Patent Description:
The inventions relate to fluid flow and delivery devices and methods, and more particularly to poppet valves used to control fluid flow and delivery.

Poppet style valves are well known for use as flow control mechanisms for gas and liquid fluid delivery, flow control, and pressure control. Poppet valve arrangements include an axially movable stem having a sealing portion (e.g., enlarged disc, tapered end) that seals against an annular seat in a valve passage when the stem is in a closed position and axially separates from the seat when the stem is in an open position, to permit fluid flow through the valve passage. Many different types of fluid control devices utilize poppet valve mechanisms, including, for example, diaphragm valves, bellows valves, and pressure regulators (see <CIT>).

According to an exemplary embodiment of the present disclosure, a valve subassembly includes a body plug, a poppet, and a seat carrier. The body plug includes a tubular side wall defining a central cavity and one or more lateral flow apertures in the side wall. The poppet includes axially extending upper and lower stem portions and a radially extending poppet sealing portion between the upper and lower stem portions, with the lower stem portion and the poppet sealing portion being received in the central cavity of the body plug. The seat carrier is assembled with the body plug and includes a central bore receiving the upper stem portion of the poppet therethrough, the seat carrier retaining a seat seal in radial alignment with the poppet sealing portion.

According to another exemplary embodiment of the present disclosure, a pressure regulator includes a valve body housing, a valve subassembly, a loading mechanism, and a sensing element. The valve body housing including a central bore disposed between first and second end ports. The valve subassembly includes a body plug, a poppet, and a seat carrier. The body plug includes a tubular side wall defining a central cavity and one or more lateral flow apertures in the side wall. The body plug is installed in the central bore of the valve body, such that at least one of the one or more lateral flow apertures is in fluid communication with the first end port. The poppet includes axially extending upper and lower stem portions and a radially extending poppet sealing portion between the upper and lower stem portions, with the lower stem portion and the poppet sealing portion being received in the central cavity of the body plug. The seat carrier is assembled with the body plug and includes a central bore receiving the upper stem portion of the poppet therethrough, the seat carrier retaining a seat seal in radial alignment with the poppet sealing portion. The loading mechanism is assembled with the valve body housing and is operable to apply a set load force against the poppet for downward movement of the poppet. The sensing element is disposed between the loading mechanism and the poppet to transmit the load force from the loading mechanism to the poppet, wherein when fluid pressure within one of the first and second end ports exceeds a pressure setting corresponding to the set load force, the sensing element is movable against the set load force to permit upward movement of the poppet.

According to another exemplary embodiment of the present disclosure, a method of replacing a poppet and seat seal in a regulator valve assembly is contemplated. In the exemplary method, a regulator valve assembly is provided, including a valve body having a valve body housing defining a central bore, and a valve cartridge subassembly including a body plug and a seat carrier assembled together to retain the poppet and seat seal therebetween, with the body plug being installed in the central bore. The valve cartridge subassembly is removed from the valve body by disassembling the body plug from the valve body housing, thereby withdrawing the body plug, seat carrier, poppet, and seat seal from the central bore. A replacement valve cartridge subassembly is assembled with the regulator valve body to install a new poppet and seat seal in the valve body housing bore.

This Detailed Description merely describes exemplary embodiments and is not intended to limit the scope of the claims in any way. Indeed, the invention as claimed is broader than and unlimited by the exemplary embodiments, and the terms used in the claims have their full ordinary meaning. For example, while the specific embodiments described herein relate to pressure-reducing regulator valve arrangements, the features of the present application may additionally or alternatively be applied to other types of valves, including, for example, backpressure regulator valve arrangements, shutoff valves, check valves, and relief valves. The terms "poppet valve" and "poppet type valve," as used herein, are intended to broadly include any valve that includes a stem that carries a sealing member that is brought into sealing engagement with an annular seat by longitudinal movement of the stem. The terms "seal" and "sealing engagement" are intended to include conditions of reduced flow resulting from contact between a sealing surface and a seating surface, in addition to a leak-tight or fluid-tight seal.

While various inventive aspects, concepts and features of the inventions may be described and illustrated herein as embodied in combination in the exemplary embodiments, these various aspects, concepts and features may be used in many alternative embodiments, either individually or in various combinations and sub-combinations thereof. Unless expressly excluded herein all such combinations and sub-combinations are intended to be within the scope of the present inventions. Still further, while various alternative embodiments as to the various aspects, concepts and features of the inventions--such as alternative materials, structures, configurations, methods, circuits, devices and components, software, hardware, control logic, alternatives as to form, fit and function, and so on--may be described herein, such descriptions are not intended to be a complete or exhaustive list of available alternative embodiments, whether presently known or later developed. Those skilled in the art may readily adopt one or more of the inventive aspects, concepts or features into additional embodiments and uses within the scope of the present inventions even if such embodiments are not expressly disclosed herein. Additionally, even though some features, concepts or aspects of the inventions may be described herein as being a preferred arrangement or method, such description is not intended to suggest that such feature is required or necessary unless expressly so stated. Still further, exemplary or representative values and ranges may be included to assist in understanding the present disclosure, however, such values and ranges are not to be construed in a limiting sense and are intended to be critical values or ranges only if so expressly stated. Parameters identified as "approximate" or "about" a specified value are intended to include the specified value, values within <NUM>% of the specified value, and values within <NUM>% of the specified value, unless expressly stated otherwise. Further, it is to be understood that the drawings accompanying the present application may, but need not, be to scale, and therefore may be understood as teaching various ratios and proportions evident in the drawings. Moreover, while various aspects, features and concepts may be expressly identified herein as being inventive or forming part of an invention, such identification is not intended to be exclusive, but rather there may be inventive aspects, concepts and features that are fully described herein without being expressly identified as such or as part of a specific invention, the inventions instead being set forth in the appended claims. Descriptions of exemplary methods or processes are not limited to inclusion of all steps as being required in all cases, nor is the order that the steps are presented to be construed as required or necessary unless expressly so stated.

With reference to <FIG>, in a schematically illustrated exemplary embodiment, a poppet type valve assembly <NUM> includes a valve body <NUM> defining a valve passage <NUM> between inlet and outlet ports <NUM>, <NUM>, and an annular valve seat <NUM> extending around an axially extending central portion <NUM> of the valve passage. A poppet <NUM> is assembled with the valve body <NUM> and includes an axially extending poppet stem <NUM> and a radially extending poppet sealing portion <NUM>. An actuator <NUM> is assembled with the poppet stem <NUM> to control axial movement of the poppet <NUM> between a closed position, in which the poppet sealing portion <NUM> seals against the valve seat <NUM> (e.g., to prevent flow above an allowable leak rate), and an open position, in which the poppet sealing portion axially separates from the valve seat to permit fluid flow through the axially extending portion <NUM> of the valve passage <NUM>. The actuator <NUM> may be user operable (e.g., manually, pneumatically, or electrically operable) for selective movement of the poppet <NUM>. Alternatively, the actuator <NUM> may be configured to automatically move or permit movement of the poppet under certain predetermined system conditions. For example, an actuator arrangement may be configured to cause or permit automatic movement of the poppet <NUM> at a threshold system fluid pressure, for example, to relieve excess fluid pressure from a system (in the case of a relief valve), to prevent backflow (in the case of a check valve), or to reduce an outlet pressure (in the case of a pressure regulator). Examples of pressure regulators with poppet type valve arrangements are disclosed in a product catalog titled PRESSURE REGULATORS RHPS SERIES (MS-<NUM>-<NUM>, Rev K, May <NUM>), which is publicly available online and otherwise from Swagelok Company, and is fully incorporated herein by reference.

The seat and poppet sealing surfaces of a valve, such as a regulator valve, are often sensitive to contamination and susceptible to wear, particularly in high cycle applications. According to an exemplary aspect of the present disclosure, a valve may be provided with a poppet and seat subassembly facilitating replacement of the poppet and seat seal while shielding the poppet and seat sealing surfaces from user contact.

<FIG> and <FIG> illustrate an exemplary pressure reducing regulator valve assembly <NUM> including a regulator valve body <NUM> defining a valve passage <NUM> between first end (e.g., inlet) and second end (e.g., outlet) ports <NUM>, <NUM>, and an annular valve seat seal <NUM> disposed in the valve body between the inlet and outlet ports. A poppet <NUM> is assembled with the valve body <NUM> and includes axially extending upper and lower stem portions <NUM>, <NUM> and a radially extending poppet sealing portion <NUM> between the upper and lower stem portions. The poppet <NUM> is axially movable between a lower, open position in which the poppet sealing portion is axially spaced from the seat seal <NUM>, and an upper, closed position in which the poppet sealing portion is in sealing engagement with the seat seal.

According to an exemplary aspect of the present disclosure, the regulator valve assembly <NUM> includes a valve cartridge subassembly <NUM> (as also shown in <FIG>) configured to facilitate removal and replacement of the poppet <NUM> and seat seal <NUM>, for example, to replace worn or damaged sealing surfaces. In the illustrated example, the subassembly <NUM> includes a body plug <NUM> having a tubular side wall <NUM> defining a central cavity <NUM> receiving the sealing portion <NUM> and lower stem portion <NUM> of the poppet <NUM>, and a seat seal retaining seat carrier <NUM> that is assembled with the body plug over the poppet <NUM> to retain the poppet and seat seal <NUM> together as a replaceable cartridge subassembly.

The seat carrier <NUM> includes a male threaded lower end portion <NUM> that is threaded with a female threaded upper end portion <NUM> of the body plug <NUM>, with the lower end portion of the seat carrier engaging an upper counterbore <NUM>-<NUM> in the body plug cavity <NUM>, and an upper stem portion <NUM> of the poppet <NUM> extending into a central bore <NUM> of the seat carrier. The seat seal <NUM> is secured to or retained by (e.g., staked into, integral with) the lower end portion <NUM> of the seat carrier <NUM>, in radial alignment with the poppet sealing portion <NUM>, for engagement with the poppet sealing portion when the poppet <NUM> is in the closed position.

The body plug <NUM> is configured to be installed in a central bore <NUM> in a body housing <NUM> to form the valve body <NUM>. The exemplary body plug <NUM> includes one or more lateral apertures <NUM> in the side wall <NUM> positioned to align with the valve body inlet port <NUM>, and the exemplary seat carrier <NUM> includes one or more lateral apertures <NUM> positioned to align with the valve body outlet port <NUM>, to allow for fluid flow from the inlet port into the body plug cavity <NUM>, and between the poppet sealing portion <NUM> and the valve seat seal <NUM> to the outlet port when the poppet <NUM> is in an open position. The apertures <NUM>, <NUM> may be circumferentially spaced around the body plug <NUM> and seat carrier <NUM>, respectively, for example, to assure at least partial alignment of the inlet and outlet ports <NUM>, <NUM> with at least one of the apertures <NUM>, <NUM>, regardless of the rotational positions of the body plug <NUM> and seat carrier <NUM> in the valve body housing <NUM>. Additionally, the body plug <NUM> may be provided with an annular recess <NUM>-<NUM> intersected by the body plug apertures <NUM>, for example, to provide a fluid flow path between the body plug apertures and the inlet port <NUM>, regardless of any misalignment of the body plug apertures with the inlet port. The seat carrier bore <NUM> may be provided with a tapered internal surface <NUM>-<NUM>, for example, to facilitate expansion of gases flowing through the seat carrier bore.

O-ring/gasket seals <NUM> (and backup rings, not shown) are provided in grooves <NUM> in the body plug <NUM> to provide a leak tight body seal between the inlet port <NUM> and the lower end of the central bore <NUM>, and between the inlet port and the outlet port <NUM>. One or more O-ring/gasket seals <NUM> (and backup rings, not shown) may be provided in grooves <NUM> in the seat carrier <NUM> to provide a leak tight seal between the outlet port <NUM> and the loading mechanism <NUM> (described in greater detail below).

Many different arrangements may be provided for secure installation of the body plug <NUM> in the body housing <NUM>. For example, a male threaded portion <NUM> of the body plug <NUM> may be threaded with a female threaded portion <NUM> of the central bore <NUM>. As shown in the exploded perspective view of <FIG>, an end portion of the body plug <NUM> may be provided with flat surfaces <NUM>-<NUM> for engagement and tightening by a tool (e.g., a torque wrench). Additionally or alternatively, the end portion of the body plug <NUM> may be provided with other tool engagement features, such as holes <NUM>-<NUM> for engagement with a spanner wrench.

Accordingly, in an exemplary method of replacing a poppet <NUM> and seat seal <NUM> in a regulator valve assembly <NUM> (e.g., to replace worn/damaged sealing surfaces), a valve cartridge subassembly <NUM>, including a body plug <NUM> and a seat carrier <NUM> assembled together to retain the poppet <NUM> and seat seal <NUM> therebetween, is removed from the regulator valve body <NUM> by disassembling (e.g., unthreading) the body plug from the regulator valve body housing <NUM>, thereby withdrawing the body plug, seat carrier, poppet, and seat seal from a central bore <NUM> of the regulator valve body housing. A replacement valve cartridge subassembly, which may (but need not) be substantially identical to the removed valve cartridge subassembly, is then assembled with the regulator valve body to install a new poppet <NUM> and seat seal <NUM> in the regulator valve body bore <NUM>.

In other embodiments, a valve cartridge subassembly may include a body plug that is secured with the valve body by a bolted-on arrangement, for example, to reduce the installation torque required during assembly/reassembly. <FIG> and <FIG> illustrate an exemplary pressure reducing regulator valve assembly <NUM> including a regulator valve body <NUM> defining a valve passage <NUM> between first end (e.g., inlet) and second end (e.g., outlet) ports <NUM>, <NUM>, and an annular valve seat seal <NUM> disposed in the valve body between the inlet and outlet ports. A poppet <NUM> is assembled with the valve body <NUM> and includes axially extending upper and lower stem portions <NUM>, <NUM> and a radially extending poppet sealing portion <NUM> between the upper and lower stem portions. The poppet <NUM> is axially movable between a lower, open position in which the poppet sealing portion is axially spaced from the seat seal <NUM>, and an upper, closed position in which the poppet sealing portion is in sealing engagement with the seat seal.

The regulator valve assembly <NUM> includes a valve cartridge subassembly <NUM> (as also shown in <FIG>) configured to facilitate removal and replacement of the poppet <NUM> and seat seal <NUM>, for example, to replace worn or damaged sealing surfaces. In the illustrated example, the subassembly <NUM> includes a body plug <NUM> having a tubular side wall <NUM> defining a central cavity <NUM> receiving the sealing portion <NUM> and lower stem portion <NUM> of the poppet <NUM>, and a seat seal retaining seat carrier <NUM> that is assembled with the body plug over the poppet <NUM> to retain the poppet and seat seal <NUM> together as a replaceable cartridge subassembly <NUM>.

The seat carrier <NUM> includes a male threaded lower end portion <NUM> that is threaded with a female threaded upper end portion <NUM> of the body plug <NUM>. In the illustrated embodiment, the seat carrier <NUM> is provided with an extension or gland <NUM> seated against a lower end portion of the seat carrier, and engaging a first upper counterbore <NUM>-<NUM> in the body plug cavity <NUM>. By providing the seat carrier as a two component configuration, surface features of the seat carrier (e.g., the tapered internal surface <NUM>-<NUM>, described below) may be more easily manufactured. An upper stem portion <NUM> of the poppet <NUM> extends into a central bore <NUM> of the seat carrier <NUM>. While the seat seal may be staked with the seat carrier or seat carrier gland, in the illustrated embodiment, the seat seal <NUM> is provided as a separate sealing ring, secured between the seat carrier gland <NUM> and a second upper counterbore <NUM>-<NUM> in the body plug cavity, for engagement with the poppet sealing portion when the poppet <NUM> is in the closed position. As shown, the seat seal <NUM> may be provided with grooves retaining gasket/O-ring seals for sealing engagement with the seat carrier gland <NUM> and second upper counterbore <NUM>-<NUM>.

While many different types of sealing rings may be used, in the illustrated embodiment, the sealing ring <NUM> may be provided as an over-molded, overlaid, or otherwise interlocking annular softer material (e.g., having a hardness less than about <NUM> HRM) seal ring that is secured to or retained on (e.g., press fit, assembled over, injection molded or over-molded onto, or 3D printed onto) a harder (e.g., a hardness greater than about <NUM> HRB) inner circumferential rib, flange, rail, or other such projection protruding into the central portion of the valve passage. The rigid underlying projection allows for the use of a relatively thin (e.g., between about <NUM> and about <NUM> inches) seal ring, thereby minimizing thermal expansion, material flow, and deformation of the softer seal ring material, while providing rigid support to facilitate use in higher pressure (e.g., up to about <NUM> psi) applications. Any suitable materials may be used to provide adequate sealing performance within the valve. For example, the seal ring may be provided in suitable plastic (e.g., PEEK), and the seal ring retaining projection may be provided in a metal (e.g., stainless steel). The gasket / O-ring seals may be formed from a suitable elastomer (e.g., ethylene propylene diene monomer (EPDM), perfluoro-elastomer, or nitrile). Exemplary seat sealing rings having interlocking seal portions are described in co-pending <CIT>, entitled POPPET-STYLE VALVE ARRANGEMENTS, the entire disclosure of which is incorporated herein by reference.

The body plug <NUM> is configured to be installed in a central bore <NUM> in a body housing <NUM> to form the valve body <NUM>. The exemplary body plug <NUM> includes one or more lateral apertures <NUM> in the side wall <NUM> positioned to align with the valve body inlet port <NUM>, and the exemplary seat carrier <NUM> includes one or more lateral apertures <NUM> positioned to align with the valve body outlet port <NUM>, to allow for fluid flow from the inlet port <NUM> into the body plug cavity <NUM>, and between the poppet sealing portion <NUM> and the valve seat seal <NUM> to the outlet port <NUM> when the poppet <NUM> is in an open position. The apertures <NUM>, <NUM> may be circumferentially spaced around the body plug <NUM> and seat carrier <NUM>, respectively, for example, to assure at least partial alignment of the inlet and outlet ports <NUM>, <NUM> with at least one of the apertures <NUM>, <NUM>, regardless of the rotational positions of the body plug <NUM> and seat carrier <NUM> in the valve body housing <NUM>. Additionally, the body plug <NUM> may be provided with an annular recess <NUM>-<NUM> intersected by the body plug apertures <NUM>, for example, to provide a fluid flow path between the body plug apertures and the inlet port <NUM>, regardless of any misalignment of the body plug apertures with the inlet port.

O-ring/gasket seals (e.g., gaskets and backup rings) <NUM> are provided in grooves <NUM> in the body plug <NUM> to provide a leak tight body seal between the inlet port <NUM> and the lower end of the central bore <NUM>, and between the inlet port and the outlet port <NUM>. One or more O-ring/gasket seals (e.g., with backup rings) <NUM> may be provided in grooves <NUM> in the seat carrier <NUM> to provide a leak tight seal between the outlet port <NUM> and the loading mechanism <NUM> (described in greater detail below).

Many different arrangements may be provided for secure installation of the body plug <NUM> in the body housing <NUM>. In the illustrated embodiment, a mounting plate <NUM> is secured to a lower end of the body plug <NUM>, for example, by mounting bolts <NUM>, to secure the body plug to the body housing <NUM> when the tubular side wall <NUM> is axially inserted into the body housing bore <NUM>. In other embodiments, the mounting plate may be integrally formed with, welded to, or otherwise affixed to the body plug. As shown in <FIG>, the mounting plate <NUM> includes a ring of mounting holes <NUM>-<NUM> that align with body housing mounting holes <NUM>-<NUM> to receive mounting bolts <NUM> for securing the body plug <NUM>, when inserted in the body housing bore <NUM>, to the valve body housing <NUM>. The mounting holes <NUM>-<NUM> may be evenly spaced around the mounting plate <NUM> to allow for attachment of the mounting plate to the valve body housing <NUM> in multiple orientations. Alternatively, the mounting plate and body housing mounting holes <NUM>-<NUM>, <NUM>-<NUM> may be arranged to ensure mounting in a single orientation.

In an exemplary method of replacing a poppet <NUM> and seat seal <NUM> in a regulator valve assembly <NUM> (e.g., to replace worn/damaged sealing surfaces), a valve cartridge subassembly <NUM>, including a body plug <NUM> and a seat carrier <NUM> assembled together to retain the poppet <NUM> and seat seal <NUM> therebetween, is removed from the regulator valve body <NUM> by removing mounting bolts <NUM> from the mounting plate and body housing mounting holes <NUM>-<NUM>, <NUM>-<NUM> and withdrawing the body plug, seat carrier, poppet, and seat seal from the central bore <NUM> of the regulator valve body housing <NUM>. A replacement valve cartridge subassembly <NUM>, which may (but need not) be substantially identical to the removed valve cartridge subassembly, is then assembled with the regulator valve body housing <NUM> by axially inserting the tubular end portion <NUM> of the body plug <NUM> into the body housing bore <NUM>. As shown, the upper or leading end portions of the seat carrier <NUM> and the body plug <NUM> may be provided with tapered or chamfered surfaces <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, for example, to facilitate alignment and insertion of the seat carrier and body plug. The body plug <NUM> is then secured by mounting bolts <NUM> installed through aligned mounting holes <NUM>-<NUM>, <NUM>-<NUM> in the mounting plate <NUM> and body housing <NUM>, to secure the new poppet <NUM> and seat seal <NUM> in the regulator valve body bore <NUM>.

A regulator valve assembly may include a sensing element (e.g., diaphragm, piston) upon which fluid pressure (e.g., pressurized fluid in the outlet port of a pressure-reducing regulator) may act against a load force applied by a loading mechanism (e.g., biasing spring, pressurized "dome" chamber) to move the sensing mechanism when the fluid pressure exceeds a pressure setting, for movement of the poppet. While a poppet in a poppet and seat cartridge subassembly may extend beyond the seat carrier for engagement with an external sensing element, in the illustrated embodiments, a piston sensing element <NUM>, <NUM> is assembled with the central bore <NUM>, <NUM> of the seat carrier <NUM>, <NUM>, stacked above the upper stem portion <NUM>, <NUM> of the poppet <NUM>, <NUM>. One or more O-ring/gasket seals (e.g., with backup rings) <NUM>, <NUM> may be provided in grooves <NUM>, <NUM> in the piston <NUM>, <NUM> to seal with the seat carrier bore <NUM>, <NUM>, to provide a leak tight seal between the outlet port <NUM>, <NUM> and the loading mechanism <NUM>, <NUM>. The piston <NUM>, <NUM> may be provided with a shoulder portion <NUM>, <NUM> that engages a counterbore <NUM>, <NUM> in the seat carrier <NUM>, <NUM> to retain the piston <NUM>, <NUM> with the valve cartridge subassembly <NUM>, <NUM>.

The loading mechanism (e.g., a fluid pressurized chamber or dome loading mechanism <NUM>, <NUM>, as shown) applies a downward force to the poppet <NUM>, <NUM> through the piston <NUM>, <NUM>, to bias the poppet toward the open position. The outlet port <NUM>, <NUM> is in fluid communication with the piston <NUM>, <NUM>, such that pressurized fluid in the outlet port applies an upward force against the piston. In such an arrangement, when the outlet port pressure exceeds a set pressure, the upward fluid pressure force against the piston <NUM>, <NUM> exceeds the downward loading mechanism force, causing the piston to move upward, thereby allowing the poppet <NUM>, <NUM> to move to the closed position.

As shown, the poppet <NUM>, <NUM> may be provided with an internal passage <NUM>, <NUM> extending from the lower stem portion <NUM>, <NUM> of the poppet to an upper portion of the poppet downstream of (i.e., above) the seat seal <NUM>, <NUM> with a gasket seal <NUM>, <NUM> (in groove <NUM>, <NUM>) providing a seal between the poppet lower stem portion and a narrower base portion <NUM>-<NUM>, <NUM>-<NUM> of the body plug cavity <NUM>, <NUM>, such that when the poppet <NUM>, <NUM> is in the closed position, the inlet or upstream fluid pressure on the poppet is offset by the outlet or downstream fluid pressure. This arrangement may be referred to as a balanced poppet design, which may, for example, provide for reduced seat load, for example, to reduce wear/deformation of the seat. In such an arrangement, a poppet spring <NUM>, <NUM> may be provided in the body plug cavity <NUM>, <NUM>, compressed between a lower counterbore <NUM>-<NUM>, <NUM>-<NUM> and the poppet <NUM>, <NUM> (e.g., at shoulder <NUM>, <NUM>) to provide a consistent closing/sealing force against the poppet, independent of system fluid pressure.

To assemble the exemplary valve subassembly <NUM> of <FIG>, <FIG>, and <FIG>, the poppet <NUM> and poppet spring <NUM> are inserted into the central cavity <NUM> of the body plug <NUM> with the lower stem portion <NUM> of the poppet received in the narrower base portion <NUM>-<NUM> of the body plug cavity <NUM>, and the poppet spring engaging the lower counterbore <NUM>-<NUM> of the body plug cavity. The piston <NUM> is installed through the central bore <NUM> of the seat carrier <NUM>, from the bottom end, with the lower shoulder portion <NUM> of the piston engaging the counterbore <NUM> in the seat carrier. The seat carrier <NUM>, with the staked seat seal <NUM>, is threadably assembled with the body plug <NUM>, with the lower end portion <NUM> of the seat carrier engaging the upper counterbore <NUM>-<NUM> in the body plug cavity <NUM>.

To assemble the exemplary valve subassembly <NUM> of <FIG>, <FIG>, and <FIG>, the poppet <NUM> and poppet spring <NUM> (secured with the poppet <NUM> using retaining ring <NUM>) are inserted into the central cavity <NUM> of the body plug <NUM> with the lower stem portion <NUM> of the poppet received in the narrower base portion <NUM>-<NUM> of the body plug cavity <NUM>, and the poppet spring engaging the lower counterbore <NUM>-<NUM> of the body plug cavity. The piston <NUM> is installed through the central bore <NUM> of the seat carrier <NUM>, from the bottom end, with the lower shoulder portion <NUM> of the piston engaging the counterbore <NUM> in the seat carrier. The seat seal assembly <NUM> and seat carrier gland <NUM> are inserted in the body plug counterbores <NUM>-<NUM>, <NUM>-<NUM>, and the seat carrier <NUM> is threadably assembled with the body plug <NUM>, such that the seat seal assembly is sealingly secured between the seat carrier extension and the second upper body plug counterbore <NUM>-<NUM>.

Many different types of loading mechanisms may be utilized to apply a selected downward biasing force against the sensing element. In the illustrated examples, a piston sensing dome loading arrangement <NUM>, <NUM> includes upper and lower dome housing shell members <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM> (secured together, for example, by bolts <NUM>, <NUM>) assembled with the valve body housing <NUM>, <NUM> (e.g., by mounting screws, <NUM>, <NUM>) to define a dome chamber <NUM>, <NUM>, and a dome loading diaphragm <NUM>, <NUM> having an outer periphery captured between the upper and lower shell members, with a diaphragm screw <NUM>, <NUM> installed through a central opening in the dome loading diaphragm and positioned to engage the upper end portion <NUM>, <NUM> of the piston <NUM>, <NUM>. In the illustrated examples, support plates <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM> are secured to the diaphragm screw <NUM>, <NUM> above and below the dome loading diaphragm <NUM>, <NUM> by a nut <NUM>, <NUM>, to provide additional support for the diaphragm. The upper dome housing shell member <NUM>-<NUM>, <NUM>-<NUM> includes a pressurization port <NUM>, <NUM> (e.g., defined by welded end cap <NUM>-<NUM>, <NUM>-<NUM>) for supplying a pressurized fluid at a set pressure (e.g., from a secondary pressure regulator) to the dome chamber <NUM>, <NUM>, to apply a corresponding load force against the dome loading diaphragm <NUM>, <NUM> to move the diaphragm screw <NUM>, <NUM> against the piston <NUM>, <NUM>. In another exemplary embodiment, an actuator arrangement may include a compressed spring that applies a downward biasing force (directly or indirectly) to the diaphragm. In one such embodiment, compression of the spring may be adjustable to increase or decrease the downward biasing force exerted by the spring. For example, a spring guide engaging the upper end of the spring may be lowered or raised (e.g., by a rotatable knob or handle) to increase or reduce the compression of the spring. Exemplary dome pressurized and spring loading arrangements are described in the above incorporated PRESSURE REGULATORS RHPS SERIES catalog. Other types of sensing mechanisms may also be used instead of the exemplary piston, such as, for example, diaphragm elements or piston elements external to the valve subassembly, as described in the above incorporated PRESSURE REGULATORS RHPS SERIES catalog.

Claim 1:
A valve subassembly (<NUM>, <NUM>) comprising:
a body plug (<NUM>, <NUM>) including a tubular side wall (<NUM>, <NUM>) defining a central cavity (<NUM>, <NUM>) and one or more lateral flow apertures (<NUM>, <NUM>) in the side wall;
a poppet (<NUM>, <NUM>) including axially extending upper and lower stem portions (<NUM>, <NUM>; <NUM>, <NUM>) and a radially extending poppet sealing portion (<NUM>, <NUM>) between the upper and lower stem portions, with the lower stem portion and the poppet sealing portion being received in the central cavity of the body plug;
a seat carrier (<NUM>, <NUM>) including a central bore (<NUM>, <NUM>) receiving the upper stem portion of the poppet therethrough, the seat carrier retaining a seat seal (<NUM>, <NUM>) in radial alignment with the poppet sealing portion; and
a piston (<NUM>, <NUM>) assembled with the central bore of the seat carrier and including a lower end portion engaging the upper stem portion of the poppet and an upper end portion extending above the seat carrier;
wherein the seat carrier is assembled with the body plug to retain the poppet, the seat seal, and the piston together with the seat carrier and the body plug as a replaceable cartridge subassembly.