Pipe connection component using fastening ring and having simple structure, and pipe connection method using same

Abstract

According to the pipe connection component and the pipe connection method of the present invention, when a flange and a fastening ring welded or coupled to an expansion pipe unit are fastened by a bolt and a nut, an eccentric bolt head is supported by the fastening ring and the nut is supported by the flange, so that the fastening ring and the flange are fastened and become watertight. Therefore, the pipe connection structure can be simplified and the pipe connection unit can have an excellent watertightness.

Description

A pipe connecting fitting with a simple structure using a fastening ring, and a pipe connecting method using the same

[0001] The present invention relates to a pipe connection fitting, and more specifically, to a pipe connection fitting in which, when a bolt is tightened with a nut, an eccentric bolt head is supported by a fastening ring and inserted into a guide part, thereby achieving fastening and watertightness between the fastening ring and the flange, which simplifies the structure of the flange and provides an excellent watertightness effect for the pipe connection part.

[0002] In addition, the present invention also relates to a pipe connection method using this pipe connection fitting.

[0003] This application is filed claiming priority based on Korean Patent Application 10-2024-0146590 (filing date Oct. 24, 2024, pipe connecting fitting having a simple structure using a fastening ring, and pipe connecting method using the same), and all contents included in the application specification and drawings of Korean Patent Application 10-2024-0146590 are incorporated into this specification.

[0004] Generally, while highly corrosion-resistant metal pipes such as stainless steel pipes have many advantages, the need to use expensive materials like stainless steel results in high manufacturing costs. Furthermore, limitations in forming processes like bending cause many difficulties in construction, and they can only be manufactured as straight pipes.

[0005] Furthermore, metal pipes manufactured as straight tubes are cut to specific lengths for transportation, but there is a problem in that connecting these pipes during on-site construction requires a large number of parts, labor, and time. In addition, there is also the issue that when metal pipes are buried in the ground, they are not free from corrosion caused by soil or electrical corrosion.

[0006] On the other hand, resin pipes have excellent corrosion resistance, are lightweight, easy to install, and are inexpensive, but leakage can occur as the connections separate due to shrinkage and expansion caused by temperature changes.

[0007] The inventors have developed metal-resin composite tubes capable of solving the above-mentioned problems and have registered them under Korean Patents No. 1166886, No. 1870573, No. 2148114, No. 2169618, No. 2225756, No. 2264916, etc.

[0008] Configurations for connecting composite pipes are disclosed in Korean Registered Utility Model No. 164003, etc. However, the configurations disclosed in the aforementioned documents have problems such as high manufacturing costs due to their complex structure, insufficient watertightness and bonding strength, and a high likelihood of leakage occurring over time after construction.

[0009] The present invention is proposed to solve the above problems, and aims to provide a pipe connection fitting with excellent watertightness of the pipe connection part, wherein the structure of the flange can be simplified and the connection and watertightness of the pipe connection part are achieved by the eccentric bolt head being supported by the fastening ring and inserted into the guide part when the bolt is tightened with a nut.

[0010] Another objective of the present invention is to provide a pipe connection method using the pipe connection fitting.

[0011] To achieve the above objective, a pipe connecting fitting (100)(200) according to a preferred embodiment of the present invention connects a first pipe (1) and a second pipe (2). Specifically, the pipe connecting fitting (100)(200) may include: a fastening ring (10) having a circular ring shape and installed to be fixed to the expansion portion (5) of the first pipe (1); a groove ring (31) installed in a groove (3) continuously formed along the circumferential direction of the second pipe (2); a watertight ring (33) installed between the expansion portion (5) and the second pipe (2); a flange (20) installed on the second pipe (2) to correspond to the fastening ring (10), having a bolt hole (21) and a guide portion (22) formed at a predetermined interval; and a bolt (41) installed in the bolt hole (21), having a body (42) with screw threads and a bolt head (43).

[0012] When the body (42) passes through the bolt hole (21) and is tightened by the nut (44), the bolt head (43) is supported by the fastening ring (10) and the nut (44) is supported by the flange (20), thereby allowing the fastening ring (10) and the flange (20) to be fastened together.

[0013] The guide portion (22) extends toward the fastening ring (10) to cover at least a portion of the bolt head (43), and the inner surface of the guide portion (22) is formed to interfere with each other when the bolt head (43) rotates. Accordingly, the guide portion (22) prevents arbitrary rotation of the bolt (41).

[0014] In the pipe connection fitting (100) according to the first embodiment of the present invention, the expansion portion (5) may include a first horizontal portion (5a) formed horizontally at the end of the first pipe (1), a first inclined portion (5b) formed to be inclined inward toward the pipe from the rear end of the first horizontal portion (5a), a second horizontal portion (5c) extended horizontally from the rear end of the first inclined portion (5b), and a second inclined portion (5d) formed to be inclined inward toward the pipe from the rear end of the second horizontal portion (5c). The second pipe (2) is inserted up to the second horizontal portion (5c), and the fastening ring (10) is joined to the first horizontal portion (5a) by welding.

[0015] Preferably, the side (12) of the two sides of the fastening ring (10) that contacts the bolt head (43) forms an angle (θ) of 75° to 90° with the first horizontal portion (5a).

[0016] In the pipe connection fitting (200) according to the second embodiment of the present invention, the expansion portion (5) comprises a vertical portion (5e) formed vertically at the end of the first pipe (1), a first horizontal portion (5a) formed horizontally at the inner end of the vertical portion (5e) to be perpendicular to the vertical portion (5e), ​​a first inclined portion (5b) formed to be inclined toward the inside of the pipe at the rear end of the first horizontal portion (5a), a second horizontal portion (5c) extended horizontally at the rear end of the first inclined portion (5b), and a second inclined portion (5d) formed to be inclined toward the inside of the pipe at the rear end of the second horizontal portion (5c). The second pipe (2) is inserted up to the second horizontal portion (5c). The vertical portion (5e) is formed continuously vertically along the circumferential direction at the end of the first horizontal portion (5a).

[0017] The fastening ring (10) is installed to be in contact with the first horizontal section (5a) and the vertical section (5e), ​​and when the nut (44) is tightened, the pressing force of the bolt head (43) acts on one side (12) of the fastening ring (10), and the opposite side (13) of the fastening ring (10) is supported by the vertical section (5e). Also, the nut (44) is supported by the flange (20).

[0018] The bolt head (43) preferably has a rectangular cross section, an elliptical cross section, or a cross section where the longitudinal length is longer than the unidirectional length. The body (42) is connected to the bolt head (43) at an eccentric point from the center of the bolt head (43), and the eccentric bolt head (43) is supported by the fastening ring (10).

[0019] A pipe connection method using the above pipe connection fitting (100) comprises: (a) a step of installing a flange (20) having bolt holes (21) and guide portions (22) formed at predetermined intervals along the circumferential direction, a groove ring (31) inserted into a groove (3) and a watertight ring (33) on a second pipe (2); (b) a step of joining a circular ring-shaped fastening ring (10) to an expansion portion (5) by welding; (c) a step of inserting the second pipe (2) into the expansion portion (5); and (d) a step of allowing the body (42) of a bolt (41) to pass through the bolt hole (21) and then tightening it with a nut (44) so ​​that the bolt head (43) is supported by the fastening ring (10) and the nut (44) is supported by the flange (20).

[0020] In step (d) above, the inner surface of the guide part (22) is formed to interfere with the arbitrary rotation of the bolt head (43), thereby preventing arbitrary rotation of the bolt (41).

[0021] A pipe connection method using the above pipe connection fitting (200) comprises: (a) a step of installing a flange (20) having bolt holes (21) and guide portions (22) formed at predetermined intervals along the circumferential direction, a groove ring (31) inserted into a groove (3) and a watertight ring (33) on a second pipe (2); (b) a step of installing a circular ring-shaped fastening ring (10) on an expansion portion (5), wherein the fastening ring (10) contacts the vertical portion (5e) and the first horizontal portion (5a) of the expansion portion (5); and (c) a step of inserting the second pipe (2) into the expansion portion (5). and, (d) a step of, after the body (42) of the bolt (41) passes through the bolt hole (21), tightening with a nut (44) so ​​that the bolt head (43) presses against one side (12) of the fastening ring (10) and the opposite side (13) of the fastening ring (10) is supported by the vertical part (5e) and the nut (44) is supported by the flange (20); wherein, the fastening ring (10) may be welded to the first horizontal part (5a) and / or the vertical part (5e).

[0022] The present invention has the following effects.

[0023] First, when the bolt is tightened with a nut, the eccentric bolt head is supported by the fastening ring and the nut is supported by the flange, thereby achieving fastening and watertightness between the fastening ring and the flange, which simplifies the structure of the flange.

[0024] Second, the watertightness of the pipe connection is excellent.

[0025] FIG. 1 is a perspective view showing a state in which a pipe connecting fitting according to a first embodiment of the present invention connects both pipes (first and second pipes).

[0026] FIG. 2a is a perspective view showing the fastening ring of the pipe connection fitting of FIG. 1.

[0027] FIG. 2b is a perspective view showing the fastening ring of FIG. 2a coupled to the expanded portion of the first tube.

[0028] FIG. 3 is an exploded perspective view showing the flange, bolt, and nut of the pipe connection fitting of FIG. 1.

[0029] Fig. 4 is a front view of Fig. 1.

[0030] Fig. 5 is a cross-sectional view of AA' of Fig. 4.

[0031] FIG. 6 is a perspective view showing the state in which a pipe connecting fitting according to a second embodiment of the present invention connects both pipes (first and second pipes).

[0032] FIG. 7a is an exploded perspective view showing the fastening ring of the pipe connection fitting of FIG. 6 and the first pipe.

[0033] FIG. 7b is a combined perspective view of FIG. 7a.

[0034] Fig. 8 is a cross-sectional view of Fig. 6.

[0035] Hereinafter, the present invention will be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention. Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely embodiments of the present invention and do not represent all aspects of the technical spirit of the present invention; therefore, it should be understood that various equivalents and modifications capable of replacing them may exist at the time of filing this application.

[0036]

[0037] In this specification, "pipe connecting fitting" refers to parts for connecting pipes to each other or a combination of such parts. As described above, the present invention was developed to connect metal pipes or composite pipes disclosed in Korean Registered Patents No. 1166886, No. 1870573, No. 2148114, No. 2169618, No. 2225756, No. 2264916, etc., but it may be used for other pipes as well. (Meanwhile, all contents described in the registration publications of the above registered patents are incorporated into this specification.) Furthermore, in the description and claims below, "first pipe (1)" and "second pipe (2)" are used in a comprehensive sense to include not only metal pipes or composite pipes but also all general pipes. Therefore, the scope of rights of the present invention should not be interpreted as being limited only to composite pipes.

[0038] Also, the first pipe (1) and / or the second pipe (2) refers to both pipes to be connected, but may also refer to a connecting pipe inserted between the two pipes to be connected to connect both pipes.

[0039]

[0040] [1st Example]

[0041] FIG. 1 is a perspective view showing a state in which a pipe connecting fitting according to a first embodiment of the present invention connects both pipes (first and second pipes), FIG. 2a is a perspective view showing a fastening ring of the pipe connecting fitting, and FIG. 2b is a perspective view showing the fastening ring coupled to the first pipe. FIG. 3 is an exploded perspective view showing a flange, a bolt, and a nut of the pipe connecting fitting.

[0042] As shown in the drawing, the pipe connection fitting (100) includes a fastening ring (10) installed on the first pipe (1), a groove ring (31 in FIG. 5), a backup ring (32), a watertight ring (33) and a flange (20) installed on the second pipe (2), and a bolt (41) and a nut (44) for fastening the fastening ring (10) and the flange (20).

[0043] An expanded section (5) is formed at one end of the first pipe (10). The expanded section (5) is a part formed by expanding the diameter of one end of the first pipe (10), and is the part into which the second pipe (2) is inserted when connecting the first and second pipes (10) (20). The other end of the first pipe (1) can be inserted into the expanded section (5) of an adjacent pipe (not shown in the drawing).

[0044] Meanwhile, 'the first tube (1)' and 'the second tube (2)' are distinguished for convenience of explanation, and 'the first tube (1)' and 'the second tube (2)' may be of the same type of tube or different types of tubes. Also, in this specification, the first and second tubes (1) and (2) are collectively referred to as 'tubes'.

[0045] Also, the first and second tubes (1)(2) shown in FIGS. 1, 4 to 8 are shown with only a portion of their lengths for the convenience of illustration. Therefore, the lengths and diameters of the first and second tubes (1)(2) should not be interpreted restrictively as they are shown in the drawings.

[0046] As illustrated in FIG. 5, the expansion section (5) comprises a first horizontal section (5a) formed horizontally, a first inclined section (5b) formed to be inclined inward toward the pipe from the rear end of the first horizontal section (5a), a second horizontal section (5c) extended horizontally from the rear end of the first inclined section (5b), and a second inclined section (5d) formed to be inclined inward toward the pipe from the rear end of the second horizontal section (5c).

[0047] The outer surface of the first horizontal section (5a) can be joined to the inner surface (14) of the fastening ring (10) and be in close contact with each other. In order to allow welding after installing the fastening ring (10) on the first horizontal section (5a), the outer diameter of the first horizontal section (5a) is equal to the inner diameter of the fastening ring (10), or the outer diameter of the first horizontal section (5a) is slightly smaller than the inner diameter of the fastening ring (10).

[0048] Meanwhile, the first horizontal section (5a), the first inclined section (5b), and the second horizontal section (5c) have an inner diameter larger than the outer diameter of the other end of the second tube (2). Therefore, the other end of the second tube (2) can be inserted up to the second horizontal section (5c), but insertion is restricted by being caught on the second inclined section (5d). Thus, the second inclined section (5d) acts as a stopper.

[0049] A groove (3) is formed at the other end of the second tube (2). The groove (3) is formed by continuously recessing along the circumferential direction of the second tube (2). A groove ring (31) is installed in the groove (3).

[0050] The fastening ring (10) has a circular ring shape. The fastening ring (10) has an inner surface (14), two side surfaces (12)(13) and an outer surface (11). The inner surface (14) is formed to fit with the first horizontal section (5a) (i.e., the inner surface (12) is formed horizontally so that it is in close contact with the first horizontal section (5a)), and the inner surface (14) has a shorter length (width) than the first horizontal section (5a) so that the lower ends of the two side surfaces (12)(13) can be welded to the first horizontal section (5a).

[0051] Both sides (12)(13) are joined to the first horizontal section (5a) by welding at their lower ends.

[0052] Of the two sides (12)(13), the side (12) is the part that contacts the bolt head (43) and applies bolt fastening force when tightening the nut (44). It is preferable that the side (12) forms an angle (θ) of approximately 75° to 90° with the first horizontal part (5a), and more preferably, an angle (θ) of 80° to 89°. If the angle (θ) is smaller than 75°, the contact area with the bolt head (43) becomes smaller, so problems such as damage to the contact part may occur, and if the angle (θ) exceeds 90°, it is not desirable because there is a possibility that the bolt head (43) may detach from the side (12).

[0053] Preferably, the side surface (contacting surface) of the bolt head (43) facing the side (12) can be inclined at the same angle (θ) as the side (12). If the facing surface (contacting surface) is inclined at the same angle (θ) as the side (12), the possibility of the bolt head (43) detaching from the side (12) can be reduced.

[0054] The outer surface (11) of the fastening ring (10) is spaced apart from the body (42) of the bolt (41) by a predetermined distance.

[0055] The flange (20) is connected to the fastening ring (10) to connect the first and second pipes (1)(2). The flange (20) is installed at the other end of the second pipe (2) so as to correspond to the fastening ring (10). The flange (20) includes bolt holes (21) and guide portions (22) formed at predetermined intervals along the circumferential direction. Additionally, it is preferable that the inner surface of the flange (20) be in close contact with the outer surface and rear surface of the groove ring (31).

[0056] A gentle groove (24) is formed in the circumferential direction between the flange (20) and the bolt hole (21). This groove is intended to reduce the weight of the flange (20) and save material.

[0057] A bolt (41) is installed in the bolt hole (21). Although FIG. 3 shows a bolt (41) and a nut (44) installed in only one bolt hole (21), bolts (41) and nuts (44) are installed in all bolt holes (21) of the flange (20).

[0058] The bolt (41) includes a body (42) having screw threads (not shown in the drawing) and a bolt head (43) formed on the top of the body (42).

[0059] And, a guide portion (22) is formed around each bolt hole (21). As shown in FIGS. 1 and FIGS. 3 to 5, the guide portion (22) has a semicircular column structure that wraps approximately 150° to 210° of the outer part of the bolt hole (21) (far from the center of the second tube) and extends long toward the fastening ring (10).

[0060] In addition, at least a portion of the bolt head (43) is inserted into the inner side of the guide portion (22), and the inner surface of the guide portion (22) preferably has a cross-sectional structure that interferes with each other when the bolt head (43) rotates arbitrarily so as to prevent the bolt (41) from rotating arbitrarily. For example, as shown in the drawing, if the bolt head (43) has a rectangular cross-section, the inner surface of the guide portion (22) also has a semicircle that surrounds the rectangular cross-section or a cross-section that fits the rectangular cross-section. To prevent the bolt head (43) from rotating arbitrarily, it is preferable that the guide portion (22) covers at least 1 / 3 of the longitudinal side of the bolt head (43).

[0061] Instead of the above rectangular cross section, the bolt head (43) may have an elliptical cross section, a polygonal structure with different longitudinal and unidirectional lengths, etc. Furthermore, it is preferable that the long side of the above rectangular cross section is positioned perpendicular to the circumferential direction of the fastening ring (10), the major axis of the above elliptical cross section is positioned perpendicular to the circumferential direction of the fastening ring (10), or the direction of the above longitudinal section is positioned perpendicular to the circumferential direction of the fastening ring (10).

[0062] After the bolt (41) passes through the bolt hole (21) and the nut (44) is tightened, the bolt head (43) is supported by the fastening ring (10) and the nut (44) is supported by the flange (20), and at least a portion of the bolt head (43) is inserted into the guide portion (22), thereby firmly fastening the fastening ring (10) and the flange (20), preventing arbitrary rotation of the bolt (41), and ensuring a tight watertight seal.

[0063] It is preferable that the body (42) of the bolt (41) be connected (joined) to the bolt head (43) at an eccentric point from the center of the bolt head (43). Also, it is preferable that this eccentric bolt head (43) be supported by the fastening ring (10).

[0064] Meanwhile, the groove ring (31) has a ring structure and is installed to be inserted into the groove (3). The groove ring (31) may be a single integrated ring, but it is preferable for easy installation that two or three arcs are joined together to form a ring so as to be rotatable.

[0065] The lower cross-section of the groove ring (31) is inserted into the groove (3), and the upper cross-section of the groove ring (31) protrudes upward from the groove (3). This protruding part serves to secure the flange (20) and support the backup ring (32). That is, when the bolt (41) is tightened by the nut (44), the flange (20) receives a force directed toward the fastening ring (10), and by the groove ring (31) supporting this force, the flange (20) is secured to the second pipe (2), the backup ring (32) and the water seal ring (33) are in close contact, and the expanded portion (5) is in close contact with the water seal ring (33).

[0066] It is preferable that the outer surface and rear end surface of the groove ring (31) be in close contact with the inner surface of the flange (20).

[0067] A backup ring (32) is installed between the water seal ring (33) and the groove ring (31). The backup ring (32) is a perfectly circular ring and transmits the load acting by the fastening force of the flange (20) and the fastening ring (10) or the load acting by the pulling force acting on the first and second pipes (1) (2) to the water seal ring (33) or the groove ring (31). The backup ring (32) can be made of a material selected from metal, rubber, synthetic resin, and plastic.

[0068] Preferably, one side of the backup ring (32) (the side facing the water seal) is formed to protrude in a Λ cross section along the circumferential direction, and this protruding part is inserted into a groove (V cross section shape, 33a) on the rear side of the water seal (33). More preferably, the angle of the Λ cross section of the protruding part is greater than the angle of the V cross section of the groove (33a), and accordingly, as the protruding part is inserted into the groove (33a), it pushes the groove (33a) to both sides, thereby causing the water seal (33) to be more closely attached to the expansion part (5) and the second tube (2).

[0069] The water seal (33) is a perfectly circular ring and is installed between the second tube (2) and the expansion section (5). The water seal (33) can be made of rubber, silicone, synthetic resin, etc. The water seal (33) is in close contact with the second tube (2) and the expansion section (5) when the bolt (41) is tightened by the nut (44). Preferably, the outer surface of the water seal (33) is formed to fit with the first inclined section (5b) and the first horizontal section (5a).

[0070] Two wings (33b) are continuously formed along the circumferential direction on the side facing the first inclined portion (5b) of the two sides of the water seal (33). When the nut (44) is tightened, the two wings (33b) are each in close contact with the first inclined portion (5b) and the second tube (2) to form a water seal.

[0071]

[0072] [2nd Example]

[0073] FIG. 6 is a perspective view showing a state in which a pipe connecting fitting according to a second embodiment of the present invention connects both pipes (first and second pipes), FIG. 7a is an exploded perspective view showing the fastening ring of the pipe connecting fitting and the first pipe, and FIG. 7b is an assembled perspective view of FIG. 7a.

[0074] The pipe connection fitting (200) includes a fastening ring (10) installed on the first pipe (1), a groove ring (31), a backup ring (32), a watertight ring (33), and a flange (20) installed on the second pipe (2), and a bolt (41) and a nut (44) for fastening the flange (20) and the fastening ring (10).

[0075] The pipe connection fitting (200) differs from the pipe connection fitting (100) in that a vertical portion (5e) is formed in the expansion portion (5) and the connection ring (10) is supported by the vertical portion (5e) when the bolt (41) and nut (44) are fastened. Also, among the components of the pipe connection fitting (200), the groove ring (31), backup ring (32), watertight ring (33), flange (20), connection ring (10), bolt (41), and nut (44) are the same as in the first embodiment, so their description is omitted here.

[0076] The vertical section (5e) is formed continuously vertically along the circumferential direction from the end of the first horizontal section (5a). The vertical section (5e) is formed continuously along the circumferential direction of the first tube (10), and can be formed by bending the end of the tube vertically or by welding a flat ring to the end of the first horizontal section (5a).

[0077] The side (13) and the inner surface (14) of the fastening ring (10) are perpendicular, and the side (13) is formed to be fitted with the vertical portion (5e), ​​and the inner surface (14) is formed to be fitted with the first horizontal portion (5a). The inner surface (14) of the fastening ring (10) may have a shorter length than or equal to the length of the first horizontal portion (5a).

[0078] When the bolt (41) is tightened by the nut (44), the bolt head (43) presses against the side (12) and the side (13) is supported by the vertical part (5e).

[0079] Meanwhile, although not shown in the drawing, the lower end of the side (12) may be welded to the first horizontal section (5a), or the upper end of the side (13), preferably the side (13), may be welded to the vertical section (5e), ​​or the lower end of the side (12) may be welded to the first horizontal section (5a) and the side (13) may be welded to the vertical section (5e).

[0080] Additionally, the side (12) may be formed at an angle (θ) to the first horizontal portion (5a). The angle (θ) has been described above. Furthermore, the surface of the bolt head (43) facing the side (12) may be formed at an angle (θ) equal to that of the side (12), and this point has also been described above.

[0081]

[0082] [How to connect pipes]

[0083] Below, we will explain a method of connecting pipes using a pipe connection fitting (200).

[0084] First, at the construction site, a flange (20), a groove ring (31), a backup ring (32), and a watertight ring (33) are installed on the second pipe (2), and a fastening ring (10) is installed on the first pipe (1).

[0085] Next, the other end of the second tube (2) is inserted into the expansion section (5).

[0086] Next, the side (13) of the fastening ring (10) is installed so that it is in close contact with the vertical portion (5e) and the inner surface (14) is in close contact with the first horizontal portion (5a). Then, a bolt (41) is installed to pass through the bolt hole (21) and tightened with a nut (44) so ​​that the bolt head (43) presses against the side (12) and the nut (44) is supported by the flange (20) and at least a portion of the bolt head (43) is inserted into the guide portion (22).

[0087] As the bolt (41) is tightened with a nut (44), the groove ring (31), the backup ring (32), and the water seal ring (33) come into close contact with each other, and the groove (33a) and the wing (33b) of the water seal ring (33) spread out to both sides and come into close contact with the expansion portion (5) and the second tube (2).

[0088] Meanwhile, although the pipe connection method using the pipe connection fitting (200) of the second embodiment has been described above, the pipe connection method using the pipe connection fitting (100) of the first embodiment will be easily understood by a person skilled in the art who has referred to the above description, so the description thereof will be omitted here.

Claims

1. In a pipe connecting fitting connecting the first pipe (1) and the second pipe (2), A fastening ring (10) having a circular ring shape, installed to be fixed to the expansion portion (5) of the first pipe (1); A groove ring (31) installed in a groove (3) formed continuously along the circumferential direction of the second tube (2); Water sealing ring (33) installed between the expansion section (5) and the second pipe (2); A flange (20) installed in the second pipe (2) to correspond to the fastening ring (10) and having bolt holes (21) formed at predetermined intervals; and, A bolt (41) having a body (42) with threads formed thereon and a bolt head (43) installed in a bolt hole (21); A pipe connection fitting characterized by the fact that the body (42) passes through the bolt hole (21) and is tightened by the nut (44), so that the bolt head (43) is supported on the fastening ring (10) and the flange (20) are connected.

2. In Paragraph 1, The expansion section (5) includes a first horizontal section (5a) formed horizontally at the end of the first pipe (1), a first inclined section (5b) formed to be inclined toward the inside of the pipe from the rear end of the first horizontal section (5a), a second horizontal section (5c) extended horizontally from the rear end of the first inclined section (5b), and a second inclined section (5d) formed to be inclined toward the inside of the pipe from the rear end of the second horizontal section (5c). The second tube (2) is inserted up to the second horizontal section (5c), and A pipe connecting fitting characterized by the fastening ring (10) being joined to the first horizontal section (5a) by welding.

3. In Paragraph 2, A pipe connecting fitting characterized in that the side (12) in contact with the bolt head (43) among the two sides of the fastening ring (10) forms an angle (θ) of 75° to 90° with the first horizontal portion (5a).

4. In Paragraph 1, The expansion section (5) includes a vertical section (5e) formed vertically at the end of the first pipe (1), a first horizontal section (5a) formed horizontally at the inner end of the vertical section (5e) so as to be perpendicular to the vertical section (5e), ​​a first inclined section (5b) formed to be inclined toward the inside of the pipe at the rear end of the first horizontal section (5a), a second horizontal section (5c) extended horizontally at the rear end of the first inclined section (5b), and a second inclined section (5d) formed to be inclined toward the inside of the pipe at the rear end of the second horizontal section (5c). The second tube (2) is inserted up to the second horizontal section (5c), and A pipe connection fitting characterized in that the fastening ring (10) is installed to be in contact with the first horizontal section (5a) and the vertical section (5e), ​​and when the nut (44) is tightened, the pressing force of the bolt head (43) acts on one side (12) of the fastening ring (10) and the opposite side (13) of the fastening ring (10) is supported by the vertical section (5e).

5. In Paragraph 1, The bolt head (43) has a rectangular cross section or an elliptical cross section or a cross section with different lengths in the longitudinal and unidirectional directions, A pipe connection fitting characterized in that the body (42) is connected to the bolt head (43) at an eccentric point from the center of the bolt head (43), and the eccentric bolt head (43) is supported by a fastening ring (10).

6. A method of connecting a first tube (1) having an expanded portion (5) and a second tube (2) having a groove (3) formed along the circumferential direction, (a) A step of installing a flange (20) having bolt holes (21) formed at predetermined intervals along the circumferential direction, a groove ring (31) inserted into a groove (3) and a watertight ring (33) on a second pipe (2); (b) a step of joining a circular ring-shaped fastening ring (10) to the expansion portion (5) by welding; (c) a step of inserting the second tube (2) into the expansion section (5); and, (d) a step of connecting the fastening ring (10) and the flange (20) by allowing the body (42) of the bolt (41) to pass through the bolt hole (21) and then tightening it with a nut (44) so ​​that the bolt head (43) is supported by the fastening ring (10) and the nut (44) is supported by the flange (20); characterized by including the step of connecting the fastening ring (10) and the flange (20).

7. A method of connecting a first tube (1) having an expanded section (5) and a second tube (2) having a groove (3) formed along the circumferential direction, (a) A step of installing a flange (20) having bolt holes (21) formed at predetermined intervals along the circumferential direction, a groove ring (31) inserted into a groove (3) and a watertight ring (33) on a second pipe (2); (b) A step of installing a circular ring-shaped fastening ring (10) in the expansion section (5), wherein the fastening ring (10) is in contact with the vertical section (5e) and the first horizontal section (5a) of the expansion section (5); (c) a step of inserting the second tube (2) into the expansion section (5); and, (d) A step of connecting the fastening ring (10) and the flange (20) by allowing the body (42) of the bolt (41) to pass through the bolt hole (21) and then tightening it with a nut (44) so ​​that the bolt head (43) presses against one side (12) of the fastening ring (10), the opposite side (13) of the fastening ring (10) is supported by a vertical part (5e), ​​and the nut (44) is supported by a flange (20); characterized by including the step of connecting the fastening ring (10) and the flange (20).

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