Embodiments of the subject matter disclosed herein generally relate to pump systems, and in particular to sealing systems.
Pumping systems may be used in a variety of applications, such as industrial applications where pumping systems are used to elevate a working fluid pressure. One such application is hydraulic fracturing systems, where high pressure pumps are used to increase a fluid pressure of a working fluid (e.g., fracturing fluid, slurry, etc.) for injection into an underground formation. The working fluid may include particulates, which are injected into fissures of the formation. When the fluid is removed from the formation, the particulates remain and “prop” open the fissures, facilitating flow of oil and gas. In many applications, reciprocating pumps are used where a fluid is introduced into a fluid end inlet passage and out through an outlet passage. A plunger reciprocates within a bore to add energy to the fluid. Due to the particulates and corrosive nature of the working fluid, various sealing elements may be utilized to block fluid ingress that may damage sealing surfaces.
Applicant recognized the problems noted above herein and conceived and developed embodiments of systems and methods, according to the present disclosure, for pump control operations.
In an embodiment, a sealing assembly for a pump includes a header ring having a tapered radially outer surface and a sloped radially inner surface. The assembly also includes a first seal configured to couple to the header ring, the first seal having a groove that receives a bead extending from the header ring. The assembly further includes a second seal axially aligned with the first seal.
In an embodiment, a pumping system includes a housing, a plunger configured to reciprocate along an axis of the housing, and a packing assembly positioned between at least a portion of the housing and the plunger. The packing assembly includes a header ring having an outer surface bearing against the housing and an inner surface bearing against the plunger, the header ring having a thickness such that the plunger compresses the header ring against the housing, wherein the outer surface includes tapered portion and the inner surface includes sloped entry radius at an axially bottom portion. The packing assembly also includes a seal positioned axially higher than and coupled to the header ring, the seal having a groove configured to receive a bead of the header ring, the bead extending axially away from the bottom portion, wherein the seal includes a radially extending sealing feature along a length of the seal.
In an embodiment, a packing stack includes a header ring extending axially from a bottom to a top, the top having a bead, the header ring having an inner surface with a curved profile extending from the top to the bottom, a bottom thickness being less than a midpoint thickness, and an outer surface with a tapered profile extending from the top to the bottom, the tapered profile arranged at an angle such that a top thickness is less than the bottom thickness. The packing stack also includes a seal extending axially from a bottom end to a top end, at least a portion of the bottom end overlapping the top of the header ring, the seal having a groove that receives the bead, an inner seal surface, and an outer seal surface, the seal being positioned axially aligned with the header ring.
The present technology will be better understood on reading the following detailed description of non-limiting embodiments thereof, and on examining the accompanying drawings, in which:
The foregoing aspects, features, and advantages of the present disclosure will be further appreciated when considered with reference to the following description of embodiments and accompanying drawings. In describing the embodiments of the disclosure illustrated in the appended drawings, specific terminology will be used for the sake of clarity. However, the disclosure is not intended to be limited to the specific terms used, and it is to be understood that each specific term includes equivalents that operate in a similar manner to accomplish a similar purpose.
When introducing elements of various embodiments of the present disclosure, the articles “a”, “an”, “the”, and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including”, and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Any examples of operating parameters and/or environmental conditions are not exclusive of other parameters/conditions of the disclosed embodiments. Additionally, it should be understood that references to “one embodiment”, “an embodiment”, “certain embodiments”, or “other embodiments” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Furthermore, reference to terms such as “above”, “below”, “upper”, “lower”, “side”, “front”, “back”, or other terms regarding orientation or direction are made with reference to the illustrated embodiments and are not intended to be limiting or exclude other orientations or directions. Additionally, like reference numbers may be used for like features throughout the disclosure, however, such use for convenience only and not intended to limit the scope of the present disclosure.
Embodiments of the present disclosure include packing sealing elements (e.g., a header ring and the chevron V ring(s)). The header ring includes a geometry with a sloped entry radius to reduce seal wear (e.g., eliminate nibbling) and aid in installation of a plunger without causing damage to a header ring. The header ring also includes an angled outer diameter surface, which may have an angle between 0.5-8 degrees, respective to a centerline plunger bore axis to aid in tight fitment of the header ring in the fluid end bore and enhanced sealing. Various embodiments include one or more chevron V rings, which may have commercially available geometries, positioned behind the header ring forming a stack of a certain height. Both the header ring and chevron V ring(s) may be constructed from polyurethane. The polyurethane may be a commercially available composition, or a custom blended engineered composite. The polyurethane composite may include additional elements in order to form a composite polyurethane compound formulated for optimal wear resistance and chemical resistance when used in hydraulic fracturing pump operations. Such materials that may be blended in with the polyurethane to form the composite material are glass fibers, carbon fibers, carbon nanotubes, graphene, polytetrafluoroethylene (PTFE), aramid-fabrics, Kevlar fabrics, alumina powder, ceramic fiber, white graphene, nano-ceramics, or some combination of these materials. The header ring is formulated with a hardness in the range of 50-100 shore A durometer. The chevron V rings may be formulated with a hardness in the range of 50-100 shore D durometer.
As noted above, various embodiments of the present disclosure may include packing sealing elements with a geometry that includes a sloped entry radius to reduce seal wear. The header ring may also have an angled outer diameter surface. The header ring may also include, on its outer diameter, one or more flared sealing winglets, as described herein, that are designed for enhanced sealability with the packing bore of the fluid end. One or more chevron V rings may be positioned behind the header ring, forming a stack of a certain height. The chevron V rings including one or more flared sealing winglets on both the inner diameter and outer diameter, as shown herein, and may act as backup sealing lips for enhanced sealing. Both the header ring and chevron V ring(s) are constructed from polyurethane, in certain embodiments. The polyurethane may be a commercially available composition, or a custom blended engineered composite. The polyurethane composite may include additional elements in order to form a composite polyurethane compound formulated for optimal wear resistance and chemical resistance when used in hydraulic fracturing pump operations. Such materials that may be blended in with the polyurethane to form the composite are glass fibers, carbon fibers, carbon nanotubes, graphene, PTFE, aramid-fabrics, Kevlar fabrics, alumina powder, ceramic fiber, white graphene, nano-ceramics or some combination of these materials. The header ring may be formed with a hardness in the range of 50-100 shore A durometer. The chevron V rings may be formed with a hardness in the range of with a hardness in the range of 50-100 shore D durometer.
Embodiments of the present disclosure may also include packing sealing elements, as included above such as a header ring and chevron V ring(s), where one or more chevron V rings may be positioned behind the header ring forming a stack of a certain height. The chevron pressure rings may include one or more annular grooved recesses on the inner diameter, as described below. These annular grooved recesses may act as reservoirs for collecting lubricating grease or oil being pumped into the packing gland while the pump is in operation, thereby reducing friction by evenly dispersing grease around and/or along the reciprocating plunger and thus reducing overall frictional wear and heat buildup in the sealing elements, extending packing sealing element service life. Both the header ring and chevron V rings may be formed from polyurethane. The polyurethane may be a commercially available composition, or a custom blended engineered composite. The polyurethane composite may include additional elements in order to form a composite compound formulated for optimal wear resistance and chemical resistance when used in hydraulic fracturing pump operations. Such materials that may be blended in with the polyurethane to form the composite are glass fibers, carbon fibers, carbon nanotubes, graphene, Teflon, Aramid-fabrics, Kevlar fabrics, alumina powder, ceramic fiber, white graphene, nano-ceramics or some combination of these materials. The header ring may be formed with a hardness in the range of 50-100 shore A durometer. The chevron V rings may be formed with a hardness in the range of with a hardness in the range of 50-100 shore D durometer.
Embodiments of the present disclosure include packing sealing elements, such as a header ring and chevron V ring(s), where the chevron V rings may include, on their inner diameter, an insert of PTFE/Teflon or similar ultra-low/low friction material. These PTFE inserts can be bonded to the chevron V rings or snapped in place, the inserts acting as low friction wiper seals, which serve to retain grease close to the sealing areas of the chevron V rings where most frictional wear occurs during pumping operations. Lubricating grease or oil is pumped into the packing gland while the pump is in operation, reducing friction by evenly dispersing grease around/along the reciprocating plunger and thus reducing overall frictional wear and heat buildup in the sealing elements, extending packing sealing element service life. Both the header ring and chevron V rings may be from polyurethane. The polyurethane may be a commercially available composition, or a custom blended engineered composite. The polyurethane composite may include additional elements in order to form a unique and proprietary composite compound formulated for optimal wear resistance and chemical resistance when used in hydraulic fracturing pump operations. Such materials that may be blended in with the polyurethane to form the composite are glass fibers, carbon fibers, carbon nanotubes, graphene, Teflon, Aramid-fabrics, Kevlar fabrics, alumina powder, ceramic fiber, white graphene, nano-ceramics or some combination of these materials. The header ring may be formed with a hardness in the range of 50-100 shore A durometer. The chevron V rings may be formed from a material with a hardness in the range of 50-100 shore D durometer. In embodiments, the chevron V rings may be formed from a material, such as PTFE/Teflon, with a hardness in the range of 50-150 shore A durometer.
Embodiments of the present disclosure include packing sealing elements, such as a header ring and chevron V ring(s), where the header ring also has an insert of a different material on its outer diameter that acts as a reinforcing stiffener. In various embodiments, the insert may include a PTFE or Teflon material, but it should be appreciated that a variety of materials may be included. Furthermore, in certain embodiments, combinations of materials may be utilized as well as multiple inserts, which may all be different materials. The header ring also includes a barb like feature on the top side designed to tightly interlock with the chevron V rings when assembled together. One or more chevron V rings are positioned behind the header ring forming a stack of a certain height. The chevron V rings include a geometry that interlocks with the top barb feature of the header ring. Both the header ring and chevron V rings may be constructed from polyurethane. The polyurethane may be a commercially available composition, or a custom blended engineered composite. The polyurethane composite may include additional elements in order to form a composite compound formulated for optimal wear resistance and chemical resistance when used in hydraulic fracturing pump operations. Such materials that may be blended in with the polyurethane to form the composite are glass fibers, carbon fibers, carbon nanotubes, graphene, Teflon, Aramid-fabrics, Kevlar fabrics, alumina powder, ceramic fiber, white graphene, nano-ceramics or some combination of these materials. The header ring may be formed with a hardness in the range of 50-100 shore A durometer. The chevron V rings may be formed with a hardness in the range of with a hardness in the range of 50-100 shore D durometer. The insert may be formed with a hardness in the range of 50-100 shore A durometer. The insert may be formed from a material with a hardness in the range of 50-100 shore D durometer. In embodiments, the insert may be formed from a material, such as PTFE/Teflon, with a hardness in the range of 50-150 shore A durometer.
It should be appreciated that various components of the pump assembly 100 have been removed for clarity with the following discussion. For example, a power end has been removed in favor of focusing on the illustrated fluid end 102 of the pump assembly 100. The power end may include a crankshaft that is driven by an engine or motor to facilitate operations. The fluid end 102 includes a fluid end block 104 that may house one or more components discussed herein. A plunger rod 106 is driven (e.g., via the crankshaft) to reciprocate within the fluid end block 104 along a plunger axis 108. The plunger rod 106 is positioned within a bore 110 extending through at least a portion of the fluid end block 104. The illustrated bore 110 is arranged along the plunger axis 108 (e.g., first axis) and intersects a pressure chamber 112, which is arranged along a pressure chamber axis 114 (e.g., second axis), which is positioned substantially perpendicular to the plunger axis 108. It should be appreciated that the pump assembly 100 may include multiple plunger rod and pressure chamber arrangements, which may be referred to as a plunger throw. For example, the pump assembly 100 may be a triplex pump, quadplex pump, quintuplex pump, and the like.
The illustrated fluid end block 104 includes an inlet passage 116 and an outlet chamber 118, which are generally coaxial and arranged along the pressure chamber axis 114. In other words, the inlet passage 116 and the outlet chamber 118 are axially aligned with respect to one another and/or the pressure chamber 112. Fluid enters the pressure chamber 112 via the inlet passage 116, for example on an up stroke of the plunger rod 106, and is driven out of the pressure chamber 112 an outlet passage 120, for example on a down stroke of the plunger 106.
Respective valve assemblies 122, 124 are arranged within the inlet passage 116 and the outlet chamber 118. These valve assemblies 122, 124 are spring loaded in the illustrated embodiment, but it should be appreciated that such an arrangement is for illustrative purposes only. In operation, a differential pressure may drive movement of the valve assemblies. For example, as the plunger rod 106 is on the upstroke, pressure at the inlet passage 116 may overcome the spring force of the valve assembly 122, thereby driving fluid into the pressure chamber 112. However, on the down stroke, the valve assembly 122 may be driven to a closed position, while the spring force of the valve assembly 124 is overcome, thereby enabling the fluid to exit via the outlet passage 120.
Piston pumps or plunger pumps, such as the pump assembly 100 shown in
Embodiments of the present disclosure described herein may overcome one or more problems identified with traditional sealing elements. By way of example, embodiments may provide one or more sealing elements formed from materials specifically formulated for suitability with fracturing or other high pressure, high temperature, severe service operations. For example, sealing elements may be formed from a thermoplastic polyurethane (TPU). Furthermore, various sealing geometries may be deployed in order to provide improved sealing performance.
In the illustrated configuration, the header ring 214 acts as a wiper ring to prevent or block abrasives or solids from entering the region including the seal rings 216, 218. The annular gland 212 compresses the various sealing elements within the housing 206. As shown, vertical features or nubs (e.g., beads) may interface with grooves of adjacent sealing elements to anchor the components together. In these prior art configurations, the components are often metallic, such as brass.
Embodiments of the present disclosure overcome various drawbacks and problems with the illustrated prior art configurations. By way of example, embodiments may include a full radius at the entry feature to prevent a sharp edge where the seal could fatigue and initiate a tear. This gradual slopped radius also allows for easier installation of the plunger with a lower risk of causing damage to the header ring when installing the plunger, which is a common issue due to the nature of how the heavy and difficult to handle plungers are installed. Additionally, the outer diametrical surface has been tilted such that when the header ring is engaged around the plunger, the seal rocks slightly backwards until the outer diametrical surface is flush with the seal gland allowing for a tighter inner diameter fit with the same volume fill properties during seal energization.
Furthermore, the materials used to create the header rings and the pressure (V-rings) also offer improvements over current systems. The material used may be a base material of TPU with a 90 Durometer Shore A on the header ring and 60 Durometer Shore D on the chevron V rings. Additionally, in various embodiments, these may include reinforcing elements in the molding process such as carbon fiber, glass fiber, and/or aramid (Kevlar fibers). Embodiments may also incorporate boron fibers or ceramic fibers such as silicon carbide (SiC) or aluminum oxide (Al2O3). Additionally, embodiments may use nano-technology as stiffening elements such as the inclusion of graphene, white graphene (Boron Nitride), and carbon nanotubes, core-shell rubber (CSR) nano-particles, and nano-ceramic particles. Embodiments also provide improved manufacturing processes. For example, the sealing elements may be injection molded, which offers improvements over traditional compression molding or laminating processes.
Further illustrated in
The illustrated embodiment further includes the winglets 618 on an inner surface 624 (e.g., radially inward portion) of the seals 604, 606. In this configuration, the inner surface 624 is proximate the reciprocating plunger 106 (e.g., the surface 614). Moreover, it should be appreciated that there may be any reasonable number of winglets 618, and the illustrated two on each seal 604, 606 is for illustrative purposes only. In operation, pressure may apply a force in an upward direction (e.g., to the right relative to the plane of the page) and encounter the winglets 618. The pressure may cause the winglets 618 to pivot radially outwardly (e.g., rotate in a counter clockwise direction for the winglets 618 on the inner surface 624 and a clockwise direction for the winglets 618 on the outer surface 622) and increase the sealing pressure against the respective surfaces 612, 614. Accordingly, the sealing performance of the stack 600 may be improved.
Further illustrated is a barb 924 positioned on the bead 908. The barb 924 in the illustrated embodiment extends outwardly from the bead 908, and may be an integral part of the bead 908, thereby forming a mushroom shaped bead 908 that may provide improved connection to the groove 910. In various embodiments, a bead profile 926 may be substantially matched by a groove profile 928, which may include a reduced diameter portion 930 to reduce the likelihood that the bead 908 is inadvertently removed from the groove 910. For example, a shoulder 932 of the barb 924 may engage a stop 934 formed at the reduced diameter portion 920. It should be appreciated that the mushroom shaped profile 928 is for illustrated purposes only, and in various embodiments, may have a variety of different shapes. For example, the profile 928 may be T-shaped, include an arm on one end (e.g., shaped like a lower case “r”), or the like.
It should be appreciated that while various embodiments described herein are illustrated as separate configurations, that various embodiments may join or otherwise incorporate features into a single arrangement. By way of example, the winglets 618 may be utilized with the recesses 718 and/or the insert 820. Furthermore, the insert 920 in the header ring may be incorporated in embodiments of
The foregoing disclosure and description of the disclosed embodiments is illustrative and explanatory of the embodiments of the disclosure. Various changes in the details of the illustrated embodiments can be made within the scope of the appended claims without departing from the true spirit of the disclosure. The embodiments of the present disclosure should only be limited by the following claims and their legal equivalents.
This application claims priority to and the benefit of co-pending U.S. Provisional Application Ser. No. 63/058,819 filed Jul. 30, 2020 titled “COMPOSITE PUMP PACKING SEALING ELEMENTS,” the full disclosure of which is hereby incorporated herein by reference in its entirety for all purposes.
Number | Date | Country | |
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63058819 | Jul 2020 | US |