Flange temporary fastening jig and flange fastening method

Abstract

To provide a temporary fixing jig for a flange and a flange fastening method for improving efficiency of work for fastening a first flange and a second flange.SOLUTION: A flange temporary fastening jig for temporarily fastening a first flange of a first pipe to a second flange disposed at a predetermined position, the flange temporary fastening jig comprising: A main body portion including a pair of leg portions and a connection portion connected to one end portion of each of the pair of leg portions, and a pair of pin portions respectively erected from the pair of leg portions and respectively inserted into two of a plurality of first bolt holes formed in the first flange and two of a plurality of second bolt holes formed in the second flange, in which the pair of pin portions is disposed so as to be symmetrical with respect to a pipe center line of the first flange and the second flange.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a flange temporary fastening jig and a flange fastening method. [Background technology]

[0002] Conventionally, a flange temporary fastening jig used when fastening two pipe flanges with bolts has been known. Fig. 14 is a schematic diagram of the flange temporary fastening jig disclosed in Patent Document 1. The flange temporary fastening jig includes a pair of reamer pins 104 and connecting members (not shown in Fig. 14) connected to each of the pair of reamer pins 104. In the drawing, the pair of reamer pins 104 are arranged at the same height, so only one of the pins, which is located on the front side of the drawing, is shown.

[0003] The first flange 101 and the second flange 102 are temporarily fastened together by inserting each reamer pin 104 into the bolt hole 101a of the first flange 101 and the bolt hole 102a of the second flange 102. The insertion position of the reamer pin 104 is below the center of the first flange 101 and the second flange 102. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2020-34069 Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, when the worker releases the first flange 101 after the temporary fastening, the weight of the pipe including the first flange 101 acts on the first flange 101 in the manner indicated by arrow A, causing the top of the first flange 101 to separate from the second flange 102. Therefore, when fastening the first flange 101 and the second flange 102 with bolts, it is necessary to support the pipe including the first flange, making it difficult for a single worker to perform the fastening work. The more workers required to fasten the pipes, the lower the work efficiency becomes.

[0006] An object of the present disclosure is to provide a flange temporary fastening jig and a flange fastening method that improve the efficiency of the work of fastening a first flange and a second flange. [Means for solving the problem]

[0007] A flange temporary fastening jig according to at least one embodiment of the present disclosure includes: A flange temporary fastening jig for temporarily fastening a first flange of a first pipe to a second flange arranged in a predetermined position, a main body including a pair of legs and a connecting portion connected to one end of each of the pair of legs; a pair of pin portions extending from the pair of legs, the pair of pin portions being inserted into two of the plurality of first bolt holes formed in the first flange and two of the plurality of second bolt holes formed in the second flange, respectively; Equipped with The pair of pin portions are arranged symmetrically with respect to the piping center line of the first flange and the second flange.

[0008] A flange fastening method according to at least one embodiment of the present disclosure includes: A flange fastening method for fastening the first flange and the second flange using the flange temporary fastening jig, a pin insertion step of inserting the pair of pin portions of the flange temporary fastening jig into any two of the plurality of first bolt holes formed in the first flange and any two of the plurality of second bolt holes formed in the second flange, respectively; a lower bolt insertion step of inserting bolts into a first lower bolt hole located below at least one of the two first bolt holes among the plurality of first bolt holes and a second lower bolt hole located below at least one of the two second bolt holes among the plurality of second bolt holes after the pin insertion step; a lower bolt tightening step of tightening the bolt inserted in the lower bolt inserting step; an upper bolt insertion step of inserting bolts into a first upper bolt hole located above at least one of the two first bolt holes among the plurality of first bolt holes and a second upper bolt hole located above at least one of the two second bolt holes among the plurality of second bolt holes after the lower bolt fastening step; an upper bolt fastening step of fastening the bolt inserted in the upper bolt inserting step; a pin extraction step of extracting the pair of pin portions after the upper bolt insertion step; a bolt insertion step of inserting a bolt into each of the two first bolt holes and the two second bolt holes; a bolt tightening step of tightening the bolt inserted in the bolt inserting step; Equipped with. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide a flange temporary fastening jig and a flange fastening method that improve the efficiency of the work of fastening a first flange and a second flange. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a schematic diagram of a first pipe, a second pipe, and a third pipe. [Figure 2] FIG. 2 is a schematic diagram of a first flange and a second flange. [Figure 3] FIG. 2 is a schematic central cross-sectional view of a first flange and a second flange. [Figure 4] FIG. 10 is a schematic view showing temporary fastening of the first flange 7 and the second flange. [Figure 5] FIG. 10 is a schematic view of a flange temporary fixing jig. [Figure 6] FIG. 10 is another schematic view of the flange temporary fixing jig. [Figure 7] FIG. 7 is a partially enlarged view of FIG. [Figure 8] 1 is a flowchart showing a flange fastening method. [Figure 9] FIG. 10 is a schematic view of the first flange into which the pin portion of the flange temporary fixing jig is inserted. [Figure 10] FIG. 10 is a schematic view of a gasket inserted between a pair of pin portions. [Figure 11] FIG. 10 is a schematic diagram of the gasket after the height position has been adjusted. [Figure 12] FIG. 10 is a schematic view of the first flange after bolt tightening is completed. [Figure 13] FIG. 10 is a schematic view of a first flange according to a modified example. [Figure 14] FIG. 10 is a schematic view showing temporary fastening of a first flange and a second flange according to a conventional example. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, several embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present disclosure. For example, expressions expressing relative or absolute arrangement such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial" not only express such an arrangement exactly, but also express a state in which there is a relative displacement with a tolerance or an angle or distance to the extent that the same function is obtained. For example, expressions such as "identical," "equal," and "homogeneous" that indicate that something is in an equal state not only indicate a state of strict equality, but also indicate a state in which there is a tolerance or a difference to the extent that the same function is obtained. For example, expressions representing shapes such as a square shape or a cylindrical shape not only represent shapes such as a square shape or a cylindrical shape in the strict geometric sense, but also represent shapes including uneven portions, chamfered portions, etc., to the extent that the same effect can be obtained. On the other hand, the expressions "comprise," "include," or "have" one element are not exclusive expressions that exclude the presence of other elements. Note that the same components will be denoted by the same reference numerals and the description thereof will be omitted.

[0012] FIG. 1 is a schematic diagram of a first pipe 1, a second pipe 2, and a third pipe 3. These pipes are, for example, pipes for guiding fuel gas to a combustor of a gas turbine. The second pipe 2 and the third pipe 3 are arranged in predetermined positions, and the first pipe 1 is attached to both pipes. Specifically, one of two first flanges 7 formed at both ends of the first pipe 1 is attached to the second flange 4 of the second pipe 2, and the other first flange 7 is attached to the third flange 6 of the third pipe 3. The first pipe 1 is, for example, a flexible pipe.

[0013] When attaching the first flange 7 and the second flange 4, a fastening operation is performed using bolts 5 and nuts 8 shown in Figure 3. During the fastening operation, the first flange 7 must be held in a predetermined position, and for this purpose a temporary flange fastening jig 10 shown in Figure 2 is used. Furthermore, when attaching the other first flange 7 to the third flange 6, the temporary flange fastening jig 10 is also used before the fastening operation. In the following, to avoid duplication of explanation, the attachment of the first flange 7 and the second flange 4 will be described in detail, and the attachment of the first flange 7 and the third flange 6 will not be described.

[0014] FIG. 2 is a schematic diagram of the first flange 7 and the second flange 4. FIG. 3 is a schematic central cross-sectional view of the first flange 7 and the second flange 4. The first flange 7 has four first bolt holes 31 formed therein, spaced equally apart along the circumferential direction of the first pipe 1. The second flange 4 has four second bolt holes 41 formed therein, each facing the four first bolt holes 31. Bolts 5 are inserted into the first bolt holes 31 and the second bolt holes 41, and nuts 8 are fastened to the inserted bolts 5. A gasket 9 is sandwiched between the first flange 7 and the second flange 4. The gasket 9 serves to prevent leakage of fuel gas flowing through the first pipe 1 and the second pipe 2. Note that the bolts 5 and nuts 8 are not shown in FIG. 2.

[0015] As shown in FIG. 2, the four first bolt holes 31 include two first socket bolt holes 32, a first upper bolt hole 33, and a second upper bolt hole 44. The two first socket bolt holes 32 are located at approximately the same height as the center of the flow path of the first piping 1 (the second socket bolt hole 42, located at the back of the page, is not shown in FIG. 2). The two first socket bolt holes 32 are used not only as holes for inserting bolts 5 but also when temporarily fastening the first flange 7 to the second flange 4 (details will be described later). The first upper bolt hole 33 is located above each of the first socket bolt holes 32, and the first lower bolt hole 35 is located below each of the first socket bolt holes 32. These four first bolt holes 31 have approximately the same inner diameter.

[0016] The four second bolt holes 41 include two second insert bolt holes 42, a second upper bolt hole 44, and a second lower bolt hole 46. The two second insert bolt holes 42 face the two first insert bolt holes 32, the second upper bolt hole 44 faces the first upper bolt hole 33, and the second lower bolt hole 46 faces the first lower bolt hole 35. These four second bolt holes 41 have approximately the same inner diameter.

[0017] 4 to 7, the configuration of the flange temporary fastening jig 10 will be described. Before fastening the first flange 7 to the second flange 4 with the bolts 5 and nuts 8, the first flange 7 is temporarily fastened in a predetermined position relative to the second flange 4. During this temporary fastening operation, the flange temporary fastening jig 10 is used.

[0018] As shown in FIGS. 4 to 6 , the flange temporary fastening jig 10 includes a main body 15. The main body 15 includes a pair of linearly extending legs 12 and a connecting portion 13 connected to one end 11 of each of the pair of legs 12. The connecting portion 13 has a curved portion 18 that curves convexly in a direction from the other end 19 of the leg 12 toward the one end 11. The flange temporary fastening jig 10 also includes a pair of pins 16 that extend upright from each of the pair of legs 12. The pins 16 are formed separately from the main body 15. The maximum outer diameter of the pins 16 is substantially the same as the inner diameters of the first bolt hole 31 and the second bolt hole 41. The pins 16 extend from the base end 21 of the pins 16 toward the tip 22 of the pins 16. The rigidity of the connecting portion 13 allows the positional relationship between the pair of pins 16 to be maintained regardless of the state of use of the flange temporary fastening jig 10.

[0019] When the first flange 7 is temporarily fastened to the second flange 4, the pair of pins 16 are inserted into the two first socket bolt holes 32 and the two second socket bolt holes 42, respectively. This holds the first flange 7 facing the second flange 4. At this time, the center lines of the flow paths of the first pipe 1 and the second pipe 2 are approximately aligned (see FIG. 3). This aligned flow path center line may be referred to below as the "piping center line M." When the first flange 7 and the second flange 4 are temporarily fastened, the pair of pins 16 are symmetrical with respect to the pipe center line M (see FIG. 9).

[0020] At this time, the insertion positions (center positions of the pin portions 16) of the pair of pin portions 16 are both at substantially the same height as the piping center line M. Therefore, even if the worker releases the flange temporary fastening jig 10 after temporary fastening, the pair of pin portions 16 causes the position of the center of the first flange 7 to remain almost unchanged, and the upper half of the first flange 7 is unlikely to separate from the second flange 4. Therefore, the worker can insert bolts 5 into the first lower bolt hole 35 and the second lower bolt hole 46, and also into the first upper bolt hole 33 and the second upper bolt hole 44, without supporting the first piping 1. This reduces the number of workers required to fasten the first flange 7 and the second flange 4, thereby realizing a flange temporary fastening jig that improves the efficiency of the fastening work.

[0021] 5 and 6, the configuration of the flange temporary fastening jig 10 will be further described. The pair of pin portions 16 includes a pair of flat surfaces 17 facing each other. The shortest distance between the pair of flat surfaces 17 in the direction in which the pair of flat surfaces 17 face each other (arrow B) is substantially the same as the outer diameter of the gasket 9. After the pair of pin portions 16 are inserted, when an operator inserts the gasket 9 from above between the first flange 7 and the second flange 4, the pair of flat surfaces 17 can adjust the position of the gasket 9 in the direction of arrow B (details will be described later). In the example shown in FIGS. 5 and 6, arrow B corresponds to a substantially horizontal direction (for example, the left-right direction) when the pair of pin portions 16 are inserted.

[0022] 5 and 7, each of the pair of legs 12 has a leg end surface 14, which is the end surface in the vertical direction of the pin portion 16. When viewed along the piping center line M, the leg end surface 14 has a surrounding surface 14S that surrounds the base end 21 of the pin portion 16 around the circumferential direction of the pin portion 16.

[0023] A flange fastening method for fastening the first flange 7 to the second flange 4 will be described with reference to Figures 8 to 12. In the following description, "step" may be abbreviated as "S." The flange fastening method shown in Figure 8 is carried out by an operator.

[0024] First, with the first flange 7 facing the second flange 4, a pin insertion step (S11) is performed in which the pin portions 16 are inserted into the first socket bolt holes 32 and the second socket bolt holes .

[0025] In S11, the worker holds the first pipe 1 with one hand and aligns the first flange 7 with the second flange 4, and holds the curved portion 18 of the flange temporary fastening jig 10 with the other hand and inserts the pin portion 16 into the first insertion bolt hole 32 and the second insertion bolt hole 42 (see FIG. 9). The pin portion 16 is inserted from the first flange 7 side toward the second flange 4 side. The surrounding surface 14S of the leg portion 12 abuts against the first flange 7 around the circumferential direction of the pin portion 16.

[0026] By fitting pin portion 16 into first socket bolt hole 32 and second socket bolt hole 42, the vertical and horizontal positions of first flange 7 and second flange 4 are aligned. Even if the worker releases his or her hands from first flange 7, first flange 7 is stably held in a position facing second flange 4.

[0027] When pin portion 16 is inserted, curved portion 18 is curved so as to convex upward (see FIG. 9). Therefore, when inserting pin portion 16, the worker can easily grasp curved portion 18. When viewed along the piping center line M, curved portion 18 is located above first upper bolt hole 33 and second upper bolt hole 44.

[0028] Furthermore, because the surrounding surface 14S can abut against the first flange 7 around the circumferential direction of the pin portion 16, even if the worker releases the flange temporary fastening jig 10, the main body 15 of the flange temporary fastening jig 10 can be prevented from tilting relative to the first flange 7. This allows the first flange 7 to be temporarily fastened to the second flange 4 in a stable manner.

[0029] After S11, a lower bolt insertion step (S13) is performed in which bolts 5 are inserted into the first lower bolt hole 35 and the second lower bolt hole 46. Nuts 8 are attached to the inserted bolts 5. At this time, the nuts 8 are not completely tightened, and are attached in a somewhat loose state. Therefore, a small gap is formed between the first flange 7 and the second flange 4.

[0030] Next, a gasket insertion step (S15) is performed in which the gasket 9 is inserted from above between the first flange 7 and the second flange 4. The gasket 9 abuts against the pair of flat surfaces 17. This allows the position of the gasket 9 in the opposing direction of the pair of flat surfaces 17 (left and right direction in FIG. 10) to be adjusted to the desired position, thereby improving the efficiency of the positioning work of the gasket 9. Note that when S15 is performed, the gasket 9 abuts from above against the bolt 5 inserted in the lower bolt insertion step (S13), which prevents the gasket 9 from falling off.

[0031] Next, an upper bolt insertion step (S17) is performed in which bolts 5 are inserted into first upper bolt holes 33 and second upper bolt holes 44. Nuts 8 are attached to the inserted bolts 5. At this time, the nuts 8 are not completely tightened, but are attached in a somewhat loose state. Here, when S17 is performed, curved portion 18 of flange temporary fastening jig 10 is positioned above first upper bolt holes 33 and second upper bolt holes 44 (see FIG. 10), so the worker can insert bolts 5 that have passed through the inside of curved portion 18 into first upper bolt holes 33 and second upper bolt holes 44. Because curved portion 18 does not interfere with the insertion of bolts 5, bolts 5 can be easily inserted. This improves the efficiency of the temporary fastening work of first flange 7 and second flange 4.

[0032] Next, a gasket position adjustment step (S19) is performed to adjust the height position of the gasket 9. By performing S19, the center of the gasket 9 is substantially aligned with the piping center line M. Next, a lower bolt tightening step (S21) to tighten the bolts 5 inserted in the lower bolt insertion step (S13) and an upper bolt tightening step (S23) to tighten the bolts 5 inserted in the upper bolt insertion step (S17) are performed in this order. In S21 and S23, the nuts 8 are tightened until the bearing surfaces of the bolts 5 are firmly pressed against the first flange 7. By performing S21 and S23, the gasket 9 is sandwiched between the first flange 7 and the second flange 4.

[0033] Next, a pin extraction step (S25) is performed to extract the pair of pin portions 16. Thereafter, a bolt insertion step (S27) is performed to insert two bolts 5 into the two first socket bolt holes 32 and the two second socket bolt holes 42, respectively, and a bolt tightening step (S29) is performed to tighten the inserted bolts 5 (see FIG. 12). S29 is the same as S21 and S23. This completes the tightening operation, and the first flange 7 is attached to the second flange 4. Thereafter, the worker simply attaches the first flange 7 to the third flange 6 (see FIG. 1) in the same order as S11 to S29.

[0034] In S11, the pin portion 16 may be inserted from the second flange 4 side to the first flange 7 side. In this case, the surrounding surface 14S of the leg portion 12 abuts against the second flange 4 around the pin portion 16 in the circumferential direction.

[0035] 13 shows a first flange 7 according to a modified example. As shown in the figure, the first upper bolt hole 33 may be positioned at the same height as one of the two first socket bolt holes 32. In this case, the first upper bolt hole 33 is positioned higher than the remaining first socket bolt hole 32. Similarly, although not shown in detail, the second upper bolt hole 44 may be positioned at the same height as one of the two second upper bolt holes 44, or may be positioned above the remaining second upper bolt hole 44.

[0036] According to the above-described modified example, one of the pair of pin portions 16 is located above the piping center line M. Therefore, even if the worker releases the flange temporary fastening jig 10 after temporary fastening, the upper half of the first flange 7 is less likely to separate from the second flange 4 due to the pin portion 16 located on the upper side.

[0037] The present disclosure is not limited to the above-described embodiment. The first pipe 1, the second pipe 2, and the third pipe 3 may constitute, for example, a boiler pipe group. In this case, these pipes may be fuel pipes that guide liquid fuel into the furnace, or gas pipes that guide air into the furnace. The first pipe 1 illustrated in FIG. 1 is a flexible pipe, but instead, a regular type of pipe that does not have flexibility may be used as the first pipe 1. The leg portion 12 illustrated in FIG. 5 extends linearly, but may instead extend curvedly.

[0038] Furthermore, the number of first bolt holes 31 is not limited to four and may be, for example, eight. In this case, the number of first upper bolt holes 33 and the number of first lower bolt holes 35 will both be plural. Similarly, the number of second bolt holes 41 may be, for example, eight.

[0039] The contents of the above-described embodiments can be understood, for example, as follows.

[0040] 1) A flange temporary fastening jig according to at least one embodiment of the present disclosure includes: A flange temporary fixing jig for temporarily fixing a first flange (7) of a first pipe (1) to a second flange (4) arranged in a predetermined position, a main body (15) including a pair of legs (12) and a connecting portion (13) connected to one end (11) of each of the pair of legs; a pair of pin portions (16) extending from the pair of legs, the pair of pin portions (16) being inserted into two of the plurality of first bolt holes (31) formed in the first flange and two of the plurality of second bolt holes (41) formed in the second flange, respectively; Equipped with The pair of pin portions are arranged symmetrically with respect to the piping center line (M) of the first flange and the second flange. Jig for temporarily fastening flanges.

[0041] According to the above configuration 1), the pair of pin portions are inserted into the two first bolt holes, respectively, and into the two second bolt holes, respectively, thereby temporarily fastening the first flange to the second flange. At this time, the insertion position of at least one of the pair of pin portions is substantially at the same height as the center line of the pipe or above the center line of the pipe. Therefore, even if the worker releases his / her hand from the flange temporary fastening jig after temporary fastening, the position of the center of the first flange remains almost unchanged due to at least one of the pair of pin portions, and the upper half of the first flange is unlikely to separate from the second flange. Therefore, the worker can insert bolts into the other first bolt holes of the first flange and the other second bolt holes of the second flange without supporting the first pipe. This reduces the number of workers required for fastening the first flange and the second flange, thereby achieving a flange temporary fastening jig that improves the efficiency of the fastening operation.

[0042] 2) In some embodiments, the flange temporary fastening jig described in 1) above, The pair of pin portions include a pair of flat surfaces (17) facing each other.

[0043] According to the above configuration 2), the outer peripheral surface of the gasket inserted between the first flange and the second flange can abut against each of the pair of flat surfaces. The position of the gasket in the opposing direction of the pair of flat surfaces can be adjusted to a desired position, thereby improving the efficiency of the gasket positioning work.

[0044] 3) In some embodiments, the flange temporary fastening jig according to 1) or 2) above, the plurality of first bolt holes include a first upper bolt hole (33) located above at least one of the two first bolt holes into which the pair of pin portions are respectively inserted, With the pair of pin portions inserted, the connection portion is located above the first upper bolt hole when viewed along the piping center line.

[0045] According to the configuration of 3) above, when the pair of pins are inserted, the connection portion is located above the first upper bolt hole. This makes it easier for workers to insert bolts into the first upper bolt hole and the second upper bolt hole opposite the first upper bolt hole. This improves the efficiency of the work of temporarily fastening the first flange and the second flange.

[0046] 4) In some embodiments, the flange temporary fastening jig described in 3) above, In the state where the pin portion is inserted, the connection portion has a curved portion (18) that is curved so as to be convex upward when viewed along the center line of the pipe.

[0047] According to the above configuration 4), when the curved portion functions as a gripping portion for the worker, the worker can easily grip the flange temporary fastening jig, thereby facilitating the temporary fastening work of the first flange and the second flange.

[0048] 5) In some embodiments, the flange temporary fastening jig according to any one of 1) to 4) above, The leg portion has a leg end surface (14) which is an end surface in the vertical direction from the base end (21) of the pin portion toward the tip end (22), When viewed along the center line of the pipe, the leg end surface has a surrounding surface (14S) that surrounds the base end of the pin portion in the circumferential direction of the pin portion.

[0049] According to the configuration of 5) above, when a pair of pins are inserted into the two first bolt holes and the two second bolt holes, the surrounding surface can abut against the first flange or the second flange around the circumferential direction of the pin. This prevents the main body from tilting even when the worker releases the flange temporary fastening jig, as the surrounding surface abuts against the first flange or the second flange. This allows the first flange 7 to be temporarily fastened to the second flange 4 in a stable manner.

[0050] 6) A flange fastening method according to at least one embodiment of the present disclosure includes: A flange fastening method for fastening the first flange and the second flange using the flange temporary fastening jig described in 1), a pin insertion step (S11) of inserting the pair of pin portions of the flange temporary fastening jig into any two of the plurality of first bolt holes formed in the first flange and any two of the plurality of second bolt holes formed in the second flange, respectively; a lower bolt insertion step (S13) of inserting a bolt (5) into a first lower bolt hole (35) located below at least one of the two first bolt holes among the plurality of first bolt holes, and a second lower bolt hole (46) located below at least one of the two second bolt holes among the plurality of second bolt holes; a lower bolt fastening step (S21) of fastening the bolt inserted in the lower bolt inserting step; an upper bolt insertion step (S17) of inserting a bolt (5) into a first upper bolt hole (33) located above at least one of the two first bolt holes among the plurality of first bolt holes, and a second upper bolt hole (44) located above at least one of the two second bolt holes among the plurality of second bolt holes; an upper bolt fastening step (S23) of fastening the bolt inserted in the upper bolt inserting step; After the upper bolt insertion step, a pin extraction step (S25) of extracting the pair of pin portions; a bolt insertion step (S27) of inserting a bolt (5) into each of the two first bolt holes and the two second bolt holes; a bolt tightening step (S29) of tightening the bolt inserted in the bolt inserting step; Equipped with Flange fastening method.

[0051] According to the configuration 6) above, the same technical advantages as those of the configuration 1) above can be obtained.

[0052] 7) In some embodiments, the flange fastening method described in 6) above, The method further includes a gasket insertion step (S15) after the lower bolt insertion step and before the upper bolt insertion step, in which a gasket (9) is inserted between the first flange and the second flange while being abutted against a pair of opposing flat surfaces formed on a pair of pin portions.

[0053] The configuration 7) above provides the same technical advantages as the configuration 2). [Explanation of symbols]

[0054] 1: First piping 2: Second piping 3: Third piping 4: Second flange 5: Bolt 6: Third flange 7: First flange 8: Nut 9: Gasket 10: Flange temporary fixing jig 11: One end 12: Legs 13: Connection part 14: Leg end surface 14S: Encircled surface 15: Main body 16: Pin section 17:Flat surface 18: Curved section 19:Other end 21 :Proximal end 22: Tip 31: First bolt hole 32: First socket bolt hole 33: First upper bolt hole 35: First lower bolt hole 41: Second bolt hole 42: Second socket bolt hole 44: Second upper bolt hole 46: Second lower bolt hole B: Arrow M: Piping center line

Claims

1. A flange temporary fastening jig for temporarily fastening a first flange of a first pipe to a second flange arranged in a predetermined position, a main body including a pair of legs and a connecting portion connected to one end of each of the pair of legs; a pair of pin portions extending from the pair of legs, the pair of pin portions being inserted into two of the plurality of first bolt holes formed in the first flange and two of the plurality of second bolt holes formed in the second flange, respectively; Equipped with The pair of pin portions are arranged symmetrically with respect to the piping center line of the first flange and the second flange. Jig for temporarily fastening flanges.

2. The pair of pin portions includes a pair of flat surfaces facing each other. The flange temporary fastening jig according to claim 1.

3. the plurality of first bolt holes include a first upper bolt hole located above at least one of the two first bolt holes into which the pair of pin portions are respectively inserted, When the pair of pin portions are inserted, the connection portion is located above the first upper bolt hole when viewed along the piping center line. The flange temporary fastening jig according to claim 1 or 2.

4. When the pin portion is inserted, the connecting portion has a curved portion that is curved so as to be convex upward when viewed along the center line of the pipe. The flange temporary fixing jig according to claim 3.

5. the leg portion has a leg portion end surface that is an end surface in an upright direction from a base end of the pin portion to a tip end thereof, When viewed along the center line of the pipe, the leg end surface has a surrounding surface that surrounds the base end of the pin portion in the circumferential direction of the pin portion. The flange temporary fastening jig according to claim 1 or 2.

6. A flange fastening method for fastening the first flange and the second flange using the flange temporary fastening jig according to claim 1, a pin insertion step of inserting the pair of pin portions of the flange temporary fastening jig into any two of the plurality of first bolt holes formed in the first flange and any two of the plurality of second bolt holes formed in the second flange, respectively; a lower bolt insertion step of inserting bolts into a first lower bolt hole located below at least one of the two first bolt holes among the plurality of first bolt holes and a second lower bolt hole located below at least one of the two second bolt holes among the plurality of second bolt holes after the pin insertion step; a lower bolt tightening step of tightening the bolt inserted in the lower bolt inserting step; an upper bolt insertion step of inserting bolts into a first upper bolt hole located above at least one of the two first bolt holes among the plurality of first bolt holes and a second upper bolt hole located above at least one of the two second bolt holes among the plurality of second bolt holes after the lower bolt fastening step; an upper bolt fastening step of fastening the bolt inserted in the upper bolt inserting step; a pin extraction step of extracting the pair of pin portions after the upper bolt insertion step; a bolt insertion step of inserting a bolt into each of the two first bolt holes and the two second bolt holes; a bolt tightening step of tightening the bolt inserted in the bolt inserting step; Equipped with Flange fastening method.

7. The method further includes a gasket inserting step of inserting a gasket between the first flange and the second flange while bringing the gasket into contact with a pair of opposing flat surfaces formed on a pair of pin portions, after the lower bolt inserting step and before the upper bolt inserting step. The flange fastening method according to claim 6.

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