Valve having protected, moveable seal and seal assembly therefor

A sealing apparatus includes a moveable seal holder with a cavity and includes a seal assembly disposed at least partially in the cavity. The seal assembly includes a resilient seal member including a fluid-facing end with a fluid-facing end surface, and the seal assembly includes an actuator plate configured to reciprocate between a first and a second position relative to the protective plate. The first actuator plate includes a fluid-facing end surface and a first camming surface. The seal assembly further includes a first protective plate disposed between the seal member and the first actuator plate. The actuator plate is configured to compress the seal member and to move the fluid-facing end surface of the seal member outward from a resting position when the actuator plate is in the second position.

BACKGROUND

Field of the Disclosure

This disclosure relates generally to valves with linearly moving plates configured to close flow passages, including annular flow passages. More particularly, it relates to an apparatus and methods for sealing with moving seal assemblies having a resilient seal member. Still more particularly, this disclosure relates to blow-out preventers, ram valves, gate valves, and similar equipment suitable for high pressure applications.

Background to the Disclosure

Blow-out preventers (BOP's) and ram valves may be used to close rapidly a flow passage so as to prevent an unexpected surge in pressure from causing an uncontrolled flow of fluid out of an oil well (i.e. a well blowout). Considering BOP's more closely, BOP's commonly include a linearly moving plate or plates having a resilient seal member extending from its leading end. Some plates are contoured to seal the annular space around a tubular member that extends through the BOP valve. Whether the plates have a flat or a contoured leading end, during normal operation the plates are retracted from a flow passage but the seal member remains exposed to the fluid that is flowing through the passage. When the fluid includes entrained, abrasive particles, the normal flow through the valve can result in erosion of the seal member, making the valve less effective or ineffective for the purpose of closing and sealing the fluid passage when the valve is activated to close.

SUMMARY OF THE DISCLOSED EMBODIMENTS

These and other needs in the art are addressed in one embodiment by a sealing apparatus. In an embodiment, the sealing apparatus includes a moveable seal holder, a cavity in the seal holder, and a seal assembly disposed at least partially in the cavity. The seal assembly includes a resilient seal member including a fluid-facing end with a fluid-facing end surface. The seal assembly also includes a first actuator plate configured to reciprocate between a first and a second position relative to the protective plate. The first actuator plate includes a fluid-facing end surface and a first camming surface. In addition, the seal assembly includes a first protective plate disposed between the seal member and the first actuator plate. The actuator plate is configured to compress the seal member and to move the fluid-facing end surface of the seal member outward from a resting position when the actuator plate is in the second position.

In some embodiments, the seal assembly is configured such that movement of the first actuator plate from the first position toward the second position causes the first camming surface of the first actuator plate to bear against the first protective plate and to compress the resilient seal member. In some embodiments, the seal assembly is configured such that when the first actuator plate is in the first position, the thickness of the resilient seal member at the fluid-facing end has a first thickness, and when the actuator plate is in the second position, the thickness of the resilient seal member at the fluid-facing end has a second thickness that is less than the first thickness.

In some embodiments, the cavity in the seal holder includes opposing, first and second receiving surfaces, the seal assembly is disposed between the first and second receiving surfaces, and the first actuator plate further comprises a second camming surface configured to engage the first receiving surface of the cavity as the first actuator plate is moved from the first position toward the second position. In some embodiments, the fluid-facing end of resilient seal member has curved recess configured to seal against a cylindrical pipe. In some embodiments, the fluid-facing end surface of resilient seal member is concave when the first actuator plate is in the first position, and the fluid-facing surface end of resilient seal member is convex when the first actuator plate is in the second position.

In some embodiments, the first position of the first actuator plate, the fluid-facing end surface of the first actuator plate extends beyond the fluid-facing end surface of the seal member, and, in the second position of the first actuator plate, the fluid-facing end surface of the seal member extends to or beyond the fluid-facing end surface of the first actuator plate.

In some embodiments, the seal assembly further comprises a plurality of pins, each of the pins extending into a receiving slot that limits the distance the first actuator plate may travel. In some embodiments, the pins extend from the first actuator plate and the slots are formed in the first protective plate, and the protective plate is bonded to the seal member. In some embodiments, the first actuator plate further comprises a body portion that is free of camming surfaces and a wedge portion extending from the body portion to the fluid-facing end surface of the first actuator plate and including the first camming surface. In some embodiments, the slots have a functional length through which the pins can move, and the functional length of the slots is less than the camming length.

In some embodiments, the sealing apparatus further comprises a valve body having a fluid passageway therethrough, and a seat in the valve body configured to engage sealingly the seal member of the moveable seal holder. In some of these embodiments, the moveable seal holder is configured to move from an open position in which the resilient seal member is spaced apart from the seat to a closed position in which the resilient seal member sealingly engages the seat to prevent fluid flow through the body.

In some embodiments, the fluid-facing end of resilient seal member has curved recess configured to seal against a cylindrical pipe, and the sealing apparatus further comprises a BOP body having an interior surface defining a fluid passageway and being configured to receive a tubular member having a given diameter extending through the passageway. The moveable seal holder is disposed within the BOP body and is configured to move from an open position in which the resilient seal member is spaced apart from the tubular member to a closed position in which the curved recess of the resilient seal member configured to engage sealingly a tubular member of the given diameter to prevent fluid flow through the BOP.

In some embodiments, the seal assembly further comprises a second protective plate comprising a camming surface and a second protective plate disposed between the seal member and the second actuator plate. In these embodiments, the cavity in the seal holder includes opposing, first and second receiving surfaces, and the seal assembly is disposed between the first and second receiving surfaces. Further, the seal assembly is configured such that movement of the second actuator plate from a first position toward a second position causes the camming surface of the second actuator plate to compress the resilient seal member by bearing against the second protective plate or against the second receiving surface of the cavity.

These and other needs in the art are addressed in yet another embodiment by a method for sealing a fluid passageway. The method includes disposing a resilient seal member within a seal holder, the seal member extending parallel to a first axis, the seal member having a fluid-facing end surface with a resting position. The method also includes, configuring a first actuator plate to move relative to the seal member and the seal holder. In addition the method includes, compressing the seal by moving the first actuator plate and causing the fluid-facing end surface of the seal member to extend outward along the first axis, beyond the seal holder and beyond the resting position.

In some embodiments of the method, moving the first actuator plate involves moving it parallel to the first axis. In some embodiments of the method, the first actuator plate is configured to apply to the seal member a compression force parallel to or along a second axis that crosses the first axis.

In some embodiments of the method, compressing the seal member by moving the first actuator plate includes applying an actuation force parallel to the first axis. In some embodiments of the method, the seal holder is disposed within a valve body having a flow passageway, and the seal holder is configured for movement along the first axis relative to the valve body. In some embodiments of the method, causing the fluid-facing end surface of the seal member to extend outward results in closing the flow passageway.

In some embodiments, the method also includes disposing the first actuator plate within the seal holder along a first surface of the seal member, and disposing a second actuator plate within the seal holder along a second surface of the seal member. The first and second surfaces of the seal member are parallel to the first axis; and compressing the seal includes moving both actuator plates relative to the seal member, parallel to the first axis.

Thus, embodiments described herein include a combination of features and characteristics intended to address various shortcomings associated with certain prior devices, systems, and methods. The various features and characteristics described above, as well as others, will be readily apparent to those of ordinary skill in the art upon reading the following detailed description, and by referring to the accompanying drawings.

NOTATION AND NOMENCLATURE

The following description is exemplary of certain embodiments of the disclosure. One of ordinary skill in the art will understand that the following description has broad application, and the discussion of any embodiment is meant to be exemplary of that embodiment, and is not intended to suggest in any way that the scope of the disclosure, including the claims, is limited to that embodiment.

The figures are not necessarily drawn to-scale. Certain features and components disclosed herein may be shown exaggerated in scale or in somewhat schematic form, and some details of conventional elements may not be shown in the interest of clarity and conciseness. In some of the figures, in order to improve clarity and conciseness, one or more components or aspects of a component may be omitted or may not have reference numerals identifying the features or components. In addition, within the specification, including the drawings, like or identical reference numerals may be used to identify common or similar elements.

As used herein, including in the claims, the terms “including” and “comprising,” as well as derivations of these, are used in an open-ended fashion, and thus are to be interpreted to mean “including, but not limited to . . . .” Also, the term “couple” or “couples” means either an indirect or direct connection. Thus, if a first component couples or is coupled to a second component, the connection between the components may be through a direct engagement of the two components, or through an indirect connection that is accomplished via other intermediate components, devices and/or connections. The recitation “based on” means “based at least in part on.” Therefore, if X is based on Y, then X may be based on Y and on any number of other factors. The word “or” is used in an inclusive manner. For example, “A or B” means any of the following: “A” alone, “B” alone, or both “A” and “B.”

In addition, when used herein including the claims, the words “generally” and “substantially” mean within a range of plus or minus 10%. When used herein, including the claims, the word “uniform” is equivalent to the phrase “uniform or substantially uniform.”

In addition, the terms “axial” and “axially” generally mean along a given axis, while the terms “radial” and “radially” generally mean perpendicular to the axis. For instance, an axial distance refers to a distance measured along or parallel to a given axis, and a radial distance means a distance measured perpendicular to the axis. Furthermore, any reference to a relative direction or relative position is made for purpose of clarity, with examples including “top,” “bottom,” “up,” “upper,” “upward,” “down,” “lower,” “clockwise,” “left,” “leftward,” “right,” and “right-hand.” For example, a relative direction or a relative position of an object or feature may pertain to the orientation as shown in a figure or as described. If the object or feature were viewed from another orientation or were implemented in another orientation, it may be appropriate to describe the direction or position using an alternate term.

DETAILED DESCRIPTION OF THE DISCLOSED EXEMPLARY EMBODIMENTS

The following discussion describes various embodiments of a sealing apparatus that compresses a sealing member to move or extend a fluid-facing end surface of the sealing member in order to close a fluid passage. Compressing the sealing member pushes a portion of its body toward its fluid-facing end surface and into the fluid passage. When the seal member is relaxed and the valve is open, that portion of the seal member's body is retracted from the fluid passageway and thereby protected from fluid flow. In some embodiments, the fluid-facing end surface or a portion of it is also retracted from the fluid passageway and is thereby protected from the fluid flow when the seal member is relaxed and the valve is open. In some instances, an embodiment of the sealing apparatus is used for safety or process control at a hydrocarbon well, including situations that require a high-speed closure of a fluid passageway. Embodiments of the sealing apparatus may, in other instances, be employed in gate valves, such as valves controlling the flow of fluid of various types in pipelines, refineries or other industrial facilities.

Referring toFIG.1, in an exemplary embodiment, a valve50, a sealing apparatus, includes a valve body52, multiple rams100, and multiple hydraulic piston-cylinder assemblies54, each is configured to apply an actuation force parallel to a ram axis62to actuate one of the rams100. In this example, valve50is configured as a blow-out-preventer (BOP) suitable for use at the wellhead of a hydrocarbon well and includes two rams100. In some applications, multiple BOP valves50will be used in series at a wellhead of an oil well during drilling, production, maintenance, or other well operations. BOP valve50is configured to allow a tubular member or strings of tubular members, such as pipe56to be installed into, retained within, or be removed from the oil well. In various instances for various embodiments, the tubular member or string may include, as examples, a bottom hole assembly, drill pipe, casing, or coiled tubing.

Valve body52, which may also be called a BOP body, includes a flow axis61, the ram axis62perpendicular to flow axis61, and an interior surface64. Interior surface64includes a flow channel66, which is a throughbore passing entirely through body52along flow axis61, and a cylindrical actuator recess or channel68extending along ram axis62and intersecting channel66. The rams100are slidingly received within channel68on opposite sides of axis61. When installed as shown, pipe56extends entirely through channel66, generally centered on axis61and passing between rams100. An annular fluid passageway70surrounds pipe56, providing a path for fluid communication through valve50and into a well or well bore. The positioning of the rams100within body52divides flow channel66and, more specifically, divides annular passageway70into an upper fluid zone72and a lower fluid zone73. Valve50is configured to close and to open fluid communication between annular zones72,73by sliding rams100along ram axis62toward or away from each other and pipe56. Valve50is shown in an open condition with rams100retracted to a position away-from flow axis6. Rams100are configured to seal simultaneously against each other and against the outer surface of pipe56or another tubular member when closed around it.

Referring now toFIG.1andFIG.2, ram100is a sealing apparatus and is configured as an assembly that includes a ram body102as well as a seal104and an actuator106, both of which extend out from a channel or cavity108in ram body102. Ram body102is therefore configured as a moveable seal holder. Seal104and actuator106may be configured as an assembly. Ram100also includes a generally semi-circular recess or channel118passing through ram body102, seal104, and actuator106. The inclusion of semi-circular channel118configures ram100as a pipe ram capable of sealing the annular flow passageway70located around pipe56or any of a variety of tubular members. Actuator106extends further out of cavity108than does seal104when disposed in the resting position that is shown, the resting position corresponding to the open condition of valve50. In the examples ofFIGS.1and2, seal104is configured as a plate-backed seal.

Best shown inFIG.3, ram body102is generally cylindrical and includes a central or longitudinal ram axis111, a transverse axis112, a front end114, a back end115, a generally cylindrical outer surface116, the cavity108, and semi-circular portions of channel118centered along axis112. Transverse axis112is located at front end114and intersects axis111at 90 degrees. Cavity108is generally rectangular, extending through front end114depth wise along axis111and extending laterally in width through outer surface116at two opposite locations. Cavity108includes an upper receiving surface122, a lower receiving surface123, a rear surface124, and a keyway126located in lower surface123. Surfaces122,123oppose each other, extend parallel to axis111, are perpendicular to transverse axis112. Lengthwise, keyway126is perpendicular to both axes111,112. When assembled into valve50(FIG.1), axis111aligns with axis62.

FIG.4shows that plate-backed seal104includes a resilient seal member150bonded between upper and lower protective plates170. Seal104includes a semi-circular channel or recess140extending through the front ends of seal member150and plates170. Recess140is centered about an axis144located at one end of seal104and is configured to be positioned around tubular member56. Plate-backed seal104is configured to have axis144be positioned parallel to ram axis112(FIG.3). A boss or key145extends laterally along bottom of lower plate170and is configured to limit the axial movement of seal104with respect to ram body102when received in keyway126(FIG.2).

Continuing to referenceFIG.4, seal member150includes a front, fluid-facing end or end surface152, an opposite end surface154, a laterally-extending top surface156positioned against upper plate170, a laterally-extending bottom surface158positioned against lower plate170, and two side surfaces159. Fluid-facing end surface152includes portion a portion or all of recess region140and two generally rectangular regions153aligned with axis144and located on opposite sides of recess140. Seal member150, including end surface152, is characterized by a resting height or thickness160extending between plates170. Seal member150may be fabricated from an elastomeric or rubber material, as examples. The fluid-facing end surface152is convex, bulging outward as it extends from top and bottom towards a central plane that can be imagined to pass through seal member150parallel to the two plates170. The convexity of surface152extends along both regions153and along recess140.

Referring now to bothFIG.4andFIG.5, upper protective plate170includes a top surface171, and multiple, spaced-apart holes172open through top surface171. Lower protective plate170is similar or identical to upper plate170and includes a bottom surface173. Plates170also include a fluid-facing end or end surfaces176, parallel or generally parallel to surface152. Multiple pins174extend from each plate170into seal member150, proximal the end surface154. In at least this embodiment, plates170extend from fluid-facing end surface152of seal member150toward the rear end surface154, but are slightly shorter than seal member150, not reaching the end surface154. In some embodiments, one or both plates170extend entirely across seal member150, reaching the end surface154.

Referring toFIG.6,FIG.7, andFIG.8, actuator106includes a central body axis201, a body portion202, a wedge portion204, a central wedge portion206, a fluid-facing end surface212, an opposite end surface214, a top surface216, a bottom surface218, first and second side surfaces219, and multiple receiving slots220. When actuator106is installed within ram body102, plate axis201is aligned parallel to ram axis111. In this embodiment, actuator106is configure as a generally planar member and may also be called actuator plate106. Actuator plate106also includes a semi-circular channel or recess208centered on a traverse axis211and passing through body portion202, wedge portion204, and end surface212. Central axis201defines the lengthwise direction for plate106and divides in half each of the portions202,204,206and recess208. Axis212is perpendicular to axis201. Top and bottom surfaces216,218are parallel or substantially parallel and extend across body portion202; body portion202is free of camming surfaces. Fluid-facing end surface212is perpendicular or substantially perpendicular to top and bottom surfaces216,218. Side surfaces219are tapered, curved, or otherwise contoured to conform or generally to match the outer surface116of ram body102adjacent the location of actuator plate106. As best seen inFIG.6, actuator plate106includes two receiving slots220, which are located between wedge portion204and end surface214, on opposite sides of axis201and recess208. Slots220extend parallel to axis201, and each has a slot length221. When assembled, as discussed below, each slot220slidingly receives a fastener or pin to limit the movement of plate106. Normally, plate106and its slots220moves relative to the pins, but for sake of discussion, the two extreme positions222A,222B of a pin are indicated within one of the slots220onFIG.6, as if the pin were to move. The center-to-center distance223between the two pin positions222A,222B defines the maximum travel distance of plate106and may also be called the functional length of slots220. In various embodiments, slots220are configured to prevent plate106from traveling entirely into cavity108of ram body102. This configuration may be achieved, for example, by a particular axial positioning of slots220with respect to axis201or by making functional length223of the slots less than the wedge length242.

Wedge portion204extends lengthwise from body portion202to end surface212, extends widthwise between side surfaces219and is divided widthwise into two portions by recess208, which is between sides219. Wedge portion204includes a top camming surface232, an extension surface234extending from surface232to end surface212, and a bottom camming surface236. Measured along or parallel to axis201, wedge portion204has a wedge length242; a portion of this length is the camming length243of top camming surface232, and the remaining portion is the length of extension surface234. Top camming surface232is oriented at a wedge angle246with respect to top surface216. In the embodiment shown inFIG.8, wedge angle246equals 30 degrees, and surface232achieves a height247from top surface216. Extension surface234is parallel to top surface216and is disposed at the same height247. Bottom camming surface236is oriented at the same wedge angle246with respect to bottom surface218, extends the same camming length243, and achieves the same height247; although, surface236intersects fluid-facing end surface212without an intermediate extension surface, such as surface234. Consequently, the wedge length of surface236is equal to its camming length243in this embodiment.

Referring still toFIGS.6,7, and8, central wedge portion206extends lengthwise along axis201, ending at the center of recess208and is curved to match the curvature of recess208. Wedge portion206includes a central top camming surface252, an extension surface254extending from surface252to recess208, and a central bottom camming surface256. Top and bottom camming surfaces232,256are oriented at the wedge angle246with respect to top and bottom surfaces216,218, respectively, extend the same camming length243, and achieve the same height247, as previously described. Central bottom camming surface256intersects fluid-facing end surface212without an intermediate extension surface, such as surface254; consequently, the wedge length of surface256is equal to its camming length243.

In some embodiments, actuator plate106flexes or bends along its length (front to back) when it is slides against and compresses plate-backed seal104within ram cavity108. In some embodiments, the lengths, angles and the resulting heights of some camming surfaces232,236,252,256or extension surfaces234,254may differ from others of this group of surfaces. In some embodiments, the wedges also include extension surfaces extending from bottom camming surfaces236,256, or an extension surface may taper with respect to top surface216rather than being parallel. Although wedge angle246was described as 30 degrees in the exemplary embodiment disclosed above, in various embodiments the wedge angle246is selected from a value within the range 5 to 30 degrees (end points included, typical) or within the range 10 to 22.5 degrees, from 5 to 40 degrees, or selected from a value within any range that is within one of these ranges, as examples. Other values of angle246may provide acceptable performance of actuator plate106as it slides across plate-backed seal104. In some embodiments, the total wedge angle of a wedge portion202,206is twice the value of the wedge angle246.

In the embodiment shown inFIG.9, actuator plate106is slidingly coupled to plate-backed seal104by multiple fasteners or pins258forming a seal assembly260. One of the pins258is firmly coupled within each of the holes172on upper protective plate170(FIG.4) and extends into an aligned slot220of plate106. Thus, inFIG.9, assembly260includes two pins258. Pins258serve at least to guide and to limit the movement of actuator plate106relative to plate170and seal member150during compression and during re-expansion, acting as a mechanical stop in some instances. Pins253serve to prevent plate106from falling into the wellbore and to prevent plate106from becoming lodged within ram body102, as examples.FIG.9shows a resting position of plate106with respect to plate-backed seal104. In this resting position, the end surface214of plate106is offset “forward” from the end surface154at the back of plate-backed seal104by a distance262, such that surface214is closer to recess140of seal104. The elongate slots220extend ahead of pins258by at least a portion of the distance262. In the resting position, the recess208in plate106is offset forward from recess140in plate-backed seal104.

Referring now toFIG.10, seal assembly260is positioned within cavity108of ram body102with key145received within keyway126. The offset distance262leaves a gap264at the rear of cavity108when plate106and plate-backed seal104are resting within ram body102, as shown. The bottom surface218of plate106engages the upper protective plate170, and top surface216engages upper receiving surface122of cavity108. The gap264and the forward position of slots220(with respect to pins258;FIG.9) configure actuator plate106to slide toward the rear of ram cavity108to a second, compression position when an actuation force is applied to the end surface212of wedge portion204. The actuation force may be directed parallel or generally parallel to axis111, as examples. At the same time, slots220and pins258limit the distance actuator plate106may travel as it moves toward the compression position. Referring now toFIG.2as well asFIG.10, which both show a first or resting position of plate-backed seal104and plate106within ram body102. The resting thickness160of seal member150is again indicated. Plate-backed seal104rests against the rear surface124and extends beyond cavity108and front end114by a distance265less than or equal to the difference between wedge length242and camming length243. Thus, in this embodiment, the distance265is less than or equal to the length of extension surfaces234,254(FIG.6). Along the top of actuator plate106, wedge portions204,206are offset beyond front end114of ram body102by the full wedge length242. However, as is visible along the bottom of plate106, wedge portions204,206are offset beyond plate-backed seal104by a shorter length, e.g. the camming length243, due to the extension of seal104beyond cavity108. Similarly, in the embodiment shown inFIG.10, fluid-facing end surface212of actuator plate106extends beyond the fluid-facing end surface152of seal member150.

FIG.11shows an example of a condition in which actuator plate106has been moved to a second, compression position further into cavity108of ram body102causing plate-backed seal104to be compressed to a shorter height or thickness along axis144, perpendicular to axis111. Referring toFIG.8as well asFIG.11, the plate-backed seal104is configured such that movement of the actuator plate106from the resting position (FIG.10) toward the compression position causes the top camming surfaces232,252of actuator plate106to bear against the upper receiving surface122of cavity108and causes the bottom camming surfaces236,256to bear against the upper protective plate170and compress the resilient seal member150. Preferably, this action involves segments of wedge portion204located on both sides of recess208(FIG.9) as well as central wedge portion206. In general, the volume of seal member150remains constant as it transitions between compression and relaxation states. Consequently, when it is compressed in one direction, it expands in one or more other direction.

In particular, the front portion of seal member150that includes fluid-facing end surface152has been compressed to a height or thickness270that is less than the resting thickness160(FIG.10). Seal member150experiences the greatest compressed adjacent wedge portions204,206. Seal member150experiences gradually less compression in the portions that extend toward opposite end surface154. Adjacent the end surface154, seal member150experiences visibly less compression or, potentially, no compression based on the configuration of actuator plate106. In some instances, end surface154expands to a greater height to compensate for the compression at the other end of seal member150. InFIG.11, plate106has compressed plate-backed seal104to a condition in which upper plate170and the top surface156of seal member150are positioned at an angle272with respect to their resting position. In this example angle272equals 10 degrees. The average, compressed thickness of seal member150along its axial length is less than its resting thickness160(FIG.10). The previously convex fluid-facing end surface152of the seal member150has moved or extended outward beyond its resting position, extending further beyond the fluid-facing end surfaces176of protective plates170. Surface152has become even more convex as a result of actuator plate106being in the compression position. The end surface152extends axially beyond the fluid-facing end surface212of the actuator plate106, at least in the example shown, in which no opposing object or surface limits the outward movement of surface152.

FIG.12shows two rams100, as are used in valve50ofFIG.1, with a tubular member52located between rams100. The two rams100have been brought proximal each other so that the end surfaces212of the two actuator plates106are pressed together as may be achieved by the action of opposing actuation forces274exerted through rams100parallel or generally parallel to ram axis111. As a result, each plate160is in a compression position. The wedge portions204on plates106are configured to convert the actuation forces274to compression forces acting on seal member150, acting parallel, or generally parallel, along the transverse axis112, which is perpendicular or oblique to ram axis111and forces274. Referring toFIG.4for detailed features, on each corresponding seal104inFIG.12, the fluid-facing end surface152of seal member150has extended outward beyond its resting position. The rectangular regions153of the facing end surfaces152have contacted each other, and the opposing recesses regions140have expanded to contact tubular member52circumferentially. On average, each end surface152extends to the axial location of the intersecting fluid-facing end surfaces212on plates106that have contacted each other. Along annular fluid passageway70, fluid zone72located on one side of the seal assemblies104is sealed, i.e. separated from fluid communication, from fluid zone73located on the opposite side of the seal assemblies104. The entire circumference of tubular member52is sealed by seal members150. The side surfaces159of seals150expand outward to seal against the cylindrical channel68of BOP valve body52in which rams100are slidingly received (FIG.1). In the example ofFIG.12, plates106have deformed, becoming curved upward along their length as a result of compressing seal member150, but other embodiments may be configured to minimize or effectively eliminate such deformation of plate106.

FIG.13shows a plate-backed seal280that includes a resilient seal member282bonded between upper and lower protective plates170with a semi-circular recess140extending through the front ends of seal282and plates170. Plate-backed seal280is configured to be installed within ram body102as an alternative to plate-backed seal104. Seal280has the same features and generally the same functionality as seal104, and seal member282has the same features and generally the same functionality as seal member150except, the seal member282includes a front, fluid-facing end or end surface284with a concave groove286extending laterally, along its length, along two generally rectangular regions153and semi-circular recess140. Concave groove286is recessed behind the fluid-facing end surfaces176of plates170, indicating that seal282is in a resting position relative to plates170.

When plate-backed seal280is installed in a ram body102with an actuator plate106, they are configured similar the resting position shown inFIG.10, but fluid-facing end surface284is concave. Similar to the configuration ofFIG.11, when the associated actuator plate106is pressed to a second, compression position further within ram body102, the plate-backed seal280(FIG.13) compresses along144to a shorter height or thickness, and concave front end surface284budges outward beyond fluid-facing end surfaces176of protective plates170, becoming convex. For embodiments using similar materials, the outward extension achieved by surface284of seal member282during compression is less than is achieved by fluid-facing end surface152of seal member150, but both surfaces152,284are convex when compressed.

Referring toFIG.14, another embodiment of a sealing apparatus, consistent with the present disclosure is a valve300that includes a valve body52, multiple “blind” rams310, and multiple hydraulic piston-cylinder assemblies54, each configured to actuate one of the rams. In some instances, valve300may be used as a BOP. In some instances, valve300may be used as a blow-out preventer (BOP). Body52includes a flow axis61, a ram axis62perpendicular to flow axis61, and an interior surface64. Interior surface64includes a flow channel66, which is a through-bore passing entirely through body52along flow axis61, and an actuator channel68extending along ram axis62and intersecting channel66. During an exemplary installation, flow axis61is vertical and ram axis is horizontal. The rams310are slidingly received within channel68on opposite sides of axis61. The positioning of the rams310within body52divides the fluid passageway that is channel66into an upper fluid zone72and a lower fluid zone73. Valve50is configured to close and to open fluid communication between zones72,73by sliding rams310along ram axis62toward or away from each other. Rams310are configured to seal against each other.

Ram310is a sealing apparatus and, in this embodiment, is configured as an assembly that includes a generally cylindrical ram body312as well as a plate-backed seal314and an actuator316. Plate-backed seal314and actuator316extend out from a cavity318in ram body312, extending parallel to axis62when installed in valve body52. Actuator316extends further out than does seal314in the resting position ofFIG.14. Ram body312is therefore configured as a moveable seal holder.

Ram body312includes a central or longitudinal axis111aligned with axis62, a front end320, an outer surface116contoured to match channel68in body52and the cavity318. Like cavity108of ram100, cavity318is generally rectangular, extending through front end320parallel to axis111and extending laterally in width through outer surface116at two opposite locations. Cavity318includes an upper receiving surface122and a lower receiving surface123, that oppose each other and extend parallel to axis111. Front end320is laterally uniform in shape, lacking the curvature or discontinuity of an intermediate feature, such as channel118ofFIG.3.

As best shown inFIG.15plate-backed seal314includes a resilient seal member330bonded between upper and lower protective plates350. Plate-backed seal314is similar in features and functionality to plate-backed seal104(FIG.4), except plate-backed seal314lacks a semi-circular recess140extending through the front ends of seal member330and plates350. A boss or key145extends laterally along bottom of lower plate350perpendicular to axis111and is configured to limit the movement of plate-backed seal314with respect to ram body312(FIG.14).

Seal member330includes a front, fluid-facing end or end surface332, an opposite end surface154, and two side surfaces159. Surface332is laterally uniform in shape, lacking the curvature or discontinuity of an intermediate feature, such as semi-circular recess140ofFIG.4. More specifically, in the example ofFIG.15, Fluid-facing end surface332extends directly, i.e. straight, between the two side surfaces159and perpendicular to axis111. Seal member330, including end surface332, is characterized by a resting height or thickness160extending between plates350. Seal member330may be fabricated from an elastomeric or rubber material, as examples. The fluid-facing end surface332is convex, bulging outward beyond the two plates350.

Continuing to referenceFIG.15, upper protective plate350is rectangular and includes a fluid-facing end or end surface356parallel or generally parallel to surface332and includes multiple, spaced-apart holes172. Lower protective plate350is similar or identical to upper plate350. Multiple pins174extend from each plate350into seal member330, proximal the end surface154. In at least this embodiment, plates350extend from fluid-facing end surface332of seal member330toward the rear end surface154, but are slightly shorter than seal member330, not reaching the end surface154.

Referring toFIG.16andFIG.17, actuator316includes similar in features and functionality to actuator plate106(FIG.6), except actuator316lacks a semi-circular recess208and a central wedge portion206. Accordingly, actuator316includes body portion362, a wedge portion364, a fluid-facing end surface366, an opposite end surface214, a top surface216, a bottom surface218, first and second side surfaces219, and multiple receiving slots220. In this embodiment, actuator316is configure as a generally planar member and may also be called actuator plate316. Body portion362is rectangular or generally rectangular. Top and bottom surfaces216,218are parallel or substantially parallel and extend across body portion362; body portion362is free of camming surfaces. Fluid-facing end surface366is perpendicular or substantially perpendicular to top and bottom surfaces216,218.

Wedge portion364extends lengthwise from body portion362to end surface366, and extends widthwise directly between two side surfaces219. Thus, wedge portion364and the end surface366are laterally uniform in shape, lacking the curvature or discontinuity of an intermediate feature, such as recess208(FIG.6). Like wedge portion204, wedge portion364includes a top camming surface232, an extension surface234extending from surface232to end surface366, and a bottom camming surface236, each having the dimensions previously described with respect toFIG.8.

Referring again toFIG.14, actuator plate316is slidingly coupled to plate-backed seal314by multiple fasteners or pins, forming a seal assembly, like seal assembly260inFIG.9.FIG.14shows a resting position of plate316with respect to plate-backed seal314. In this resting position, the end surface214(FIG.16) of plate316is offset “forward” from the end surface154at the back of plate-backed seal314, leaving a gap264within the top rear of channel318.

Referring still toFIG.14, the operation of valve300to close and to open is similar to valve50, except valve300is configured to seal when no tubular member is located between the opposing rams310.FIG.14shows valve300in an open condition, with each pair of plate316and plate-backed seal314in a non-compressed, resting position with respect to ram body312. The convex, fluid-facing end surface332extends outward beyond the fluid-facing end surfaces356of protective plates350. In order for valve300to close and seal, the two rams310are pushed towards each other by piston-cylinder assemblies54so that the end surfaces366of the two plates316are pressed together, causing each plate to go to a compression position with respect to ram body312. Each plate316moves further into the receiving cavity318of ram body312, causing plate-backed seal314to be compressed to a shorter height or thickness along axis61due to the action of top and bottom camming surfaces232,236, as previously described. As a result, the fluid-facing end surfaces332of seal members330extend further outward, beyond their resting position, further beyond the fluid-facing end surfaces356of protective plates350. Ultimately, end surfaces332of the two opposing seals members330contact each other. In some at least some instances, the already convex surfaces332becomes more convex. On average, each end surfaces332extends to the axial location of the fluid-facing end surfaces366on the plates316that contacted each other. Plate-backed seal314become angled, and the front portion of seal member330, including end surface332, compress to a thickness that is less than the resting thickness160, similar to angle272and thickness270shown inFIG.11. Once valve300ofFIG.14is closed fluid passageway or channel66is divided such that fluid zone72located on one side of the seals314becomes sealed from the other fluid zone73located on the opposite side of the seals314. The side surfaces159of seals330expand outward to seal against the channel68in which rams310are slidingly received.

Referring now toFIG.18, another embodiment of a sealing apparatus, consistent with the present disclosure is a gate valve400that includes a valve body402, a bonnet404, a valve stem406extending from bonnet404into body402along a stem axis407, a fluid passageway408, and a gate410slidingly received in body402and coupled to stem406for reciprocation, to open and close passageway408. Stem406is exemplified as a captured valve stem406with gate410threadingly coupled for movement along stem406. However, in some embodiments, a rising valve stem is used, and gate400is rotationally coupled to it without threads. Valve stem406is configured to apply to gate410an actuation force parallel to axis407.

Fluid passageway408extends from inlet416to an exit417along a flow axis418that is perpendicular or generally perpendicular to stem axis406. A valve seat420is located within Fluid passageway408between inlet416and exit417. A groove422extends upward from passageway408or seat420and slidingly receives gate410. InFIG.18, valve400is partially open, having gate410situated between an open position and a closed position, partially inserted into valve seat420.

Gate410is a sealing apparatus and is configured as an assembly that includes a plate-backed seal314and an actuator plate316extending out from a cavity318in a gate body432, extending parallel to axis407. Actuator plate316extends further out than does assembly314in the resting position ofFIG.18. Gate body432is therefore configured as a moveable seal holder. Plate-backed seal314and actuator plate316are also in the resting with respect to body432when gate410moves upward to the open position. Actuator plate316and plate-backed seal314are slidingly disposed adjacent each other, at least within cavity318, forming a seal assembly. In at least some embodiments this seal assembly includes pins238like seal assembly260inFIG.9.

Gate body432extends along axis407from a sealing end434to coupling end436and includes a cavity318extending inward from sealing end434. Gate body432is rectangular or generally rectangular, having two flat outer surfaces438parallel to axis407that assist in blocking fluid flow through passageway408and slidingly engage valve seat420. Sealing end434is received within seat420. Cavity318is as described above for valve300, including a receiving surface122and a receiving surface123, extending parallel to axis407. Sealing end434is laterally uniform in shape, lacking the curvature of an intermediate feature, such as channel118ofFIG.3.

Plate-backed seal314inFIG.18is as described above for valve300, and includes, for example, a resilient seal member330bonded between a first and a second protective plate350(Shown inFIG.15; not visible inFIG.18). As described above seal includes a front, fluid-facing end surface332. So also, seal assembly is rectangular or generally rectangular, lacking a semi-circular recess140extending through the front ends of seal member330and plates350so that fluid-facing end surface332is laterally uniform (e.g. from first side159to second side159,FIG.350) in shape, lacking the curvature of an intermediate feature, such as recess140ofFIG.4.

Actuator plate316inFIG.18is as described above for valve300, and includes, for example, a body portion362and a wedge portion364extending from portion362to a fluid-facing end surface366. As described, actuator plate316is rectangular or generally rectangular, lacking a semi-circular recess208so that wedge portion364and surface366are laterally uniform in shape, lacking the curvature of an intermediate feature, such as recess208ofFIG.6.

Continuing to ReferenceFIG.18, gate410may be called a blind gate or a blind ram because gate body432or plate-backed seal314are laterally uniformly in shape, lacking the curvature of an intermediate feature (such as channel118of ram104and recess140of seal104inFIGS.2and4). Regarding being uniformly shaped, in the embodiment ofFIG.18, sealing end434of body432, end surface332of seal member330, and end surface366of plate316extend straight in the direction that is perpendicular both axis407and axis418(i.e. extend “out-of-the-page”). In other embodiments, gate410and its end surfaces434,332,336may include a curvature that extends downward while being laterally uniformly in shape, lacking the curvature or discontinuity of an intermediate feature.

When gate410is moved fully into seat420to achieve the closed position, plate316and seam member330press against the distal side of channel408, contacting either valve body402or seat420. For example, valve400is configured so that fluid-facing end surface366engages a portion of seat420, causing plate316to move to a compression position with respect to seal member330and gate body432. This relative movement of plate316, aided by wedge portions364, causes seal member330to extend further, so that fluid-facing end surface332becomes more convex as it extends to seal passageway408. Seat420also seals against portions of gate body432. Thus, the gate body432is configured to move from an open position in which seal member330is spaced apart from the seat420to a closed position in which seal member420sealingly engages seat420to prevent fluid flow through body402. The wedge portion364on plate316are configured to convert the actuation force of stem406, which acts along axis406, to a compression force acting on seal member150perpendicular, generally perpendicular, or oblique to axis406.

InFIG.19, another embodiment of a sealing apparatus, consistent with the present disclosure is a ram assembly, or simply, ram510includes a longitudinal or central axis511, a ram body512, a plate-backed seal280, and at least one actuator assembly515. Seal280and actuator515extend out from a cavity518in ram body312, having components extending parallel to axis511. Ram body512is therefore configured as a moveable seal holder. Ram body512includes a front end114, a back end115, and the cavity518. Cavity518includes a first and a second channel518A,518B offset from one another, perpendicular to axis511. Cavity channels518A,518B extend through front end114, parallel to axis511.

Plate-backed seal280is as described above with regard toFIG.13. For example, plate-backed seal280includes a includes a resilient seal member282bonded between upper and lower protective plates170with a semi-circular channel or recess140extending through the front ends of seal282and plates170. As described above, seal282includes a front, fluid-facing end surface284with a lateral, concave groove286, and an opposite end surface154. End surface284is concave top-to-bottom between plates170due to groove286and includes the recess140and generally rectangular regions153on opposite sides of recess140. End surfaces284,154extend between plates170, crossing axis511. Plate-backed seal280is received within the surface or surfaces of cavity channel518A and is held by a key145extending perpendicular to axis511and positioned in a keyway. Plates170also include a fluid-facing end surfaces176parallel to or aligned with surfaces284.

Continuing to referenceFIG.19, actuator assembly515includes an actuator plate520and an actuator plate or rod522, coupled by a linkage524. Linkage524includes multiple linkage members525, including an intermediate linkage member528coupled in series by rotational couplings526. Intermediate linkage member528is mounted for rotation about a pivot axis530fixed with respect to ram body512. Actuator plate520includes an actuation surface521that is positioned and configured to engage the end surface154of seal282. Rod522includes a contact end surface523against which a force may be exerted by, for example, a similar surface on an actuator rod522of an opposing ram (not shown) or by a another movable or static surface. In at least some embodiments, the end surface523of rod522is a fluid-facing end surface. Actuator rod522is518B slidingly received within the surface or surfaces of cavity channel518B. Coupled as shown within ram body512, plate-backed seal280and actuator assembly515form seal assembly540. In some embodiments, assembly540includes multiple actuator assemblies515arranged laterally (deeper intoFIG.19), configured so that each actuator plate520engages a region of end surface154on seal282. Optionally, the multiple actuator assemblies515share a single actuator plate520.

FIG.19shows a resting position of actuator plate520adjacent end surface154of seal282, prior to application of an actuation force545. Front, fluid-facing end surface284is also in a resting position, concave and recessed between the plates170. Actuator assembly515is configured such that exertion of the leftward force545on end surface523of rod522results in plate520and actuation surface521exerting a rightward compression force against the seal's end surface154, which compresses seal282and extends the front, fluid-facing end surface284, achieving a second, compression position for seal assembly540. When actuator plate520is in this compression position, the fluid-facing end surface284extends beyond its resting position and extends beyond the fluid-facing end surfaces176of the first and second protective plates170. When force545is released, the resiliency of seal member282causes the seal assembly540to return to the resting position ofFIG.19.

Thus, actuator plate520and rod522are configured to reciprocate between the resting position and the compression position, moving relative to the protective plates170and to the ram body512. The movement of plate520and rod522alternatively compresses and relaxes seal member282and surface284.

In various embodiments, ram510is compatible for installation and use in the various valves disclosed herein. As an example, in some embodiments, ram510is configured as a blind ram, including a plate-backed seal314in place of plate-backed seal280, for use in valve300(FIG.14) or gate valve400(FIG.18) or another valve in accordance with principles described herein. The plate-backed seal314may have a convex or a concave fluid-facing surface on its sealing member. In some embodiments, ram510includes a plate-backed seal104(FIG.4) having a convex fluid-facing surface on its sealing member, in place of plate-backed seal280, which has a concave fluid-facing surface.

FIG.20shows a method560for sealing a fluid passageway in accordance with the principles described herein. Blocks562through570describe an embodiment of the method. Various embodiments of method400may include fewer operations than described, and other embodiments of method560include additional operations.

Referring again toFIG.7actuator plate106includes both a wedge portion204at the outermost end of plate106divided by recess208and also a central wedge portion206that is set-back at the inner most part of recess208. However, in some embodiments, an actuator plate includes a wedge portion204that extends on either side of a recess208but includes no central wedge portion206. In other features, the actuator plate is similar to or derived from plate106. Referring again toFIG.8, although top camming surfaces232,252and bottom camming surfaces236,256employ the same wedge angle246, in some other embodiments a different wedge angle is used for the bottom camming surfaces. Although actuator plate106was shown with camming surfaces232,252,236,256extending away from both top surface216and bottom surface218, some embodiments include camming surfaces extending from only top surface216and from only bottom surface218, and in some instances, the wedge angle is twice the value described for wedge angle246.

A particular resting position and a particular compression position of actuator plate106were presented in the discussion above. In other instances or for other embodiments, a different position of actuator plate106relative to ram body102or relative to plate-backed seal104may be defined to be the resting or the compression position. Different compression positions of plate106cause end surface152of the seal member150to bulge, to extend further outward by different distances.

FIG.9augmented byFIG.4, showed multiple pins258firmly coupled within the holes172on protective plate350and extends into an aligned slot220of plate106. In some other embodiments, the pins extend from the actuator plate and the slots are formed in the protective plate.

As explained for valve50, so also for some embodiments of a valve300,400, the fluid-facing end surface332of the seal member is concave, having a shape similar to the outer regions153on surface284inFIG.13, including periods when an accompanying actuator plate is in the resting position. Optionally, a fluid-facing end surface of a seal member is flat.

Some embodiments of a valve50,300,400include a second actuator plate located on the opposite side of the plate-backed seal104,314to function similarly and simultaneously with the actuator106,316. As an example,FIG.21shows a ram600that may be installed as a moveable seal holder within valve50in place of a ram100. Ram600includes a ram body102extending along an axis111, a plate-backed seal604, and with a pair of actuator plates106. Ram body102and actuators106are as previously described. Seal604has the same features as seal104, except, in this example key145is absent and seal604includes two protective plates610that extend the full length of a seal member150, parallel to axis111. First and second actuators106are located on opposite sides of seal104within channel108of body102. Ram600may be used together with another ram600, forming a pair of rams, within a valve. In various other embodiments an embodiment of seal604includes a key145and the second actuator106of the pair is short enough so as not to interfere with key145, or key145is split into sections and the actuator second actuator includes slots to slide-past the sections of key145.

Referring again toFIG.2andFIG.14, although rams,100,310were described as being generally cylindrical in cross-section with respect to axis111, in some embodiments, a ram body102,312is generally rectangular, square, oval, or obround, as examples, having an outer surface that slidingly engages a similarly shaped actuator channel in a valve body. The sides of the corresponding seam member104,314are similarly shaped. Similarly, referring again toFIG.18, rather than being rectangular in cross-section with respect to axis407, some embodiments of gate body432have a cross-section that is generally square, round, oval, or obround, as examples; some of these embodiments have outer surfaces438that are curved rather than flat. Although, various embodiments described herein include a seal assembly or a plate-backed seal with a resilient seal member bonded to a protective plate, in some embodiments, a resilient seal member is coupled to or contacts a protective plate in another way. For example, a resilient seal member may be disposed or maintained adjacent a protective plate within an assembly or may be held to a protective plate by a fastener. The protective plate is to transfer and distribute a compression force from an actuator plate to the resilient seal member.

While exemplary embodiments have been shown and described, modifications thereof can be made by one of ordinary skill in the art without departing from the scope or teachings herein. The embodiments described herein are exemplary only and are not limiting. Many variations, combinations, and modifications of the systems, apparatuses, and processes described herein are possible and are within the scope of the disclosure. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims. The inclusion of any particular method step or operation within the written description or a figure does not necessarily mean that the particular step or operation is necessary to the method. The steps or operations of a method listed in the specification or the claims may be performed in any feasible order, except for those particular steps or operations, if any, for which a sequence is expressly stated. In some implementations two or more of the method steps or operations may be performed in parallel, rather than serially.