Internal Pressure Type Slip Joint Using Multiple Seal and Guide Combination

Abstract

The present invention relates to a slip joint for absorbing axial displacement caused by thermal expansion, contraction, or structural displacement of a pipe, comprising a slip body connected to an external pipe, a slip cover screw-coupled to one side of the slip body, and a slip tube accommodated inside the slip body and capable of reciprocating axially. A plurality of seals are provided in the area spanning the inner surface of the slip body and the slip cover, spaced apart axially along the outer surface of the slip tube to disperse the pressure of a high-pressure fluid in stages. A guide ring is disposed inside the slip body to suppress eccentricity of the slip tube, and a cushioning member made of an elastic material is interposed between the outer surface of the guide ring and the inner surface of the slip body to block direct metal contact between the guide ring and the slip body and to mitigate friction and vibration. Accordingly, the present invention secures stable sealing performance even in high-pressure environments through the combination of multiple seals and guides, improves wear resistance and durability by blocking metal contact and reducing friction through the cushioning member, and enables on-site maintenance without pipe separation due to the screw-coupled structure, thereby minimizing equipment downtime.

Description

Technology Field

[0001] The present invention relates to an expansion joint device for pipe connection, and more specifically, to a pressure-resistant slip joint that can be applied to pipes through which high-pressure fluid flows and can be used in both single and double structures, secures stable sealing performance even in high-pressure environments through a combination of multiple seals and guides, and allows for immediate maintenance on-site without disconnecting the pipes in the event of a leak. Background Technology

[0002] Generally, piping lines are installed to transport fluids such as hot water, oil, gas, and steam in various industrial plants, combined heat and power plants, and large ships. Since these piping lines may expand, contract, or deform due to changes in temperature and pressure of the outside air and the transported fluid, or due to earthquakes and wind pressure, slip joints are installed at the pipe connections to absorb this.

[0003] Regarding conventional slip joints, Korean Registered Patent No. 10-1173209 (hereinafter referred to as the "prior art") discloses a slip joint for piping. The slip joint of the prior art has a structure in which a front packing part, a packing compression ring, and a rear packing part are sequentially inserted into the interior of a slip housing, and a packing pressure port is connected to the rear end of the slip housing by a packing pressure bolt. Due to this structure, if fluid leakage occurs due to the packing wearing out from long-term use, the leakage can be blocked by tightening the packing pressure bolt to additionally pressurize the packing.

[0004] However, the slip joint of the aforementioned prior art has a structure in which phosphor bronze slip guides installed on the inner surface of the packing catch and packing pressure port come into direct contact with the outer surface of the slip tube; consequently, during the repetitive reciprocating motion of the slip tube, wear of the slip guides and the slip tube is accelerated due to direct metal-to-metal friction, leading to a problem of reduced durability. Furthermore, since the packing pressure port of the aforementioned prior art has a structure in which the packing pressure port is fastened to the slip housing by multiple bolts, maintenance work is complex and time-consuming, as replacing the internal packing in the event of leakage requires disassembling multiple bolts and separating the packing pressure port. In addition, the aforementioned prior art makes it difficult to effectively prevent uneven wear of the packing caused by the eccentricity of the slip tube in high-pressure environments, and 60 kg / cm² 2 There are limitations in securing stable sealing performance under high pressure conditions above this level. The problem to be solved

[0005] The present invention aims to solve the problems of the prior art described above by arranging a multi-seal structure including an O-ring and a piston seal in the area spanning the inner circumference of the slip body and slip cover, thereby dispersing the pressure of the high-pressure fluid in stages, resulting in 60 kg / cm² 2 The purpose is to provide a pressure-resistant slip joint capable of ensuring stable sealing performance even in high-pressure environments.

[0006] In addition, another objective of the present invention is to provide a pressure-resistant slip joint capable of significantly improving wear resistance and durability by interposing a cushioning member made of an elastic material between a guide ring that suppresses eccentricity of the slip tube and the inner surface of the slip body, thereby blocking direct metal contact between the guide ring and the slip body, and mitigating friction and vibration generated during the repetitive axial reciprocating movement of the slip tube.

[0007] In addition, another objective of the present invention is to provide a pressure-resistant slip joint that reduces maintenance time and costs and minimizes equipment downtime by fastening the slip body and slip cover with a screw connection structure, thereby allowing the slip cover to be disassembled and the internal seal and guide ring to be inspected and replaced immediately on-site without disconnecting the piping in the event of a leak. means of solving the problem

[0008] To achieve the above objectives, a pressure-resistant slip joint using a combination of multiple seals and guides according to one embodiment of the present invention comprises a slip body connected to an external pipe, a slip cover screw-coupled to one side of the slip body, and a slip tube accommodated inside the slip body and capable of reciprocating in the axial direction, wherein a plurality of seals are provided in the area spanning the inner circumference of the slip body and the slip cover, spaced apart in the axial direction along the outer circumference of the slip tube to disperse the pressure of a high-pressure fluid in stages, a guide ring is disposed inside the slip body to suppress eccentricity of the slip tube, and a cushioning member made of an elastic material is interposed between the outer circumference of the guide ring and the inner circumference of the slip body, thereby blocking direct metal contact between the guide ring and the slip body and mitigating friction and vibration generated during the repetitive axial reciprocating movement of the slip tube.

[0009] It is preferable that the slip body and slip cover are connected by a screw connection structure so that, in the event of a leak, the plurality of seals and guide rings can be replaced on-site by disassembling the slip cover without separating the external piping.

[0010] Preferably, the plurality of seals above include a piston seal disposed on the outer surface of the slip tube to block axial leakage of high-pressure fluid, a first O-ring disposed on both sides of the piston seal to be in close contact with the outer surface of the slip tube, and a second O-ring and a third O-ring disposed in the screw coupling area of ​​the slip body and the slip cover to block leakage between the slip body and the slip cover.

[0011] It is preferable that the second O-ring and the third O-ring are spaced apart axially in the screw coupling area of ​​the slip body and the slip cover, and the piston seal and the first O-ring are arranged axially on the outer surface of the slip tube so that the fluid pressure is reduced stepwise as it passes through each seal.

[0012] The above cushioning member is preferably an elastic member having a lip structure, configured to primarily perform the function of blocking contact between the guide ring and the slip body and absorbing friction and vibration rather than a sealing function.

[0013] It is preferable that the above buffer member be a lip seal of the seal type.

[0014] The above guide ring is preferably formed of phosphor bronze, an oil-free bearing material, or a metal material having self-lubricating properties.

[0015] It is preferable that a set bar be connected to the slip tube through a bolt for the set bar, thereby restricting the axial movement of the slip tube during shipment to maintain the distance between faces, and then releasing the set bar after installation is complete so that the slip tube can freely reciprocate.

[0016] It is preferable that a stop nut is fixed to the outer surface of the slip tube by a bolt for the stop nut, and that the stop nut is installed at the shortest side of the side where the slip tube is inserted into the slip body and the slip cover, so that when the slip tube moves in a direction of detachment from the slip body, it catches on the end side of the slip body side during screw coupling between the slip body and the slip cover, thereby preventing excessive detachment of the slip tube.

[0017] It is preferable that the above slip joint be selectively configured as a single structure in which the slip cover is coupled to only one side of the slip tube, or a double structure in which the slip cover is coupled to each side of the slip tube. Effects of the invention

[0018] The pressure-resistant slip joint using a multi-seal and guide combination according to the present invention has a plurality of O-rings and piston seals spaced apart in the axial direction in the area spanning the inner circumference of the slip body and the slip cover, thereby dispersing the pressure of a high-pressure fluid in stages, so that 60 kg / cm² 2 Stable sealing performance without leakage can be secured even in high-pressure environments above this level.

[0019] In addition, the present invention interposes an elastic cushioning member between the outer surface of a guide ring that suppresses eccentricity of the slip tube and the inner surface of a slip body, thereby blocking direct metal-to-metal contact and mitigating friction and vibration. Consequently, friction and wear are significantly reduced even during the repetitive axial reciprocating movement of the slip tube, greatly improving wear resistance and durability.

[0020] In addition, since the slip body and slip cover are fastened with a screw connection structure, the slip cover can be disassembled to immediately inspect and replace the internal seal and guide ring on-site without disconnecting the piping in the event of a leak, thereby facilitating maintenance and minimizing equipment downtime. Furthermore, since the same multi-seal and guide combination structure can be applied to both single and double structures, the present invention offers excellent product standardization and scalability. Brief explanation of the drawing

[0021] FIG. 1 is an external view of a pressure-resistant single slip joint using a combination of multiple seals and guides according to one embodiment of the present invention. FIG. 2 is an exploded perspective view of a pressure-resistant single slip joint using a combination of multiple seals and guides according to an embodiment of the present invention. FIG. 3 is a cross-sectional view of a pressure-resistant single slip joint with a set bar installed using a combination of multiple seals and guides according to an embodiment of the present invention. FIG. 4 is a cross-sectional view of a pressure-resistant single slip joint using a combination of multiple seals and guides according to an embodiment of the present invention with the set bar removed. FIG. 5 is a partial cross-sectional view illustrating the axial arrangement structure of multiple seals and guide rings according to one embodiment of the present invention. FIG. 6 is a partial cross-sectional view illustrating a structure in which a seal is installed between a guide ring and a slip body according to an embodiment of the present invention. FIG. 7 is an enlarged view showing a screw coupling structure between a slip body and a slip cover according to one embodiment of the present invention. Specific details for implementing the invention

[0022] Hereinafter, various embodiments and / or aspects are disclosed with reference to the drawings. For illustrative purposes, numerous specific details are disclosed in the following description to aid in a general understanding of one or more aspects. However, it will also be recognized by those skilled in the art that these aspects may be practiced without such specific details. The following description and the accompanying drawings describe specific exemplary aspects of one or more aspects in detail. However, these aspects are exemplary, and some of the various methods in the principles of the various aspects may be used, and the description is intended to include all such aspects and their equivalents.

[0023] As used herein, terms such as "examples," "examples," "aspects," "examples," etc., may not be interpreted as implying that any aspect or design described is better or more advantageous than other aspects or designs.

[0024] Additionally, the terms “comprising” and / or “comprising” should be understood to mean that the relevant feature and / or component is present, but not to exclude the presence or addition of one or more other features, components and / or groups thereof.

[0025] Additionally, terms including ordinal numbers, such as first, second, etc., may be used to describe various components, but said components are not limited by said terms. Such terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component. The term "and / or" includes a combination of a plurality of related described items or any of a plurality of related described items.

[0026] Furthermore, in the embodiments of the present invention, all terms used herein, including technical or scientific terms, unless otherwise defined, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in the embodiments of the present invention.

[0027] FIG. 1 is an external view of a pressure-resistant single slip joint using a combination of multiple seals and guides according to an embodiment of the present invention; FIG. 2 is an exploded perspective view of a pressure-resistant single slip joint using a combination of multiple seals and guides according to an embodiment of the present invention; FIG. 3 is a cross-sectional view of a pressure-resistant single slip joint using a combination of multiple seals and guides according to an embodiment of the present invention with a set bar installed; FIG. 4 is a cross-sectional view of a pressure-resistant single slip joint using a combination of multiple seals and guides according to an embodiment of the present invention with the set bar removed; FIG. 5 is a partial cross-sectional view for explaining the axial arrangement structure of multiple seals and guide rings according to an embodiment of the present invention; FIG. 6 is a partial cross-sectional view for explaining the structure in which a seal is installed between a guide ring and a slip body according to an embodiment of the present invention; FIG. 7 is an enlarged view showing a screw coupling structure between a slip body and a slip cover according to an embodiment of the present invention.

[0028] Meanwhile, in the following description, some components described in the drawings may be omitted or excessively enlarged or reduced in order to explain the function of each component of the present invention, but it will be understood that such illustrated components do not limit the technical features and scope of rights of the present invention.

[0029] In addition, in the following description, multiple drawings will be referred to simultaneously to explain a single technical feature or a component constituting the invention.

[0030] A pressure-resistant slip joint using a combination of multiple seals and guides according to one embodiment of the present invention has a configuration comprising a slip body (1) connected to an external pipe as shown in FIGS. 1 to 7, a slip cover (2) screw-coupled to one side of the slip body (1), and a slip pipe (4) that is accommodated inside the slip body (1) and capable of reciprocating in the axial direction. Here, a slip joint refers to an expansion joint device for absorbing axial displacement caused by thermal expansion, contraction, earthquakes, wind pressure, or structural displacement in a piping line. The present invention relates particularly to a pressure-resistant slip joint that employs a combination structure of multiple seals and guide rings to provide stable sealing performance even in high-pressure environments of 60 kg / cm² or more.

[0031] Referring to FIGS. 1 and 2, the slip body (1) is a member formed in a cylindrical tube shape and connected to an external pipe, and can generally be formed from stainless steel, for example, STS304. STS304 is an austenitic stainless steel with excellent corrosion resistance, heat resistance, and mechanical strength, and has the advantage of not causing corrosion or deformation even when used for a long time in a piping environment where high-pressure fluid flows. However, the material of the slip body (1) is not limited to this, and depending on the usage environment, stainless steel with enhanced corrosion resistance such as STS316 or STS316L, duplex stainless steel, or special alloy steel may be used. A flange (3) for connection to an external pipe is formed on one side of the slip body (1), or it can be connected to the pipe by means of welding or screw connection, and a threaded portion is formed on the other side for screw connection with the slip cover (2).

[0032] As shown in FIGS. 2 and 7, the slip cover (2) is a member that is screw-coupled to one side of the slip body (1), and like the slip body (1), it can be formed of a stainless steel material such as STS304. The slip cover (2) performs the function of fixing and supporting various seals and guide rings (11) housed inside through screw coupling with the slip body (1). In particular, since the slip body (1) and the slip cover (2) are connected by a screw coupling structure in the present invention, there is a structural advantage that, in the event of a leak, the multiple seals and guide rings (11) inside can be immediately replaced on-site by rotating only the slip cover (2) to disassemble it without separating the external piping. This screw coupling structure can significantly reduce maintenance time and costs compared to the conventional bolt fastening method, and has the effect of minimizing equipment downtime.

[0033] Referring to FIG. 7, the screw connection structure of the slip body (1) and the slip cover (2) is described in more detail. A female screw or a male screw is formed on the inner or outer surface of one end of the slip body (1), and a male screw or a female screw is formed on the end of the slip cover (2) in correspondence to this, so that they are screw-connected to each other. The screw connection method must be able to secure sufficient fastening force so that the slip cover (2) does not detach due to the pressure of the internal fluid, and if necessary, the pitch of the screw threads, the number of screw threads, and the effective length of the screw can be set to match the design pressure. In addition, to reinforce the airtightness of the screw connection part, a second O-ring (7) and a third O-ring (8), which will be described later, may be placed in the screw connection area. Accordingly, according to one embodiment of the present invention, the slip body (1) and the slip cover (2) are connected by a screw connection structure, so that in the event of leakage, the plurality of seals and guide rings (11) can be replaced on-site by disassembling the slip cover (2) without separating the external piping.

[0034] As shown in FIGS. 2 to 4, the slip tube (4) is a member that is accommodated inside the slip body (1) and arranged to be reciprocally movable in the axial direction. The slip tube (4) is formed in a cylindrical tube shape and may be formed from stainless steel material such as STS304. Since the outer surface of the slip tube (4) contacts a plurality of seals described later to form a sealing surface, the surface roughness must be managed to be below a certain level, and polishing or coating treatment may be performed as necessary. A flange (3) for connection to an external pipe may be formed at one end of the slip tube (4), or it may be connected to the pipe by means of welding, screw connection, etc. The slip tube (4) is configured to be able to freely reciprocate within a certain range inside the slip body (1) to absorb axial displacement caused by thermal expansion, contraction, vibration, uneven settlement, etc. acting on the piping line.

[0035] As one of the key technical features of the present invention, as illustrated in FIGS. 3 to 5, a plurality of seals are provided in the area covering the inner circumference of the slip body (1) and the slip cover (2), spaced apart axially along the outer circumference of the slip tube (4) to disperse the pressure of the high-pressure fluid in stages. Here, the plurality of seals includes a first O-ring (6), a second O-ring (7), a third O-ring (8), and a piston seal (9), and each seal performs different functions at different locations and acts complementarily to effectively block leakage of the high-pressure fluid. This multi-seal structure has the advantage of significantly improving sealing reliability compared to a single seal structure, and in particular, can exhibit stable sealing performance even in high-pressure environments of 60 kg / cm² or more.

[0036] Referring to FIG. 5, the specific arrangement and function of the plurality of seals are described as follows: the plurality of seals includes a piston seal (9) that is placed on the outer surface of the slip tube (4) to block axial leakage of high-pressure fluid, a first O-ring (6) that is placed on both sides of the piston seal (9) and is in close contact with the outer surface of the slip tube (4), and a second O-ring (7) and a third O-ring (8) that are placed in the screw connection area of ​​the slip body (1) and the slip cover (2) to block leakage between the slip body (1) and the slip cover (2).

[0037] The piston seal (9) is a primary sealing element that is positioned on the outer surface of the slip tube (4) to primarily block axial leakage of high-pressure fluid. The piston seal (9) can generally be formed from FPM material, i.e., fluororubber material. FPM has excellent heat resistance, oil resistance, and chemical resistance, which is an advantage that allows it to maintain elasticity and sealing performance for a long time even in high-temperature and high-pressure fluid environments. The shape of the piston seal (9) can generally be formed in the form of a lip seal or a U-shaped cross-section, so that when fluid pressure is applied, the lip portion adheres more strongly to the outer surface of the slip tube (4) to exert a self-sealing action. However, the material of the piston seal (9) is not limited to FPM, and various elastomer or plastic materials such as NBR, EPDM, PTFE, and polyurethane may be applied depending on the type and temperature of the fluid used.

[0038] The first O-ring (6) is positioned on both sides of the piston seal (9) and comes into close contact with the outer surface of the slip tube (4), thereby assisting in the sealing function of the piston seal (9) and serving to secondarily block the leakage of a small amount of fluid passing through the piston seal (9). The first O-ring (6) can be formed from FPM material and has a ring shape with a circular cross-section. The O-ring is a general-purpose sealing element that has a simple structure, is easy to install, and provides excellent airtightness by adhering to the sealing surface through compressive deformation. By positioning the first O-ring (6) on both sides of the piston seal (9), uniform sealing performance can be maintained regardless of which direction the slip tube (4) moves, and a double or triple sealing effect can be achieved through the combination of the piston seal (9) and the first O-ring (6).

[0039] As shown in FIGS. 5 and 7, the second O-ring (7) and the third O-ring (8) are placed in the screw connection area of ​​the slip body (1) and the slip cover (2) to block leakage between the slip body (1) and the slip cover (2). Since the screw connection structure has a fine gap between the screw threads due to its structural characteristics, there is a possibility that high-pressure fluid may leak through this gap. Therefore, in the present invention, the airtightness of the screw connection part is secured by axially spaced arrangement of the second O-ring (7) and the third O-ring (8) in the screw connection area. The second O-ring (7) and the third O-ring (8) can be formed from FPM material and have a ring shape corresponding to the shape of the screw connection area. By axially spaced arrangement of the second O-ring (7) and the third O-ring (8), fluid leakage through the screw connection part is blocked in multiple stages, and a double safety structure is formed in which the sealing function can be maintained by the other O-ring even if one O-ring is damaged.

[0040] Referring to FIG. 5, the arrangement order of the multiple seals is described in more detail as follows: the second O-ring (7) and the third O-ring (8) are spaced apart axially in the screw connection area of ​​the slip body (1) and the slip cover (2), and the piston seal (9) and the first O-ring (6) are arranged axially on the outer surface of the slip tube (4), so that the fluid pressure is reduced stepwise as it passes through each seal. This multi-stage pressure reduction structure has the effect of dispersing the pressure burden acting on each seal to extend the lifespan of individual seals and enables stable sealing performance to be maintained even in a high-pressure environment. In addition, since the fluid pressure is reduced stepwise as it sequentially passes through each seal from the high-pressure side to the low-pressure side, only a relatively low pressure acts on the seal at the final stage, thereby preventing premature wear or damage to the seal.

[0041] As another key technical feature of the present invention, as illustrated in FIGS. 3 to 6, a guide ring (11) is disposed inside the slip body (1) to suppress eccentricity of the slip tube (4). The guide ring (11) serves to guide and support the slip tube (4) so ​​that its central axis coincides with the central axis of the slip body (1) when the slip tube (4) reciprocates axially inside the slip body (1). If the slip tube (4) is eccentric, multiple seals come into uneven contact with the outer surface of the slip tube (4), causing uneven wear, which can lead to reduced sealing performance and leakage. By suppressing this eccentricity of the slip tube (4), the guide ring (11) maintains that multiple seals come into uniform contact with the outer surface of the slip tube (4), thereby improving the stability of sealing performance and the lifespan of the seals.

[0042] According to one embodiment of the present invention, the guide ring (11) is formed from phosphor bronze, an oil-less bearing material, or a metal material having self-lubricating properties. Phosphor bronze is an alloy of copper with added tin, and because it has excellent wear resistance, a low coefficient of friction, self-lubricating properties, and corrosion resistance, it is widely used as a material for sliding bearings or guide members. The oil-less bearing material is a material in which a lubricant is impregnated into a porous sintered metal, and it has the advantage of providing stable lubrication performance for a long period without the need for separate lubrication. Metal materials having self-lubricating properties include graphite-containing bronze and MoS2-containing alloys, and these materials provide excellent lubrication performance even under high load and low speed conditions. By forming the guide ring (11) with such a material, friction between the guide ring (11) and the slip tube (4) is minimized even when the slip tube (4) moves back and forth repeatedly, ensuring smooth movement of the slip tube (4), and wear of the guide ring (11) is suppressed, thereby maintaining a stable guide function for a long period. However, the material of the guide ring (11) is not limited to the above example, and various materials such as brass, metal, engineering plastic, and PTFE composite can be applied depending on the usage environment.

[0043] Referring to FIG. 6, the most significant difference of the present invention is explained as follows: an elastic cushioning member (10) is interposed between the outer surface of the guide ring (11) and the inner surface of the slip body (1), thereby blocking direct metal contact between the guide ring (11) and the slip body (1) and mitigating friction and vibration that occur during the repetitive axial reciprocating movement of the slip tube (4). In conventional slip joints, the guide ring and the housing body have a structure in which metals are in direct contact, so friction and wear occur between the guide ring and the body during the repetitive reciprocating movement of the slip tube, resulting in a problem of reduced durability. In the present invention, by interposing an elastic cushioning member (10) between the outer surface of the guide ring (11) and the inner surface of the slip body (1), direct metal contact is blocked, and friction and vibration that occur during the reciprocating movement of the slip tube (4) are mitigated, thereby significantly improving wear resistance and durability.

[0044] According to one embodiment of the present invention, the cushioning member (10) is an elastic member having a lip structure and is configured to primarily perform the function of blocking contact between the guide ring (11) and the slip body (1) and absorbing friction and vibration, rather than a sealing function. The cushioning member (10) is formed of an elastic rubber or plastic material and performs the role of physically blocking direct metal-to-metal contact between the guide ring (11) and the slip body (1). In addition, the cushioning member (10) performs the function of cushioning shock and vibration transmitted to the guide ring (11) and the slip body (1) by elastically absorbing when minute eccentricity or vibration occurs in the slip tube (4). Due to this cushioning function, wear on the guide ring (11) and the slip body (1) is significantly reduced despite the repetitive reciprocating movement of the slip tube (4), thereby greatly improving the durability of the slip joint.

[0045] According to one embodiment of the present invention, the cushioning member (10) is preferably a lip seal. The lip seal is an annular elastic member having a lip structure, can be formed from FPM material, and is arranged to surround the outer surface of the guide ring (11). The lip structure of the lip seal is elastically attached to the outer surface of the guide ring (11) to fill the gap between the guide ring (11) and the slip body (1), and performs a cushioning function to absorb micro-vibrations or shocks that occur during the reciprocating movement of the slip tube (4). Although the lip seal can additionally have the function of suppressing fluid leakage through the gap between the guide ring (11) and the slip body (1), in the present invention, since a plurality of seals (first O-ring (6), second O-ring (7), third O-ring (8), piston seal (9)) perform the main sealing function, the cushioning member (10) should be understood as primarily performing the function of blocking metal contact and mitigating friction / vibration rather than the sealing function. The material of the cushioning member (10) is not limited to FPM, and various elastomer or plastic materials such as NBR, EPDM, PTFE, and polyurethane may be applied depending on the usage environment.

[0046] Accordingly, a pressure-resistant slip joint using a combination of multiple seals and guides according to one embodiment of the present invention comprises a slip body (1) connected to an external pipe, a slip cover (2) screw-coupled to one side of the slip body (1), and a slip tube (4) that is accommodated inside the slip body (1) and capable of reciprocating in the axial direction. A plurality of seals are provided in the area spanning the inner circumference of the slip body (1) and the slip cover (2), spaced apart in the axial direction along the outer circumference of the slip tube (4) to disperse the pressure of a high-pressure fluid in stages. A guide ring (11) is disposed inside the slip body (1) to suppress eccentricity of the slip tube (4). A cushioning member (10) made of an elastic material is interposed between the outer circumference of the guide ring (11) and the inner circumference of the slip body (1), thereby blocking direct metal contact between the guide ring (11) and the slip body (1) and mitigating friction and vibration that occur during the repetitive axial reciprocating movement of the slip tube (4).

[0047] Referring to FIG. 3, a slip joint according to one embodiment of the present invention may further include a set bar (12) and a bolt (13) for the set bar to temporarily restrict the axial movement of the slip pipe (4). The set bar (12) is connected to the slip pipe (4) via the bolt (13) for the set bar to restrict the axial movement of the slip pipe (4) upon shipment to maintain the face-to-face distance, and after installation is complete, the set bar (12) is released to allow the slip pipe (4) to move freely back and forth. Here, the face-to-face distance refers to the axial distance between the flange (3) of the slip body (1) and the flange (3) of the slip pipe (4) when the slip joint is installed in the piping line, and this face-to-face distance must be maintained at a value pre-set according to the design of the piping line. The set bar (12) prevents the slip pipe (4) from moving arbitrarily and changing the distance between faces during the transportation and storage process from when the slip joint is shipped from the factory until it is installed at the site, and after installation on the piping line at the site is completed, the set bar (12) is released or removed so that the slip pipe (4) can freely move back and forth as originally intended.

[0048] The set bar (12) can be formed from ABS material, and ABS is an engineering plastic with excellent impact strength, heat resistance, and processability as a copolymer of acrylonitrile, butadiene, and styrene. Since the set bar (12) is formed from ABS material, it is lightweight yet has sufficient strength, so it can effectively restrict the movement of the slip pipe (4) and can be easily released or removed after installation is complete. However, the material of the set bar (12) is not limited to ABS, and other plastic or metal materials may be applied depending on the usage environment. The bolt (13) for the set bar can be formed from stainless steel such as STS304 and is a fastening member for fastening the set bar (12) to the slip pipe (4). Accordingly, according to one embodiment of the present invention, a set bar (12) is connected to the slip tube (4) through a set bar bolt (13) to restrict the axial movement of the slip tube (4) during shipment to maintain the distance between faces, and after installation is completed, the set bar (12) is released so that the slip tube (4) can freely move back and forth.

[0049] Referring to FIG. 4, a slip joint according to one embodiment of the present invention may further include a stop nut (5) and a bolt (14) for the stop nut to prevent excessive detachment of the slip tube (4). The stop nut (5) is fixed to the outer surface of the slip tube (4) by the bolt (14) for the stop nut and serves to prevent the slip tube (4) from moving excessively in the direction of detachment from the slip body (1). Specifically, the stop nut (5) is installed at the shortest side of the side where the slip tube (4) is inserted into the slip body (1) and the slip cover (2), so that when the slip tube (4) moves in the direction of detachment from the slip body (1), it is caught on the end side of the slip body (1) during screw coupling between the slip body (1) and the slip cover (2), thereby preventing excessive detachment of the slip tube (4).

[0050] The stop nut (5) can be formed from stainless steel such as STS304 and may have a ring shape or a split ring shape mounted on the outer surface of the slip pipe (4). The bolt (14) for the stop nut is formed from stainless steel such as STS304 to fix the stop nut (5) to the slip pipe (4), and a plurality of them may be spaced apart in the circumferential direction. The anti-detachment structure by the stop nut (5) prevents the slip pipe (4) from completely detaching from the slip body (1) due to pressure or external force acting in the piping line, thereby ensuring the safety and reliability of the slip joint. Accordingly, according to one embodiment of the present invention, a stop nut (5) is fixed to the outer surface of the slip tube (4) by a stop nut bolt (14), and the stop nut (5) is installed at the shortest side of the side where the slip tube (4) is inserted into the slip body (1) and the slip cover (2), so that when the slip tube (4) moves in a direction of detachment from the slip body (1), it is caught on the end side of the slip body (1) side during screw coupling between the slip body (1) and the slip cover (2), thereby preventing excessive detachment of the slip tube (4).

[0051] Meanwhile, the stop nut (5) not only prevents excessive movement of the slip tube (4) in the direction of escape, but also performs the function of preventing the slip tube (4) from being excessively inserted into the slip body (1). Referring to FIG. 4, the flange (3) side end of the slip cover (2) is formed so that the inner diameter gradually decreases, and due to this inner diameter reduction structure, a slanted portion is formed on the inner surface of the flange (3) side end of the slip cover (2) to have an inner diameter smaller than the outer diameter of the slip tube (4). When the slip tube (4) moves in the direction of being inserted into the slip body (1), the stop nut (5) fixed to the outer surface of the slip tube (4) catches on the slanted portion formed on the flange (3) side end of the slip cover (2), thereby restricting further insertion of the slip tube (4).

[0052] Accordingly, the depth to which the slip tube (4) is inserted into the slip body (1) is limited to a certain range by the combination of the stop nut (5) and the inner diameter reduction structure of the slip cover (2). Accordingly, the slip tube (4) can only reciprocate between the position where the stop nut (5) is engaged on the end side of the slip body (1) and the position where it is engaged on the inclined part of the slip cover (2) so that the inner diameter becomes smaller. This structure clearly defines the bidirectional movement range of the slip tube (4), thereby securing a safe operating range of the slip joint and preventing the slip tube (4) from moving excessively and causing damage to the inner seal or guide ring (11).

[0053] A slip joint according to one embodiment of the present invention may be selectively configured as a single structure or a double structure. The embodiment illustrated in FIGS. 1 to 4 shows a slip joint of a single structure, in which a slip cover (2) is attached to only one side of the slip tube (4). In contrast, a double structure is a structure in which a slip cover (2) is attached to each side of the slip tube (4), and both ends of the slip tube (4) are supported and sealed by the slip body (1) and the slip cover (2), respectively. The double structure has the advantage of having a larger amount of displacement absorption in both directions compared to the single structure, and since the slip tube (4) is supported equidistantly on both sides, the possibility of eccentricity or uneven wear occurring is lower. Since the multi-seal and guide combination structure of the present invention is applicable to both single and double structures, it offers excellent product standardization and scalability. Accordingly, according to one embodiment of the present invention, the slip joint is selectively configured as a single structure in which the slip cover (2) is coupled only to one side of the slip tube (4), or as a double structure in which the slip cover (2) is coupled to each side of the slip tube (4).

[0054] The slip joint of the present invention can be applied to various industrial fields. For example, it can be applied to piping lines through which high-temperature, high-pressure steam flows in power generation plants such as thermal power plants, nuclear power plants, and combined heat and power plants, and to piping lines through which various chemical fluids flow in petrochemical plants and oil refineries. In addition, it can be applied to engine rooms of large ships or cargo piping systems of LNG carriers, and can also be applied to heating pipes or water supply pipes in buildings such as office buildings or apartments. Since the slip joint of the present invention exhibits stable sealing performance even in high-pressure environments of 60 kg / cm² or higher, it is particularly suitable for high-pressure piping systems and can be usefully applied in various industrial fields requiring high sealing reliability due to a multi-seal structure and easy maintenance due to a screw connection structure.

[0055] In addition, the dimensions, shape, material, etc. of each member constituting the slip joint of the present invention are not limited to the above embodiments and can be varied in various ways depending on the diameter of the pipe to be applied, design pressure, type and temperature of the fluid used, required displacement absorption amount, etc. For example, the diameters of the slip body (1), slip cover (2), and slip pipe (4) can be manufactured in various sizes to match the pipe diameter, and the number or arrangement order of the plurality of seals can also be varied according to the required sealing performance. In addition, the number or placement position of the guide rings (11) can be varied according to the length of the slip pipe (4) or the required guide performance, and a plurality of guide rings (11) may be spaced apart on both sides of the slip body (1). The shape or material of the cushioning member (10) can also be varied in various ways depending on the usage environment, and various shapes such as packing shapes and bushing shapes can be applied in addition to the lip seal shape. All such various variations should be understood as being included within the scope of the technical concept of the present invention.

[0056] Although the embodiments have been described above with reference to limited embodiments and drawings, those skilled in the art will understand that various modifications and variations are possible from the description above. Terms such as "include," "compose," or "have" as described above imply that components may be inherent unless specifically stated otherwise; therefore, they should be interpreted as allowing for the inclusion of additional components rather than excluding other components. Furthermore, the scope of protection of the present invention shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of the present invention.

Claims

Claim 1 A slip body connected to an external pipe; a slip cover screw-coupled to one side of the slip body; The multi-seal and guide combination is characterized by comprising a slip tube accommodated inside the slip body and capable of reciprocating in the axial direction, wherein a plurality of seals are provided in an area spanning the inner circumference of the slip body and the slip cover, spaced apart in the axial direction along the outer circumference of the slip tube to disperse the pressure of a high-pressure fluid in stages, wherein the plurality of seals include a piston seal disposed on the outer circumference of the slip tube to block axial leakage of the high-pressure fluid, a first O-ring disposed on both sides of the piston seal to be in close contact with the outer circumference of the slip tube, and a second O-ring and a third O-ring disposed in the screw coupling area of ​​the slip body and the slip cover to block leakage between the slip body and the slip cover, wherein a guide ring is disposed inside the slip body to suppress eccentricity of the slip tube, and a cushioning member made of an elastic material is interposed between the outer circumference of the guide ring and the inner circumference of the slip body to block direct metal contact between the guide ring and the slip body and to mitigate friction and vibration generated during the repetitive axial reciprocating movement of the slip tube. Pressure-resistant slip joint. Claim 2 A pressure-resistant slip joint using a multiple seal and guide combination, characterized in that, in claim 1, the slip body and the slip cover are fastened with a screw connection structure, so that in the event of leakage, the plurality of seals and guide rings can be replaced on-site by disassembling the slip cover without separating the external piping. Claim 3 delete Claim 4 A pressure-resistant slip joint using a multi-seal and guide combination, characterized in that, in claim 1, the second O-ring and the third O-ring are spaced apart axially in the screw coupling area of ​​the slip body and the slip cover, and the piston seal and the first O-ring are arranged axially on the outer surface of the slip tube, so that the fluid pressure is reduced stepwise as it passes through each seal. Claim 5 A pressure-resistant slip joint using a multi-seal and guide combination, characterized in that, in claim 1, the cushioning member is an elastic member having a lip structure and is configured to block contact between the guide ring and the slip body and to absorb friction and vibration. Claim 6 A pressure-resistant slip joint using a combination of multiple seals and guides, characterized in that, in claim 5, the buffer member is a lip seal of the seal type. Claim 7 A pressure-resistant slip joint using a multi-seal and guide combination, characterized in that, in claim 1, the guide ring is formed of phosphor bronze, an oil-less bearing material, or a metal material having self-lubricating properties. Claim 8 A pressure-resistant slip joint using a combination of multiple seals and guides, characterized in that, in claim 1, a set bar is coupled to the slip tube through a bolt for the set bar, thereby restricting the axial movement of the slip tube during shipment to maintain the inter-face distance, and after installation is completed, the set bar is released to allow the slip tube to move freely back and forth. Claim 9 A pressure-resistant slip joint using a multi-seal and guide combination, characterized in that, in claim 1, a stop nut is fixed to the outer surface of the slip tube by a bolt for the stop nut, and the stop nut is installed at the shortest side of the side where the slip tube is inserted into the slip body and the slip cover, so that when the slip tube moves in a direction of detachment from the slip body, it catches on the end side of the slip body side when the slip body and the slip cover are screw-coupled, thereby preventing excessive detachment of the slip tube. Claim 10 A pressure-resistant slip joint using a multiple seal and guide combination, characterized in that, in claim 1, the slip joint is selectively configured as a single structure in which the slip cover is coupled to only one side of the slip tube, or a double structure in which the slip cover is coupled to each side of the slip tube.

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