Patent Description:
Industrial processing plants use pressure regulators in a wide variety of applications such as, for example, controlling fluid flow (e.g., gas, liquid) in a processing operation. A valve body of a conventional regulator valve is divided into several parts, which must be tightly secured together to maintain internal pressure of the regulator. The valve body requires a plurality of mounting flanges, flange bolts, and must be disassembled to access the internal components of the regulator for repair or replacement.

Document <CIT> discloses a valve used to control the flow of fluids, and more particularly, to valves used in compressed gas desiccant dryer systems, the valve comprising a housing having at least two openings to allow for the ingress and egress of compressed gas; a seat for at least one of the openings and integral therewith, the seat having a rod axially aligned with the seat, the rod being slidably carried by a support on the interior of the valve housing, the support being secured to the interior of the housing; a disc-like sealing member corresponding to each seat sized larger than the passageway through the seat, the sealing member being disposed on the rod and movable with respect to the seat between sealing face-to-face contact therewith. Further fluid control devices are disclosed by documents <CIT>, <CIT>, <CIT>, <CIT> and by document <CIT> disclosing a serial arrangement of such devices.

The present invention relates to a fluid control device as defined in appended claim1. Further advantageous features are defined in dependent claims <NUM> to <NUM>.

The present invention also relates to a control system according to appended claim <NUM>. Further advantageous features are defined in dependent claims <NUM> to <NUM>.

Any one or more of these aspects may be considered separately and/or combined with each other in any functionally appropriate manner. In addition, any one or more of these aspects may further include and/or be implemented in any one or more of the optional exemplary arrangements and/or features described hereinafter. These and other aspects, arrangements, features, and/or technical effects will become apparent upon detailed inspection of the figures and the following description.

In <FIG>, an exemplary fluid regulator <NUM> is constructed according to the teachings of the present disclosure. The regulator <NUM> includes a valve body <NUM> having a central bore <NUM> and an actuator assembly <NUM> disposed in the bore <NUM>. The valve body <NUM> defines an inlet <NUM>, an outlet <NUM>, and a flow path <NUM> connecting the inlet <NUM> and the outlet <NUM>. The bore <NUM> formed in the valve body <NUM> is centered on a longitudinal axis X of the valve body <NUM>, and the flow path <NUM> is peripherally disposed relative to the bore <NUM>. A control element <NUM> is movable relative to the valve body <NUM> between a closed position (<FIG>), in which the control element <NUM> engages a valve seat <NUM> disposed in the flow path <NUM>, and an open position (<FIG>), in which the control element <NUM> is spaced away from the valve seat <NUM>. The actuator assembly <NUM> is operatively coupled to the control element <NUM> and is configured to move the control element <NUM> axially along the longitudinal axis X to open and close the regulator <NUM>. An inlet fitting <NUM> is coupled to the valve body <NUM> at the inlet <NUM> and is configured to retain the actuator assembly <NUM> and the control element <NUM> within the bore <NUM> of the valve body <NUM>. The inlet fitting <NUM> is removably coupled to the valve body <NUM>. For example, external threads on the inlet fitting <NUM> may couple to internal threads in the inlet <NUM> of the valve body <NUM>. Similarly, the inlet fitting <NUM> may be bolted to the inlet <NUM> of the valve body <NUM>. Because the inlet fitting <NUM> is removable from the valve body <NUM>, the internal components (e.g., the actuator assembly <NUM> and the control element <NUM>) of the regulator <NUM> are insertable and removable through the inlet <NUM>. However, in another example, the inlet <NUM> and the outlet <NUM> may be switched (i.e., such that fluid flows from the right to the left in <FIG>) in which case the internal components of the regulator <NUM> would be removably disposed through the outlet <NUM> of the valve body <NUM>. In either example, the valve body <NUM> may be a single-cast (e.g., integrally formed) valve body <NUM>.

The actuator assembly <NUM> includes a sleeve <NUM>, a stem <NUM> extending through the sleeve <NUM>, a first piston <NUM> coupled to the stem <NUM>, and a second piston <NUM> coupled to the stem <NUM> and spaced away from the first piston <NUM>. The sleeve <NUM>, the stem <NUM>, or both the sleeve <NUM> and the stem <NUM> provide pathways to permit internal fluid communication to actuate the actuator assembly <NUM>. As shown in <FIG> and <FIG>, the sleeve <NUM> includes separable first and second sleeve portions 50a, 50b. The first sleeve portion 50a has a cylindrical wall 66a and a first plate <NUM> and the second sleeve portion 50b has a cylindrical wall 66b and a second plate <NUM>. When the first and second sleeve portions 50a, 50b are positioned adjacent to each other as shown in <FIG> they collectively form the sleeve <NUM> in which the first wall <NUM> is spaced from the second wall <NUM>. The cylindrical walls 66a, 66b (together forming a wall labeled as <NUM>) and the first and second plates <NUM>, <NUM> define a first cavity <NUM> in which the first piston <NUM> is slidably disposed and a second cavity <NUM> in which the second piston <NUM> is slidably disposed. As shown in <FIG> and <FIG>, and described in more detail below, a pathway <NUM> is formed in the cylindrical wall <NUM> of the sleeve <NUM> to provide fluid communication between an upstream surface <NUM> of the first piston <NUM> and an upstream surface <NUM> of the second piston <NUM>. Also described further below, the stem <NUM> includes a passage <NUM> (shown in dashed lines in <FIG>) extending partially through the stem <NUM> that provides fluid communication between a downstream <NUM> surface of the first piston <NUM> and a downstream surface <NUM> of the second piston <NUM>. As used herein, the term "upstream" refers to a side facing the inlet <NUM> (i.e., upstream of the flow path <NUM>), and the term "downstream" refers to a side facing the outlet <NUM> (i.e., downstream the flow path <NUM>).

As shown in <FIG>, the internal components of the regulator <NUM> are configured to align with the longitudinal axis X of the valve body <NUM>. The sleeve <NUM> is particularly constructed to align the stem <NUM>, the first piston <NUM>, and the second piston <NUM> with the control element <NUM> such that the actuator assembly <NUM> and the control element <NUM> are properly aligned within the bore <NUM> of the valve body <NUM>. For example, the first plate <NUM> and the second plate <NUM> each define an aperture <NUM>, <NUM>, respectively, that is aligned with a longitudinal axis E of the sleeve <NUM>. The longitudinal axis E is coaxial with the longitudinal axis X of the valve body <NUM> when the sleeve <NUM> is disposed in the bore <NUM>. The cylindrical wall <NUM> of the sleeve is shaped to substantially match a contoured wall defining the bore <NUM> of the valve body <NUM> so that the sleeve <NUM> is properly axially aligned when it is fully inserted into the valve body <NUM>. The sleeve <NUM> includes a first end <NUM> and a second end <NUM>. In the illustrated embodiment, the first end <NUM> has an inner diameter S<NUM> that is different than an inner diameter S<NUM> of the second end <NUM>. In other embodiments, however, different sleeve geometries might be used such as to correspond to different geometries of the bore <NUM>. The inner diameter S<NUM> of the first end <NUM> is sized and shaped to slidably receive the control element <NUM>. The second end <NUM> is configured to abut against an inner wall of the valve body <NUM> such that the internal components of the regulator <NUM> are secured (e.g., clamped) in place when the inlet fitting <NUM> is secured to the valve body <NUM>. When the control element <NUM> is in the fully open position, the second piston <NUM> is adjacent to the second end <NUM> of the sleeve <NUM>.

The first and second pistons <NUM>, <NUM> are configured to slide together against a smooth interior surface of the cylindrical wall <NUM> of the sleeve <NUM> in response to changes in pressure sensed by the actuator assembly <NUM>. The first and second pistons <NUM>, <NUM> are securely attached to the stem <NUM> such that the stem <NUM> and pistons <NUM>, <NUM> move relative to the sleeve <NUM> while the sleeve <NUM> remains in a fixed position relative to the valve body <NUM>. The stem <NUM> has a longitudinal axis F that is arranged to align with the longitudinal axis X of the valve body <NUM>. As discussed further below, a plurality of chambers <NUM>, <NUM>, <NUM>, and <NUM> are formed between the sleeve <NUM> and the first and second pistons <NUM>, <NUM> and have varying internal volumes when the regulator <NUM> opens and closes. In particular, as shown in <FIG>, a first chamber <NUM> is disposed between the first plate <NUM> of the sleeve <NUM> and the first piston <NUM>, a second chamber <NUM> is disposed between the first piston <NUM> and the second plate <NUM> of the sleeve <NUM>, a third chamber <NUM> is disposed between the second plate <NUM> of the sleeve <NUM> and the second piston <NUM>, and a fourth chamber <NUM> is disposed downstream of the second piston <NUM>. The fourth chamber <NUM> is partially defined by the cylindrical wall <NUM> of the sleeve <NUM> and the valve body <NUM>. A travel indicator assembly <NUM> is partially disposed in the fourth chamber <NUM> and provides a visual indication of the position (e.g., partially open, fully open, closed) of the regulator <NUM>.

In operation, the actuator assembly <NUM> actuates the control element <NUM> between the open position and the closed position in response to the balance of fluid pressures in the first, second, third, and fourth chambers <NUM>, <NUM>, <NUM>, and <NUM> that operate on the first and second pistons <NUM>, <NUM>. In the illustrated example, the first and third chambers <NUM>, <NUM> are in fluid communication via the pathway <NUM> formed in the sleeve portions 50a, 50b (as described below), and the second and fourth chambers <NUM>, <NUM> are in fluid communication via the passage <NUM> of the stem <NUM>. Fluid pressure in the first and third chambers <NUM>, <NUM> operates on the upstream surfaces <NUM>, <NUM> of the first and second pistons <NUM>, <NUM>, respectively, to urge the first and second pistons <NUM>, <NUM> in a first direction H toward the open position of the regulator <NUM>. Fluid pressure in the second and fourth chambers <NUM>, <NUM> operates on the downstream surfaces <NUM>, <NUM> of the first and second pistons <NUM>, <NUM>, respectively, to urge the first and second pistons <NUM>, <NUM> in a second direction G (opposite the first direction H) toward the closed position of the regulator <NUM>.

The chamber <NUM>, <NUM>, <NUM>, and <NUM> of the regulator <NUM> may be defined in relation to the location of the inlet <NUM> and the outlet <NUM>, and generally in the direction of fluid flow. For example, fluid flows generally in the direction from the inlet <NUM> and towards the outlet <NUM> such that the first chamber <NUM> is an upstream chamber (i.e., the first upstream chamber <NUM>) to the first piston <NUM> and the second chamber <NUM> is a downstream chamber (i.e., the first downstream chamber <NUM>) to the first piston <NUM>. Similarly, the third chamber <NUM> is an upstream chamber (i.e., the second upstream chamber <NUM>) to the second piston <NUM> and the fourth chamber <NUM> is a downstream chamber (i.e., the second downstream chamber <NUM>) to the second piston <NUM>. Through the pathways in the sleeve <NUM> and/or stem <NUM>, the first and second upstream chambers <NUM>, <NUM> are in fluid communication with each other, and the first and second downstream chambers <NUM>, <NUM> are in fluid communication with each other.

The regulator <NUM> further includes a spring <NUM>, a valve cage <NUM>, and a seal assembly <NUM> secured in the valve body <NUM> by the inlet fitting <NUM>. The spring <NUM> is disposed between a spring seat <NUM> formed in the first plate <NUM> of the sleeve <NUM> and a spring seat <NUM> formed in the control element <NUM>. As shown in <FIG> and <FIG>, the control element <NUM> includes a plurality of spokes <NUM> extending between a central hub <NUM> and an outer ring <NUM> surrounding the spring <NUM>. The central hub <NUM> defines a hub aperture <NUM> that is sized to receive a first end <NUM> of the stem <NUM>. As shown in <FIG>, the spokes <NUM> of the control element <NUM> extend radially outward from the central hub <NUM> at an angle. The apertures between the spokes <NUM> enable fluid pressure at the inlet <NUM> to operate on the upstream and downstream sides of the control element <NUM> surfaces equally such that the fluid inlet pressure does not act to urge the control element <NUM> in the direction H. The control element <NUM> is configured to slide with the stem <NUM> relative to the cage <NUM> and relative to the sleeve <NUM> between the open and closed positions. In the closed position, the outer ring <NUM> of the control element <NUM> cooperates with the seal assembly <NUM> to prevent fluid from flowing from the inlet <NUM> to the outlet <NUM>. In particular, a radially outward portion of an upstream end of the outer ring <NUM> (opposite the spring seat <NUM>) is configured to engage with the radial seal assembly <NUM> of the valve seat <NUM> as described in greater detail below. One or more seals may be disposed between the control element <NUM> and the sleeve <NUM>.

<FIG> illustrates a spacer <NUM> that is coupled to the inlet end of the valve body <NUM>. In operation, the spacer <NUM> is clamped between a flange at the upstream end of the regulator <NUM> and a corresponding flange (not shown) positioned upstream of the spacer <NUM> by bolts that span between the flanges and compress gaskets <NUM> that are positioned between the spacer <NUM> and each flange (only one such gasket <NUM> is shown). The spacer <NUM> can be removed by removing the bolts to enable insertion or removal of the internal components of the regulator <NUM> (e.g., the seal assembly <NUM>, the actuator assembly <NUM> components, the control element <NUM> components, etc.) while the regulator <NUM> is installed.

<FIG> illustrates the seal assembly <NUM> of <FIG> in more detail. The seal assembly <NUM> includes a retaining ring <NUM> and a radial seal ring <NUM> disposed in a groove between the retaining ring <NUM> and the inlet fitting <NUM>. In the closed position, the outer ring <NUM> of the control element <NUM> sealably engages with the seal ring <NUM> to provide a fluid-tight engagement. The radial seal ring <NUM> is formed from a material such as Polytetrafluoroethylene (PTFE), which provides wear and chemical resistance and a smaller sealing force against the control element <NUM>. A first O-ring <NUM> is positioned radially outward of the radial seal ring <NUM> within the groove between the retaining ring <NUM> and the inlet fitting <NUM> to urge the radial seal ring <NUM> into contact with the control element <NUM> when the regulator <NUM> is in the closed position. A second O-ring <NUM> is positioned between the retaining ring <NUM> and the inlet fitting <NUM>. A fastener <NUM> secures the retaining ring <NUM> in place relative to the inlet fitting <NUM>.

<FIG> illustrate the actuator assembly <NUM> of <FIG> in more detail. In these figures, the connections between the stem <NUM> and the first plate <NUM>, the stem <NUM> and the second plate <NUM>, the stem <NUM> and the first piston <NUM>, and the stem <NUM> and the second piston <NUM> are more clearly illustrated. These figures also illustrate the varying diameters (or thicknesses) along the length of the stem <NUM>. Each of the varying diameters of the stem <NUM> is sized to match up specifically with one of the first plate <NUM>, the first piston <NUM>, the second plate <NUM>, and the second piston <NUM>. The stem <NUM> is divided into segments or portions that slide relative to the first plate <NUM> of the sleeve <NUM> and relative to the second plate <NUM> of the sleeve <NUM>. In <FIG>, a first portion <NUM> of the stem <NUM> is disposed through the aperture <NUM> of the first plate <NUM>. The aperture <NUM> of the first plate <NUM> is particularly sized to receive the first portion <NUM> of the stem <NUM>, which has an outer diameter D<NUM>. A packing assembly <NUM> is secured to the first plate <NUM> and is configured to permit the stem <NUM> to slide relative to the first plate <NUM> while providing a sealed connection between the first plate <NUM> and the first portion <NUM> of the stem <NUM>. <FIG> also illustrates the first piston <NUM> attached to a stepped portion <NUM> formed in the outer surface of the stem <NUM>. The first piston <NUM> is secured to the stem <NUM> via a retaining plate <NUM> and fasteners <NUM>. The retaining plate <NUM> is disposed in an annular groove <NUM> formed in the stem <NUM> and that is sized to receive the retaining plate <NUM> such that the first piston <NUM> does not slide relative to the stem <NUM>. Turning to <FIG>, the aperture <NUM> of the second plate <NUM> is particularly sized to receive a second portion <NUM> of the stem <NUM>, which has an outer diameter D<NUM> that is different from the outer diameter D<NUM> of the first portion <NUM>. <FIG> also illustrates the second piston <NUM> attached to a stepped portion <NUM> formed in the outer surface of the stem <NUM>. The second piston <NUM> is secured to the stem <NUM> via a retaining cap <NUM>, which is threaded onto the stem <NUM>. In other examples, the second piston <NUM> may be secured to the stem <NUM> by other suitable connections.

As shown in <FIG>, the stepped portions <NUM>, <NUM> and the different outer diameters D<NUM>, D<NUM> of the stem <NUM> correspond to a particular placement of the stem <NUM> relative to the first and second plates <NUM>, <NUM> of the sleeve <NUM>. In operation, the stem <NUM> slides relative to the first plate <NUM> of the sleeve <NUM> along a length L<NUM> of the first portion <NUM> and relative to the second plate <NUM> of the sleeve <NUM> along a length L<NUM> of the second portion <NUM>. The geometric configurations of the stem <NUM> and the valve body <NUM> ensure that the first plate <NUM>, second plate <NUM>, first piston <NUM>, and second piston <NUM> are properly aligned within the valve body <NUM>.

As shown in <FIG>, and <FIG>, the corresponding engagements between the stem <NUM> and the first and second plates <NUM>, <NUM> of the sleeve <NUM> also ensure proper alignment of the pathway <NUM> connecting the first and third chambers <NUM>, <NUM> and proper alignment of the passage <NUM> formed in the stem <NUM> connecting the second and fourth chambers <NUM>, <NUM>. As shown in <FIG>, the passage <NUM> includes a radial channel <NUM> (e.g., extending in a radial direction relative to the longitudinal axis X), and a longitudinal channel <NUM> centrally disposed in the second portion <NUM> of the stem <NUM> and extending axially through to a second end <NUM> of the stem <NUM>. The radial channel <NUM> is in fluid communication with the second chamber <NUM> and is positioned adjacent to the downstream surface <NUM> of the first piston <NUM>. The longitudinal channel <NUM> extends axially along the longitudinal axis X of the valve body <NUM>, and terminates in the fourth chamber <NUM>. The radial channel <NUM> is perpendicular to the longitudinal channel <NUM>, however, in other examples, the channels <NUM>, <NUM> may not be perpendicular to each other but, instead, may be non-parallel. Further, the stem <NUM> may be a plurality of connected components to provide the stem configuration, and may have a plurality of passages running parallel and/or staggered relative to each other to connect different chambers <NUM>, <NUM>, <NUM>, and <NUM> of the actuator assembly <NUM>.

Returning briefly to <FIG>, the pathway <NUM> formed in the sleeve <NUM> is partially illustrated. The pathway <NUM> includes one or more channels having both a lateral portion <NUM>, which is depicted in <FIG>, and an axial portion hidden from view in <FIG>. Each lateral portion <NUM> extends radially inward from the cylindrical wall <NUM> within a portion of the second plate <NUM>. Each lateral portion <NUM> of the pathway <NUM> connects to a bore <NUM> formed in a downstream surface of the second plate <NUM> of the sleeve <NUM> to provide fluid communication between the lateral portion <NUM> of the pathway <NUM> and the third chamber <NUM>. Turning now to <FIG> and <FIG>, first and second exemplary arrangements of an axial portion of the pathway <NUM> formed in the sleeve <NUM> are illustrated. Turning first to <FIG>, the axial portion of the pathway <NUM> includes one or more channels 206A (four channels are shown but more or fewer may be employed in different arrangements), where each channel 206A extends through the cylindrical wall <NUM> of the sleeve <NUM> to connect the first chamber <NUM> with the lateral portion <NUM> of the pathway <NUM>. The channels 206A are formed in an exterior surface <NUM> of the sleeve <NUM> such that the pathway <NUM> is at least partially defined between the sleeve <NUM> and the valve body <NUM>. In the second exemplary arrangement in <FIG>, the axial portion of the pathway <NUM> includes one or more channels 206B formed between an inner surface <NUM> of the cylindrical wall <NUM> and the outer surface <NUM> of the cylindrical wall <NUM> such that the axial portion of each of the channels 206B is embedded within the cylindrical wall <NUM> of the sleeve <NUM>. In either arrangement, the axial portion <NUM> of the pathway <NUM> ultimately extends between the lateral portion <NUM> and the upstream end of the second sleeve portion 50b. The downstream surface of the first plate <NUM> includes one or more grooves that comprise a further portion of the pathway <NUM> such that the first and third chambers <NUM>, <NUM> are fluidly connected.

<FIG> of the regulator <NUM> illustrates a drain hole <NUM> formed in the valve body <NUM>. The drain hole <NUM> fluidly couples the flow path <NUM> of the valve body <NUM> and the atmosphere, and may provide an access port to drain process fluid remaining in the valve body <NUM> (e.g., condensation). The drain hole <NUM> may be sealed with a plug that is accessible from an exterior surface <NUM> of the valve body <NUM>.

<FIG>, <FIG>, <FIG> illustrate front and top views of the regulator <NUM> in the closed position (<FIG>), a partially open position (<FIG>), and a fully open position (<FIG>). A pilot device may be operatively coupled to the regulator <NUM> to control piston movement of the actuator assembly <NUM> and regulate flow through the regulator <NUM>. In particular, the pilot device may be configured to sense a fluid pressure upstream or downstream of the regulator <NUM> and adjust a loading pressure that is supplied to actuate the regulator <NUM> accordingly. In the illustrated example, a first channel <NUM> (<FIG>, <FIG>, <FIG>) extends laterally (radially outwardly from the longitudinal axis X) through a side wall of the valve body <NUM> and terminates in the bore <NUM> to provide an external fluid connection with the pathway <NUM>. The second sleeve portion 50b is structured such that the axial portion (e.g., 206A, 206B) of the pathway <NUM> is fluidly coupled with the first channel <NUM>. As such, the first channel <NUM> is in fluid communication with the first and third chambers <NUM>, <NUM> via the pathway <NUM>. A second channel <NUM> extends laterally through the side wall of the valve body <NUM> and terminates in the bore <NUM> to provide an external fluid connection with the fourth chamber <NUM>. As such, the second channel <NUM> is in fluid communication with the second and fourth chambers <NUM>, <NUM> via the passage <NUM> in the stem <NUM>. The channels <NUM>, <NUM> may be located in other portions of the valve body <NUM> and/or may be configured to provide fluid pressure to other portions of the actuator assembly <NUM> inside the valve body <NUM>. The channels <NUM>, <NUM> may terminate at a connection fitting (e.g., a tubing fitting) at the exterior surface of the valve body <NUM> to facilitate connection to sense and loading lines as described below.

In a typical arrangement, the second channel <NUM> receives downstream pressure via a sense line and the first channel <NUM> receives loading pressure from the pilot device via a loading line such that the regulator <NUM> functions as a pressure reducing regulator. In such an arrangement, when the downstream pressure is at or above the pilot device's pressure setpoint, the pilot device supplies the downstream pressure as the loading pressure to the first channel <NUM>. Accordingly, the force generated by the spring <NUM> and the fluid pressure (i.e., the downstream pressure) in the second and fourth chambers <NUM>, <NUM> operating on the downstream surfaces <NUM>, <NUM> of the first and second pistons <NUM>, <NUM>, respectively, exceeds the force generated by the fluid pressure (i.e., the downstream pressure) in the first and third chambers <NUM>, <NUM> operating on the upstream surfaces <NUM>, <NUM> of the first and second pistons <NUM>, <NUM>, respectively. As a result, the shaft <NUM> and the connected control element <NUM> are moved fully in the direction G until the first and second pistons <NUM>, <NUM> are adjacent the first and second plates <NUM>, <NUM> and the control element <NUM> engages the valve seat <NUM> as shown in <FIG>. In this position, fluid is prevented from flowing from the inlet <NUM> to the outlet <NUM>.

When downstream demand increases such that the downstream pressure drops below the pilot device's pressure setpoint, the pilot device supplies an increased pressure (i.e., a pressure greater than the downstream pressure) as the loading pressure to the first channel <NUM>. At this increased loading pressure, the force generated by the fluid pressure (i.e., the increased loading pressure) in the first and third chambers <NUM>, <NUM> operating on the upstream surfaces <NUM>, <NUM> of the first and second pistons <NUM>, <NUM>, respectively, exceeds the force generated by the spring <NUM> and the fluid pressure (i.e., the downstream pressure) in the second and fourth chambers <NUM>, <NUM> operating on the downstream surfaces <NUM>, <NUM> of the first and second pistons <NUM>, <NUM>, respectively. As a result, the shaft <NUM> and the connected control element <NUM> are moved in the direction H, which causes the control element <NUM> to disengage from the seat <NUM> and enables fluid to flow from the inlet <NUM> to the outlet <NUM>. The force balance determines the actual position of the shaft <NUM> and the connected control element <NUM>, and the flow capacity of the regulator <NUM> increases as the control element <NUM> moves away from the seat <NUM> in the direction H to the partially open position in <FIG> and further to the fully open position in <FIG>. While the above example describes a typical connection of a pilot device to the first and second channels <NUM>, <NUM>, the regulator <NUM> can also be configured differently. For example, the first channel <NUM> may alternatively be connected to the upstream pressure and the second channel <NUM> may be connected to the loading pressure supplied by a pilot device such that the regulator <NUM> functions as a backpressure regulator.

Turning now to <FIG>, alternative stem arrangements for use with the axial regulator <NUM> of <FIG> are constructed according to the teachings of the present disclosure. Second, third, fourth, and fifth exemplary stems <NUM>, <NUM>, <NUM>, and <NUM> are configured to slidably couple to the sleeve <NUM> of the actuator assembly <NUM> and therefore may replace the first exemplary stem <NUM>. Each of the second, third, fourth, and fifth exemplary stems <NUM>, <NUM>, <NUM>, and <NUM> define a first passage to fluidly couple the second and fourth chambers <NUM>, <NUM> and a second passage to fluidly couple the first and third chambers <NUM>, <NUM>. Accordingly, the actuator assembly <NUM> utilizing one of the second, third, fourth, and fifth exemplary stems <NUM>, <NUM>, <NUM>, and <NUM> may include a sleeve <NUM> similar to the first exemplary sleeve <NUM> illustrated in the previous figures but without one or more pathways <NUM> formed in the cylindrical sleeve <NUM>.

In <FIG>, the second exemplary stem <NUM> extends between a first end <NUM> and a second end <NUM> and includes a first passage <NUM>, a second passage <NUM>, and a third passage <NUM>. The stem <NUM> may include the same shape as the stem <NUM> of <FIG> to facilitate assembly with the dual-piston actuator assembly <NUM>. Similar to the stem <NUM> of <FIG>, the longitudinal axis F of the second exemplary stem <NUM> is coaxial with the longitudinal axis X of the valve body <NUM>. Additionally, the stem <NUM> includes a first portion <NUM> having a diameter D<NUM> and a second portion <NUM> having a diameter D<NUM>. A first stepped portion <NUM> separates the first and second portions <NUM>, <NUM> of the stem <NUM>, and a second stepped portion <NUM> separates the second portion <NUM> and the second end <NUM>. Similar to the passage <NUM> of the stem <NUM> of <FIG>, the first passage <NUM> extends partially through the stem <NUM> in a direction parallel with the longitudinal axis F. The first passage <NUM> includes a radial channel <NUM> (e.g., extending in a radial direction relative to the longitudinal axis F), and a longitudinal channel <NUM> extending between the radial channel <NUM> and the second end <NUM> of the stem <NUM>. More particularly, the radial channel <NUM> extends through an exterior surface <NUM> of the stem <NUM> in the second portion <NUM> so that the radial channel <NUM> is in fluid communication with the second chamber <NUM> and is positioned adjacent to the downstream surface <NUM> of the first piston <NUM>. The longitudinal channel <NUM> extends axially relative to the longitudinal axis X of the valve body <NUM>, and terminates in the fourth chamber <NUM>.

By comparison to the stem <NUM> of <FIG>, the second exemplary stem <NUM> is configured to fluidly couple the first and third chambers <NUM>, <NUM> of the regulator <NUM>. The second and third passages <NUM>, <NUM> are symmetrical about the longitudinal F axis of the stem <NUM> and extend between the first portion <NUM> through to the second portion <NUM> of the stem <NUM>. The second passage <NUM> includes a first radial channel <NUM> formed in the first portion <NUM> of the stem <NUM>, a second radial channel <NUM> formed in the second portion <NUM> of the stem <NUM>, and a longitudinal channel <NUM> extending between the first and second radial channels <NUM>, <NUM>. The first and second radial channels <NUM>, <NUM> are positioned relative to the stem <NUM> such that the second passage <NUM> is in fluid communication with the first and third chambers <NUM>, <NUM> of the regulator <NUM>. As such, it will be appreciated that the first plate <NUM> and the second plate <NUM> of the sleeve <NUM>, for example, are shaped to permit fluid communication between the first and third chambers <NUM>, <NUM>, via the radial channels <NUM>, <NUM> and connected to the longitudinal channel <NUM>. It will also be appreciated that the third passage <NUM> is substantially similar to the second passage <NUM> such that any details of the second passage <NUM> apply equally to the third passage <NUM>. The first, second, and third passages <NUM>, <NUM>, and <NUM> may have the same inner diameter, or the first passage <NUM> may have an inner diameter that is greater than the inner diameter of each of the second and third passages <NUM>, <NUM>. In one example, a combined flow capacity of the second and third passages <NUM>, <NUM> substantially matches the flow capacity of the first passage <NUM>.

In <FIG>, the third exemplary stem <NUM> is constructed according to the teachings of the present disclosure. The third exemplary stem <NUM> is similar to the second exemplary stem <NUM> of <FIG>, however, the stem <NUM> includes first and second passages. Similar to the second exemplary stem <NUM>, the first passage <NUM> is axially aligned with the longitudinal axis F, and the second passage <NUM> is parallel and radially offset relative to the longitudinal axis F. Additionally, the longitudinal axis F of the third exemplary stem <NUM> is coaxial with the longitudinal axis X of the valve body <NUM>. In the illustrated example, an inner diameter of the first passage <NUM> is equal to an inner diameter of the second passage <NUM>. However, in other examples, the inner diameter of the passages <NUM>, <NUM> are different. In yet another example, both of the first passage <NUM> and the second passage <NUM> may be radially offset relative to the longitudinal axis F.

In <FIG>, the fourth exemplary stem <NUM> is constructed according to the teachings of the present disclosure. When the fourth exemplary stem <NUM> is disposed in the valve body <NUM>, the longitudinal axis F of the stem <NUM> is coaxial with the longitudinal axis X of the valve body <NUM>. The fourth exemplary stem <NUM> is similar to the second exemplary stem <NUM> of <FIG>, however, the second and third passages <NUM>, <NUM> extend from the first end <NUM> to the second portion <NUM> of the stem <NUM>. To facilitate manufacturing, the first passage <NUM> is formed by drilling the longitudinal channel <NUM> from the second end <NUM>, and the second, and third passages <NUM>, <NUM> are formed by drilling the longitudinal channels <NUM> from the first end <NUM> of the stem <NUM>. A radial channel <NUM> extends through the first portion <NUM> of the stem <NUM> to connect the longitudinal channels <NUM> of the first and second passages <NUM>, <NUM>. A stopper <NUM> is perpendicularly disposed relative to the longitudinal channels <NUM> of the second and third passages <NUM>, <NUM> to isolate fluid communication of the second and third passages <NUM>, <NUM> between the first and third chambers <NUM>, <NUM>. To further isolate the longitudinal channels <NUM> of the second and third passages <NUM>, <NUM>, a stopper <NUM>, <NUM> is disposed in one of the longitudinal channels <NUM> at the first end <NUM> of the stem <NUM>.

In <FIG>, the fifth exemplary stem <NUM> is constructed according to the teachings of the present disclosure. The fifth exemplary stem <NUM> is formed by overlapping the first, second, and third passages without connecting the first passage <NUM> with either of the second or third passages <NUM>, <NUM>. When the fifth exemplary stem <NUM> is disposed in the valve body <NUM>, the longitudinal axis F of the stem <NUM> is coaxial with the longitudinal axis X of the valve body <NUM>. This overlapping construction can be formed using additive manufacturing (AM) techniques. As shown in <FIG>, the radial channel <NUM> of the first passage <NUM> is angled such that the radial channel <NUM> does not connect with the second and third passages <NUM>, <NUM>. In <FIG>, the first, second, and third passages <NUM>, <NUM>, <NUM> are aligned such that the first passage <NUM> is axially aligned with the longitudinal axis F, and each of the second and third passages <NUM>, <NUM> is radially offset relative to the longitudinal axis F and is spaced evenly from the first passage <NUM>. However, as shown in <FIG>, the first passage <NUM> is radially offset relative to the longitudinal axis F so that the first passage <NUM> does not intersect with a second radial channel <NUM> (disposed through the second portion <NUM> of the stem <NUM>) of the second and third passages <NUM>, <NUM>. The first passage <NUM> curves around the radial second channel <NUM> of the second and third passages <NUM>, <NUM>, as shown in <FIG>, such that the first passage <NUM> is axially aligned with the longitudinal axis F at the second end <NUM> of the stem <NUM>, as shown in <FIG>.

In <FIG>, the first exemplary indicator assembly <NUM> is constructed according to the teachings of the present disclosure. The indicator assembly <NUM> is operatively coupled to the regulator <NUM> and provides a visual display based on the position of the regulator <NUM>. The visual display is externally located relative to the valve body <NUM> so that an operator will understand the position of the control element <NUM> from a distance. Specifically, the indicator assembly <NUM> is operatively coupled to the stem <NUM>, so that when the control element <NUM> moves between the open and closed positions, the stem <NUM> causes the indicator assembly <NUM> to display a change in position of the control element <NUM>. The indicator assembly <NUM> is at least partially disposed in a radial bore <NUM> formed in the valve body <NUM>, and includes a rod <NUM>, an indicator <NUM> operatively coupled to the rod <NUM>, a spring <NUM>, and a plug <NUM>. The rod <NUM> is perpendicularly disposed relative to the longitudinal axis X of the valve body <NUM>, and is aligned with a longitudinal axis Y. The rod <NUM> of the indicator assembly <NUM> is movable between a first position when the control element <NUM> is in the closed position, as shown in <FIG>, <FIG>, and <FIG>, and a second position when the control element <NUM> is in the open position, as shown in <FIG> and <FIG>. It will be appreciated that the indicator assembly <NUM> also occupies additional positions between the first and second positions to display the positioning of the control element <NUM> when the regulator <NUM> is between the open and closed positions, such as, for example, when the control element <NUM> is in the partially open position shown in <FIG>. In <FIG>, the longitudinal axis Y of the rod <NUM> is oriented at an angle β of <NUM> degrees relative to the longitudinal axis F of the stem <NUM> and the longitudinal axis X of the valve body <NUM>. However, in other examples the angle β between the longitudinal axis Y of the indicator assembly <NUM> and the longitudinal axis X of the valve body <NUM> may be anywhere between <NUM> degrees to <NUM> degrees.

In <FIG>, the rod <NUM> includes a first end <NUM> slidably coupled to the second end <NUM> of the stem <NUM> and a second end <NUM> spaced away from the first end <NUM> and operatively coupled to the indicator <NUM>. Specifically, the first end <NUM> of the rod <NUM> is slidably coupled to a conical cap <NUM> that is secured to the second end <NUM> of the stem <NUM>. The cap <NUM> has a bore <NUM> that is both sized to receive the second end <NUM> of the stem <NUM> and is in fluid communication with the passage <NUM> of the stem <NUM> to maintain fluid communication between the passage <NUM> and the fourth chamber <NUM>. The cap <NUM> has a sloped outer surface <NUM> that tapers from a wide first end <NUM> to a narrow second end <NUM>. In other words, the second end <NUM> of the cap <NUM> has an outer diameter that is smaller than an outer diameter of the first end <NUM> of the cap <NUM> such that the rod <NUM> is axially displaced relative to the longitudinal Y axis as the stem <NUM> moves axially relative to the longitudinal axis X of the valve body <NUM>. In particular, the outer surface <NUM> of the cap <NUM> is sloped at an angle α relative to the longitudinal axis X. In <FIG>, the second end <NUM> of the cap <NUM> is in contact with a roller ball <NUM> securably coupled to the first end <NUM> of the rod <NUM>. The roller ball <NUM> facilitates the movement of the rod <NUM> relative to the stem <NUM> as the stem <NUM> moves between the open and closed positions.

The rod <NUM> moves axially (e.g., upwards in the J direction and downwards in the K direction) along the Y axis to move the indicator <NUM> outside of the valve body <NUM> according to the position of the control element <NUM>. A guide sleeve <NUM> is disposed between the valve body <NUM> and the rod <NUM> to steadily guide the rod <NUM>. The extent to which the indicator <NUM> extends outside of the valve body <NUM> is indicative of the degree of opening of the regulator <NUM>. For example, when the control element <NUM> is in the open position, the roller ball <NUM> is in contact with the first end <NUM> of the cap <NUM> and the indicator <NUM> is fully extended in the direction J. When the control element <NUM> is in the closed position, however, the roller ball <NUM> is in contact with the second end <NUM> of the cap <NUM> and the indicator <NUM> is fully retracted in the direction K. The extension of the indicator <NUM> relative to the valve body <NUM> as shown in <FIG> (fully open) is greater than the extension of the indicator <NUM> relative to the valve body <NUM> as shown in <FIG> (partially open), which is, in turn, greater than the extension of the indicator <NUM> relative to the valve body <NUM> as shown in <FIG>, because the rod <NUM> is displaced a minimal amount when roller ball <NUM> is adjacent to the second end <NUM> of the cap <NUM> (in the closed position) and is displaced a maximum amount when the roller ball <NUM> is adjacent to the first end <NUM> of the cap <NUM> (in the open position).

The indicator <NUM> is slidably coupled to the plug <NUM> and is extendable outside of the valve body <NUM>. In the illustrated example, the indicator <NUM> is secured to the second end <NUM> of the rod <NUM>, however, the indicator <NUM> may be part of the rod <NUM>. The indicator assembly <NUM> also includes the spring <NUM> contained between the plug <NUM> and a spring seat <NUM>. The spring seat <NUM> is carried by the rod <NUM> and moves axially along the longitudinal axis Y (e.g., upwards in the J direction and downwards in the K direction) and compresses the spring <NUM> against the plug <NUM>. The spring <NUM> ensures that the roller ball <NUM> maintains contact with the cap <NUM>. External threads <NUM> of the plug <NUM> rotatably couple to internal threads <NUM> of the bore <NUM> of the valve body <NUM> to secure the plug <NUM> to the valve body <NUM>. The plug <NUM> may be removed from the body <NUM> by rotating the plug <NUM> relative to the valve body <NUM> to access the indicator assembly <NUM> or to adjust the calibration of the indicator <NUM>. The indicator <NUM> is visible through a cover <NUM> attached to the plug <NUM>. The cover <NUM> is preferably be transparent so that an operator can easily view the length the indicator <NUM> extending outside of the valve body <NUM>. In some examples, the cover <NUM> may have a scale with measurements or markings that correspond to the different positions of the indicator <NUM>. In some examples, the indicator <NUM> may have a color (e.g., red) that is clearly visible through the cover <NUM> and against the environment in which the regulator <NUM> is installed.

Generally in operation, when the regulator <NUM> opens, the actuator assembly <NUM> causes the stem <NUM> to move in the H direction. As the stem <NUM> moves, the sloped surface <NUM> of the cap <NUM> slides against the roller ball <NUM> and pushes the rod <NUM> in the J direction perpendicular relative to the H direction. The rod <NUM>, which carries the indicator <NUM>, moves the indicator <NUM> in the J direction such that the indicator <NUM> extends outside the valve body <NUM> and slides into view relative to the cover <NUM> to display the positioning of the regulator <NUM>. As the rod <NUM> moves in the J direction, the rod <NUM> causes the spring seat <NUM> to compress the spring <NUM> against the plug <NUM> so that when the stem <NUM> moves in the G direction, the spring <NUM> expands and biases the spring seat <NUM> to move the rod <NUM> in a K direction (opposite the J direction). As the rod <NUM> moves in the K direction, the indicator <NUM> also moves in the K direction and slides out of view relative to the cover <NUM>.

The indicator assembly <NUM> advantageously provides accurate readings of the position of the regulator <NUM> based on an orientation of the indicator assembly <NUM> relative to the longitudinal axis X of the valve body <NUM>. As shown in <FIG>, the indicator assembly <NUM> is perpendicular relative to the longitudinal axis F of the stem and longitudinal axis X of the valve body <NUM> such that angle β is <NUM> degrees. To determine the displacement of the stem <NUM> or the displacement of rod <NUM> the following equation may be used: <MAT> where L is displacement of the travel indicator <NUM>, Δx is the displacement of the stem <NUM>, Δh is the displacement of the rod <NUM> in the direction perpendicular to the axial direction of the stem <NUM>. Because the angle β =<NUM>, the equation may be simplified to the following: <MAT>.

While the travel indicator assembly <NUM> has been described in the context of its use in the pressure regulator <NUM>, the travel indicator assembly <NUM> can also be utilized in other types of fluid control devices. As will be described further below, different iterations of the travel indicator assembly may include at least one feature that is operatively coupled to the rod and operatively couplable to a stem to indicate travel of the stem of the pressure regulator or other fluid control device. In the following examples, the roller ball feature of the travel indicator assembly is replaced by, for example, a rack and pinion feature, a cord and roller feature, or a hinged arm feature.

<FIG> illustrates a second exemplary indicator assembly <NUM> constructed according to the teachings of the present disclosure. The second exemplary indicator assembly <NUM> may replace the first exemplary indicator assembly <NUM> to operate with the regulator <NUM> of <FIG>. The second exemplary indicator assembly <NUM> is similar to the indicator assembly <NUM> discussed above, except the second exemplary indicator assembly <NUM> utilizes engagement of the stem <NUM> and a rod <NUM> to convert axial movement (e.g., in the G and H directions) of the stem <NUM> of the regulator <NUM> to rotational movement (e.g., in the R and T directions) of the rod <NUM> to display the positioning of the control element <NUM> in a rack and pinion embodiment (<FIG>) or, alternatively, to convert axial movement (e.g., in the G and H directions) of the stem <NUM> to axial movement (e.g., in the J and K directions) of the rod <NUM> to display the positioning of the control element <NUM> in a rack and rack embodiment (<FIG>). Elements of the second exemplary indicator assembly <NUM> which are similar to the elements of the first exemplary indicator assembly <NUM> are designated by the same reference numeral, incremented by <NUM>. A description of many of these elements is abbreviated or even eliminated in the interest of brevity.

The second exemplary indicator assembly <NUM> of <FIG> is arranged in either a rack and pinion configuration, or a rack and rack configuration (<FIG>). In the rack and pinion embodiment illustrated in <FIG>, an indicator <NUM> of the indicator assembly <NUM> does not move in the vertical direction along the Y axis, but instead rotates relative to the Y axis when the stem moves axially along the longitudinal axis X. For example, movement of the stem <NUM> in the H direction causes the rod <NUM> of the indicator assembly <NUM> to rotate in a T direction about the longitudinal axis Y of the stem <NUM>. The rotational motion of the indicator assembly <NUM> may be configured in a number of different ways. In the illustrated example of <FIG>, the rod <NUM> has a corrugated outer surface <NUM> providing a plurality of teeth that are configured to matingly engage with a corrugated outer surface <NUM> of the second end <NUM> of the stem <NUM>. The teeth of the outer surface <NUM> of the rod <NUM> engage with the teeth of the corrugated surface <NUM> of the stem <NUM> such that as the stem <NUM> moves axially in the G or H directions, the stem <NUM> engages the teeth of the rod <NUM> to rotate the rod <NUM> in either the T or R directions, respectively. The corrugated surface <NUM> of the stem and the teeth of the outer surface <NUM> of the rod <NUM> may be arranged to provide a particular gear ratio to provide a desired degree of rotation of the rod <NUM> corresponding to the full linear travel of the stem <NUM>.

As the indicator <NUM> rotates, a position of the control element <NUM> may be displayed based on the rotational position of the indicator <NUM>. In the illustrated example, the second piston <NUM> is adjacent to the second end <NUM> of the sleeve <NUM> such that the control element <NUM> is in the open position. In the open position, the indicator <NUM> displays a triangular flag with a pointed end pointing toward the inlet <NUM> of the valve body <NUM>. In the closed position, the flag of the indicator <NUM> may be configured to point toward the outlet <NUM> of the valve body <NUM>. In another example, the flag of the indicator <NUM> may be pointed toward the inlet <NUM> when the regulator <NUM> is closed, and the flag of the indicator <NUM> may be pointed toward the outlet <NUM> when the regulator <NUM> is open. The indicator <NUM> may display positioning of the regulator <NUM> in other ways, for example, by exposing different colors or displaying text as the indicator <NUM> rotates in a display case or cover <NUM>. In yet other examples, the indicator <NUM> provide a different visible signal to communicate the positions of the regulator <NUM>. For example, the indicator may match up with different measurements or markings on the cover <NUM> based on the position of the regulator <NUM>.

In operation, the stem <NUM> moves in the H direction to open the regulator <NUM>. The corrugated outer surface <NUM> of the stem <NUM> engages the corrugated outer surface <NUM> of the rod <NUM>, causing the rod <NUM> to rotate in the T direction (counterclockwise in <FIG>) about the Y axis. As shown in <FIG>, the regulator <NUM> is in the fully open position and the flag of the indicator <NUM> is pointing away from the outlet <NUM> (i.e., toward the inlet <NUM>). When the regulator <NUM> closes, the stem <NUM> moves in the G direction (opposite the H direction) and engages the rod <NUM> to rotate the rod <NUM> in a direction R (clockwise in <FIG>) about the Y axis. Rotation of the rod <NUM> causes rotation of the flag of the indicator <NUM> such that when the control element <NUM> is in the closed position, the flag of the indicator <NUM> points toward the outlet <NUM> of the valve body <NUM>.

In the rack and rack embodiment illustrated in <FIG>, the rod <NUM> includes helical threads <NUM> that are configured to engage with helical threads <NUM> of the stem <NUM>. In this configuration, the helical threads <NUM> of stem <NUM> engage the helical threads <NUM> of the rod <NUM> when the stem <NUM> moves in the G or H direction to move the rod <NUM> axially in the J or K direction. As the stem <NUM> moves in the H direction, the helical threads <NUM> of the stem <NUM> engage the helical threads <NUM> of the rod <NUM> to move the rod <NUM> in the J direction, extending the indicator <NUM> into the display cover <NUM>. As the stem <NUM> moves in the G direction, the helical threads <NUM> of the stem <NUM> engage the helical threads <NUM> of the rod <NUM> to move the rod <NUM> in the K direction to lower the indicator <NUM> within the display cover <NUM>. Thus, like the travel indicator assembly <NUM>, the rack and rack embodiment of the travel indicator assembly <NUM> indicates the position of the regulator <NUM> based on the position of the indicator <NUM> along the Y axis. In another example, the indicator assembly <NUM> may be constructed differently to translate axial movement of the stem <NUM> into rotational movement of the rod <NUM> and indicator <NUM>. In yet another example, a fluid regulator may be constructed such that rotational movement of the stem <NUM> moves the control element <NUM> between open and closed positions. In this case, the indicator assembly <NUM> would be configured to convert the rotational movement of the stem <NUM> into axial movement of the rod <NUM> and indicator <NUM> to display the positioning of the regulator <NUM>.

<FIG> illustrates a third exemplary indicator assembly <NUM> constructed according to the teachings of the present disclosure. The third exemplary indicator assembly <NUM> may replace the first exemplary indicator assembly <NUM> to operate with the regulator <NUM> of <FIG>. The third exemplary indicator assembly <NUM> is similar to the indicator assembly <NUM> discussed above, except the third exemplary indicator assembly <NUM> includes a cord <NUM> and roller assembly <NUM> to translate an axial movement of the stem <NUM> (e.g., in the G and H directions) to an axial movement of the rod <NUM> (e.g., in the J and K directions). Elements of the third exemplary indicator assembly <NUM> which are similar to the elements of the first exemplary indicator assembly <NUM> are designated by the same reference numeral, incremented by <NUM>. A description of many of these elements is abbreviated or even eliminated in the interest of brevity.

As shown in <FIG>, the rod <NUM> is operatively coupled to the stem <NUM> by way of the cord <NUM> and roller assembly <NUM>. In particular, the cord <NUM> is operatively coupled to the second end <NUM> of the stem <NUM> at a first hook <NUM> and to a first end <NUM> of the rod <NUM> at a second hook <NUM>. The roller assembly <NUM> is coupled to the cord <NUM> to transmit displacement of the stem <NUM> to the rod <NUM> via the cord <NUM>. The cord <NUM> bends around the roller assembly <NUM> such that a portion of the cord <NUM> moves in the G and H directions with the stem <NUM>, and a portion of the cord <NUM> moves in the J and K directions with the rod <NUM>. The cord <NUM> is a flexible material, such as a steel wire to bend around the roller assembly <NUM>, yet is sufficiently rigid so the cord <NUM> remains in tension between the stem <NUM> and the rod <NUM>. A spring <NUM> is disposed between a spring seat <NUM> extending radially outward from the rod <NUM> and a plug <NUM>. The spring <NUM> expands in the J direction when the stem <NUM> moves in the H direction and compresses in the K direction when the stem <NUM> moves in the G direction. In operation, the stem <NUM> pulls the cord <NUM> in the G direction to close the regulator <NUM>, and the rod <NUM> pulls the cord <NUM> in the J direction when the stem <NUM> moves in the H direction. The spring <NUM> helps ensure that the steel cord <NUM> stays taught to properly respond to the movement of the stem <NUM>. In this case, the indicator <NUM> is the second end <NUM> of the rod <NUM> such that the rod <NUM> is slidably disposed through a bore in the plug <NUM> to extend outside of the valve body <NUM> to indicate the positioning of the control element <NUM>. However, in another example, the rod <NUM> and the indicator element <NUM> are separate components.

<FIG> illustrates a fourth exemplary indicator assembly <NUM> constructed according to the teachings of the present disclosure. The fourth exemplary indicator assembly <NUM> may replace the first exemplary indicator assembly <NUM> to operate with the regulator <NUM> of <FIG>. The fourth exemplary indicator assembly <NUM> is similar to the first exemplary indicator assembly <NUM> discussed above, except the fourth exemplary indicator assembly <NUM> includes a rigid arm <NUM> connecting the stem <NUM> and the rod <NUM> to translate an axial movement of the stem <NUM> (e.g., in the G and H directions) to an axial movement of the rod <NUM> (e.g., the J and K directions). Elements of the fourth exemplary indicator assembly <NUM> which are similar to the elements of the first exemplary indicator assembly <NUM> are designated by the same reference numeral, incremented by <NUM>. A description of many of these elements is abbreviated or even eliminated in the interest of brevity.

As shown in <FIG>, the arm <NUM> has a first end <NUM> hingedly coupled to the second end <NUM> of the stem <NUM> and a second end <NUM> hingedly coupled to a first end <NUM> of the rod <NUM>. Similar to the third exemplary indicator assembly <NUM>, the rod <NUM> of the fourth exemplary indicator assembly <NUM> is integrally formed with the indicator <NUM>. The arm <NUM> is a rigid member that translates axial movement of the stem <NUM> to axial movement of the rod <NUM>. When the regulator <NUM> opens, the stem <NUM> pushes the first end <NUM> of the arm <NUM> in the H direction, which causes the second end <NUM> of the arm <NUM> to slide in the J direction within a bore <NUM> of the valve body <NUM>. The second end <NUM> is hingedly coupled to the first end <NUM> of the rod <NUM> to permit the arm <NUM> to swivel in a V direction when the first end <NUM> moves in the H direction. When the regulator <NUM> closes, the stem <NUM> pulls the first end <NUM> of the arm <NUM> in the G direction, causing the second end <NUM> of the arm <NUM> to slide in the K direction within the bore <NUM> of the valve body <NUM>. The arm <NUM> swivels in a M direction (opposite of the direction V) when the first end <NUM> of the arm <NUM> moves in the G direction. In another example, the indicator assembly <NUM> may include a second arm <NUM> hingedly coupled to the stem <NUM> and the rod <NUM>.

Referring again to <FIG>, a method of assembling or installing the regulator <NUM> generally includes the steps of providing a single-cast valve body <NUM>, assembling the actuator assembly <NUM>, operatively coupling the control element <NUM> to the stem <NUM>, aligning the actuator assembly <NUM> with the longitudinal axis X of the valve body <NUM>, inserting the actuator assembly <NUM> into the bore <NUM> of the valve body <NUM> through the inlet <NUM>, and securing the actuator assembly <NUM> to the valve body <NUM> by operatively coupling the inlet fitting <NUM> to the valve body <NUM>. To assemble the actuator assembly <NUM>, the first and second pistons <NUM>, <NUM> and the first and second sleeve portions 50a, 50b are assembled to the stem <NUM>. Specifically, the step of assembling the actuator assembly <NUM> includes sliding the second end <NUM> of the stem <NUM> through the aperture <NUM> of the second plate <NUM> and an aperture of the second piston <NUM> and sliding the first end <NUM> of the stem <NUM> through an aperture of the first piston <NUM> and the aperture <NUM> of the second plate <NUM>. The first and second pistons <NUM>, <NUM> are secured to the stem <NUM> as described above. The hub <NUM> of the control element <NUM> is slid onto the first end <NUM> of the stem <NUM> and secured thereto. The cap <NUM> is secured to the second end <NUM> of the stem <NUM>. The stem <NUM> and the components attached thereto are then fully inserted into the valve body <NUM> along with the cage <NUM>, and all of the internal components are maintained in the valve body <NUM> by securing the inlet fitting <NUM> to the inlet <NUM>.

Turning now to <FIG>, a control system <NUM> includes the first exemplary axial regulator <NUM> of <FIG> in series with a second axial regulator <NUM>. The first axial regulator <NUM>, or a "monitor," may be identical to the second axial regulator <NUM>, or a "working regulator," but the monitor <NUM> acts as a back-up regulator and is located upstream from the working regulator <NUM> and set at a slightly higher pressure set point. In normal operation, because the working regulator <NUM> maintains the control pressure (i.e., the fluid pressure at the outlet <NUM> of the working regulator <NUM>) at a lower pressure than the set point of the monitor <NUM>, the monitor <NUM> remains in the fully open position. However, if the working regulator <NUM> malfunctions in a manner than causes the control pressure to increase, then the monitor <NUM> takes over and maintains the control pressure at the slightly higher monitor set point. For ease of reference, and to the extent possible, the same or similar components of the axial regulator <NUM> will retain the same reference numbers as outlined above with respect to the first exemplary axial regulator, although reference numbers will be increased by <NUM>.

The control system <NUM> includes the monitor <NUM>, the working regulator <NUM> coupled to the monitor by a conduit <NUM>, and a network of pilots and pressure stabilizers. In particular, the control system <NUM> includes a first pilot <NUM>, a second pilot <NUM>, a first pressure stabilizer <NUM>, a third pilot <NUM>, and a second pressure stabilizer <NUM>.

The first and second pressure stabilizers <NUM>, <NUM> may be standard pressure stabilizers, such as the Tartarini® Type SA/<NUM> Pressure Stabilizer. The first and second stabilizers <NUM>, <NUM> receive a fluid pressure from the inlet <NUM> of the monitor <NUM> and provide a consistent pilot supply pressure to the first and third pilots <NUM>, <NUM>, respectively, in accordance with the control pressure.

The first pilot <NUM> may be a standard spring-to-open pilot, such as a Tartarini® PRX <NUM> Pilot. The first pilot <NUM> includes a first port <NUM>, a second port <NUM>, a third port <NUM>, and a fourth port <NUM> formed in a housing of the pilot <NUM>. The first port <NUM> receives a pilot supply pressure from the first pressure stabilizer <NUM>. The second port <NUM> is in fluid communication with a first port <NUM> of the second pilot <NUM> and in fluid communication with the first and third chambers <NUM>, <NUM> of the monitor <NUM> via the first channel <NUM>. The third port <NUM> is in fluid communication with the fourth chamber <NUM> of the monitor <NUM> via the second channel <NUM>. The fourth port <NUM> is in fluid communication with the outlet <NUM> of the working regulator <NUM>.

The first pilot <NUM> is responsive to fluid pressure at the third port <NUM>, which is ultimately fluidly coupled to the control pressure. In normal operation, the control pressure is less than the set point of the first pilot <NUM> such that the first pilot <NUM> is in the open position with the first port <NUM> coupled to the second port <NUM>. In this open position, the pilot supply pressure from the first pressure stabilizer <NUM>, which is received at the first port <NUM>, is routed to the first and third chambers <NUM>, <NUM> of the monitor <NUM>, which maintains the monitor <NUM> in the open position. If the working regulator <NUM> fails such that the pressure at the outlet <NUM> exceeds the set point of the first pilot <NUM>, the first pilot <NUM> transitions to the closed position such that the first port <NUM> is not coupled to the second port <NUM>. When the first pilot <NUM> is in the closed position, pressure is relieved from the first and third chambers <NUM>, <NUM> to the outlet <NUM> of the working regulator <NUM> via the connection of the second and fourth ports <NUM>, <NUM> and the monitor <NUM> modulates to maintain the control pressure at the set point of the first pilot <NUM>.

The second pilot <NUM> may be a standard spring-to-close pilot, such as a Tartarini® PRX <NUM> Pilot. The second pilot <NUM> includes the first port <NUM>, a second port <NUM>, and a third port <NUM> formed in a housing of the second pilot <NUM>. The first port <NUM> of the second pilot <NUM> is in fluid communication with the first and third chambers <NUM>, <NUM> of the monitor <NUM> via the first channel <NUM>. The second port <NUM> is in fluid communication with the outlet <NUM> of the working regulator <NUM>. The third port <NUM> is in fluid communication with the control pressure via the second channel <NUM>.

The second pilot <NUM> is responsive to fluid pressure at the third port <NUM>, which is ultimately fluidly coupled to the control pressure as described above. The second pilot <NUM> functions as a quick-dump pilot that enables the first and third chambers <NUM>, <NUM> of the monitor <NUM> to be evacuated to the outlet <NUM> of the working regulator <NUM> via a higher-flow path between the first port <NUM> and the second port <NUM> when the second pilot <NUM> is in the open position (i.e., when the control pressure exceeds the set point of the second pilot <NUM>). This quick-dump arrangement enables the monitor <NUM> to close more quickly than if the monitor <NUM> was connected only to the first pilot <NUM>.

The third pilot <NUM> may be a standard spring-to-open pilot, such as a Tartarini® PRX <NUM> Pilot. The third pilot <NUM> includes a first port <NUM>, a second port <NUM>, a third port <NUM>, and a fourth port <NUM> formed in a housing of the pilot <NUM>. The first port <NUM> receives a pilot supply pressure from the second pressure stabilizer <NUM>. The second port <NUM> is in fluid communication with first and third chambers <NUM>, <NUM> of the working regulator <NUM> via a first channel <NUM>. The third port <NUM> is in fluid communication with a fourth chamber <NUM> of the working regulator <NUM> via a second channel <NUM>, which is ultimately coupled to the control pressure.

The third pilot <NUM> functions in the same manner as the first pilot <NUM>. When the control pressure is less than the set point of the third pilot <NUM>, the third pilot <NUM> is in the open position with the first port <NUM> coupled to the second port <NUM>. In this open position, the pilot supply pressure from the second pressure stabilizer <NUM>, which is received at the first port <NUM>, is routed to the first and third chambers <NUM>, <NUM> of the working regulator <NUM>, which maintains the working regulator <NUM> in the open position. When the control pressure exceeds the set point of the third pilot <NUM>, the third pilot <NUM> transitions to the closed position such that the first port <NUM> is not coupled to the second port <NUM>. In this closed position, pressure is relieved from the first and third chambers <NUM>, <NUM> to the outlet <NUM> of the working regulator <NUM> via the connection of the second and fourth ports <NUM>, <NUM> and the working regulator <NUM> travels to the closed position. In this manner, the working regulator modulates to maintain the control pressure at the set point of the third pilot <NUM>.

When the monitor operates in its normal, fully-open position, there is very little pressure drop across the monitor <NUM>. In this arrangement, the fluid pressure at the inlet <NUM> of the monitor <NUM> may be significantly greater than the control pressure. Thus, the fluid pressure operating on the cross-sectional area of the stem <NUM> in the open direction (i.e., at the inlet <NUM>) may be significantly greater than the fluid pressure operating on the cross-sectional area of the stem <NUM> in the closed direction (i.e., in the second and fourth chambers <NUM>, <NUM> of the monitor <NUM>). When this pressure differential is large enough, the spring <NUM> of the piston assembly <NUM> may be unable to fully close the monitor <NUM>. To resolve this imbalance, the regulator <NUM> may be modified to include a balance structure at a second end <NUM>, <NUM> of the stem <NUM>, <NUM>, respectively.

Turning to <FIG>, a floating balance assembly <NUM> is operatively coupled to the body <NUM> of the regulator <NUM>. The axial regulator <NUM> of <FIG> is similar to the axial regulator <NUM> of <FIG>. Thus, for ease of reference, and to the extent possible, the same or similar components of the axial regulator <NUM> will retain the same reference numbers as outlines above with respect to the first exemplary axial regulator <NUM>, although reference numbers will be increased by <NUM>.

In <FIG>, the floating balance assembly <NUM> includes an end cap <NUM>, a stem <NUM>, a bushing <NUM>, and one or more O-rings <NUM>. A flange <NUM> of the end cap <NUM> is coupled to the body <NUM> of the regulator <NUM> and, along with the stem <NUM>, isolates the fourth chamber <NUM> from the outlet <NUM>. The one or more O-rings <NUM> provide a seal between the floating stem <NUM> and the end cap <NUM> to maintain isolation between the fourth chamber <NUM> and the outlet <NUM>. In the illustrated example, the stem <NUM> floats within a bore <NUM> formed in the end cap <NUM> such that the stem <NUM> is movable along the X axis of a regulator body <NUM>. The stem <NUM> moves in an axial direction depending on fluid pressure at the outlet <NUM> and in the fourth chamber <NUM>.

As shown in <FIG>, the floating stem <NUM> straddles the fourth chamber <NUM> of the actuator assembly <NUM> and the outlet <NUM>. When the regulator <NUM> is utilized as a working regulator, the control pressure in the second and fourth chambers <NUM>, <NUM> is approximately equal to the pressure at the outlet <NUM>. Because the control pressure operating on a first end <NUM> of the floating stem <NUM> is substantially equal to the outlet pressure operating on a second end <NUM> of the floating stem <NUM>, the floating stem <NUM> exerts essentially no force on the stem <NUM> and thus does not impact operation of the regulator <NUM>. However, when the regulator <NUM> is utilized as a monitor, the control pressure in the second and fourth chambers <NUM>, <NUM> is significantly lower than the pressure at the outlet <NUM>. Because the control pressure operating on the first end <NUM> of the floating stem <NUM> is substantially less than the outlet pressure operating on the second end <NUM> of the floating stem <NUM>, the floating stem <NUM> moves to the left (in the orientation shown in <FIG>) and contacts the stem <NUM>. The force of the outlet pressure operating on the second end <NUM> of the floating stem <NUM> thus functions to assist the regulator <NUM> in moving towards the closed position. Moreover, because the outlet pressure is substantially equal to the inlet pressure when the regulator <NUM> functions as a monitor, the pressure operating on the second end <NUM> of the floating structure is substantially equal to the inlet pressure operating on the unbalanced cross-sectional area of the stem <NUM>. Accordingly, the floating balance assembly <NUM> provides a structure that operates in a first mode of operation, in which the floating stem <NUM> engages the stem <NUM> of the actuator assembly <NUM> and a second mode of operation, in which the floating stem <NUM> is separated from the stem <NUM>. In the first mode of operation, the floating stem <NUM> is operatively coupled to the control element, and exerts a first force on the control element. In the second mode of operation, the floating stem <NUM> is effectively decoupled from the control element.

As shown in <FIG>, the first end <NUM> of the floating stem <NUM> has a semi-spherical shape in which a internal channel <NUM> is formed. The internal channel <NUM> includes a longitudinal section <NUM> and a lateral section <NUM> that is perpendicular relative to the longitudinal section <NUM>. When the balance assembly <NUM> is in the first mode of operation, as shown in <FIG>, the internal channel <NUM> is in fluid communication with a passage <NUM> that partially extends through the stem <NUM>. In this way, when the first end <NUM> of the floating stem <NUM> is in contact with the second end <NUM> of the stem <NUM> of the actuator assembly <NUM>, the passage <NUM> of the stem <NUM> and the internal channel <NUM> of the floating stem <NUM> fluidly couple the second chamber <NUM> with the fourth chamber <NUM> of the regulator <NUM>. The semi-spherical shape of the first end <NUM> may advantageously help guide the floating stem <NUM> as it slides within the cap <NUM>. However, in other examples, the first end <NUM> of the floating stem <NUM> may have a different geometry and may be provided without an internal channel.

Although the balance assembly <NUM> has been described as having a floating stem <NUM>, in an alternate embodiment, the stem <NUM> of the balance assembly <NUM> might be attached to the stem <NUM>. In such an arrangement, the fixed stem <NUM> essentially operates as an extension of the stem <NUM> of the actuator assembly <NUM>. Because the fixed stem <NUM> is coupled to the stem <NUM>, the outlet pressure would always operate to exert a closing force on the stem <NUM>. Thus, different from the floating stem arrangement, the fixed stem balance structure arrangement would exert a force equal to the outlet pressure operating on the cross-sectional area of the second end <NUM> of the stem <NUM> regardless of whether the regulator <NUM> functions as a monitor or as a working regulator.

The axial regulator <NUM> of the present disclosure advantageously simplifies regulator construction, manufacturing, maintenance, and assembly. To access the internal components of the disclosed regulator <NUM>, an operator need only remove the inlet fitting <NUM> from the valve body <NUM> and slide the internal components out of the bore <NUM> through the inlet <NUM>, which can be accomplished with the regulator <NUM> installed in a pipeline via the spacer <NUM>. Assembly of the regulator <NUM> is also simplified as the internal components may be properly arranged prior to inserting the actuator assembly <NUM> into the valve body <NUM>, thereby ensuring accurate alignment and placement of the components. Repair or replacement of the regulator components is also simplified, and access to the internal components may be achieved through the inlet <NUM> or, in some cases, a different access entry from the inlet <NUM>. The removability of the internal components further enables the valve body <NUM> to be used with different types of internal components to provide different functionality. For example, different internal components may be inserted into the valve body <NUM> to enable the resulting device to function as a control valve or a slam-shut safety valve. The stem <NUM> of the regulator <NUM> also facilitates assembly. As discussed above, the stem <NUM> has different portions with varying outer diameters. When positioning the stem <NUM> relative to the sleeve <NUM> prior to inserting the internal components into the valve body <NUM>, the operator need only match the apertures <NUM>, <NUM> of the plates <NUM>, <NUM> of the sleeve <NUM> with the corresponding thicknesses (i.e., segments) of the stem <NUM>. Additionally, the operator may ensure that the passage <NUM> of the stem <NUM> fluidly connects the first and second downstream chambers <NUM>, <NUM> and the pathway <NUM> of the sleeve <NUM> fluidly connects the first and second upstream chambers <NUM>, <NUM> before disposing the actuator assembly <NUM> within the valve body <NUM>.

The dual piston actuator assembly <NUM> affords the regulator <NUM> a compact design while providing adequate pressure sensing area. The pistons <NUM>, <NUM> are arranged in series and the upstream chambers <NUM>, <NUM> and the downstream chambers <NUM>, <NUM> defined in part by each piston <NUM>, <NUM> are in fluid communication, respectively. In this way, the dual piston actuator assembly <NUM> effectively provides a pressure sensing area similar to or even greater than that of a much larger single-piston actuator assembly, but in a relatively compact configuration. The size of the regulator <NUM> is further reduced through the axial insertion of the internal components, which permits the valve body <NUM> to be a single component rather than multiple components that are joined with large and heavy flanges. The compact size enables the regulator <NUM> to be designed for installation in large line sizes (e.g., a <NUM> inch line), whereas the size and weight of prior art axial regulators may limit the design of such regulators to smaller line sizes.

Additionally, the actuator assembly <NUM> is arranged such that the first and second pistons <NUM>, <NUM> move in sealing engagement with the sleeve <NUM>, and not an interior wall of the valve body <NUM>. This simplifies the manufacturing process as only the sleeve <NUM>, and not the valve body <NUM>, needs to be machined to provide a smooth sliding interior surface <NUM>. Accordingly, the larger valve body <NUM> can be manufactured using a lower-cost technique such as rough casting rather than machining. Thus, the dual piston actuator assembly <NUM> consequently reduces the manufacturing cost of the regulator <NUM>.

The second, third, fourth, and fifth exemplary stems <NUM>, <NUM>, <NUM>, and <NUM> also simplify the dual-piston actuator assembly <NUM>. As described above, each of the second, third, fourth, and fifth exemplary stems <NUM>, <NUM>, <NUM>, and <NUM> provides at least two passages to fluidly connect the first and third chambers <NUM>, <NUM>, and the second and fourth chambers <NUM>, <NUM>. Because each of the stems <NUM>, <NUM>, <NUM>, and <NUM> provides a fluid connection between the first and third chambers <NUM>, <NUM>, the sleeve <NUM> of the regulator <NUM> may not include one or more pathways <NUM> extending through the cylindrical portion <NUM> of the sleeve <NUM> and the second disk <NUM>. In this way, the regulator <NUM> would not require the same sealing mechanisms disposed in the bore <NUM> and between the valve body <NUM> and the sleeve <NUM> to effectively seal the pathway <NUM> of the actuator assembly <NUM>. Rather, the control pressure is routed through the stem <NUM>, <NUM>, <NUM>, <NUM> and not formed in the cylindrical wall <NUM> of the sleeve <NUM>.

The indicator assemblies <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> of the present disclosure advantageously provide accurate readings of the position of the regulator <NUM> and compact designs by converting the axial displacement of the stem <NUM> into an indicator movement that is conveniently on the outside of the regulator <NUM>.

Any of the components of the regulator <NUM> may be made using an additive manufacturing (AM) technique or process that builds three-dimensional objects by adding successive layers of material on a material or receiving surface. In particular, the first, second, third, fourth, and fifth stems <NUM>, <NUM>, <NUM>, and <NUM> could be made using AM to achieve the staggered passage arrangement and even more complex passage arrangements. The AM technique may be performed by any suitable machine or combination of machines. The AM technique may typically involve or use a computer, three-dimensional modeling software (e.g., Computer Aided Design, or CAD, software), machine equipment, and layering material. Once a CAD model is produced, the machine equipment may read in data from the CAD file and layer or add successive layers of liquid, powder, sheet material (for example) in a layer-upon-layer fashion to fabricate a three-dimensional object. The AM technique may include any of several techniques or processes, such as, for example, a stereolithography ("SLA") process, digital light processing ("DLP"), a fused deposition modeling ("FDM") process, a multi-jet modeling ("MJM") process, a selective laser sintering ("SLS") process, a selective laser melting ("SLM") process, an electronic beam melting ("EBM") process, and an arc welding AM process. In some embodiments, the AM process may include a directed energy laser deposition process. Such a directed energy laser deposition process may be performed by a multi-axis computer-numerically-controlled ("CNC") lathe with directed energy laser deposition capabilities. Other manufacturing techniques may be utilized to create a stem for an axial regulator according to the present disclosure, and are not limited to the techniques herein.

Claim 1:
A fluid control device (<NUM>) comprising:
a valve body (<NUM>) defining an inlet (<NUM>), an outlet (<NUM>), and a flow path connecting the inlet (<NUM>) and the outlet (<NUM>);
a valve seat;
a control element movable relative to the valve body (<NUM>) between a closed position, in which the control element engages the valve seat, and an open position, in which the control element is spaced away from the valve seat;
an actuator assembly (<NUM>) responsive to a sense pressure to control fluid flow through the fluid control device (<NUM>), the actuator assembly including a cavity defining a sensing chamber, and a stem (<NUM>) operatively coupled to the control element and extending through the sensing chamber;
a balance assembly (<NUM>) operatively coupled to the control element in a first mode of operation and decoupled from the control element in a second mode of operation;
wherein the balance assembly (<NUM>) is configured to apply a force to the control element in the first mode of operation to urge the control element toward the valve seat,
wherein the balance assembly (<NUM>) comprises a floating stem (<NUM>) disposed between the sensing chamber of the actuator assembly (<NUM>) and the outlet (<NUM>) of the valve body (<NUM>), and
wherein the floating stem (<NUM>) is in contact with the stem (<NUM>) of the actuator assembly (<NUM>) in the first mode of operation and is spaced away from the stem (<NUM>) of the actuator assembly (<NUM>) in the second mode of operation.