Valve plug assembly for pressure regulator

A valve plug adapted for sealing engagement with a seat ring. The valve plug includes a cylindrical body with an annular flange having a groove. A pair of bores is disposed in the body, each bore having a first diameter, a first end, and a second end disposed within the body. Each bore is also adapted to receive a fastener to couple the valve plug to a mounting portion, and a recess is disposed at the second end of the bore, forming a stepped portion. The recess is adapted to receive at least one of a portion of a retainer or a portion of the fastener. A sealing disk is disposed within the groove of the annular flange and is one of a machined sealing disk or a molded sealing disk.

FIELD OF THE DISCLOSURE

The present disclosure generally relates to fluid control devices and, more particularly, to valve plug assembly for a fluid control device.

BACKGROUND

Fluid control devices include various categories of equipment with control valves and regulators. Such control devices are adapted to be coupled within a fluid process control system such as chemical treatment systems, natural gas delivery systems, etc., for controlling the flow of a fluid therethrough. Each control device includes a body defining a fluid flow-path and a control member assembly for adjusting a dimension of the flow-path. A seat ring is disposed within a throat of the valve body.

The control member assembly typically includes a valve plug assembly having a sealing disk with a sealing surface. When the outlet pressure of the valve body is high, a sealing surface of the sealing disk may sealingly engage the seat ring and close the throat. This prevents the flow of fluid through the regulator. In one example, the sealing disk may be a machined sealing disk used with the regulator, and in another example, the sealing disk may be a molded sealing disk.

More specifically,FIG. 1depicts one known valve plug assembly10. In this example, the valve plug assembly10is attached to a mounting member, such as a disk holder12or a sleeve adapter, for example, which is coupled to a sleeve14. The valve plug assembly10includes a machined, polyurethane sealing disk16with a sealing surface17. The machined sealing disk16is coupled to the disk holder12by a retainer18. Screws20and washers22secure the retainer18and the sealing disk16to the disk holder12, for example, but other fasteners may alternatively be used.

FIG. 2depicts another known valve plug assembly100. In this example, the valve plug assembly100is again attached to a mounting member, such as a disk holder112, or sleeve adapter, which is coupled to a sleeve114. The valve plug assembly100includes a molded nitrile rubber, such as NBR, sealing disk116having a sealing surface117. The molded sealing disk116is coupled to a retainer130having a different geometric configuration than the retainer18ofFIG. 1, for example. Screws132and washers134again secure the retainer130and the sealing disk116to the disk holder112, but other fasteners may again be used. In this example, a seat ring136is depicted, which is adapted to be in contact with the sealing surface117of the sealing disk116.

As described, the machined sealing disk16depicted inFIG. 1and the molded sealing disk116ofFIG. 2require different retainers18,130be used to secure the sealing disks16,116, respectively, to the disk holders12,112, for example. In addition, while screws20,132and nuts22,134are both used to secure the retainers18,130to the disk holders12,112, often the retainers18,130require a different number and kind of screws20,132and/or nuts22,134. Such variations in the retainers18,130and corresponding screws20,132and nuts22,134used for each of the machined sealing disk16and the molded sealing disk116, respectively, makes service of such disks16,116more complicated. Said another way, servicing the sealing disks16,116requires a user to know whether the valve plug assembly10,100includes the machined sealing disk16or the molder sealing disk116so that a required corresponding retainer and screws and nuts are used, for example.

In addition, and as depicted inFIG. 1, an additional o-ring24or similar sealing mechanism is required to be disposed adjacent to the machined sealing disk16between the retainer18and the disk holder12. This additional o-ring24used with the machined sealing disk16is not required or needed with the molded sealing disk116depicted inFIG. 2, for example. Thus, a user replacing or servicing the machined sealing disk16would need to make sure an additional and proper o-ring24or similar sealing mechanism was also included during installation and/or after replacing, repairing and/or servicing the sealing disk16, for example.

SUMMARY OF THE DISCLOSURE

One aspect of the present disclosure includes a valve plug adapted for sealing engagement with a seat ring. The valve plug comprises a cylindrical body with an annular flange radially extending from the body and having a groove. A pair of bores is disposed one or more of on or in the body, each bore having a first diameter, a first end adapted to be in contact with a mounting portion, and a second end disposed within the body. In addition, each bore is adapted to receive a fastener to couple the valve plug to the mounting portion. A recess is disposed at the second end of each bore, and each recess has a second diameter larger than the first diameter of the bore to form a stepped portion at the second end of each bore. The recess is adapted to receive at least one of a portion of a retainer or a portion of the fastener. A sealing disk is disposed within the groove of the annular flange. The sealing disk is one of a machined sealing disk that is machined into the groove or a molded sealing disk that is molded to the groove and has a sealing surface adapted to engage a seating surface of the seat ring. So configured, when the sealing disk is the machined sealing disk, the recess receives a portion of a retainer, and when the sealing disk is the molded sealing disk, the recess receives a portion of the fastener. In this way, the same valve plug and one or more fasteners are interchangeably used with both the machined sealing disk and the molded sealing disk.

According to another aspect of the present disclosure, a fluid control device, comprises a valve body defining a flow path for a fluid, a seat ring disposed within the flow path; and an actuator coupled to the valve body. The actuator includes a control assembly adapted for displacement relative to the seat ring for regulating a flow of the fluid through the flow-path. The control assembly includes a mounting portion and a valve plug coupled to the mounting portion and adapted to sealingly engage the seat ring. The valve plug comprises a cylindrical body and an annular flange radially extending from the cylindrical body, the annular flange having a groove. In addition, the valve plug includes a pair of bores disposed in the cylindrical body, each bore having a first diameter, a first end in contact with the mounting portion, and a second end disposed within the cylindrical body. Further, each bore is adapted to receive a fastener to couple the valve plug to the mounting portion. A recess is disposed at the second end of each bore, and each recess has a second diameter larger than the first diameter of the bore to form a stepped portion at the second end of each bore. Further, the recess is adapted to receive at least one of a portion of a retainer or a portion of the fastener. In addition, a sealing disk is disposed within the groove of the annular flange. The sealing disk is one of a machined sealing disk that is machined into the groove or a molded sealing disk that is molded to the groove and has a sealing surface adapted to engage a seating surface of the seat ring.

In further accordance with any one or more of the foregoing first and second aspects, the valve plug may include any one or more of the following forms.

According to one aspect, the sealing disk may comprise polyurethane at least in part, and the valve plug may comprise a metal material. In addition, the sealing disk may comprise the machined sealing disk, and further include a gasket disposed within the groove between the flange and the machined sealing disk.

According to another aspect, the flange may include a top surface adapted to contact the disk holder and a bottom surface, and the groove may extend into the bottom surface of the flange. In addition, the body may include a top surface and a bottom surface, the first end of each bore at the top surface of the body, and the second end of each bore disposed within the body a distance from the bottom surface of the body.

In yet another aspect, the recess may be a screw head recess adapted to receive a screw head of the fastener. In addition, the screw head of the fastener may be moved out of a flow path to improve stability of a regulator.

In still another aspect, the sealing disk may include the molded sealing disk, and the fastener may then couple the valve plug to the mounting portion without a retainer. When the sealing disk is the molded sealing disk, the molded sealing disk may comprise a nitrile material at least in part, and the valve plug may comprise a metal material.

In another aspect, the distance between each bore in the valve plug may be the same. Said another way, each bore in the valve plug may be equidistant from the other bore.

In addition, the when the sealing disk is the machined sealing disk, the control device may further comprise a retainer in contact with the valve plug to secure the valve plug to the mounting portion. A portion of the retainer may be disposed within the recess of the valve plug, and a screw head of the fastener may be disposed within the retainer. Further, the retainer may also include a portion in contact with the sealing surface of the valve plug.

In yet another aspect, when the sealing disk is the machined sealing disk, the recess may receive a portion of a retainer, and when the sealing disk is the molded sealing disk, the recess may receive a portion of the fastener, such that the same valve plug and one or more fasteners are interchangeably used with both the machined sealing disk and the molded sealing disk.

DETAILED DESCRIPTION OF THE DISCLOSURE

A valve plug adapted for sealing engagement with a seat ring is disclosed. The valve plug includes a cylindrical body and an annular flange extending from the body, the annular flange having a groove. A pair of bores is disposed in the cylindrical body, each bore having a first end adapted to be in contact with a mounting portion, a second end disposed within the body, and adapted to receive a fastener to couple the valve plug to the mounting portion. A recess is disposed at the second end of each bore and is adapted to receive at least one of a portion of a retainer or a portion of the fastener. A sealing disk is disposed within the groove of the annular flange, the sealing disk one of a machined sealing disk or a molded sealing disk, the sealing disk having a sealing surface adapted to engage a seating surface of the seat ring. When the sealing disk is a machine sealing disk, the recess receives a portion of a retainer, and when the sealing disk is a molded sealing disk, the recess receives a portion of the fastener, such that the same valve plug and one or more fasteners are interchangeably used with both the machined sealing disk and the molded sealing disk, requiring fewer parts for installation and service of the valve plug.

Referring now toFIG. 3, a fluid flow control device or regulator assembly200including a valve plug assembly210of the present disclosure is depicted. The regulator assembly includes a valve body212and an actuator214. The valve body212defines a flow-path216and includes a throat218. InFIG. 3, the regulator assembly200is configured in a flow-up configuration. The actuator214includes an upper actuator casing220, a lower actuator casing222, and a control member assembly224. The control member assembly224is disposed within the upper and lower actuator casings220,222and is adapted for bi-directional displacement in response to changes in pressure across the regulator assembly200. So configured, the control member assembly224controls the flow of fluid through the throat218. Additionally, as is depicted, the regulator assembly200includes a seat ring226(depicted in part) disposed in the throat218of the valve body212. When the outlet pressure of the valve body212is high, a sealing surface of the control member assembly224may sealingly engage the seat ring226and close the throat218, as described more below, to prevent the flow of fluid through the regulator200.

The seat ring226depicted inFIG. 3further includes a partially rounded or tapered surface227. The rounded or tapered surface227serves to streamline the flow of the fluid through an orifice229. As fluid flows through the valve body212, it flows from the left of the valve body212, as depicted inFIG. 3and up through the throat218via the orifice229in the seat ring226. Then, the fluid deflects off a lower surface of the control member224, and out to the right of the valve body212ofFIG. 3.

Generally, the control member assembly224is adapted to be engaged by a seating surface230(FIGS. 4 and 5) of the seat ring226when the control member assembly224is in a closed position (not depicted), preventing the fluid from flowing through the valve body212. More specifically, the control member assembly224further includes a tubular member232, a mounting subassembly234, and the valve plug assembly210, e.g., disk holder assembly. The tubular member232includes an upper end232aand a lower end232b. The lower end232bis open and accommodates the mounting subassembly234. The valve plug assembly210is coupled to the mounting subassembly234, for example, as generally depicted inFIG. 3.

Referring now toFIG. 4, the valve plug assembly210includes a valve plug240or a disk holder having a machined sealing disk, as explained more below. The valve plug240includes a generally cylindrical body242having a center portion244and an annular flange246radially extending from the body242. The annular flange246includes a bottom portion248, such as a bottom surface, and an annular groove250disposed in the bottom portion248. At least one bore252, and in one example, a pair of bores252is disposed in the body242of the valve plug240. The pair of bores252includes a bore252disposed on either side of the center portion244of the body, and each bore252is equidistant from the other bore252, as depicted inFIG. 4. The bore252also includes a first diameter D1, a first end254adapted to be in contact with a mounting portion256of the mounting assembly234(FIG. 3), and a second end258disposed within the body242. The bore252is adapted to receive a fastener259to couple the valve plug240to the mounting portion256, for example. In one example, the fastener259is a threaded fastener or threaded screw and in another example the fastener is a nail or stud. One of ordinary skill in the art will appreciate that various other fasteners may alternatively be used and still fall within the scope of the present disclosure.

The valve plug240further includes a recess260disposed at the second end258of the bore252. The recess260includes a second diameter D2larger than the first diameter D1of the bore252to form a stepped portion262at the end258of the bore252. In this example, the recess260is adapted to receive a portion264of a retainer266.

More specifically, the retainer266includes at least one bore267that is axially aligned with the bore252of the valve plug240. In addition, the at least one bore267of the retainer266has a diameter that is substantially identical to the diameter D1of the bore252of the valve plug240. Further, the retainer266also includes at least one recess269disposed at one end of the at least one bore267of the retainer266. The recess269has a diameter that is substantially identical to the diameter D2of the recess260of the valve plug240. In this way, the bore267of the retainer266also receives a portion of the fastener259, and the recess269of the retainer266receives a screw head261of the fastener259, for example. In one example, the recess269of the retainer266is a screw head recess. One of ordinary skill in the art will appreciate that the at least one bore267of the retainer266may include a pair of bores267or a plurality of bores267, wherein each bore267of the retainer266is axially aligned with each bore252of the valve plug240, for example, and still fall within the scope of the present disclosure. Further, one of ordinary skill in the art will also appreciate that the at least one recess269may include a pair of recesses269disposed at the ends of the each bore267of a pair of bores267and also still fall within the scope of the present disclosure.

Still referring toFIG. 4, the valve plug240further includes a sealing disk268disposed within the groove250of the annular flange248. In this example, the sealing disk268is a machined sealing disk that is machined into the groove250and includes a sealing surface270adapted to engage the seating surface230of the seat ring226. In this example, the machined sealing disk268comprises polyurethane at least in part, and the valve plug240comprises a metal material.

In another example, the valve plug240may further include a gasket272disposed in the groove250between the sealing disk268and the annular flange246. The gasket272prevents high pressure and air from getting behind the sealing disk268in high pressure applications of the regulator assembly200, which causes moderate to severe unwanted vibrations of the valve plug240. As a result, the gasket272significantly reduces, if not eliminates, any unwanted vibrations due to high pressure and/or air behind the sealing disk268during operation of the regulator assembly200.

As further depicted inFIG. 4, the body242of the valve plug240further includes a top surface274and a bottom surface276. The first end254of the bore252is disposed at the top surface274of the body242. The second end258of the bore252is disposed within the body242a distance from the bottom surface276of the body242.

Referring now toFIG. 5, the valve plug assembly210is again depicted, the valve plug assembly210having the valve plug240(or disk holder, for example), but instead of the machined sealing disk268(FIG. 4), a molded sealing disk280is included within the valve plug240. Because the valve plug240ofFIG. 5is essentially the same as the valve plug240of FIG.4, parts of the valve plug240ofFIG. 4identical to the valve plug240ofFIG. 5share the same reference numerals and are mostly explained above relative toFIG. 4, for the sake of brevity.

As depicted inFIG. 5, the valve plug240includes the cylindrical body242with the center portion244and the annular flange246radially extending from the body242. The annular groove250is disposed in the bottom portion248of the annular flange246and receives the molded sealing disk280. The dimensions of the valve plug240, such as the diameter and the length of the groove250in the annular flange246of the body242, fit both the machined sealing disk268depicted inFIG. 4and the molded sealing disk280ofFIG. 5. This interchangeability of types of sealing disks268,280able to be used with the valve plug240of the present disclosure, for example, allows fewer parts to be used in servicing the valve plug240of the actuator assembly ofFIG. 3, as explained more below.

Still referring toFIG. 5, the bores252disposed in the body242of the valve plug240include the first end254adapted to be in contact with the mounting portion256of the mounting assembly234(FIG. 3), and the second end258disposed within the body242. The bore252is again adapted to receive the fastener259, as described above, to again couple the valve plug240to the mounting portion256, for example.

The recess260disposed at the second end258of the bore252has the second diameter D2larger than the first diameter D1of the bore252to form the stepped portion262at the second end258of the bore252. In this example, however, the recess260is adapted to receive a screw head261of the fastener259, as depicted inFIG. 5. More specifically, in this example, the recess260is a screw head recess that receives the screw head261of the fastener259, such that the screw head261is moved out of the flow path216(FIG. 3), improving the stability of the regulator assembly200. So configured, in this example, no retainer266is required to secure the valve plug240to the mounting portion256, for example, as required for the machined sealing disk268ofFIG. 4. Said another way, the fastener260and screw head261, the screw head261fitting directly into the recess260of the valve plug240, couple the valve plug240having the molded sealing disk280to the mounting portion256without any need for a retainer.

While two bores252are depicted inFIGS. 4 and 5, one of ordinary skill in the art will appreciate that only one bore252and recess260or more than two bores252and associated recesses260may alternatively be used and still fall within the scope of the present disclosure. Likewise, each bore252and recess260will include corresponding fasteners260and screw heads261.

One of ordinary skill in the art will also appreciate that both the machined sealing disk268and the molded sealing disk280include a generally ring-shaped disk made of resilient material, such as polyurethane or nitrile rubber, as described above relative to the machined sealing disk268and the molded sealing disk280, respectively. In one example, the machined sealing disk268may be fixed or bonded to the valve plug240with an adhesive.

One of ordinary skill in the art will further appreciate the various advantages of the valve plug240of the present disclosure. For example, using fewer parts than conventional designs, the new valve plug240described above allows both the machined sealing disk268and the molded sealing disk280to use the same valve plug240and fasteners259. As a result, installation and service of the valve plug240(and fluid control device) is more efficient and easier to manage than conventional valve plugs, one of which was required for machined sealing disks and another, different valve plug and associated parts were required for molded sealing disks. In addition, both the retainer266and valve plug240include the recesses260,261for receiving a screw head of the fastener259, for example. So configured, whether the sealing disk is the machined sealing disk268or the molded sealing disk280, both recesses260,261move the screw head of each fastener259out of the flow path216(FIG. 3) to improve stability of the regulator.

In light of the foregoing, the description of the present disclosure should be understood as merely providing examples of the present invention and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention.

As used herein any reference to “one example” or “an example” means that a particular element, feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of the phrase “in one example” in various places in the specification are not necessarily all referring to the same example.

This detailed description is to be construed as examples and does not describe every possible embodiment, as describing every possible embodiment would be impractical, if not impossible. One could implement numerous alternate embodiments, using either current technology or technology developed after the filing date of this application.

While various embodiments have been described herein, it is understood that the appended claims are not intended to be limited thereto, and may include variations that are still within the literal or equivalent scope of the claims.