The present invention relates to the field of high pressure reciprocating pumps and, in particular, to fluid ends of high pressure reciprocating pumps and closure and/or sealing assemblies for the same.
High pressure reciprocating pumps are often used to deliver high pressure fluids during earth drilling operations. One or more sealing arrangements are typically provided in the fluid end to seal conduits formed in the fluid end and prevent, or at least discourage, leakage. More specifically, the fluid end may define one or more internal pumping chambers and conduits may define pathways between the one or more internal pumping chambers and external surfaces of the fluid end. At least some segments of these conduits may be sealed with a closure assembly that may include a closure element (e.g., a cover, plug, and/or sleeve), a seal element, and a retaining element. Alternatively, a closure assembly may include some subset of these elements. In any case, seals in a fluid end segment may prevent, or at least discourage, leakage through the conduits of a fluid end.
The present application relates to techniques for closing a segment of a fluid end of a high pressure reciprocating pump. The techniques may be embodied as a closure element and/or a closure assembly, either of which may be provided independent of any other elements or as part of a fluid end, a kit, and/or a reciprocating pump. Additionally, the techniques may be embodied as a fluid end and as a method for closing a segment of a fluid end of a high pressure reciprocating pump.
More specifically, in accordance with at least one embodiment, the present application is directed to a closure element for a fluid end of a reciprocating pump. The closure element is installable within a segment of a casing of the fluid end to substantially close the segment and includes a main body that extends from an interior surface to an exterior surface. At least a portion of the main body has a non-circular cross-sectional shape.
Among other advantages, the non-circular shape creates sealing and retaining options that may be advantageous as compared to traditional sealing and retaining techniques. For example, the closure element may be self-retaining and/or may be retained within a bore without threading, which is often a high-stress point that is prone to failure. More specifically, closure elements are often secured in a segment with a retaining element that is secured to a fluid end via a threaded connection formed between threads machined into the fluid end and threads of the retaining element. These threads are typically subject to high levels of cyclical stress and, thus, if the retaining element is not installed or preloaded correctly, the threads may experience fatigue failure.
Still further, the non-circular cross-sectional shape allows a sealing location to move inwards, adjacent a pumping chamber, or outwards, adjacent an exterior of the fluid end, each of which may provide additional life span advantages for the closure element and/or the fluid end within which the closure element is installed. For example, a closure element with a non-circular cross-sectional shape may be retained adjacent the pumping chamber of a fluid end and may protect the interior edges of a fluid end segment, which are often a point of failure, from wear. Additionally or alternatively, when the closure element is retained adjacent the pumping chamber or external surface, the closure element can define a corner for a corner seal, which may avoid traditional pitfalls associated with radial seals (i.e., outer diameter seals) used on closure elements for fluid ends. For example, when a closure element has a non-circular cross-sectional shape, a bore or corner seal may be used to seal around the closure element. Still further, in some instances, the sealing area can be located on a removable piece. Then, if the sealing surface becomes damaged (which typically happens over time during normal pumping operation), the sealing area can be repaired via a part replacement instead of via an invasive repair (e.g., a weld repair).
In at least some embodiments, the non-circular cross-sectional shape is an extended ovular shape. This shape may ensure that the closure element is removable from, but also securable within, a bore segment of a fluid end. Additionally or alternatively, the main body may include a seating section proximate the interior surface and a closure section proximate the exterior surface, one or both of which may have the non-circular cross-sectional shape. For example, the seating section may extend radially beyond the closure section, the seating section may have a first non-circular cross-sectional shape, and the closure section may have a second non-circular cross-sectional shape that is smaller than the first non-circular cross-sectional shape. Alternatively, the seating section may extend radially beyond the closure section and only one of the seating section and the closure section may include the non-circular cross-sectional shape. In either case, the two sections may allow the closure element to be secured within the fluid end, e.g., against the fluid end and/or a retaining element, and/or to form a corner seal when secured within a fluid end bore segment.
In at least some instances where the seating section extends radially beyond the closure section, the seating section may define a non-circular shoulder between the seating section and the closure section. In some of these embodiments, the closure section defines a seal channel adjacent or proximate to the non-circular shoulder. Either way, this allows some flexibility for the sealing area and may, advantageously, move the sealing area away from locations that are hard to repair. Still further, in some embodiments, the closure element includes one or more installation elements disposed on and extending away from the exterior surface so that that the one or more installation elements are accessible from an exterior of the segment of the casing of the fluid end when the closure element is installed within the segment. Such elements may enable a user to easily install or remove the closure element from a fluid end bore segment.
In accordance with additional embodiments, the present application is directed to a closure assembly. The closure assembly may be formed with the foregoing closure element embodiments, as well as variations thereof. Thus, the closure assembly may realize any of the foregoing advantages. Additionally, the closure assembly may include a retaining assembly that is coupleable to the exterior surface of the closure element. Generally, the retaining assembly may prevent, or at least discourage, the closure element from being blown out (i.e., removed) of a bore segment, e.g., by pressure in a pumping chamber. In some embodiments, the retaining assembly may also prevent, or at least discourage, the closure element from being sucked into a pumping chamber of the fluid end (e.g., during an intake stroke of a reciprocating component operating in or adjacent the fluid end).
In at least some embodiments, the retaining assembly also includes couplers that removably couple a retaining element to the closure element. Additionally or alternatively, the retaining assembly may be configured to be disposed entirely within the segment of the casing of the fluid end when the closure element is installed within the segment of the casing of the fluid end. In fact, in such embodiments, the retaining assembly may appear to be part of the closure element and, thus, such embodiments may sometimes be referred to as “two-part closure element” embodiments. Among other advantages, such embodiments may allow a closure element to seal adjacent a pumping chamber, potentially reducing the size of the pumping chamber, which is advantageous for pumping compressible fluids. Additionally or alternatively, a retaining assembly disposed within a fluid end bore may reduce the overall footprint of a fluid end (since the retaining assembly does not extend therefrom), potentially reducing snag/trip hazards around the fluid end (e.g., as compared to retaining assemblies that protrude from a fluid end).
Alternatively, in some instances, at least a portion of the retaining assembly is configured to be disposed at least partially exteriorly of the casing of the fluid end when the closure element is installed within the segment of the casing of the fluid end. For example, the retaining assembly may include a retainer, such as an annular retaining ring with a non-circular cross section, disposed exteriorly of the casing of the fluid end. The retainer can define a seat on which a shoulder of the portion of the main body of the closure element with the non-circular cross-sectional shape may sit. Then, the sealing area for the closure element may be formed against this annular ring, which can be easily repaired or replaced (e.g., without invasive repairs). Moreover, in at least some embodiments, the retainer may be secured to a fluid end with a plurality of couplers, but need not be removed to replace the closure element. Instead, the non-circular cross-sectional shape of the closure element may allow the closure element to be replaced or serviced quickly, without removing plurality of couplers (e.g., by rotating the closure element into an installation/removal orientation while the retainer remains in place).
In accordance with additional embodiments, the present application is directed to a fluid end of a reciprocating pump including a casing with intersecting conduits that collectively define a plurality of segments extending from an external surface of the casing to a pumping chamber defined within the casing. At least a portion of at least one segment of the plurality of segments has a non-circular cross-sectional shape configured to receive and secure a closure element with a non-circular cross-sectional shape. At least because of the non-circular cross-sectional shape, this fluid end may realize many of the advantages discussed above in connection with the closure elements and/or the closure assemblies presented herein.
In some embodiments, the plurality of segments include an intake segment that provides a fluid inlet for the pumping chamber, a discharge segment that that provides a fluid outlet for the pumping chamber, a reciprocation segment, and an access segment. The reciprocation segment is configured to operably couple a reciprocating component to the pumping chamber so that the reciprocating component can draw fluid into the pumping chamber via the intake segment and discharge fluid from the pumping chamber via the discharge segment. The access segment provides access to at least the pumping chamber. In some instances, the access segment has the non-circular cross-sectional shape. Additionally or alternatively, the discharge segment may have the non-circular cross-sectional shape.
Regardless of the segments included in a fluid end, the portion of the at least one segment of the plurality of segments that has the non-circular cross-sectional shape may comprise a segment portion adjacent to the pumping chamber. Alternatively, the portion of the at least one segment of the plurality of segments that has the non-circular cross-sectional shape may comprise a segment portion adjacent to the external surface of the casing.
In accordance with additional embodiments, the present application is directed to a method of closing an externally open segment of a fluid end of a reciprocating pump with a closure assembly. The method includes inserting a non-circular closure element into a segment of a fluid casing in a first direction while the non-circular closure element is disposed in a first orientation. Then, the non-circular closure element is rotated to a second orientation that is angularly offset from the first orientation with respect to at least one axis of rotation. After and/or during the rotation, the non-circular closure element is moved within the segment of a fluid casing in a second direction. The second direction is opposite the first direction and, thus, causes the non-circular closure element to seat within the segment. In some of these embodiments, the rotating occurs in a pumping chamber of the fluid end and involves a first rotation of approximately ninety degrees about a first axis of rotation and a second rotation of approximately ninety degrees about a second axis of rotation.
Notably, among other advantages, the closure element can be seated into a bore segment without a retaining element and/or without threading. At least because this method utilizes a non-circular closure element, this method may also realize any advantages described above. This method may also be executed with any variations of closure elements or closure assemblies described herein.
The foregoing advantages and features will become evident in view of the drawings and detailed description.
To complete the description and in order to provide for a better understanding of the present application, a set of drawings is provided. The drawings form an integral part of the description and illustrate embodiments of the present application, which should not be interpreted as restricting the scope of the invention, but just as examples. The drawings comprise the following figures:
Like reference numerals have been used to identify like elements throughout this disclosure.
The following description is not to be taken in a limiting sense but is given solely for the purpose of describing the broad principles of the invention. Embodiments of the invention will be described by way of example, with reference to the above-mentioned drawings showing elements and results according to the present invention.
Generally, the present application is directed to a fluid end of a reciprocating pump, closure assemblies for the fluid end, and/or portions thereof. The fluid end presented herein has at least one bore with a non-circular cross-sectional shape while the closure assemblies presented herein include least some components or sections with non-circular cross-sectional shapes. Typically, fluid ends for reciprocating pumps have bores with circular cross-sectional shapes (e.g., cylindrical bores) while closure elements therefor (e.g., valve covers, plugs, sleeves, etc.) have corresponding circular/cylindrical shapes to allow the closure elements to close and/or seal the bore.
These circular/cylindrical closure elements are typically secured in a bore segment with a threaded retaining element that engages threads machined into the fluid end. Such an arrangement creates at least two issues. First, a cylindrical closure element secured in a cylindrical bore can define sealing areas on the inner surface of the bore. This surface is often defined by the fluid end and, thus, can be very difficult to repair (e.g., repair may require an invasive weld repair). Second, with such an arrangement, the threads on the retaining element are subject to high levels of cyclical stress. Thus, if the retaining element is not preloaded correctly, the threads may experience fatigue failure.
The closure assemblies and/or the fluid end presented herein resolve these issues and, thus, can extend the lifespan of both the fluid end and the closure element. Initially, in at least some embodiments, a closure element with a non-circular cross-sectional shape can be secured within a fluid end bore without a threaded retaining element, thereby eliminating a potential point of failure. Instead, the closure element can be retained directly on a fluid end and/or on a retaining element that is fixed in place on a fluid end (e.g., the retaining element need not be removed for installation or removal of the closure element). This may also make the closure assembly easy to install, decreasing the amount of time required for installation and/or removal which, in turn, decreases downtime. Moreover, in at least some embodiments where a seal disposed around a closure element seals against a retaining element, the fluid end will not define a sealing area and, thus, will not experience wear associated with the sealing area. Additionally or alternatively, the non-circular cross-sectional shapes of the present application may allow the seals to be/provide bore or corner seals, which may be more robust than radial seals (e.g., seals between nested components of different radial dimensions).
Now referring to
Often, the reciprocating pump 100 may be quite large and may, for example, be supported by a semi-tractor truck (“semi”) that can move the reciprocating pump 100 to and from a well. Specifically, in some instances, a semi may move the reciprocating pump 100 off a well when the reciprocating pump 100 requires maintenance. However, a reciprocating pump 100 is typically moved off a well only when a replacement pump (and an associated semi) is available to move into place at the well, which may be rare. Thus, often, the reciprocating pump is taken offline at a well and maintenance is performed while the reciprocating pump 100 remains on the well. If not for this maintenance, the reciprocating pump 100 could operate continuously to extract natural oil and gas (or conduct any other operation). Consequently, any improvements that extend the lifespan of components of the reciprocating pump 100, especially typical “wear” components, and extend the time between maintenance operations (i.e., between downtime) are highly desirable.
Still referring to
The sectional view of
As can be seen in
Regardless of the diameters of conduit 212 and conduit 222, each conduit may include two segments, each of which extend from the pumping chamber 208 to the external surface 210 of the casing 206. Specifically, conduit 212 includes a first segment 2124 and a second segment 2126 that opposes the first segment 2124. Likewise, conduit 222 includes a third segment 2224 and a fourth segment 2226 that opposes the third segment 2224. In the depicted embodiment, the segments of a conduit (e.g., segments 2124 and 2126 or segments 2224 and 2226) are substantially coaxial while the segments of different conduits are substantially orthogonal. However, in other embodiments, segments 2124, 2126, 2224, and 2226 may be arranged along any desired angle or angles, for example, to intersect pumping chamber 208 at one or more non-straight angles.
In the depicted embodiment, conduit 212 defines a fluid path through the fluid end 104. Segment 2126 is an intake segment that connects the pumping chamber to a piping system 106 delivering fluid to the fluid end 104. Meanwhile, segment 2124 is an outlet or discharge segment that allows compressed fluid to exit the fluid end 104. Thus, in operation, segments 2126 and 2124 may include valve components 51 and 52, respectively, (e.g., one-way valves) that allow segments 2126 and 2124 to selectively open. Typically, valve components 51 in the inlet segment 2126 may be secured therein by a piping system 106. Meanwhile valve components 52 in outlet segment 2124 may be secured therein by a closure assembly 53 that, in the prior art example depicted in
On the other hand, segment 2226 defines, at least in part, a cylinder for plunger 202, and/or connects the casing 206 to a cylinder for plunger 202. For example, in the depicted embodiment, a casing segment 35 is secured to segment 2226 and houses a packing assembly 36 configured to seal against a plunger 202 disposed interiorly of the packing assembly 36. In any case, reciprocation of a plunger 202 in or adjacent to segment 2226, which may be referred to as a reciprocation segment, draws fluid into the pumping chamber 208 via inlet segment 2126 and pumps the fluid out of the pumping chamber 208 via outlet segment 2124. Notably, in the depicted prior art arrangement, the packing assembly 36 is retained within casing segment 35 with a retaining element 37 that is threadably coupled to casing segment 35.
Segment 2224 is an access segment that can be opened to access to parts disposed within casing 206 and/or surfaces defined within casing 206. During operation, access segment 2224 may be closed by a closure assembly 54 that, in the prior art example depicted in
Overall, in operation, fluid may enter fluid end 104 (or fluid end 104′) via multiple openings, as represented by opening 216 in
Also, during operation of pump 100, the first segment 2124 (of conduit 212), the third segment 2224 (of conduit 222), and the fourth segment 2226 (of conduit 222) may each be “closed” segments. By comparison, the second segment 2126 (of conduit 212) may be an “open” segment that allows fluid to flow from the external surface 210 to the pumping chamber 208. That is, for the purposes of this application, a “closed” segment may prevent, or at least substantially prevent, direct fluid flow between the pumping chamber 208 and the external surface 210 of the casing 206 while an “open” segment may allow fluid flow between the pumping chamber 208 and the external surface 210. To be clear, “direct fluid flow” requires flow along only the segment so that, for example, fluid flowing from pumping chamber 208 to the external surface 210 along segment 2124 and channel 108 does not flow directly to the external surface 210 via segment 2124.
Now turning to
In fact,
Still referring to
As can be seen in
It is possible to install the closure element 402 in or adjacent the pumping chamber 308 because the overall shape (e.g., the largest dimension) of the closure element 402 is non-circular so that the closure element 402 has an elongated overall dimension 442 and a narrow overall dimension 444, which is smaller than the elongated overall dimension 442. As is described in detail below, dimensions 442 and 444 allow the closure element 402 to be easily inserted into and seated against a non-circular portion of the non-circular segment 3224.
The features of the closure element 402 also facilitate this positioning and installation. More specifically, moving from the exterior surface 410 to the interior surface 406, the closure element 402 includes a closure section 430 and a seating section 438. That is, the closure element 402 includes a closure section 430 adjacent, or at least proximate, to the exterior surface 410 and a seating section 438 adjacent, or at least proximate, to the interior surface 406. The seating section 438 extends radially beyond the closure section 430 and, thus, defines a shoulder 436 between the closure section 430 and the seating section 438. As is described in further detail below, shoulder 436 can engage (e.g. sit on) a seat of the non-circular segment 3224 to secure, or at least orient/align, the closure element 402 within the non-circular segment 3224.
In the depicted embodiment, the closure section 430 has a radial surface 432 that has a non-circular cross-sectional shape. Similarly, the seating section 438 has a radial surface 439 that has a non-circular cross-sectional shape. In fact, the radial surface 439 of the seating section 438 and the radial surface 432 of the closure section 430 have non-circular cross-sectional shapes that are substantially the same. That is, the closure section 430 has a first non-circular cross-sectional shape and the seating section 438 has a second non-circular cross-sectional shape that is smaller than, but similarly proportioned to, the first non-circular cross-sectional shape. Consequently, the closure section 430 and the seating section 438 define a shoulder 436 with a face 437 of substantially constant width and of substantially the same shape as the radial surface 439 and the radial surface 432. In the depicted embodiment, the non-circular shape of these various sections or features is an elongated oval, insofar as “elongated oval” or variations thereof, such as “elongated ovular shape,” are used to denote a shape formed from two semi-circular lines connected by straight lines. However, this is just an example and other non-circular shapes, including one or more ellipses, can be used to achieve a non-circular shape.
In fact, all of the depicted shaping and dimensioning is provided as an example and other embodiments need not have such dimensions and/or shaping. Instead, the closure element 402, and the overall assembly 401, should have dimensions and shaping that correspond with the dimensions and shaping of the non-circular segment 3224. For example, in some embodiments, the seating section 438 might have a non-circular shape and the closure section 430 might have a different non-circular shape or even a circular shape. In fact, in some embodiments, it may be advantageous to have a circular closure section 430. This is because machining non-circular shapes may be more difficult than machining circular shapes. When the closure element 402 includes a circular closure section 430, the non-circular segment 3224 may also include a corresponding circular section. Consequently, a circular closure section 430 may decrease the amount of complex machining required to manufacture the closure element 402 and non-circular segment 3224, which may lower the costs associated with manufacturing the fluid end 304 and the closure assembly 400 presented herein.
However, to preserve the advantages of the non-circular overall shape of the closure assembly 400, when the closure section 430 has a circular shape or a non-circular shape that differs from the non-circular shape of the seating section 438, the overall dimensions of the closure section 430 should not extend beyond the narrow overall dimension 444 of the closure element 402. Any extension beyond the narrow overall dimension 444 might restrict or prevent the closure element 402 from being installed in the non-circular segment 3224. In any case, if only one of the closure section 430 and the seating section 438 includes a non-circular cross-sectional shape, the shoulder 436 may have a different shape than both of these sections. This is because an inner boundary of the shoulder 436 is defined by the closure section 430 and the outer boundary of the shoulder 436 is defined by the seating section 438.
Still referring to
Specifically, the exterior surface 410 includes a central protrusion 414 that defines a bore 416 and that is surrounded by a plurality of receivers 412 (e.g., bores). Correspondingly, the retaining element 472, which extends from an interior surface 474 to an exterior surface 476, defines bores 478 configured to align with the receivers 412 and a central bore 479 that aligns with the protrusion 414. As can be seen, the bores 478 of the depicted embodiment are countersunk to minimize the distance that couplers 495 installed therein extend beyond the exterior surface 476. Meanwhile, the central bore 479 can sit on the protrusion 414 of the closure element 402 to center the retaining element 472 on the exterior surface 410 of the closure element 402 while the couplers 495 are installed through bores 478 and into receivers 412.
In at least some embodiments, the closure element 402 has a first surface hardness and the retaining assembly 470, or at least portions thereof, such as a retaining element 472 of the retaining assembly 470, have a second surface hardness that is less hard than the first surface hardness. The increased hardness of the closure element 402 will respond to higher loads between the closure element 402 and the fluid end 304 during pumping operations and, thus, will prolong the life of a closure assembly including the closure element 402. However, the entire closure element 402 need not have this increased hardness and, for example, the interior surface 406 and/or tapered edges 408 might have increased hardness as compared to a remainder of the closure element 402. For example, the closure element 402 might have a coating on the tapered edges 408 to provide the increased hardness. In some instances, the coating might provide corrosion resistance, friction resistance, and/or improved sealing, either instead of or in addition to providing increased hardness. Moreover, in some embodiments, the inner wall of the fluid end bore, or at least a portion thereof, may be coated with such a coating, perhaps instead of coating the closure element 402.
Still referring to
Notably, in the depicted embodiment, the seal carrier 462 may be positioned upstream of the seal 461 (such an arrangement is also illustrated in
More specifically, the retaining element 472′ includes holes 481 that extend from the interior surface 474 to the exterior surface 476, or vice versa, so that flexible installation elements 485 can be installed through a main body of the retaining element 472′. Additionally, a connecting passageway 482 is formed on the interior surface 474. The connecting passageway 482 allows a single flexible installation element 485 to be fed through two holes 481 while also extending across a portion of the interior surface 474. This creates a leverage or grip point that a user can use to manipulate the closure assembly 400′, e.g., during installation of the closure assembly 400′ into a fluid end 304. Also, the connecting passageway 482 allows the flexible installation elements 485 to extend along the interior surface 474 without protruding therefrom. Thus, the flexible installation elements 485 will not impact the interface between the interior surface 474 of the retaining assembly 470′ and the exterior surface 410 of the closure element 402 when couplers 495 couple the retaining assembly 470′ to the closure element 402 (e.g., to secure a seal 461 and seal carrier 462 in place therebetween). This placement also ensures that the flexible installation elements 485 do not wear, change the geometry, or otherwise negatively affect the closure element 402 while still enabling easy installation and/or removal of the flexible installation elements 485.
With the holes 481 and connecting passageway 482, the flexible installation elements 485 may be installed onto a retaining element 472′ prior to coupling the retaining element 472′ to a closure element 402, while the interior surface 474 of the retaining element 472′ is still easily accessible. The flexible installation elements 485 can be fed through one hole 481, routed to a second hole 481 via the connecting passageway 482, and fed back out of the retaining element 472′ via the second hole. Then, retaining element 472′ can be coupled to closure element 402 while the flexible installation elements 485 are disposed between the retaining element 472′ and the closure element 402.
In the depicted embodiment, the retaining element 472′ includes two pairs of holes 481 and each pair of holes 481 is connected by a connecting passageway 482. The pairs of holes 481 are located above and below the central bore 479, but within the elongated, ovular arrangement of bores 478. In other embodiments, the holes 481 and/or connecting passageway 482 may be disposed in any desirable location. In fact, in other embodiments, the closure element 402 need not include holes 481 and may include any other features that allow flexible handles 485 to the closure element, such as eye bolts, connected blind holes, etc. However, regardless of how the flexible handles 485 are coupled to the closure element 402, it may be beneficial to arrange flexible handles 485 symmetrically and/or evenly with respect to a center of the retaining element 472′ (e.g., around and/or with respect to bore 479) because symmetrically or evenly spaced flexible installation elements 485 may allow for linear translation that avoids tilting or rotation.
Additionally, in the depicted embodiment, the flexible installation elements 485 are wires, but other embodiments may utilize any elongate, flexible material as flexible installation elements 485. In any case, the flexible installation elements 485 will allow a user/operator to manipulate the retaining assembly 470′ from a location that is exterior of the fluid end 304. This, in turn, reduces the amount of time that operators will need to have their hands inside of a non-circular segment 3224 of the fluid end 304. In some instances, the flexible installation elements 485 may also make it easier for an operator/user to retrieve the retaining assembly 470′ and/or closure assembly 400′ if the retaining assembly 470′ and/or closure assembly 400′ falls into an unwanted location, such as into the pumping chamber 308.
In the depicted embodiment, the pressure relief conduit 423 is a passageway that extends through the main body of the closure element 420, initiating at entrance 421 and terminating at exit 422. The entrance 421 is disposed on the interior surface 406 and the exit 422 is disposed on the radial surface 432 of the closure section 430, intersecting the channel 434 of the closure section 430 that receives a seal assembly. More specifically, in the depicted embodiment the exit 422 is configured to intersect the channel 434 at a location that is upstream (e.g. closer to a pumping chamber) of a seal 461 positioned in channel 434. Thus, fluid flowing through the pressure relief conduit 423 may enter the channel 434 but the seal 461 will prevent the fluid from bypassing the closure element 420 to exit the segment. Alternatively, the closure element 420 and/or a retaining assembly coupled thereto might include other sealing features that ensure fluid exiting the pressure relief conduit 423 at exit 422 does not escape a fluid end segment in which the closure element 420 is installed. In any case, the pressure relief conduit 423 will not prevent the closure element 420 from closing a segment in which it is installed.
Overall, the pressure relief conduit 423 provides a flow path along which fluid may flow past the seating section 438 without contacting the tapered edges 408 of the interior surface 406 or the shoulder 436 defined by the seating section 438. This prevents, or at least discourages, high pressure fluid from seeping past shoulder 436 and/or creating localized pressure increases at the tapered edges 408 and/or shoulder 436. This diminishment of pressure is important because during pumping operations, the tapered edges 408 and/or the shoulder 436 act as load bearing surfaces and wear of these surfaces past a certain point will cause the closure element 420 to fail. Testing has shown that the pressure relief conduit 423 can reduce or relieve wear generated from localized pressure acting on these surfaces and/or from fluid flowing directly over these surfaces. That is, the pressure relief conduit 423 can allow fluid to flow freely past the seating section 438 and tapered edges 408, which may reduce wear on the seating section 438 and/or tapered edges 408. The diminishment of pressure provided by pressure relief conduit 423 may also help ensure that the closure element 420 remains properly positioned in a fluid end segment. This is because reducing the pressure acting on the bearing surfaces of the closure element 420 (e.g., via interior surface 406 and/or tapered edges 408) will reduce the risk of pressure moving the closure element 420 out of alignment in its segment and/or causing micromovements of the closure element 420.
In the depicted embodiment, the closure element 420 includes a single pressure relief conduit 423 that is generally aligned with a straight section of the elongated ovular shape of the closure element 420. Additionally, the pressure relief conduit 423 is comprised of two straight bores: one bore extending from the entrance 421 in a depth dimension of the closure element 420; and one bore extending from the first bore to the exit 422 along the narrow overall dimension 444 (see
As one example of how the pressure relief conduit 423 may vary in different embodiments,
To be clear, while the Figures described thus far depict a non-circular closure assembly 400 as a plug-style closure assembly, the same principles, structures, and/or features may also be applicable to a sleeve-style/type closure element and could be used to close and/or seal other non-circular segments of a fluid end, such as a non-circular version of segment 2226. That is, although not shown herein, a sleeve-style, non-circular closure assembly 400 may extend between casing 206 and a packing arrangement. Thus, in some instances, non-circular closure assembly 400 disposed in segment 2226 may be referred to as a packing sleeve. For the purposes of this application, a sleeve- or plug-style closer element may be referred to as a stationary closure element. However, the techniques presented herein need not be limited to stationary closure elements and may also be used in combination with plungers or other movable closure elements, which, for the purposes of this application, may be referred to as movable closure elements. That is, the non-circular concepts presented herein could also be applied to and/or utilized with packing elements.
More specifically, the concepts presented herein (e.g., in connection with closure assembly 400) may be applied to a packing arrangement and a movable closure element. That is, a sleeve-style, non-circular closure assembly may embodied as a packing arrangement and plunger. In such instances, the plunger 202 acts as a closure element and the packing acts as a seal element to form a sealing assembly for the closure assembly presented herein. To be clear, for the purposes of this application, a sealing assembly formed from a packing arrangement and plunger may be referred to as a sealing assembly for a movable closure element. By comparison, sealing assemblies embodied as plug-style or sleeve-style closure elements (with seal elements disposed around a stationary closure element) may be referred to as sealing assemblies for stationary closure elements.
Now turning to
However, to be clear, for the purposes of this application a fluid end segment may be “non-circular” when one or more portions of the segment is/are non-circular. For example, in some embodiments, the seat 332 may be non-circular and the sealing section 330 and/or the access section 320 may be circular. As a specific example, the access section 320 could have any shape provided that a radius (or major dimension) of the access section 320 is larger than the narrow overall dimension 444 of the closure assembly 400. This will ensure that the closure assembly 400 can be inserted through the sealing section 330 and into the seat 332 (or into the pumping chamber 308, at least temporarily, as is explained in further detail below). Meanwhile, the sealing section 330 can have any shape configured to mate with the channel 434 of the closure assembly 400 so that a seal 461 disposed in the channel 434 can seal against the sealing section 330.
Regardless of which sections of non-circular segment 3224 are non-circular, overall, the non-circular segment 3224 is dimensioned to allow the closure assembly 400 to be inserted through the non-circular segment 3224. More specifically, overall, the non-circular segment 3224 includes a minimal narrow dimension 342 and a minimal elongated dimension 344. Each of these dimensions is configured to allow the closure assembly 400 to be inserted through the non-circular segment 3224 when the closure assembly 400 is disposed in an installation orientation O1 (see
To achieve this, the minimal narrow dimension 342 is larger than a depth of the closure assembly 400, or at least the depth of the closure element 402 (insofar as “depth” is a dimension perpendicular to both narrow overall dimension 444 and elongated overall dimension 442). Meanwhile, the minimal elongated dimension 344 is larger than the narrow overall dimension 444 of the closure assembly 400, or at least a narrow dimension of the closure element 402. Thus, when the narrow overall dimension 444 of the closure assembly 400 is aligned with the minimal elongated dimension 344 of the non-circular segment 3224 and the depth of the closure assembly 400 is aligned with the minimal narrow dimension 342 non-circular segment 3224, the closure assembly 400 (or the closure element 402) may be inserted through the non-circular segment 3224. That is, when the closure assembly 400 (or the closure element 402) is in an installation orientation O1, the closure assembly 400 (or the closure element 402) may be inserted into and through the non-circular segment 3224.
Another important aspect of the non-circular segment 3224 is its seat 332. The seat 332 is configured to support the closure element 402 and, more specifically, to support the seating section 438 of the closure element 402. At the same time, the seat 332 forms a fluid barrier that is essentially in the pumping chamber 308 and, thus, the seat 332 may experience a large amount of wear. Accordingly, the seat 332 includes contoured edges 334 that are designed to smooth the transitions from the pumping chamber 308 and/or from the inlet segment 2126 to the seat 332 and reduce or prevent wear on the casing 306. Notably, the contoured edges 334 eliminate corners, which can be susceptible to wear, between the inlet segment 2126, the pumping chamber 308, and the seat 332. This may be particularly important since the seat 332 may be hard to access for repairs.
Now turning to
Now turning to
That all said, in
Next, in
One other notable difference is that the closure element 402′ includes installation elements 450 extending outwardly, away from the exterior surface 410′. The installation elements 450 provide a grip point on the exterior surface 410′ that can be used during installation and/or removal of the closure element 402 from a non-circular segment 3224 (e.g., like flexible installation elements 485). In the depicted embodiment, the installation elements 450 comprise two U-shaped bars that extend along the narrow overall dimension 444 of the closure element 402′, on either side of a central bore 416′. However, in other embodiments, the installation elements 450 may have any shape and/or may extend in any direction, across any portion of the exterior surface 410′. But, at the same time, it may be beneficial to arrange the installation elements 450 symmetrically and/or evenly with respect to a center of the exterior surface 410 (e.g., around and/or with respect to bore 416′ because symmetrically or evenly spaced installation elements 450 may allow for linear translation that avoids tilting or rotation. The bore 416′ may also be helpful for installation, removal, and/or securing the closure element 402′ within a non-circular segment 3224.
The collar 505 and the extensions 506 may both help prevent or discourage a user from improperly installing the non-circular closure element 402, e.g., in a manner that damages the closure element 402. First, the collar 505 may allow the extended coupler 504 to be coupled to the retaining element 472′ and/or closure element 402 (e.g., via threading), but may limit the depth the extended coupler 504 can extend into the retaining element 472′ and/or closure element 402. This may prevent the extended coupler 504 from damaging the closure element 402 during installation. Meanwhile, the extensions 506 may prevent, or at least discourage, a user from engaging the hex-shaped head of the extended coupler 504 with impact drills or other such torquing tools to drive installation of the extended coupler 504 during installation of closure assembly 500′. This may discourage a user from over-torquing the extended coupler 504 and damaging closure element 402.
The crossbar 502 may include a slot 503 extending inwards from a side of the crossbar 502 and may include stepped inner surfaces 508 at its top and bottom end. The side slot 503 may ease installation while still ensuring that the crossbar 502 securely supports the extended coupler 504. Meanwhile, the stepped inner surfaces 508 may help securely seat the crossbar 502 in the non-circular segment 3224 and against the external surface 310 of the fluid end 304. Or, in other embodiments, stepped inner surfaces 508 may help securely seat the crossbar 502 on a retainer (see, e.g., the retainer 602 of
More specifically, in the depicted embodiment, both the internal surface 604 and the external surface 610 are non-circular. However, in other embodiments, the retainer 602 need not include a non-circular internal surface 604 and a non-circular external surface 610. For example, the external surface 610 might be circular or the overall retainer 602 might have any desirable shape that can secure the crossbar 502′ to the external surface 310. The key, for at least some embodiments, is that the internal surface 604 extends at least partially over/within the exterior opening of the non-circular segment 3224″ so that the interior surface 606 can define a shoulder at a proximal end of the non-circular segment 3224″. In the embodiment depicted in
Additionally, in the embodiment of
In still other embodiments, however, the closure element 402″ need not define the channel 434′ and, for example, the channel 434′ could be defined by the retainer 602. That is, the retainer 602 might define a channel for a seal assembly 460 which could transfer wear to the closure element 402″. This might increase the lifespan of the retainer 602, reducing the number of times that the retainer 602 needs to be removed or serviced during pumping operations. Notably, removing the retainer 602 from the fluid end 304 requires multiple bolts/couplers to be removed. By comparison, the closure element 402″ might be able to be removed from the fluid end 304 without removing any bolts/couplers. Thus, it might be easier and/or quicker to service or replace the closure element 402″ than the retainer 602. That is, moving the channel 434′ to the retainer 602 might provide servicing advantages (e.g., less down time). One example of such a channel is depicted in
More specifically, the seating section 438 of the closure element 402′″ may sit against the interior surface 606 of the retainer 602, which may secure/retain the closure element 402′″ within the non-circular segment 3224″ when the closure element 402′″ is disposed in an operation orientation O2. At least because the closure element 402″ is secured within the non-circular segment 3224″ adjacent the external surface 310 (and the retainer 602), the coupler 504″ need not be extended. This may also be advantageous because it may reduce the chances that the coupler 504 experiences stresses or torques (e.g., due to misalignment). Also, to be clear, this embodiment is again depicted with a relatively straight/constant, non-circular segment 3224″, but the non-circular segment 3224″ is, again, only provided as a example and the concepts of this embodiment need not be limited to such bores.
Moreover, in
Now turning to
In a second step, the closure element 402 is rotated from its installation orientation O1 to an operational orientation O2 that is angularly offset from the installation orientation O1. For simplicity, this step is depicted in two sub-steps: sub-step 804(1) and sub-step 804(2); however, in other embodiments, this step can be accomplished in one or more operations. For example, the closure element 402 may be rotated about two axes at one time. That said, in
First, in sub-step 804(1), the closure element 402 is rotated about lateral axis A1 in a first rotational direction D2. For example, the closure element 402 may rotate approximately ninety degrees. This may align the narrow dimension of the closure element 402 with the narrow dimension of the non-circular segment 3224 and, thus, in at least some embodiments, it might not be easy to remove the closure element 402 from the pumping chamber 308 via the non-circular segment 3224 after this first rotation. But, since the depth of the closure element 402 may now be aligned with the enlarged dimension of the non-circular segment 3224, it may still be possible to remove the closure element 402 from the pumping chamber 308.
Then, in sub-step 804(2), the closure element 402 is rotated about depth axis A3 in second rotational direction D3. For example, the closure element 402 may rotate approximately ninety degrees. This rotates the enlarged dimension of the closure element 402 into alignment with the enlarged dimension of the non-circular segment 3224 and, thus, orients the closure element 402 for seating in the non-circular segment 3224. That is, after rotating the closure element 402 about two axes, the closure element 402 may be disposed in an operational orientation O2.
Next, in step 806, the closure element 402 is translated is translated along lateral axis A1 in a second lateral direction D4, as is shown in
Notably, in
Still further, some components of a closure assembly formed in accordance with the present application might be installed prior to completing the method of
While the invention has been illustrated and described in detail and with reference to specific embodiments thereof, it is nevertheless not intended to be limited to the details shown, since it will be apparent that various modifications and structural changes may be made therein without departing from the scope of the inventions and within the scope and range of equivalents of the claims. In addition, various features from one of the embodiments may be incorporated into another of the embodiments. For example, a retainer, such as a retaining ring, or any other component of a retaining assembly shown with one embodiment of a closure element can be used with any desirable closure element to forma closure assembly of the present application. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the disclosure as set forth in the following claims.
It is also to be understood that the sealing assembly described herein, or portions thereof may be fabricated from any commonly used seal materials, such as homogeneous elastomers, filled elastomers, partially fabric reinforced elastomers, and full fabric reinforced elastomers. Suitable resilient elastomeric materials includes, but re not limited to, thermoplastic polyurethane (TPU), thermoplastic copolyester (COPE), ethylene propylene diene monomer (EPDM), highly saturated nitrile rubber (HNBR), reinforced versions of the foregoing materials, such as versions reinforced with fibers or laminations of woven material, as well as combinations of any of the foregoing materials.
Similarly, it is intended that the present invention cover the modifications and variations of this invention that come within the scope of the appended claims and their equivalents. For example, it is to be understood that terms such as “left,” “right,” “top,” “bottom,” “front,” “rear,” “side,” “height,” “length,” “width,” “upper,” “lower,” “interior,” “exterior,” “inner,” “outer” and the like as may be used herein, merely describe points of reference and do not limit the present invention to any particular orientation or configuration. Further, the term “exemplary” is used herein to describe an example or illustration. Any embodiment described herein as exemplary is not to be construed as a preferred or advantageous embodiment, but rather as one example or illustration of a possible embodiment of the invention.
Finally, when used herein, the term “comprises” and its derivations (such as “comprising”, etc.) should not be understood in an excluding sense, that is, these terms should not be interpreted as excluding the possibility that what is described and defined may include further elements, steps, etc. Meanwhile, when used herein, the term “approximately” and terms of its family (such as “approximate,” etc.) should be understood as indicating values very near to those which accompany the aforementioned term. That is to say, a deviation within reasonable limits from an exact value should be accepted, because a skilled person in the art will understand that such a deviation from the values indicated is inevitable due to measurement inaccuracies, etc. The same applies to the terms “about” and “around” and “substantially.”
This application is a continuation-in-part of U.S. patent application Ser. No. 17/725,929, filed on Apr. 21, 2022, and entitled “Fluid End with Non-Circular Bores and Closures For The Same,” the disclosure of which is incorporated by reference in entirety.
Number | Date | Country | |
---|---|---|---|
Parent | 17725929 | Apr 2022 | US |
Child | 18459560 | US |