CN107002903B - Combined diaphragm piston actuator - Google Patents

Abstract

An apparatus for actuating a valve includes an actuator having a cap. A plate that engages an inner diameter of the actuator housing is positioned within the actuator housing. A pressure chamber is located within the actuator housing between the plate and the cover. The cap seal fluidly seals the pressure chamber between the cap and the actuator housing. The pressure chamber is fluidly sealed at the plate by one of a first plate seal assembly and a second plate seal assembly. The first plate seal assembly is formed by a diaphragm secured between a seal nut and a plate. The second plate seal assembly is formed by an outer diameter sidewall seal located between the inner diameter of the actuator housing and the outer diameter of the plate and a retaining seal located between the outer diameter of the seal nut and the inner diameter of the plate.

Description

Combined diaphragm piston actuator

Cross Reference to Related Applications

This application claims priority and benefit from co-pending U.S. provisional application No. 62/049539 entitled "Non Tension Diaphragm" filed on 12/9/2014, the entire disclosure of which is hereby incorporated by reference.

This application is also a continuation of, and claims priority and benefit from, the following applications: U.S. patent application No.13/679,553 entitled "Combination Diaphragm photoston activator", filed 11/16/2012, now U.S. patent No. 8,998,166; U.S. patent application No. 14/107,589 entitled "Non-Rising Stem activator," now U.S. patent No. 8,991,420, claiming priority and benefit of U.S. provisional patent application No. 61/747,753, filed 12/31/2012; and U.S. patent application No. 13/832,884 entitled "Quick Connect Valve activator," which claims priority and benefit of U.S. provisional patent application No. 61/747,479 entitled "Quick Connect Valve activator" filed on 31/12/2012; the complete disclosure of each application is incorporated herein by reference.

Technical Field

The present disclosure relates generally to valves for mineral recovery wells, and in particular to actuators for actuating valves.

Background

A gate valve is a valve having a body and a bore through the body. The gate is positioned transverse to the body and moves linearly to block or allow flow through the aperture. Some gates have apertures aligned with the holes to allow flow. The gate may be normally open, and thus the gate closes when linearly moved to push the aperture out of alignment with the aperture. Alternatively, the gate may be normally closed, and thus the gate opens when moved linearly to position the aperture in alignment with the hole. Regardless of whether the gate is normally open or normally closed, the gate is moved or actuated by a valve actuator.

the actuator may be a hydraulic, piston-type actuator, or the actuator may be a pneumatic piston or diaphragm-type actuator. In conventional diaphragm-type actuators, the diaphragm moves in response to a pressure medium (such as a gas or other fluid) pushing the diaphragm toward the gate valve. The membrane is supported by a support plate. As applicable, when the diaphragm is pushed down with a pressure medium, the diaphragm pushes the support plate down, which in turn transmits a downward force via the rod to the gate of the gate valve to open or close the gate valve.

In some prior diaphragm actuators, the outer diameter of the diaphragm support plate does not extend to the inner diameter of the housing in which the diaphragm is positioned, such that a portion of the diaphragm is suspended over the edge of the support plate and thus is not supported. As will be appreciated by those skilled in the art, unsupported areas of the diaphragm are more susceptible to failure and require a thick and reinforced diaphragm to be able to withstand the forces exerted by the pressure medium.

In some actuators, the indicator stem protrudes through a cover of the housing of a typical valve actuator. The indicator stem is part of a gland nut assembly that extends upwardly from a plate within the valve actuator housing or is threaded onto the top surface of the plate. The indicator stem seal nut sealingly engages the aperture of the plate. Leakage may occur between the indicator stem seal nut and the plate. In pneumatic type actuators having a diaphragm, the gland nut must be removed to replace the diaphragm.

In some cases, the actuator may be manually actuated by pressing against the indicator stem. However, the force on the rod can damage the rod or internal components of the actuator. It is desirable to be able to actuate the valve from the outside without exerting forces on the stem that could damage the actuator. It is also desirable to be able to remove and replace the stem without breaking the seal between the seal nut and the plate or diaphragm.

Disclosure of Invention

this application discloses embodiments of a valve actuator that may alternatively be configured for use as a diaphragm actuator, a piston actuator, or a dual or combined diaphragm and piston actuator. In various embodiments, the actuator includes modular components that may be used in one or more modes of use of the actuator; it may be interchanged with components of different sizes or configurations; and/or it may interface with components of different sizes or configurations. Embodiments herein provide significant performance, manufacturing, assembly, cost, and other benefits, such as those described below.

More specifically, in an embodiment, the valve actuator is a pneumatic valve actuator that can be used to actuate a valve (such as a gate valve). The valve actuator may be configured to use a diaphragm; or piston pressure; or both diaphragm and piston pressures. Embodiments herein allow for the manufacture of a universal actuator part that can be used in a variety of pneumatic actuator applications. In addition, embodiments provide the operator with the flexibility to use a diaphragm, piston, or dual seal actuator to actuate the valve.

Alternative systems and methods of this present disclosure provide a lifter-free diaphragm or piston actuator. Such embodiments do not have a top shaft protruding through the cover of the actuator. Instead, an indicator shaft (indicator shaft) is provided that protrudes from the non-pressurized portion of the actuator, reducing the risk of seal failure. Additionally, the presently disclosed systems and methods include an indicator shaft that may limit removal of the actuator when the actuator is pressurized with pressure media.

The diaphragm of the disclosed embodiment of this invention will resist undesirable wear during use, resulting in an extended useful life of the diaphragm. The diaphragm may resist wear, for example, by being fully supported within the actuator, by expanding or expanding the diaphragm during the actuation process without being exposed to sufficient tension, and by having additional material in areas involving potential failure.

In one embodiment of the present disclosure, an apparatus for actuating a valve includes an actuator housing having a valve end, a cap end, and a sidewall defining an inner diameter of the actuator housing. The cover is attached to the cover end of the actuator housing. A plate is positioned within the actuator housing, the plate having a central portion and an outer diameter that slidingly engages the inner diameter of the actuator housing. The pressure chamber is positioned within the actuator housing between a plate and the cover, the plate moving between an extended position and a retracted position in response to pressure medium injected into the pressure chamber. The plate is closer to the valve end in the extended position than in the retracted position. A seal nut is attached to the plate, the seal nut operable to engage the central opening of the diaphragm. The cap seal fluidly seals the pressure chamber between the cap and the actuator housing. The pressure chamber is fluidly sealed at the plate by one of a first plate seal assembly and a second plate seal assembly. The first plate seal assembly is formed by a diaphragm secured between a seal nut and a plate. The second seal assembly is formed by an outer diameter sidewall seal between the inner diameter of the actuator housing and the outer diameter of the plate and a retaining seal between the outer diameter of the seal nut and the inner diameter of the plate.

In an alternative embodiment of the present disclosure, an apparatus for actuating a valve includes an actuator housing having a valve end, a cap end, and a sidewall defining an inner diameter of the actuator housing. The cover is attached to the cover end of the actuator housing. A plate is positioned within the actuator housing, the plate having a central portion and an outer diameter that slidingly engages the inner diameter of the actuator housing. The first and second pressure chambers are located within the actuator housing between the plate and the cover. The first pressure chamber includes a diaphragm supported by a plate. A second pressure chamber is defined by the plate, the actuator housing, and the cover, the second pressure chamber having a plate seal assembly including an outer diameter sidewall seal located between an inner diameter of the actuator housing and an outer diameter of the plate. A fluid-tight region between the cover and the plate is formed by at least one of the first pressure chamber and the second pressure chamber, and the plate moves between a plate-raised position and a plate-lowered position in response to pressure medium injected into the fluid-tight region, the plate being closer to the valve end in the plate-lowered position than in the plate-raised position.

Drawings

So that the manner in which the features, benefits and objects of the present invention, as well as others which will become apparent, are attained and can be understood in more detail, more particular description of the invention briefly summarized above may be had by reference to the embodiments thereof which are illustrated in the appended drawings, which drawings form a part of this specification. It is to be noted, however, that the appended drawings illustrate only preferred embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

FIG. 1 is a side cross-sectional view of an embodiment of a dual seal piston diaphragm actuator according to an embodiment of the present disclosure, showing the plate in a plate-up position.

figure 2 is an enlarged detail view of the dual seal piston diaphragm actuator of figure 1.

FIG. 3 is a side cross-sectional view of the dual seal piston diaphragm actuator of FIG. 1, showing the plate in a plate down position.

FIG. 4 is a side cross-sectional view of a dual seal piston diaphragm actuator showing a ruptured diaphragm and an outer diameter side wall seal sealing a pressure chamber, and also showing a single piece support plate, in accordance with embodiments of the present disclosure.

FIG. 5 is a side cross-sectional view of the dual seal piston diaphragm actuator of FIG. 4 showing the replacement diaphragm sealing the pressure chamber.

FIG. 6 is a side cross-sectional detail view, swivel, of a dual seal piston diaphragm actuator according to a disclosed embodiment of the invention.

FIG. 7 is a side cross-sectional view of a dual seal piston diaphragm actuator with non-rising stem, shown in a plate-down position, in accordance with a disclosed embodiment of the invention.

Figure 8A is an enlarged side cross-sectional view of the quick connect of the dual seal piston diaphragm actuator of figure 7.

Figure 8B is a perspective view of the rotational locking system of the dual seal piston diaphragm actuator of figure 7.

Figures 9A-9C are side cross-sectional views of a septum according to a disclosed embodiment of the invention.

Detailed Description

The disclosed systems and methods will now be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. The disclosed systems and methods may, however, be embodied in many different forms and should not be construed as limited to the illustrated embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout, and prime notation (if used) indicates similar elements in alternative embodiments.

Referring to fig. 1, an actuator 100 is shown. The actuator 100 is used to open or close a valve 102 to which the actuator 100 is connected. As will be appreciated by those skilled in the art, the valve 102 may be a gate valve or any other type of valve that is actuated by extension of a linear member. The valve 102 may, for example, be in communication with a wellhead assembly disposed uphole. The wellhead assembly may include a wellhead housing, a tree above the housing, and a pipeline connected to the tree or the wellhead assembly. The pipeline and wellhead assembly may include embodiments of the valve 102 described herein. The valve 102 may also be used to regulate fluids destined to enter the wellhead assembly. The valve 102 may be used at cryogenic temperatures or otherwise in harsh environments. Bonnet 104 is attached to the body of valve 102. The valve stem 106 passes through the bonnet 104 and the packing retainer 108. The actuator 100 is used to actuate the valve 102 by pushing the valve stem 106 downward toward the valve 102. The bonnet 104 and the valve 102 are sealed to prevent the flow of fluid from the valve 102 to the actuator 100.

The actuator housing 112 includes a cylindrical body having an inner diameter surface 114. The housing 112 is made by any of a variety of techniques including, for example, stamping, extrusion, and casting. In an embodiment, the housing 112 is free of welds or seams on an inner surface, such as the inner diameter surface 114. The housing 112 may be made of NACE certified material.

In the embodiment of fig. 1, the valve end of actuator housing 112 is coupled to bonnet 104 via threads 116. In the alternative embodiment of fig. 7-8A, the valve end of the actuator housing 112 is connected to the bonnet 104 by a bonnet connector 118. The lower end of the housing 112 includes an opening defined by a connector inner diameter 120. Housing lugs 122 project inwardly from the connector inner diameter 120 and are spaced about the connector inner diameter 120 to define a housing slot 124 therebetween.

Still referring to fig. 7-8A, the bonnet 104 includes a lower flange 126 extending radially from a bonnet body 128. The lower flange 126 includes bolt holes 132. Bolts 130 may pass through bolt holes 132 to attach bonnet 104 to the body of valve 102. At the opposite end of bonnet 104 from lower flange 126, a locking flange 134 extends radially from bonnet body 128 and includes a top surface 136. The outer diameter of the locking flange 134 is less than or substantially equal to the connector inner diameter 120 such that the connector inner diameter 120 can fit over the locking flange 134.

The groove 138 is an annular groove in the outer diameter of the locking flange 134. The lower side wall of the groove 138 defines an upwardly facing shoulder 140. The width of groove 38 is greater than or approximately equal to the axial length of housing lug 122, and the width of groove 138 is defined in terms of the axial length along the axis of bonnet 104. The diameter of groove rear wall 142 is less than or approximately equal to the inner diameter defined by housing lugs 122 so that housing lugs 122 can fit within groove 138.

The slot 144 is an axial slot in the outer diameter of the locking flange 134 that extends from the top surface 136 to the groove 138. A plurality of slots 144 are spaced about the circumference of the locking flange 134 to define bonnet lugs 146 therebetween. The radial depth of each slot 144 is typically less than or equal to the radial depth of the groove 138, but may alternatively be greater than the radial depth of the groove 138. The circumferential arc length of each slot 144 is substantially equal to or greater than the circumferential arc length of each housing lug 122. The housing lugs 122 are thus able to pass axially through the slots 144.

After passing through slot 144, housing lug 122 is positioned in groove 138 below bonnet lug 146, but is not axially aligned with bonnet lug 146 when housing 112 is in the released position, and housing lug 122 contacts shoulder 140, further stopping downward movement of housing 112 relative to bonnet 104. Because housing lugs 122 are axially below bonnet lugs 146, housing 112 may rotate relative to bonnet 104. When housing 112 is rotated relative to bonnet 104 to a position in which bonnet lugs 146 are axially above housing lugs 122, housing 112 is in the locked position. In the locked position, the bonnet lugs 146 prevent upward axial movement of the housing lugs 118. In an embodiment, less than one revolution of housing 112 is required to move housing 112 from the release position to the lock position. In some embodiments, housing 112 can move as little as, and, depending on the size and number of lugs, as many as, a, 1/3, ¼, 1/6, 1/8, 1/10, or 1/16 turns to move from the released position to the locked position.

As will be understood by those skilled in the art, there is no fluid from valve 102 adjacent bonnet and housing lugs 146, 122, and thus there may be no seal between the lower end of housing 112 and the upper end of bonnet 104. Thus, in an embodiment, if any fluid is present within the lower end of the housing 112, at least a portion of that fluid may pass through the opening defined by the connector inner diameter 120 and flow to an area outside of the housing 112 and outside of the bonnet 104. In an embodiment, actuator housing 112 may be removed from bonnet 104 while fluid is present in valve 102, and no fluid will pass through bonnet 104 or otherwise exit valve 102. In other alternative embodiments, other types of connectors may be used, such as bolts.

Referring to fig. 8B, when housing 112 is in the locked position, rotational lock 148 may prevent rotation of housing 112 relative to bonnet 104. The rotary lock 148 includes a latch body 150 having one or more latch tabs 152 projecting inwardly therefrom when the latch body is positioned in a latch aperture 154. The latch aperture 154 is an opening through a sidewall of the housing 112. In an embodiment, no seal is required at the aperture 154 because there is no pressurized fluid in the housing 112 proximate the aperture 155. Indeed, in embodiments, there is no seal between the aperture 154 and the latch body 150. The latch body 150 is pivotally connected to the housing 112 by a pin 156, the pin 156 passing through a lateral hole or cross-drilled hole of the housing 112. The latch body 150 pivots on the pin 156 between an unlatched position and a latched position. Pawl 158 is a spring-loaded plunger that protrudes from one or both sides of latch body 150. Pawl 158 engages lateral aperture 160 of housing 112 to selectively prevent latch body 150 from pivoting relative to housing 112. When latch body 150 pivots radially outward from housing 112, in the unlatched position, pawl 158 contacts an outer diameter surface of housing 112 to prevent latch body 150 from pivoting inward toward the latched position. As will be appreciated by those skilled in the art, other mechanisms may be used to hold latch body 150 in place.

Latch tab 152 also includes tab side walls 162. Latch tab 152 is positioned slightly above housing lugs 122 in housing 112 such that at least a portion of latch tab 152 is in the same axial position as bonnet lugs 146 when housing 112 is dropped onto bonnet 104.

In an embodiment, a spring (not shown) may bias latch body 150 radially inward. When housing 112 is placed on bonnet 104, a portion of latch tabs 152, such as bottom 164, contacts a top edge of bonnet lugs 146 (fig. 8A), thereby deflecting latch tabs 152 radially outward. The edges of the base 164 may be tapered to facilitate such deflection. With latch tab 152 positioned radially outward from housing 112, in the unlatched position, housing lugs 122 land on shoulders 140 and housing 112 is rotated to the latched position. Detent 158 holds latch tab 152 in a radially outward, unlatched position. The operator then depresses pawl 158 to allow latch tab 152 to pivot inwardly to the latched position.

When latch tab 152 is pivoted to a position where pawl 158 is aligned with lateral aperture 160, a portion of pawl 158 is urged into lateral aperture 160 by an internal spring (not shown). In this latched position, detent 158 engages lateral hole 160 to hold latch tab 152 in the latched position and thus prevent latch tab 152 from moving to the unlatched position. In this latched position, latch tab side walls 162 engage side walls 166 of bonnet lugs 146, thereby preventing further rotation of housing 112 in either direction relative to bonnet 104. The outer surface 168 of latch tab 152 may be contoured with a radius that substantially matches the outer diameter profile of housing 112. Alternatively, outer surface 168 of latch tab 152 may be planar. Other types of rotational locks 148 may be used. For example, a pin (not shown) may be inserted through an aperture (not shown) of housing 112 into a hole (not shown) of bonnet 104. Or a different type of latching mechanism may be used.

Referring again to fig. 1, the cap end of the housing 112 is located at the opposite end of the housing 112 from the bonnet connector 118. The housing flange 170 is located at the cap end of the housing 112. The housing flange 170 flares outwardly from the housing 112. The housing flange 170 has an upwardly facing surface 172, which surface 172 is a smooth surface for forming a seal. A plurality of bolt holes 174 may be spaced around the flange 170.

Cover 176 is attached to housing 112. The cap 176 is an annular plate having an outer diameter substantially equal to the outer diameter of the housing flange 170. The downward facing surface 178 is a generally smooth, downward facing surface of the cover 176 that is aligned with the upward facing surface 172 of the housing flange 170. A plurality of bolt holes 180 are spaced around cap 176 to align with bolt holes 174. The cover bolts 182 are passed through the bolt holes 174 and the bolt holes 180 and secured with nuts. Other configurations may be used to secure cap 176 to housing 112, such as bolts inserted through bolt holes 174 to threadably engage bolt holes 180 to secure cap 176 to housing 112 (not shown), bolts inserted through bolt holes 180 to threadably engage bolt holes 170 (not shown), clips (not shown), washers (not shown), or bayonet mounts (not shown). By way of example, in the alternative embodiment of FIG. 4, rather than the bolt holes 174,180 and cover bolts 182, a series of cover tabs 184 and housing tabs 186 interact such that the cover 176 can be positioned on the actuator housing 112 and the cover 176 can then be rotated from the release position to the lock position by rotating the cover 176 less than one full turn between the release and lock positions.

The inlet 188 is an aperture through the cap 176 and spaced inwardly from the downwardly facing surface 178. The inlet 188 is connected to a source of pressurized medium fluid (not shown) that may selectively provide pressurized medium fluid through the inlet 188. The pressurized medium is typically a fluid such as compressed air, nitrogen, well gas, or other types of gases or liquids. As will be appreciated by those skilled in the art, in embodiments, additional ports may be used and connected to tubing or pressure relief devices. Illustratively, the aperture 190 is a second opening through the cap 176. The device 192 shown in the orifice 190 may be a pressure relief device that will open to relieve pressure in the housing 112 if the pressure exceeds a predetermined value. As will be appreciated by those skilled in the art, the device 192 may be one of a variety of devices used to relieve an overpressure condition, such as a pressure relief valve, a rupture disk, or a controlled valve. Alternatively, the device 192 may be a sealant injection port for selectively introducing sealant into the actuator housing 112.

Turning to fig. 2, plate 194 is an annular plate located in housing 112. The plate 194 is generally perpendicular to a central axis 196 of the housing 112. Plate 194 may span the inner diameter of housing 112 and slidingly or sealingly engage inner diameter surface 114 of housing 112. Plate 194 includes a central aperture 198. The upwardly facing surface of plate 194 is the pressure side of plate 194. Plate 194 may be a single, unitary plate (fig. 4), or may include a hub 200 and an outer plate 202. The central bore 198 has inner diameter threads 204 on the inner diameter surface. In embodiments that include a hub 200, the hub 200 has a central bore 198. Hub 200 also includes a sealing surface on the inner diameter of central bore 198. The outer diameter of hub 200 includes outer diameter threads 206 and an outer diameter sealing surface 208.

Outer plate 202 is an annular ring connected to hub 200 such that plate 194 includes outer plate 202 and hub 200. Upper surface 210 of outer plate 202 (or plate 194 if outer plate 202 is not present) slopes downwardly and outwardly, has a generally convex shape, and then extends horizontally to inner diameter surface 114. In other embodiments, the upper surface 210 of the outer plate 202 may be sloped upward and outward before extending horizontally to the inner diameter surface 114, or may be a flat surface, or may have an alternative shape that combines sloped and flat portions. The surface of plate 194 may have a contour such that the radially outward portion is axially below the radially inward portion, or such that the radially outward portion is axially above the radially inward portion (not shown). In other embodiments, the surface of the plate 194 may be flat. As shown in fig. 1, the outer diameter region of the plate is located axially closer to the valve end of the housing than the central portion of the plate. In an embodiment, plate 194 has an upwardly facing convex surface and an upwardly facing concave surface. The recessed surface may be spaced radially outwardly from the protruding surface, or alternatively, spaced radially inwardly from the protruding surface. In other embodiments, plate 194 may have a substantially planar surface, or may have a combination of contoured protrusions, depressions, or planar portions.

the inner diameter bore of outer plate 202 includes inner diameter threads 212 for threadably engaging outer diameter threads 206 of hub 200. A retention seal 214 is located in a seal groove 216 on the bore of the outer plate 202 and sealingly engages the outer diameter sealing surface 208 of the hub 200. Sidewall seal 218 is located in groove 220, groove 220 being positioned on the outer diameter of outer plate 202, and thus plate 194. Sidewall seal 218 sealingly engages inner diameter surface 114 of housing 112 to provide a dynamic seal between inner diameter surface 114 and plate 194. In an embodiment, a wear ring (not shown) may be positioned in groove 220. As will be appreciated by those skilled in the art, the wear ring will reduce friction between the outer diameter of plate 194 and inner diameter surface 114 of housing 112. The wear ring does not have the same sealing properties as the sidewall seal 218.

Indicator housing 222 is a housing that includes an indicator aperture 224 for receiving an indicator stem 226. Indicator stem 226 is a cylindrical shaft that protrudes through cap 176. Bearing 228 is a bearing surface on the inner diameter of indicator bore 224 for guiding indicator stem 226. Seal assembly 230 is a seal that dynamically seals around indicator stem 226. As will be appreciated by those skilled in the art, the seal assembly 230 may include a snap ring 232 or other retainer (not shown) to retain the seal assembly 230 in place in the indicator housing 222. Alternatively, the seal assembly 230 may be a seal cartridge, a V-lip seal with an O-ring, or other type of seal for dynamically sealing around a shaft. In alternative embodiments, such as the embodiment of fig. 7, the cap 176 is devoid of the indicator housing 222 and is devoid of the indicator stem 226 protruding through the cap 176.

Referring to fig. 2 and 6, a gland nut 234 is removably attached to the center of the plate 194. The gland nut 234 includes a cylindrical body 236. Threads 238 are on the outer diameter of body 236 and threadably engage outer diameter threads 204 of hub 200. The seal nut 234 includes a seal 240 positioned axially above the threads 238 in a seal groove 242 on an outer diameter surface of the body 236 to sealingly engage the central bore 198 of the hub 200. Alternatively, there may be no seal between the body 236 and the inner diameter of the plate 194.

In the example embodiment of fig. 2, the seal nut 234 is integrally formed with the indicator stem 226. In the example embodiment of fig. 6, indicator stem 226 is a separate component and is releasably secured to gland nut 234. In such an embodiment, the upper body 244 is a cylindrical portion of the gland nut 234 on an opposite end of the gland nut 234 from the threads 238. The upper body 244 has an end surface 246. When plate 194 is in the upper position, end surface 246 may be adjacent to or engage inner surface 248 of cap 176. A radial lock ring groove 250 may be positioned on the outer diameter of the upper body 244.

Referring to fig. 2 and 6, shoulder 252 is a shoulder extending radially from the outer diameter of body 236 of gland nut 234. The shoulder 252 is located axially above the seal groove 242. The outer diameter of shoulder 252 is greater than the inner diameter of bore 198 such that shoulder 252 radially overlaps a portion of the upwardly facing surface of plate 194. The shoulder 252 includes a downwardly facing surface 254, the surface 254 facing the plate 194 when the gland nut 234 is installed in the plate 194. Nut lip 156 projects axially downward from surface 254, near the edge of shoulder 252.

In the exemplary embodiment of FIG. 6, the locking ring groove 250 is an annular groove on the outer diameter surface of the upper body 244, on the shoulder 252. Tool receptacle 258 is a hexagonal recess for receiving an allen wrench and may be located on end surface 246. Other techniques may be used to tighten the gland nut 234. The bore 260 is a downwardly facing cylindrical recess in the lower end of the body 236. Indicator stem 226 is removably attached to gland nut 234. Indicator stem 226 includes a shaft 262 connected to a base 264. Shaft 262 is a cylindrical shaft that extends upwardly through cap 176 and is sealingly engaged by seal assembly 230. The base 264 is a cylindrical base having an outer diameter greater than the outer diameter of the shaft 262. The base recess 266 is a cylindrical bore in the lower end of the base 264 opposite the shaft 262. Chamfer 274 is a tapered surface that faces inwardly and downwardly at the mouth of recess 266. The inner diameter of recess 266 is greater than or approximately equal to the outer diameter of upper body 244. Base 264 can thus be concentrically positioned on upper body 244 such that upper body 244 engages recess 266.

Groove 268 is an annular groove extending around the inner diameter surface of recess 266. The aperture 270 is an aperture that extends radially through the sidewall of the base 264 and intersects the bottom of the groove 268. One or more apertures 270 are spaced about the circumference of the base 264. Locking ring 272 is a resilient locking ring positioned to occupy at least a portion of each of locking ring groove 250 and groove 268. Locking ring 272 may be, for example, a c-ring. In its relaxed state, locking ring 272 has an inner diameter that is smaller than the outer diameter of upper body 244, and an outer diameter that is larger than the outer diameter of upper body 244. The width of locking ring 272, defined as the axial length of the annular ring, is less than or approximately equal to the width of each groove 250 and 268.

In the example of an assembly for operation, locking ring 272 snaps onto groove 250. Indicator stem 226 is then attached to gland nut 234 by sliding base 264 onto upper body 244. Chamfer 274 presses locking ring 272 inwardly into groove 250 as recess 266 slides into upper body 244. When groove 268 is axially aligned with groove 250, locking ring 272 is able to expand outward and engage each of groove 250 and groove 268. Locking ring 272 thus prevents axial movement of indicator stem 226 relative to seal nut 234. To remove indicator stem 226 from seal nut 234, a tool or tools are inserted through aperture 270 and used to press locking ring 272 into groove 250. Indicator stem 226 may slide out of upper body 244 when locking ring 272 is pressed to the point where the outer diameter of locking ring 272 is less than the inner diameter of groove 268.

In the example embodiment of fig. 7, the lever 226 is not indicated. Cap 176 includes a cap recess 276 centered about a central axis 196 and not extending through cap 176. When plate 194 is in the plate-up position, end surface 246 of upper body 244 may be located within cover recess 276. If the cap 176 shown in FIG. 7 is replaced with a cap 176 that includes the indicator housing 222, the seal nut 234 may still have a groove 250 so that the indicator stem 226 may be added. In an alternative embodiment, an aperture (not shown) may be located in the center of cap 176. The orifice (not shown) may be plugged with a plug (not shown) to prevent the pressurized medium from escaping through the orifice (not shown). In the event that the operator wishes to use an indicator stem that is raised upward (which may be used, for example, to push plate 194 downward), the plug (not shown) may be removed and an indicator stem housing (not shown) may be inserted into an aperture (not shown) in cap 176. The indicator stem may be attached to plate 194, such as by attaching a stem (not shown) to gland nut 234 via groove 250. An indicator stem housing (not shown) may slidably and sealingly engage a stem (not shown).

looking at the example embodiment of fig. 7 and 8B, rather than indicator lever 226 indicating the position of plate 194, indicator assembly 278 may indicate the position of plate 194. Indicator housing 280 is a cylindrical housing located in indicator aperture 282. The indicator orifice 282 is an opening in the downward facing surface of the actuator housing 112, axially below a portion of the plate 194. The indicator housing 280 has a generally cylindrical shape with a connector, such as threads, on an outer diameter surface. The indicator housing 280 also includes a cylindrical bore therethrough. An annular shoulder at the lower end of the indicator housing 280 defines a reduced inner diameter.

The position indicator stem 284 is a cylindrical shaft that protrudes from an aperture defined by a shoulder of the indicator housing 280. The rib, which is an annular shoulder projecting from the outer diameter of the position indicator 284, has an outer diameter that is approximately the same as or slightly less than the inner diameter of the cylindrical bore of the indicator housing 280, but the outer diameter of the rib is greater than the inner diameter of the aperture defined by the annular shoulder at the lower end of the indicator housing 280. The portion of the position indicator stem 284 above the ribs is defined as a connector end 286. Connector end 286 may be smooth, threaded, or have other features that facilitate connection to another member.

The indicator shaft 288 is a cylindrical shaft that extends from the position indicating rod 284 to the downwardly facing surface of the plate 194. The downward facing surface of plate 194 is a portion of the indicator side of plate 194 that is opposite the pressure side of plate 194 and faces the valve end of housing 112. The upper end of indicator shaft 288 may be in contact with the downward facing surface of plate 194, but is not connected to plate 194. When plate 194 is in the plate-up position, the upper end of indicator stem 288 is below plate 194 and does not contact plate 194.

The spring may be concentric with a portion of the position indicating stem 284. The lower end of the spring contacts the shoulder at the lower end of the indicator housing 280. The upper end of the spring contacts a rib protruding from the outer diameter of the position indicating rod 284. The spring pushes position indicating lever 284 upward, and position indicating lever 284 in turn pushes indicator shaft 288 upward until shaft 288 contacts the downward facing surface of plate 194. When the actuator 100 is actuated and the plate 194 moves from the plate-up position to the plate-down position, the position indicating lever 284 is pushed downward by the indicator shaft 188. Position indicator stem 284 protrudes from housing 112 more in the plate down position than in the plate up position. When plate 194 moves back up to the plate-up position, the spring pushes indicator stem 284 up to the extent permitted by indicator stem 288 in contact with plate 194.

As shown in fig. 7, when the plate 194 is in the plate down position and the position indicator stem 284 protrudes from the actuator housing 112, a portion of the position indicator stem 284 may be positioned radially outward from the rotary lock 148 and axially aligned with the rotary lock 148. In such a position, the position indicating lever 284 prevents the rotary lock 148 from moving to the unlatched position. When pivoted outward, the latch body 150 will bump into the position indicating lever 284, preventing the latch body 150 from being in the unlatched position. Alternatively, position indicator stem 284 obstructs access to rotary lock 148 when plate 194 is not in the plate-up position. Thus, position indicating lever 284 may be used to prevent or inhibit the opening of rotary lock 148 when plate 194 is in the plate down position. In the plate-up position, position indicator 284 does not prevent access to or obstruct rotation lock 148. The lower end of position indicator stem 284 is axially above rotary lock 148 when plate 194 is in the plate-up position.

Because the orifice 282 passes through the lower end of the housing 112, the orifice 282 is isolated from and does not communicate with the pressure chamber of the actuator 100. The lower end of the housing 112 below the plate 194 may be, for example, at atmospheric pressure and may have a port (not shown) to exhaust air as the plate 194 moves downward. Thus, position indicating stem 284 does not create a leak path where pressure media may escape from actuator 100. The reduction in the number of dynamic seals, or elimination of dynamic seals, used to retain pressure media in the actuator 100 means that leakage is less likely to occur.

Referring to FIG. 1, the lower stop 290 is a cylindrical member that transfers axial forces between the plate 194 and the valve stem 106. The lower stop 290 includes a cylindrical body 292 and a shoulder 294 extending therefrom. The upwardly facing surface of shoulder 294 contacts the downwardly facing surface of plate 194. Nipple 296 extends axially from the upper end of lower stop 290. When the actuator 100 is assembled, the nipple 296 can be positioned in the bore 260 (fig. 6), thereby concentrically aligning the two members.

the lower end of the lower stop 290 includes a threaded bore 298 that is threaded on an inner diameter surface for threadably engaging the threaded end of the valve stem 106. As will be appreciated by those skilled in the art, the connection between the lower stop 290 and the valve stem 106 may be any type of connection and is not limited to a threaded connection. The outer diameter of the lower end of the lower stop 290 includes a threaded washer 300 and may include any number of spacer rings 302. The threaded washer 300 contacts another component (such as the seal retainer 108) located at the lower end of the housing 112 to stop further downward travel of the down-stop 290. The threaded washer 300 is adjusted so that it stops moving downward and thus the valve stem 106 is in the proper position to fully open or fully close the valve 102. The spacer ring 302 may be added or removed so that the opening of the gate (not shown) of the gate valve 102 is properly aligned with the passageway (not shown) of the gate valve 102. A set screw may be used to hold the threaded washer 300 in place.

The spring 304 surrounds the lower stop 290 and at least a portion of the valve stem 106 and generally extends from the top of the bonnet 104 to the downwardly facing surface of the shoulder 294. The spring 304 compresses as the plate 194 moves from the upper position to the lower position. When the fluid pressure from the inlet 188 decreases, the spring pushes the plate 194 upward away from the valve 102. As will be appreciated by those skilled in the art, fluid forces within the valve 102 may act on the valve stem 106 within the valve 102 to urge the valve stem 106 upward. The upward force on the spring 304 and the valve stem 106 may act together or independently to move the plate 194 upward.

referring to FIG. 1, diaphragm 306 is a flexible diaphragm that extends at least from inner diameter surface 114 to seal nut 234. Diaphragm 306 is positioned between plate 194 and cap 176. Referring to fig. 9A-9C, the diaphragm 306 has a body portion 308, the body portion 308 generally being formed of a cylindrical member having a plurality of folds 310. The fold 310 may be generally S-shaped (fig. 9B), generally side v-shaped (fig. 9A), generally S-shaped with a flat inner or outer ring (fig. 9C), or have other annular shapes. The folds 310 are arranged as bellows forming an inner ring 312 at the inner diameter of the body portion 308 and an outer ring 314 at the outer diameter of the body portion 308. In the example of fig. 9A-9C, diaphragm 306 is shown with two inner rings 312 and two outer rings 314. However, embodiments of the diaphragm 306 disclosed herein may alternatively have more or less than two inner rings 312 and more or less than two outer rings 314. The number of inner rings 312 and outer rings 314 will depend in part on the size of the actuator 100 in which the diaphragm 306 will be used, with the number of inner rings 312 and outer rings 314 generally increasing with increasing size of the actuator 100. In alternative examples, diaphragm 306 may have, for example, zero to six inner rings 312.

The diaphragm 306 is formed such that in a relaxed state, the diaphragm 306 is shaped as shown in figures 9A-9C with a fold 310 in the body portion 308. Diaphragm 306 may not stretch or expand as plate 194 moves between a plate-up position (fig. 1) and a plate-down position (fig. 3). In this context, stretching or expanding refers to a state in which the thickness of the material of the diaphragm 306 will decrease or thin due to the increased surface area of the material. Diaphragm 306 moves between a relaxed position (fig. 9A-9C) and an expanded position (fig. 3) by straightening fold 310 to expand and extend and axially elongate the bellows shape of diaphragm 306. After being in the extended position and returning to the relaxed position, the septum may be axially shortened by forming a fold 310 and will resume the shape shown in figures 9A-9C. The diaphragm 306 may be formed into the shape shown in the example of fig. 9A-9C, for example, by a molding process. When plate 194 is in the plate-up position, diaphragm 306 may be in the shortened position. In the shortened position, the septum 306 may be in a relaxed state or may be in a contracted state, wherein the septum is axially shorter than when in the relaxed state. When plate 194 is in the plate down position, diaphragm 306 is in the extended position.

In an alternative embodiment shown in fig. 7, the diaphragm 306 may be a less rigid member such that the fold 310 may be formed anywhere around the diaphragm 306, such as in the bottom 324 of the diaphragm 306. In such embodiments, the septum 306 may not retain a single particular shape in a relaxed state.

In another alternative embodiment shown in fig. 9C, the body portion 308 may have a recess 316 formed on an inner surface, an outer surface, or both the inner and outer surfaces of the septum 306. Dimples 316 can be spaced randomly or in a pattern on the surface. Each dimple 316 may be shaped, for example, as a partial sphere, partial cone, or other three-dimensional shape. The dimples 316 will create an uneven surface on the body portion 308 and reduce the likelihood that the surfaces of the diaphragm 316 will stick together.

At the upper end of the diaphragm 306 is a top ring 318. The top ring 318 is annular in shape and extends radially outward from the body portion 308. The top ring 318 extends radially outward past the outermost radial diameter of the fold 310. The top ring 318 may curve downward over the inner radius of the actuator housing 112 (fig. 1-2) before encountering the uppermost fold 310 of the body portion 308.

In the example embodiment of fig. 9A-9C, the diaphragm 306 includes a sealing lip 320 on an outer edge of the top ring 318. The upper seal lip portion protrudes upward from the top of the top ring 318, and the lower seal lip portion protrudes downward from the bottom of the top ring 318. The sealing lip 320 may have an upper sealing lip portion or a lower sealing lip portion, or both. In the example of fig. 9A-9C, the sealing lip 320 is shown as having both an upper sealing lip portion and a lower sealing lip portion. The sealing lip 320 may be oval, O-shaped, triangular, rectangular, or other shape in cross-section. In the example of fig. 9A-9C, the sealing lip 320 is elliptical in cross-section with the axis of the longer dimension being substantially parallel to the central axis of the diaphragm 306. This elliptical sealing lip 320 may be compressed within a generally square sealing lip recess 322 (fig. 1-2) in the actuator 100.

in certain embodiments, such as shown in fig. 7, the top ring 318 may have a hole through which a connecting member, such as the cover bolt 182, will extend. In an alternative embodiment, such as shown in fig. 1-2, the top ring 318 may lack apertures, and the actuator housing 112 and the cap 176 may be secured together by a connection means that is radially outward from the top ring 318.

Referring to fig. 9A-9C, at the end of the body portion 308 opposite the top ring is the bottom 324 of the septum 306. The bottom 324 of the diaphragm 306 is generally disc-shaped and extends inwardly from the body portion 308. The bottom 324 may meet the body portion 308 of the diaphragm 306 at a curved transition section. In the example of fig. 9A-9C, the bottom 324 may be flat in the relaxed position. When positioned in actuator 100, bottom 324 may generally follow the shape of plate 194, or may remain flatter than plate 194.

The bottom 324 has a central opening 326 centered on the central axis of the diaphragm 306. The opening lip 328 may circumscribe the central opening 326 and may include an upper opening lip projecting upward or a lower opening lip projecting downward, or both. The exemplary embodiment of fig. 9A-9C includes an upper opening lip.

The septum 306 may be formed, for example, from nitrile rubber or silicone. In areas where the diaphragm 306 may experience wear, the diaphragm 306 may be supported with additional material. Such material may be the same material that forms the entire diaphragm 306, or may be a supportive fabric or fiber. Additional material may be added, for example, on the bottom 324 of the septum, where the bottom 324 meets the body portion 308, where the top ring 318 meets the body portion 308, or along the top ring 318. In this manner, a predetermined failure point may also be built into the diaphragm 306. For example, weak points may be built into the diaphragm 306 such that the area of the diaphragm 306 that forms the seal may be maintained, even in the event of a failure of the diaphragm 306. The diaphragm may be designed to fail in another non-sealing location, such as along a central region of the body portion 308. The central region of the body portion 308 may remain free of additional material to increase the likelihood that failure of the diaphragm 306 occurs in such a central region of the body portion 308.

Referring to FIG. 1, actuator 100 includes a pressure chamber 330 located within actuator housing 112 between plate 194 and cap 176. Pressure medium injected into the pressure chamber 330 will cause the plate 914 to move between a retracted or plate-up position and an extended or plate-down position (fig. 3). In the extended position, plate 194 is closer to the valve end of actuator 100 than when plate 194 is in the retracted position.

A plurality of seals may prevent pressure medium from escaping from the pressure chamber 330. The cap seal 334 may fluidly seal the pressure chamber 330 between the cap 176 and the actuator housing 112. The cap seal 334 may include an outer diameter portion of the diaphragm 306 between the upward facing surface 172 of the housing flange 170 and the downward facing surface 178 of the cap 176. Sandwiching a portion of the diaphragm 306 between the actuator housing 112 and the cap 176 may both hold the diaphragm 306 in place and form a cap seal 334. In the example embodiment of fig. 1-3, the lid seal 334 is formed by a sealing lip 320 that engages a sealing lip groove 322. The sealing lip groove 322 is a circumferential recess defined between the upwardly facing surface 172 of the housing flange 170 and the downwardly facing surface 178 of the cap 176. A portion of the sealing lip groove 322 may be formed in the housing flange 170 and a portion of the sealing lip groove 322 may be formed in the cover 176. In an alternative embodiment, the sealing lip groove 322 may be formed entirely in one of the housing flange 170 or the cover 176. The sealing lip groove may be triangular, oval, square in cross-section, or may have alternative cross-sectional shapes. The sealing lip 320 may be compressed in the sealing lip groove 322.

In alternative example embodiments, such as shown in fig. 7, the sealing lip 320 and the sealing lip groove 322 may be absent and a cover seal may be formed by positioning the top ring 318 between the upward facing surface 172 of the housing flange 170 and the downward facing surface 178 of the cover 176. The cover bolts 182 may apply a torque to push both the upward facing surface 172 of the housing flange 170 and the downward facing surface 178 of the cover 176 toward the diaphragm 306. The diaphragm 306 sealingly engages both the upward facing surface 172 of the housing flange 170 and the downward facing surface 178 of the cap 176 to form a cap seal 334.

The plate seal assembly seals other leakage paths in the pressure chamber 330. Plate seal assembly may be a first plate seal assembly 336 formed by diaphragm 306 secured between seal nut 234 and plate 194. Looking at fig. 6, a first plate seal assembly 336 may be formed by a nut lip 256 that captures the opening lip 328. The central opening 326 may receive a lower portion of the sealing nut 234. Gland nut 234 passes through central opening 326 such that gland nut threads 238 may engage inner diameter threads 204 of plate 194. The bore 260 of the seal nut 234 may engage the nipple 296 of the lower stop 290. When seal nut 234 is threadably connected to plate 194, nut lip 256 may capture opening lip 328 to form first plate seal assembly 336 and hold diaphragm 306 in place by resisting radial movement of diaphragm 306 relative to plate 194.

in an alternative embodiment, such as shown in FIG. 7, the bottom surface of the diaphragm is free of the opening lip 328. The bottom surface of diaphragm 306 circumscribing central opening 326 is located between shoulder 252 of seal nut 234 and plate 194. An upwardly facing surface of plate 194 sealingly engages a lower surface of diaphragm 306 and a downwardly facing surface of shoulder 252 sealingly engages an upper surface of diaphragm 306. When seal nut 234 is tightened against plate 194, diaphragm 306 is compressed between plate 194 and shoulder 252.

In yet other alternative embodiments, the sealing nut 234 does not extend through the bottom 324 of the diaphragm 306, and the diaphragm 306 may not have a central opening.

Referring to fig. 1, when the diaphragm 306 is in position and both the cap seal 334 and the first plate seal assembly 336 are fluidly sealed, the pressure chamber 330 is defined by the diaphragm 306, the seal nut 234, and the cap 176, thereby defining a first pressure chamber 338. In one embodiment, diaphragm 306 is fully supported by plate 194 and actuator housing 112. In particular, the solid member is in contact with substantially all of the diaphragm 306 such that the solid member prevents the diaphragm 306 from expanding outward in response to the pressure medium. Plate 194 supports the underside of diaphragm 306 on both the convex and concave surfaces of plate 194 across the entire inner diameter of housing 112. The inner diameter surface 114 of the housing 112 supports the sides of the diaphragm 306.

When pressure medium is injected into first pressure chamber 338, the pressure medium exerts a force on diaphragm 306 and plate 194 is moved to the plate-down position. In the plate down position, there is no unsupported area of the diaphragm 306. Diaphragm 306 does not extend axially past plate 194 when plate 194 is in the plate-up position or when plate 194 is in the plate-down position. A portion of diaphragm 306 inward from inner diameter surface 114 is supported by plate 194. Because the diaphragm 306 is fully supported, it can withstand higher pressures in the first pressure chamber 338 than an unsupported diaphragm can withstand. This embodiment may therefore have a higher actuator operating pressure than a conventional unsupported diaphragm, which may be limited to 150 psig. Additionally, the membrane 306 may be free of fiber reinforcement and may be thinner than some conventional membranes.

Pressure chamber 330 is fluidly sealed at plate 194 by one of a first plate seal assembly 336 and a second plate seal assembly 340. The second plate seal assembly 340 may be formed by a sidewall seal 218 and a retaining seal 214, the sidewall seal 218 sealingly engaging the inner diametric surface 112 of the housing 112 to provide a dynamic seal between the inner diametric surface 114 and the plate 194, the retaining seal 214 on an outer diametric surface of the cylindrical body 236 sealingly engaging the central bore 198 of the plate 194. The retention seal 214 circumscribes an outer diameter of the seal nut 234 and is axially spaced from the diaphragm 306.

Embodiments of the present application provide a second pressure chamber 342. Second pressure chamber 342 may be a redundant auxiliary pressure chamber that will provide a fluid-tight pressure chamber 330, allowing actuator 100 to continue to operate at full load if first pressure chamber 338 fails (fig. 4). Referring to fig. 4, second pressure chamber 342 may be defined by plate 194, actuator housing 112, and cap 176. Second pressure chamber 342 may include a second plate seal assembly 340, second plate seal assembly 340 being formed by sidewall seal 218 and retaining seal 214, sidewall seal 218 sealingly engaging inner diametric surface 112 of housing 112 to provide a dynamic seal between inner diametric surface 114 and plate 194, retaining seal 214 being on an outer diametric surface of cylindrical body 236 sealingly engaging central bore 198 of plate 194. Second pressure chamber 342 will also have a cap seal 334. The cap seal 334 may be formed by an outer diameter portion of the diaphragm 306 that is located between the upward facing surface 172 of the housing flange 170 and the downward facing surface 178 of the cap 176 even if the diaphragm 306 ruptures. If first plate seal assembly 336 remains intact, retaining seal 214 will be redundant. Depending on the nature of the failure of first pressure chamber 338, either first plate seal assembly 336 or retaining seal 214 may provide a seal between seal nut 234 and plate 194 of second pressure chamber 342.

Second pressure chamber 342 may alternatively be intentionally used without first pressure chamber 338. Actuator 100 may be assembled without diaphragm 306 using the same components as previously described. The dual nature of the assembly allows the operator to operate the actuator as a piston actuator without holding the second set of valves and components. To operate the actuator 100 without the diaphragm 306, a sealing ring (not shown) may be positioned between the housing 112 and the cap 176. Sidewall seal 218 of plate 194 forms a seal against inner diameter surface 114, thereby defining a pressure chamber without the use of a diaphragm. The pressure medium injected through the inlet 188 pushes the plate 194 downward, thus causing the valve stem 106 to move downward.

To vary the downward force applied by the actuator 100, the outer plate 202 may be removed from the hub 200 and outer plates 202 having the same inner diameter but different outer diameters may be mounted on the hub 200. The actuator housing 112 may be replaced with a housing having an inner diameter corresponding to the outer diameter of the newly installed outer plate 202. Cover 176 is similarly replaced by a cover 176 having dimensions corresponding to the newly installed housing 112. Finally, the diaphragm 306 may be replaced with a new diaphragm 306, the new diaphragm 306 sized appropriately for the new outer plate 202, housing 112, and cover 176. Other components (such as gland nut 234, stem 226, and bonnet 104) may not be replaced when switching from one size to another.

another alternative valve actuator system includes first and second actuator assemblies (not shown). The second actuator assembly may be axially aligned with the first actuator assembly. Each actuator assembly includes an actuator housing 112, a plate 194, a cover 176, and an inlet 188. The first actuator assembly may be located axially above the second actuator assembly and have a smaller diameter than the second actuator assembly. Specifically, the actuator housing 112, the plate 194, and the cap 176 may each have a smaller diameter than the same type of components in the second actuator assembly. In an alternative embodiment, the first and second actuator assemblies may have substantially similar diameters.

In operation, pressurized medium is introduced into the pressure chamber 330 through the inlet 188. In the embodiment of fig. 1, pressurized medium enters first pressure chamber 338 and exerts a downward force on diaphragm 306 and plate 194, which pushes plate 194, lower stop 290, and valve stem 106 downward to actuate valve 102.

Looking at FIG. 4, if diaphragm 306 fails, such as ruptures, second pressure chamber 342 may replace first pressure chamber 338 and actuator 100 may continue to operate at load. Alternatively, if the diaphragm 306 leaks but is substantially intact, and the cap seal 334 and the first piston seal assembly 336 are functioning, an operator may inject sealant through the sealant injection port of the device 192 such that the sealant makes sealing contact with the damaged area of the diaphragm 306 and the first pressure chamber 338 is restored to service.

looking at FIG. 5, if diaphragm 306 fails, the operator may alternatively install tubular diaphragm 344 to provide and replace first pressure chamber 338. Tubular diaphragm 344 is an annular tubular member having a valve stem 346. A tubular diaphragm may be positioned within actuator housing 112 between plate 194 and cap 176, and may circumscribe seal nut 234 and indicator stem 226. A valve stem 346 may extend through the inlet 188 for injecting pressure medium into the tubular diaphragm 344. By adding pressure medium to tubular diaphragm 344, acting as first pressure chamber 338, tubular diaphragm 344 will expand and exert a downward force on diaphragm 306 and plate 194.

While the invention has been shown and described with respect to only some of its forms, it will be apparent to those skilled in the art that it is not so limited, but is susceptible to various changes without departing from the scope of the invention.

Claims (19)

1. An apparatus for actuating a valve, the apparatus comprising:

An actuator housing having a valve end, a cap end, a central axis, and a sidewall defining an inner diameter of the actuator housing;

A cap connected to the cap end of the actuator housing;

A plate positioned within the actuator housing, the plate having a central portion and an outer diameter that slidingly engages the inner diameter of the actuator housing;

A pressure chamber within the actuator housing between the plate and the cover, the plate moving between a plate-up position and a plate-down position in response to pressure medium injected into the pressure chamber, the plate being closer to the valve end in the plate-down position than in the plate-up position;

A seal nut connected to the plate, the seal nut operable to engage a central opening of a diaphragm; and

a cap seal fluidly sealing the pressure chamber between the cap and the actuator housing;

Wherein the pressure chamber is fluidly sealed at the plate by one of a first plate seal assembly and a second plate seal assembly;

wherein the first plate seal assembly is formed by the diaphragm secured between the seal nut and the plate;

Wherein the second plate seal assembly is formed by an outer diameter sidewall seal between the inner diameter of the actuator housing and the outer diameter of the plate and a retaining seal between an outer diameter of the seal nut and an inner diameter of the plate; and

Wherein the diaphragm moves between a shortened position and an extended position, the plate being in a plate-raised position when the diaphragm is in the shortened position and the diaphragm being in a bellows shape in cross-section formed by an inner ring having an inner ring inner diameter and an outer ring having an outer ring outer diameter relative to the central axis, the diaphragm being in the extended position when the plate is in the plate-lowered position by axially expanding the bellows shape and reducing the difference between the inner ring inner diameter and the outer ring outer diameter measured relative to the central axis such that the inner ring contacts a sidewall of the actuation housing, and wherein the outer ring and the inner ring are axially spaced apart.

2. The apparatus of claim 1, wherein the first plate seal assembly and the second plate seal assembly are redundant seal assemblies, the second plate seal assembly to fluidly seal the pressure chamber upon failure of the first plate seal assembly.

3. the device of claim 1, wherein the retention seal circumscribes the outer diameter of the seal nut and is axially spaced from the diaphragm.

4. the apparatus of claim 1, wherein:

the septum having a septum lip circumscribing the central opening of the septum;

The seal nut having an annular nut lip; and

The first plate seal assembly is defined by the diaphragm lip retained by the nut lip.

5. the device of claim 1, wherein the diaphragm has an outer diameter portion, and wherein the cap seal includes the outer diameter portion of the diaphragm between the cap and the actuator housing.

6. The device of claim 5, wherein the outer diameter portion has an annular sealing lip that engages an annular sealing lip groove between the cover and the actuator housing.

7. The apparatus of claim 1, further comprising a sealant injection port extending into the pressure chamber, the sealant injection port selectively introducing sealant into the pressure chamber and into sealing contact with a damaged region of the diaphragm.

8. The apparatus of claim 1, wherein the cover is removably connectable to the actuator housing by placing the cover on the actuator housing and rotating the cover from a released position to a locked position, the cover rotating less than one full revolution between the released position and the locked position.

9. An apparatus for actuating a valve, the apparatus comprising:

An actuator housing having a valve end, a cap end, a central axis, and a sidewall defining an inner diameter of the actuator housing;

A cover connected to the cover end of the actuator housing;

A plate positioned within the actuator housing, the plate having a central portion and an outer diameter that slidingly engages the inner diameter of the actuator housing;

A first pressure chamber and a second pressure chamber located within the actuator housing between the plate and the cover;

Wherein the first pressure chamber is defined at least in part by a diaphragm supported by the plate such that the diaphragm moves between a shortened position and an extended position, the plate being in a plate raised position when the diaphragm is in the shortened position and the diaphragm being in a bellows shape in cross-section formed by an inner ring having an inner ring inner diameter and an outer ring having an outer ring outer diameter relative to the central axis, the diaphragm being in the extended position when the plate is in the plate lowered position by axially expanding the bellows shape and reducing a difference between the inner ring inner diameter and the outer ring outer diameter measured relative to the central axis such that the inner ring contacts a sidewall of the actuation housing, and wherein the outer ring and the inner ring are axially spaced apart; the second pressure chamber defined by the plate, the actuator housing, and the cover, the second pressure chamber having a plate seal assembly including an outer diameter sidewall seal between the inner diameter of the actuator housing and the outer diameter of the plate; and

a fluid-tight region between the lid and the plate is formed by at least one of the first and second pressure chambers, and the plate moves between a plate-raised position and a plate-lowered position in response to pressure medium injected into the fluid-tight region, the plate being closer to the valve end in the plate-lowered position than in the plate-raised position.

10. The apparatus of claim 9, further comprising a cap seal fluidly sealing between the cap and the actuator housing.

11. The apparatus of claim 10, wherein the diaphragm has an outer diameter portion, and wherein the cap seal comprises the outer diameter portion of the diaphragm between the cap and the actuator housing.

12. The apparatus of claim 11, wherein the outer diameter portion of the diaphragm includes a sealing lip and the cap seal includes the sealing lip in an annular sealing lip groove between the cap and the actuator housing.

13. the apparatus of claim 9, wherein the first pressure chamber and the second pressure chamber are redundant pressure chambers that fluidly seal the fluidly sealed region, the second pressure chamber to fluidly seal the fluidly sealed region upon failure of the first pressure chamber.

14. The apparatus of claim 9, further comprising a seal nut coupled to the plate, the seal nut operable to engage a central opening of the diaphragm.

15. The apparatus of claim 14, wherein the second pressure chamber includes a retaining seal circumscribing an outer diameter of the seal nut and axially spaced from the diaphragm.

16. The apparatus of claim 14, wherein:

The septum having a septum lip circumscribing the central opening of the septum;

The seal nut having an annular nut lip; and

the first pressure chamber is at least partially defined by the diaphragm lip retained by the nut lip.

17. The apparatus of claim 9, further comprising a sealant injection port extending into the first pressure chamber, the sealant injection port selectively introducing sealant into the first pressure chamber and into sealing contact with a damaged area of the diaphragm.

18. The apparatus of claim 9, wherein the cover is removably connectable to the actuator housing by placing the cover on the actuator housing and rotating the cover from a released position to a locked position, the cover rotating less than one full revolution between the released position and the locked position.

19. The device of claim 9, wherein the diaphragm does not extend axially past the plate in each of the plate-up position and the plate-down position.