulating valve and the overall system. <CIT> relates generally to flow control devices and, more particularly, to pressure regulating flow control devices for controllably metering over a wide temperature range the flow of a fluid whose density changes with temperature and delivering the metered fluid at a regulated pressure which varies greatly with fluid temperature.

According to one aspect of the disclosure, a pressure regulating valve for use in a fluid system is provided as claimed in claim <NUM>. The pressure regulating valve includes a housing including an inlet and an outlet. The inlet is fluidly coupled to a first fluid channel and the outlet is fluidly coupled to a second fluid channel. A sleeve is positioned within the housing and the sleeve includes a first conduit and a second conduit. A spool is slidingly positioned within the sleeve and the spool includes an internal cavity, a first regulating window, a second regulating window, and a spool outlet. The internal cavity is positioned within an outer wall of the spool and formed by the outer wall of the spool. The first regulating window fluidly couples the internal cavity of the spool and the first conduit of the sleeve. The second regulating window fluidly couples the internal cavity of the spool to a drain conduit. The spool outlet fluidly couples the internal cavity of the spool and the second conduit of the sleeve.

According to another aspect of the disclosure, a method of operating a pressure regulating valve within a fluid flow system is provided as claimed in claim <NUM>. The method includes the following steps: flowing a fluid at a first pressure through an inlet of a housing and through a first conduit of a sleeve; flowing the fluid through a first regulating window of a spool into an internal cavity of the spool; translating, by the spool, towards a first end of the housing as the fluid pressure within the internal cavity of the spool increases; flowing the fluid through a second regulating window when the fluid pressure within the internal cavity of the spool reaches a pressure limit; and flowing the fluid at a second pressure through a spool outlet of the spool, through a second conduit of the sleeve, and through an outlet of the housing, wherein the first pressure is greater than the second pressure.

<FIG> is a cross-sectional view of pressure regulating valve <NUM> in a first position. <FIG> is a cross-sectional view of pressure regulating valve <NUM> in a second position. <FIG> is a cross-sectional view of pressure regulating valve <NUM> in a third position. <FIG> will be discussed together. Further, pressure regulating valve <NUM> will hereinafter be referred to as "valve <NUM>", but it is to be understood that the phrase "valve <NUM>" refers to pressure regulating valve <NUM>. Valve <NUM> is pressure regulating valve, and as such, is configured to adjust the pressure of a fluid within a fluid system to a desired working pressure. In some examples, valve <NUM> receives a fluid at an elevated pressure and valve <NUM> reduces the output pressure of the fluid before the fluid flows downstream to other components of the system. In other examples, valve <NUM> can receive a fluid at a reduced pressure and valve <NUM> can increase the output pressure of the fluid before the fluid flows downstream to other components of the system. Valve <NUM> can be used in any fluid flow system requiring pressure regulation for proper functioning of the fluid flow system. In one example, valve <NUM> can be used in a fuel system on an aircraft to adjust the pressure of the fuel flowing from a fuel tank onboard the aircraft to a combustor of a gas turbine engine.

Valve <NUM> includes housing <NUM>, sleeve <NUM>, cap <NUM>, shims <NUM>, spring <NUM>, spring seat <NUM>, pin <NUM>, and spool <NUM>. Further, valve <NUM> is fluidly coupled to first fluid channel <NUM> and second fluid channel <NUM>. First fluid channel <NUM> can be a conduit, duct, pipe, tube, etc., that is configured to transfer a fluid to an inlet of valve <NUM> at a first pressure. Second fluid channel <NUM> can be a conduit, duct, pipe, tube, etc., that is configured to transfer a fluid exiting an outlet of valve <NUM> away from valve <NUM> at a second pressure. In the specific example discussed above, first fluid channel <NUM> can fluidly couple a fuel tank on an aircraft to valve <NUM>, such that fuel can flow from the fuel tank to valve <NUM> at a first pressure. Second fluid channel <NUM> can fluidly couple valve <NUM> to a combustor of a gas turbine engine (not shown), such that the fuel can flow from valve <NUM> to the combustor of the gas turbine engine at a second pressure. In some examples, the first pressure is greater than the second pressure.

Housing <NUM> is the main body portion of valve <NUM> within which the other components of valve <NUM> are positioned. In the example shown in <FIG>, housing <NUM> has a generally hollow cylindrical shape such that an open cavity exists within outer walls of housing <NUM>, providing a space for the other components of valve <NUM> to be positioned. Housing <NUM> includes inlet <NUM>, outlet <NUM>, first end 12A, and second end 12B. Inlet <NUM> is an aperture extending fully through the outer walls of housing <NUM> and inlet <NUM> is fluidly coupled to first fluid channel <NUM>. Inlet <NUM> is configured to provide a location for a fluid to enter and flow into valve <NUM>. Outlet <NUM> is an aperture extending fully through the outer walls of housing <NUM> and outlet <NUM> is fluidly coupled to second fluid channel <NUM>. Outlet <NUM> is configured to provide a location for a fluid to exit and flow out of valve <NUM>. In the example shown, inlet <NUM> and outlet <NUM> are positioned adjacent each other on the same side of housing <NUM>, such that inlet <NUM> is positioned parallel with outlet <NUM>. In another example, inlet <NUM> and outlet <NUM> can be positioned on opposite sides of housing <NUM> but may still be positioned parallel with each other. First end 12A is a first distal end of housing <NUM> and second end 12B is a second distal end of housing <NUM> positioned opposite first end 12A of housing <NUM>.

Sleeve <NUM> is positioned within and fully surrounded by housing <NUM>. Further, sleeve <NUM> is fixedly positioned within housing <NUM> and sleeve <NUM> is generally concentric with an internal surface of housing <NUM>. As such, sleeve <NUM> can have a generally hollow cylindrical shape such that an open cavity exists within outer walls of sleeve <NUM>, providing a space for the spool <NUM> to be positioned, discussed further below. A plurality of seals <NUM> can be positioned between sleeve <NUM> and the internal surface of housing <NUM> to prevent or minimize fluid leakage between sleeve <NUM> and housing <NUM> during operation of valve <NUM> within a fluid system. In the example shown, there are three annular seals <NUM> positioned between sleeve <NUM> and the internal surface of housing <NUM> to prevent or minimize fluid leakage between the components. In other examples, there can be more than or less than three annular seals <NUM> positioned between sleeve <NUM> and the internal surface of housing <NUM> to prevent or minimize fluid leakage between the components.

Sleeve <NUM> includes first conduit <NUM>, second conduit <NUM>, and drain conduit <NUM>. First conduit <NUM> is an aperture extending fully through an outer wall of sleeve <NUM> and first conduit <NUM> is fluidly coupled to inlet <NUM> of housing <NUM>. First conduit <NUM> is configured to provide a flow path for fluid to flow from inlet <NUM> of housing <NUM> through the outer walls of sleeve <NUM> and into spool <NUM>, discussed further below. In some examples, first conduit <NUM> can be a through hole or aperture that extends through the outer walls of sleeve <NUM>. In other examples, first conduit <NUM> can be an annular groove that extends around a circumference of sleeve <NUM> and at least one aperture can extend through the outer walls of sleeve <NUM> to fluidly couple first conduit <NUM> to spool <NUM>. Second conduit <NUM> is an aperture extending fully through the outer walls of sleeve <NUM> and second conduit <NUM> is fluidly coupled to outlet <NUM> of housing <NUM>. Second conduit <NUM> is configured to provide a flow path for fluid to flow from second conduit <NUM> through outlet <NUM> of housing <NUM> and out through second fluid channel <NUM> as the fluid exits valve <NUM>. In some examples, second conduit <NUM> can be a through hole or aperture that extends through the outer walls of sleeve <NUM>. In other examples, second conduit <NUM> can be an annular groove that extends around a circumference of sleeve <NUM> and at least one aperture can extend through the outer walls of sleeve <NUM> to fluidly couple second conduit <NUM> to spool <NUM>.

Drain conduit <NUM> is positioned at an end of sleeve <NUM> closest to first end 12A of housing <NUM>. Drain conduit <NUM> is an aperture extending fully through an outer wall of sleeve <NUM> and drain conduit <NUM> is fluidly coupled to a drain system (not shown) of the fluid system. Drain conduit <NUM> is configured to provide a flow path for excess fluid to flow out from valve <NUM> through a drain system of the fluid system. More specifically, fluid leaking or flowing out from spool <NUM> can flow through an end portion of sleeve <NUM> and into and through drain conduit <NUM> to be dispensed into the drain system of the fluid system, discussed further below. In some examples, drain conduit <NUM> can be a through hole or aperture that extends through the outer walls of sleeve <NUM>. In other examples, drain conduit <NUM> can be an annular groove that extends around a circumference of sleeve <NUM> and at least one aperture can extend through the outer walls of sleeve <NUM> to fluidly couple drain conduit <NUM> to the drain system of the fluid system. In some examples, drain conduit <NUM> is positioned closest to first end 12A of housing <NUM>, second conduit <NUM> is positioned closest to second end 12B of housing <NUM>, and first conduit <NUM> is positioned between second conduit <NUM> and drain conduit <NUM>.

Cap <NUM> is coupled to first end 12A of housing <NUM> and cap <NUM> extends at least partially within and partially outside of housing <NUM>. In some examples, cap <NUM> can be coupled to housing <NUM> through a mating threaded connection. Further, in some examples a seal can be positioned between housing <NUM> and cap <NUM> to prevent fluid leakage between cap <NUM> and housing <NUM>. A portion of cap <NUM> extends in an axial direction into housing <NUM> and the distal end of cap <NUM> within housing <NUM> is positioned adjacent and abuts a distal end of sleeve <NUM>. Cap <NUM> is configured to secure sleeve <NUM> within housing <NUM>. More specifically, cap <NUM> is configured to prevent sleeve <NUM> from translating and/or rotating within housing <NUM>, ensuring sleeve <NUM> remains stationary within housing <NUM>. Cap <NUM> can have a generally hollow cylindrical shape, such that cap <NUM> is concentric with housing <NUM>. Further, the generally hollow cylindrical shape of cap <NUM> provides a space for the other components of valve <NUM> to be positioned.

A plurality of shims <NUM> and spring <NUM> are two such components of valve <NUM> that are positioned within the space or cavity of the portion of cap <NUM> extending axially into housing <NUM>. Each of the plurality of shims <NUM> are positioned within cap <NUM> and are axially aligned with a central axis of cap <NUM>, such that shims <NUM> are concentric with cap <NUM>. The plurality of shims <NUM> are positioned adjacent an inner surface of cap <NUM> and one of the plurality of shims <NUM> abuts the inner surface of cap <NUM>. The plurality of shims <NUM> are configured to be added and removed, as needed, to fine tune the spring load of spring <NUM>, setting the regulating pressure of valve <NUM>. More specifically, a greater number of shims <NUM> can be used to increase the spring load of spring <NUM>, increasing the regulating pressure of valve <NUM>. Further, a lower number of shims <NUM> can be used to decrease the spring load of spring <NUM>, decreasing the regulating pressure of valve <NUM>. The number of shims <NUM> within valve <NUM> will vary depending on the required regulating pressure of valve <NUM> for each specific fluid system. Spring <NUM> is positioned at least partially within cap <NUM> and spring <NUM> is axially aligned with the central axis of cap <NUM>, such that spring <NUM> is concentric with cap <NUM>. A first distal end of spring <NUM> abuts one of the plurality of shims <NUM> and a second distal end of spring <NUM> abuts spring seat <NUM>. Spring <NUM> is configured to induce a force on spool <NUM> to force spool <NUM> towards second end 12B of housing <NUM>, discussed further below.

Spring seat <NUM> is positioned at least partially within sleeve <NUM> and spring seat <NUM> abuts the second distal end of spring <NUM> on a first side of spring seat <NUM>. In the example shown, spring seat <NUM> is an annular component with a generally V-shaped cross-section. The second distal end of spring <NUM> abuts the first side of spring seat <NUM> and forces spring seat <NUM> towards second end 12B of housing <NUM>. Further, pin <NUM> is positioned at least partially within spring seat <NUM> and a second side of spring seat <NUM> abuts an end of pin <NUM>. Pin <NUM> is a cylindrical component that extends between spring seat <NUM> and spool <NUM>. As such, spring <NUM> is configured to induce a force onto spring seat <NUM> which then forces pin <NUM> towards spool <NUM>, inducing a force onto spool <NUM>. In other words, spring <NUM> is configured to induce a force onto spring seat <NUM> which in turn induces a force onto pin <NUM>. The force induced onto pin <NUM> is transferred through pin <NUM> to spool <NUM> to push or force each of spring seat <NUM>, pin <NUM>, and spool <NUM> towards second end 12B of housing <NUM>. When the fluid system is not operational, spring <NUM> forces spring seat <NUM>, pin <NUM>, and spool <NUM> towards second end 12B of housing <NUM> until spool <NUM> reaches a hard stop which prevents spool <NUM> from translating any closer to second end 12B. When the fluid system is operational, fluid enters spool <NUM> and the fluid pressure within spool <NUM> increases, causing spool <NUM> to translate towards first end 12A of housing <NUM>, discussed further below.

Spool <NUM> is positioned within and fully surrounded by sleeve <NUM>. Further, spool <NUM> is slidingly positioned within sleeve <NUM> such that spool <NUM> can translate in an axially direction toward and away from both first end 12A and second end 12B of housing <NUM>. Spool <NUM> is concentric with an internal surface of sleeve <NUM>, and spool <NUM> is also positioned within and concentric with an internal surface of housing <NUM>. Spool <NUM> can have a generally hollow cylindrical shape such that an open cavity exists within spool <NUM> for fluid to flow within and through. Spool <NUM> includes first spool end <NUM>, second spool end <NUM>, outer walls <NUM>, internal cavity <NUM>, first regulating window <NUM>, second regulating window <NUM>, and spool outlet <NUM>. First spool end <NUM> is a first distal end of spool <NUM> positioned closer to first end 12A of housing <NUM> and closer to spring <NUM> than any other feature of spool <NUM>. Second spool end <NUM> is a second distal end of spool <NUM> positioned closer to second end 12B of housing <NUM> than any other feature of spool <NUM>. First spool end <NUM> is positioned on an opposite side of spool <NUM> as second spool end <NUM>. First spool end <NUM> of spool <NUM> is a closed end, preventing fluid from flowing out through first spool end <NUM>. Second spool end <NUM> of spool <NUM> is an open end and plug <NUM> is positioned at least partially within and coupled to second spool end <NUM> to prevent fluid from flowing out through second spool end <NUM>.

Outer walls <NUM> of spool <NUM> define the generally hollow cylindrical shape of spool <NUM>. Further, outer walls <NUM> define and form internal cavity <NUM> within outer walls <NUM>. As such, internal cavity <NUM> is positioned within outer walls <NUM> of spool <NUM> and internal cavity <NUM> is the space or cavity in which fluid flows within and through of spool <NUM>. First regulating window <NUM> is an aperture that extends through outer walls <NUM> of spool <NUM> to internal cavity <NUM> of spool <NUM>. First regulating window <NUM> fluidly couples internal cavity <NUM> of spool <NUM> to first conduit <NUM> of sleeve <NUM>. Second regulating window <NUM> is an aperture that extends through outer walls <NUM> of spool <NUM> to internal cavity <NUM> of spool <NUM>. Second regulating window <NUM> fluidly couples internal cavity <NUM> of spool <NUM> to drain conduit <NUM> of sleeve <NUM>. Spool outlet <NUM> is an aperture that extends through outer walls <NUM> of spool <NUM> to internal cavity <NUM> of spool <NUM>. Spool outlet <NUM> fluidly couples internal cavity <NUM> of spool <NUM> to second conduit <NUM> of sleeve <NUM>. In the example shown, second regulating window <NUM> is positioned adjacent first spool end <NUM> of spool <NUM> and spool outlet <NUM> is positioned adjacent second spool end <NUM> of spool <NUM>. Further, first regulating window <NUM> is positioned between second regulating window <NUM> and spool outlet <NUM>.

In some examples, first regulating window <NUM>, second regulating window <NUM>, and spool outlet <NUM> can be through holes or apertures that extend fully through both outer walls <NUM> of spool <NUM>. In other examples, first regulating window <NUM>, second regulating window <NUM>, and spool outlet <NUM> can each be annular grooves that extend around a circumference of spool <NUM> and at least one aperture can extend through outer walls <NUM> of spool <NUM> to fluidly couple first regulating window <NUM> to first conduit <NUM>, second regulating window <NUM> to drain conduit <NUM>, and spool outlet <NUM> to second conduit <NUM>. Further, in some examples, each of first regulating window <NUM>, second regulating window <NUM>, and spool outlet <NUM> can be equal sized apertures. In other examples, each of first regulating window <NUM>, second regulating window <NUM>, and spool outlet <NUM> can be different sized apertures. In addition, in some examples, a central axis of each of first regulating window <NUM>, second regulating window <NUM>, spool outlet <NUM>, first conduit <NUM>, and second conduit <NUM> are positioned parallel with each other.

When the fluid flow system in which valve <NUM> is within is operational, fluid flows through first fluid channel <NUM> and into valve <NUM>. More specifically, fluid flows from first fluid channel <NUM> through inlet <NUM> of housing <NUM>, through first conduit <NUM> of sleeve <NUM>, and through first regulating window <NUM> of spool <NUM>, such that fluid flows into and fills internal cavity <NUM> of spool <NUM>. During operation of the fluid flow system, the fluid within internal cavity <NUM> increases in pressure, causing spool <NUM> to translate towards first end 12A of housing <NUM>. Spool <NUM> axially translates to regulate the fluid pressure within internal cavity <NUM> of spool <NUM> and within the overall valve <NUM>. Spool <NUM> regulates the pressure within valve <NUM> by reducing or increasing the flow area through first regulating window <NUM>.

Referring to <FIG>, first regulating window <NUM> has a specific flow area to allow a specified amount of fluid to flow into internal cavity <NUM>. The flow area of first regulating window <NUM> changes based on the positioning of first regulating window <NUM> relative to the outer walls of the stationary sleeve <NUM>. The flow area of first regulating window <NUM> decreases as spool <NUM> translates towards first end 12A of housing <NUM>, and the flow area of first regulating window <NUM> increases as spool <NUM> translates towards second end 12B of housing <NUM>. The fluid that flows into internal cavity <NUM> proceeds by flowing out through spool outlet <NUM> of spool <NUM>, second conduit <NUM> of sleeve <NUM>, and outlet <NUM> of housing <NUM> at a regulated fluid pressure. As the pressure within internal cavity <NUM> increases, spool <NUM> translates towards first end 12A of housing <NUM> to decrease the flow area of first regulating window <NUM>, which in turn reduces the fluid pressure within internal cavity <NUM> to maintain the regulated output fluid pressure of valve <NUM>. When comparing <FIG> and <FIG>, it is shown that the flow area of first regulating window <NUM> in <FIG> is greater than the flow area of first regulating window <NUM> in <FIG> due to spool <NUM> being positioned closer to first end 12A of housing <NUM> in <FIG> illustrates a situation in which spool <NUM> has translated towards first end 12A of housing <NUM> to reduce the flow area of first regulating window <NUM> to regulate the pressure within and flowing out of valve <NUM>.

In some scenarios, the pressure of the fluid flowing into previous valves can be at too high of pressures, leading to issues in previous pressure regulating valves. As shown in <FIG>, when the incoming fluid pressure is too high, spool <NUM> can translate far enough towards first end 12A of housing <NUM> such that first regulating window <NUM> approaches fully closed (and in some examples it can reach fully closed). This causes the flow area of first regulating window <NUM> to reduce to a small enough flow area that the fluid leakage between the components of the valve exceeds the fluid flow through first regulating window <NUM>. In turn, this can lead to issues such as pressure spikes within the system, which are undesirable because they can cause damage to components of the fluid flow system. Further, when the fluid leakage between the components of the valve reaches a high enough level, the valve is said to have lost control and can no longer regulate the fluid pressure as desired. In a situation where the valve can no longer reduce the fluid pressure before the fluid flows downstream to other components of the fluid system, the increased fluid pressure can damage components downstream of the valve. A previous solution to this scenario is to increase the size and pressure limits of the downstream components, which then increases the size and weight of components within the fluid flow system.

Valve <NUM> remedies the above described issues by including second regulating window <NUM>. If the incoming fluid pressure is at too high of a pressure and spool <NUM> translates towards first end 12A of housing <NUM> such that first regulating window <NUM> approaches fully closed of reaches fully closed (<FIG>), the fluid within internal cavity <NUM> can flow out through second regulating window <NUM> and drain conduit <NUM> to a drain system (not shown) of the fluid flow system. Flowing the fluid out through second regulating window <NUM> and drain conduit <NUM> causes the fluid pressure within spool <NUM> to decrease. In turn, as shown in <FIG>, this causes spool <NUM> to translate towards second end 12B of housing <NUM> and first regulating window <NUM> to open and allow fluid to flow through first regulating window <NUM> into internal cavity <NUM> of spool <NUM>. Second regulating window <NUM> provides a secondary flow path for fluid to flow to prevent pressure spikes and to prevent increased fluid leakage within valve <NUM>. Further, second regulating window <NUM> aids in maintaining the desired pressure within spool <NUM> to control the pressure of the fluid flowing out through spool outlet <NUM>, second conduit <NUM>, and outlet <NUM> to downstream components of the fluid flow system.

As shown in <FIG>, when the pressure of the fluid entering valve <NUM> is at a low enough level, second regulating window <NUM> can be completely closed, preventing fluid from flowing out through drain conduit <NUM>. As shown in <FIG>, as the fluid pressure within valve <NUM> increase, spool <NUM> translates towards first end 12A of housing <NUM>. When the fluid pressure within valve <NUM> reaches a certain level and spool <NUM> has translated far enough towards first end 12A, second regulating window <NUM> opens, and fluid can flow out through drain conduit <NUM> to maintain the desired fluid pressure level within spool <NUM> and valve <NUM>. Valve <NUM> can continuously translate towards and away from first end 12A to open and close second regulating window <NUM> to maintain the desired fluid pressure within valve. As shown in <FIG>, if the fluid pressure within valve <NUM> reaches a pressure limit, first regulating window <NUM> can completely close and fluid can flow out through second regulating window <NUM> and drain conduit <NUM> to reduce the fluid pressure within valve <NUM>, causing spool <NUM> to translate towards second end 12B of housing <NUM> to the position shown in <FIG>.

As such, in at least one position first conduit <NUM> is in fluid communication with first regulating window <NUM> at the same time that second regulating window <NUM> is in fluid communication with drain conduit <NUM>. This is achieved by having a maximum distance between outer edges first regulating window <NUM> and second regulating window <NUM> greater than a minimum distance between inner edges of first conduit <NUM> and drain conduit <NUM>. The distance between first regulating window <NUM> and second regulating window <NUM> and between first conduit <NUM> and drain conduit <NUM> is strategically designed to only utilize second regulating window <NUM> and drain conduit <NUM> under high fluid pressure situations. This design prevents excessive drainage flow that would increase the overall flow requirements of the system. Further, the specific pressure levels and pressure limits in which second regulating window <NUM> opens and closes will vary depending on the fluid flow system in which valve <NUM> is utilized. Valve <NUM> can be used in many different fluid systems and the fluid pressures in each system can vary, such that the size of the components of valve <NUM> can be altered to function properly at each pressure level. Valve <NUM> is advantageous over previous pressure regulating valves because valve <NUM> with second regulating window <NUM> helps maintain control of the fluid pressure within valve <NUM> at high pressure levels.

<FIG> illustrates method <NUM> of operating valve <NUM> within a fluid flow system. Method <NUM> includes steps <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>, among other steps not specifically described. Step <NUM> includes flowing a fluid at a first pressure through inlet <NUM> of housing <NUM> and through first conduit <NUM> of sleeve <NUM>. Step <NUM> includes flowing the fluid through first regulating window <NUM> of spool <NUM> into internal cavity <NUM> of spool <NUM>. Step <NUM> includes translating spool <NUM> towards first end 12A of housing <NUM> as the fluid pressure within internal cavity <NUM> of spool <NUM> increases. Step <NUM> includes flowing the fluid through second regulating window <NUM> when the fluid pressure within internal cavity <NUM> of spool <NUM> reaches a pressure limit. The pressure limit can be a predefined value that is determined using mathematical calculations or physical testing data, among other options not specifically described. Step <NUM> includes flowing the fluid at a second pressure through spool outlet <NUM> of spool <NUM>, through second conduit <NUM> of sleeve <NUM>, and through outlet <NUM> of housing <NUM>. In some examples, the first pressure is greater than the second pressure.

Method <NUM> can also include the following steps: translating spool <NUM> towards second end 12B of housing <NUM> as the fluid pressure within internal cavity <NUM> of spool <NUM> decreases; preventing fluid flow through second regulating window <NUM> when the fluid pressure within internal cavity <NUM> of spool <NUM> falls below a pressure limit; reducing a flow rate of the fluid flowing through first regulating window <NUM>, by translating spool <NUM> towards first end 12A of housing <NUM>, as the fluid pressure within internal cavity <NUM> of spool <NUM> approaches a pressure set value; and increasing a flow rate of the fluid flowing through first regulating window <NUM>, by translating spool <NUM> towards second end 12B of housing <NUM>, as the fluid pressure within internal cavity <NUM> of spool <NUM> recedes from a pressure set value. It is to be understood the described steps are examples steps of method <NUM>, and method <NUM> can include further steps not specifically described.

A pressure regulating valve for use in a fluid flow system, the pressure regulating valve comprising: a housing including an inlet and an outlet, wherein the inlet is fluidly coupled to a first fluid channel, and wherein the outlet is fluidly coupled to a second fluid channel; a sleeve positioned within the housing, the sleeve comprising a first conduit and a second conduit; and a spool slidingly positioned within the sleeve, wherein the spool comprises: an internal cavity positioned within an outer wall of the spool and formed by the outer wall of the spool; a first regulating window fluidly coupling the internal cavity of the spool and the first conduit of the sleeve; a second regulating window fluidly coupling the internal cavity of the spool to a drain conduit; and a spool outlet fluidly coupling the internal cavity of the spool and the second conduit of the sleeve.

The pressure regulating valve of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations and/or additional components:
The sleeve is fixedly positioned within and concentric with an internal surface of the housing, and wherein the first conduit is fluidly coupled to the inlet of the housing and the second conduit is fluidly coupled to the outlet of the housing.

The first regulating window extends through the outer wall of the spool to the internal cavity of the spool; the second regulating window extends through the outer wall of the spool to the internal cavity of the spool; and the spool outlet extends through the outer wall of the spool to the internal cavity of the spool.

The spool is positioned within and concentric with an internal surface of the sleeve, and wherein the spool is positioned within and concentric with an internal surface of the housing.

The first regulating window, the second regulating window, and the spool outlet are apertures that extend fully through both outer walls of the spool; and the first regulating window, the second regulating window, and the spool outlet are equal sized apertures.

In at least one position the first conduit is in fluid communication with the first regulating window at the same time that the second regulating window is in fluid communication with the drain conduit such that a maximum distance between outer edges the first regulating window and the second regulating window is greater than a minimum distance between inner edges of the first conduit and the drain conduit.

A central axis of each of the first regulating window, the second regulating window, the spool outlet, the first conduit, and the second conduit are positioned parallel with each other.

The second regulating window is positioned adjacent a first spool end of the spool; the spool outlet is positioned adjacent a second spool end of the spool; and the first regulating window is positioned between the second regulating window and the spool outlet.

The first spool end is a closed end and the second spool end is an open end, and wherein a plug is positioned at least partially within and coupled to the second spool end.

A cap coupled to a first end of the housing, wherein the cap extends partially within and partially outside of the housing; a plurality of shims positioned within the cap and axially aligned with a central axis of the cap; a spring positioned at least partially within the cap and axially aligned with the central axis of the cap, wherein the spring abuts one of the plurality of shims at a first distal end of the spring; and a spring seat positioned at least partially within the sleeve, wherein the spring seat is configured to abut a second distal end of the spring on a first side of the spring seat and abut a pin on a second side of the spring seat, wherein the pin extends between the spring seat and the spool.

The spring is configured to induce a force on the spring seat and the pin to force the spool toward a second end of the housing, and wherein the spool is configured to translate towards the first end of the housing as the fluid pressure within the spool increases.

The following are further non-exclusive descriptions of possible embodiments of the present invention.

A method of operating a pressure regulating valve within a fluid flow system, the method comprising: flowing a fluid at a first pressure through an inlet of a housing and through a first conduit of a sleeve; flowing the fluid through a first regulating window of a spool into an internal cavity of the spool; translating, by the spool, towards a first end of the housing as the fluid pressure within the internal cavity of the spool increases; flowing the fluid through a second regulating window when the fluid pressure within the internal cavity of the spool reaches a pressure limit; and flowing the fluid at a second pressure through a spool outlet of the spool, through a second conduit of the sleeve, and through an outlet of the housing, wherein the first pressure is greater than the second pressure.

The method of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations and/or additional components:.

Translating, by the spool, towards a second end of the housing as the fluid pressure within the internal cavity of the spool decreases; and preventing fluid flow through the second regulating window when the fluid pressure within the internal cavity of the spool is below a pressure limit.

Reducing a flow rate of the fluid flowing through the first regulating window, by translating the spool towards the first end of the housing, as the fluid pressure within the internal cavity of the spool approaches a pressure set value.

Increasing a flow rate of the fluid flowing through the first regulating window, by translating the spool towards a second end of the housing, as the fluid pressure within the internal cavity of the spool recedes from a pressure set value.

The first regulating window extends through an outer wall of the spool to the internal cavity of the spool; the second regulating window extends through the outer wall of the spool to the internal cavity of the spool; and the spool outlet extends through the outer wall of the spool to the internal cavity of the spool.

A maximum distance between outer edges the first regulating window and the second regulating window is greater than a minimum distance between inner edges of the first conduit and the drain conduit.

Claim 1:
A pressure regulating valve (<NUM>) for use in a fluid flow system, the pressure regulating valve comprising:
a housing (<NUM>) including an inlet (<NUM>) and an outlet (<NUM>), wherein the inlet is fluidly coupled to a first fluid channel (<NUM>), and wherein the outlet is fluidly coupled to a second fluid channel (<NUM>);
a sleeve (<NUM>) positioned within the housing (<NUM>), the sleeve comprising a first conduit (<NUM>) and a second conduit (<NUM>);
cap (<NUM>) coupled to a first end (12A) of the housing (<NUM>), wherein the cap extends partially within and partially outside of the housing;
a plurality of shims (<NUM>) positioned within the cap and axially aligned with a central axis of the cap;
a spring (<NUM>) positioned at least partially within the cap and axially aligned with the central axis of the cap, wherein the spring abuts one of the plurality of shims at a first distal end of the spring; and
a spring seat (<NUM>) positioned at least partially within the sleeve, wherein the spring seat is configured to abut a second distal end of the spring on a first side of the spring seat and abut a pin on a second side of the spring seat, wherein the pin extends between the spring seat and a spool (<NUM>) slidingly positioned within the sleeve, wherein the spool comprises:
an internal cavity (<NUM>) positioned within an outer wall (<NUM>) of the spool and formed by the outer wall of the spool;
a first regulating window (<NUM>) fluidly coupling the internal cavity of the spool and the first conduit of the sleeve;
a second regulating window (<NUM>) fluidly coupling the internal cavity of the spool to a drain conduit; and
a spool outlet (<NUM>) fluidly coupling the internal cavity of the spool and the second conduit of the sleeve;
wherein the plurality of shims (<NUM>) are configured to be added and removed as needed to fine tune a spring load of spring (<NUM>) to set a regulating pressure of the valve (<NUM>).