JP6962729B2 - Leakage prevention device - Google Patents

Description

The present invention relates to a leakage prevention device for preventing leakage in a flange joint.

Conventionally, the leakage prevention device that prevents the leakage of the flange joint has deteriorated due to corrosion of the flange joint of the piping member such as the existing fluid pipe or valve due to long-term use, or an unexpected external force such as an earthquake is generated inside. It is a device that prevents leakage in a non-interrupted state when there is a risk of fluid leakage. A leakage prevention member arranged along the outer peripheral surface of the flange and the leakage prevention member are housed and fitted onto the flange. Some are composed of a mounting member and are sealed over the outer peripheral surface of the flange joint to prevent leakage (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2016-161054 (page 5, FIG. 3)

However, in Patent Document 1, a packing as a leakage prevention member is hung on a pair of flanges facing each other and arranged in contact with the outer peripheral surfaces of the pair of flanges, and the sealing region by the packing is provided. However, since it is the edge of the outer peripheral surface near the facing surface of the flange and the linear region along the outer peripheral surface, it is not possible to obtain a sealing force to counter the fluid pressure inside the pipe, and the fluid flows from between the facing surfaces of the flange. There is a problem that there is a risk of leakage.

In particular, when the outer peripheral surfaces of a pair of flanges are connected in a state where they are displaced from each other in the radial direction or in a state where there is a dimensional difference in the radial direction, the packing hung on these flanges has a desired sealing function. The risk of leakage will increase without being able to fulfill the above.

The present invention has been made by paying attention to such a problem, and provides a leakage prevention device capable of obtaining a sufficient sealing force to prevent leakage against the fluid pressure inside the flange joint. The purpose is.

In order to solve the above problems, the leak prevention device of the present invention is used.
A leak prevention device that seals a pair of facing flanges over the outer periphery of a flange joint that is hermetically connected to prevent leakage in the flange joint.
An elastically deformable leak-preventing member having a sealing portion that seals over the outer periphery of the pair of flanges, and a mounting member having a seat portion accommodating the leak-preventing member and externally fitted to the pair of flanges. At least prepare
The sealing portion of the leakage prevention member is a first bulging portion that bulges in the inner diameter direction and is inserted into a gap between the facing surfaces of the pair of flanges in a sealed manner so as to abut the facing surfaces, and the first bulging portion. It has a second bulging portion that is connected to both sides of the bulging portion in the pipe axis direction via a groove portion, bulges on the outer diameter side of the first bulging portion, and abuts on the outer peripheral surface of the flange. It is characterized by that.
According to this feature, the sealing portion of the leakage prevention member is elastically deformed as the mounting member accommodating the leakage prevention member is fitted onto the flange, and the first bulging portion is formed between the facing surfaces of the flange. By inserting while obtaining a reaction force in the direction, the second bulging portions on both sides are positioned in the pipe axis direction, and these second bulging portions obtain a radial reaction force on the outer peripheral surface of each flange. Since they are in contact with each other, the first bulging portion connected through the groove portion and the second bulging portion on both sides can independently obtain a sufficient sealing force to oppose the pressure of the internal fluid and prevent leakage. It can be easily installed by simply accommodating the leakage prevention member and fitting it to the flange.

The seat portion of the outer fitting member has a side wall that sandwiches the leakage prevention member in the pipe axis direction, and a gap that serves as an escape allowance for the leakage prevention member that is elastically deformed between the leakage prevention member and the side wall. It is characterized in that a part is formed.
According to this feature, when the first bulge is inserted into the gap between the facing surfaces of the flange in the inner diameter direction and then the second bulge abuts on the outer peripheral surface of the flange, the leakage prevention member The gap formed in the pipe axis direction can be elastically deformed as an escape allowance.

The gap is characterized by being a recess formed on the outer surface of the leakage prevention member.
According to this feature, since the gap portion serving as the elastic deformation allowance of the leakage prevention member is formed as a recess of the leakage prevention member itself, not only the gap portion can be easily formed but also the amount of the leakage prevention member can be reduced. In addition, since the degree of freedom of deformation of the leakage prevention member is increased, it is possible to generate an elastic repulsive force while improving workability and exert a leakage prevention force corresponding to flanges of various diameters and shapes.

The leakage prevention member is characterized by having a divided structure divided in the circumferential direction.
According to this feature, the leakage prevention member divided in the circumferential direction can be easily sealed from the outer diameter side to the outer circumference of the flange joint.

The peripheral ends of the leakage prevention members that are joined to each other are characterized by having a pair of concave-convex shapes that can be fitted to each other.
According to this feature, the ends can be positioned with each other by fitting the ends having a pair of uneven shapes of the leakage prevention members divided in the circumferential direction.

The peripheral end portions of the leakage prevention members joined to each other are characterized by having a pair of facing surfaces inclined in the radial direction.
According to this feature, the ends of the leakage prevention members divided in the circumferential direction are externally fitted by the mounting member with the facing surfaces inclined in the radial direction facing each other, so that the ends are positioned on the inner diameter side. Since a pressing force in the inner diameter direction can be generated on one of the leakage prevention members having the facing surfaces and the area of the facing surfaces can be widened, the sealing performance between the ends can be improved.

The mounting member is characterized by including a fastening member for fastening the mounting member on the outer diameter side of the peripheral end portions of the leakage prevention member to be joined to each other.
According to this feature, by fastening the mounting member on the outer diameter side of the circumferential end of the leakage prevention member by the fastening member, this fastening force is applied to the circumferential end of the leakage prevention member to provide sealing property. Can be improved.

(A) is a front sectional view showing a fluid pipe to which a leakage prevention device is attached, and (b) is also a side view. (A) is a partially broken view of the structure of the mounting member as viewed from the front, (b) is a cross-sectional view taken along the line AA, (c) is a cross-sectional view taken along the line BB, and (d) is a cross-sectional view taken along the line CC. .. (A) is a front view showing the structure of the packing, (b) is a cross-sectional view taken along the line DD, and (c) is an enlarged cross-sectional view taken along the line EE. It is a partially broken view of how the existing bolts and nuts are replaced with bolts and nuts having a sealing property as seen from the side. It is a partially broken view of the state where the split body is temporarily installed on the flange joint as viewed from the front. (A) is a sectional view taken along the line FF of FIG. 5, (b) is a side sectional view showing a state in which the mounting member is reduced in diameter in the inner diameter direction from the state of (a), and (c) is mounted from the state of (b). It is a side sectional view which shows the state which the member is further reduced in diameter in the inner diameter direction. (A) is a cross-sectional view taken along the line HH of FIG. 5, (b) is a side cross-sectional view showing a state in which the mounting member is reduced in diameter in the inner diameter direction from the state of (a), and (c) is mounted from the state of (b). It is a side sectional view which shows the state which the member is further reduced in diameter in the inner diameter direction. (A) is a front sectional view showing a state in which the mounting members are close to each other in the circumferential direction, and (b) is a front sectional view showing a state in which the mounting members are further close to each other in the circumferential direction from the state of (a). (A) and (b) are explanatory views showing a mode in which a leakage prevention device is applied to a flange connected in a state where a positional deviation occurs in the radial direction. (A) to (c) are schematic views which show the modification of the mounting member. (A) and (b) are schematic views showing a modified example of packing.

A mode for implementing the leakage prevention device according to the present invention will be described below based on examples.

The leakage prevention device according to the embodiment will be described with reference to FIGS. 1 to 8. Hereinafter, the front side of the paper surface of FIG. 1A will be described as the front side (front side) of the leakage prevention device.

As shown in FIGS. 1A and 1B, reference numerals 1A and 1B are existing fluid pipes for transporting the fluid from the upstream side to the downstream side, and the fluid pipes 1A and 1B are connected to each other. Flange joints 3A are formed by providing flanges 3 and 3 (see FIG. 4) and connecting them with bolts and nuts 7, 7, ... A leak prevention device 2 is hermetically attached to the flange joint 3A over the outer periphery of the flange joint 3A to prevent leakage in the flange joint 3A. In this embodiment, the fluid in the fluid pipe is clean water, but it is not limited to the clean water in this embodiment, for example, industrial water, agricultural water, sewage, gas or a gas-liquid mixture of gas and liquid. It doesn't matter if there is.

As shown in FIG. 1, the fluid tubes 1A and 1B are made of ductile cast iron, are formed in a substantially circular shape in cross section, and the inner peripheral surface is covered with an epoxy resin layer 1a. The fluid pipe according to the present invention may be made of other metal such as cast iron or steel, or may be made of concrete, vinyl chloride, polyethylene, polyolefin or the like. Furthermore, the inner peripheral surface of the fluid pipe is not limited to the epoxy resin layer, and may be coated with, for example, mortar, or an appropriate material may be coated on the inner peripheral surface of the fluid pipe by powder coating.

Next, the structure of the leakage prevention device 2 will be described with reference to FIGS. 1 to 3. As shown in FIG. 1, in the leakage prevention device 2, the divided bodies 2A, 2A, ... Each of the divided bodies 2A is provided with a packing 4 (leakage prevention member) and a mounting member 5 so as to be formed in an annular shape by being connected. The leakage prevention device 2 is not limited to the three divisions, and may be divided into a predetermined number of 2 or 4 or more.

As shown in FIG. 2, the mounting member 5 is made of ductile cast iron, and has an arc-shaped main body portion 5A extending in the circumferential direction when viewed from the front, and connecting portions 51 and 52 provided at both ends of the main body portion 5A. , Is equipped. The connecting portions 51 and 52 are used when connecting to the adjacent mounting member 5, as will be described later.

One connection portion 51 has a rising piece 53 that rises in the outer diameter direction at one end of the main body portion 5A, and the rising piece 53 has a through hole 54 through which bolts and nuts 6 and 6 are inserted. 54 and a protruding piece 55 projecting from the central portion of the outer diameter edge of the rising piece 53 toward the adjacent mounting member 5 are provided. Further, the other connecting portion 52 has a rising piece 56 that rises in the outer diameter direction at the other end of the main body portion 5A, and the rising piece 56 has a through hole through which bolts and nuts 6 and 6 are inserted. 54, 54 and a recessed groove 57 through which a protruding piece 55 of an adjacent mounting member 5 can be inserted are provided.

Further, on the inner diameter side of the main body 5A, the groove 58 is formed so as to open in the inner diameter direction along the circumferential direction, and has a concave cross-sectional shape. Specifically, as shown in FIG. 2C, the main body 5A has an outer diameter wall portion 5a extending in the pipe axis direction (front-rear direction) and an inner diameter from both ends of the outer diameter wall portion 5a in the pipe axis direction. It is composed of side wall portions 5b and 5b extending in the direction, and the portion surrounded by the outer diameter wall portion 5a and the side wall portions 5b and 5b is the groove portion 58.

At the longitudinal end of the mounting member 5, stepped portions 51a and 52a are formed so that the groove portion 58 expands in the outer diameter direction. Further, the mounting member 5 is provided with two projecting wall portions 59, 59 protruding in the inner diameter direction outward in the pipe axis direction of the side wall portions 5b, 5b at two locations in the circumferential direction of the mounting member 5.

As shown in FIG. 3, the packing 4 is composed of an elastic member made of styrene-butadiene rubber in this embodiment, and has a main body portion 4A extending in the circumferential direction and forming an arc shape in a front view, and a main body portion 4A. The connection portions 41 and 42 provided at the outer diameter portions at both ends in the circumferential direction of the above are provided. The connecting portions 41 and 42 are used when connecting to the adjacent packing 4, as will be described later. The packing may be any elastic member, and may be, for example, nitrile rubber, ethylene propylene rubber, fluororubber, or the like.

One connecting portion 41 is inclined with an inclined surface 41a formed in a convex shape along the extending direction of the main body portion 4A so as to be inclined from one end of the main body portion 4A toward the outer diameter direction. It has a rising piece 43 that rises in the outer diameter direction at a position separated from the surface 41a in the extending direction of the main body portion 4A. Further, the other connecting portion 42 has a rising piece 44 rising in the outer diameter direction from the other end of the main body 4A and the main body so as to be inclined toward the inner diameter from the substantially central portion of the rising piece 44. It has an inclined surface 42a formed in a concave shape along the extending direction of the portion 4A.

On the end faces of the rising pieces 43, 44, substantially rectangular recesses 43a, 44a, which are recessed in the circumferential direction, are formed. Further, recesses 45 and 46 recessed in the circumferential direction are formed on the end faces of the connecting portions 41 and 42.

In particular, as shown in FIG. 3C, the main body portion 4A has substantially the same cross-sectional shape along the circumferential direction thereof, and the base portion 47 fitted into the groove portion 58 of the mounting member 5 as described later. The first bulging portion 48 that bulges from the central portion of the base portion 47 in the circumferential direction in the inner diameter direction, and the first bulging portion 48 that bulges from the base portion 47 in the circumferential direction so as to sandwich the first bulging portion 48 in the pipe axis direction in the circumferential direction. It is provided with second bulging portions 49, 49 that bulge over. Recesses 47a and 47a are formed on both sides of the base portion 47 in the pipe axis direction in the circumferential direction. The first bulging portion 48 and the second bulging portions 49, 49 function as sealing portions that seal over the outer circumferences of the flanges 3 and 3, as will be described later.

Further, groove portions 401 and 401 are formed between the first bulging portion 48 and the second bulging portions 49 and 49 along the circumferential direction, and the radial dimension L1 of the first bulging portion 48 is formed. (Dimensions between the outer peripheral end of the main body 4A and the inner peripheral end of the first bulging portion 48) are the radial dimensions L2 of the second bulging portions 49, 49 (the outer peripheral end of the main body 4A and the second bulging). It is larger than the dimensions of the inner peripheral ends of the portions 49 and 49). In other words, the second bulging portions 49, 49 bulge on the outer diameter side of the first bulging portion 48. Further, the head portions (tip portions on the inner diameter side) of the second bulging portions 49, 49 are bifurcated by the groove portions 402, 402 extending in the circumferential direction.

The split body 2A is configured by fitting the packing 4 into the groove 58 of the mounting member 5. Specifically, as shown in FIGS. 6A and 7A, the outer diameter is inserted into the groove 58 of the mounting member 5 from the base 47 side of the packing 4 through the opening on the inner diameter side. The base portion 47 of the packing 4 is press-fitted and installed on the wall portion 5a and the side wall portions 5b, 5b, and the first bulging portion 48 and the second bulging portion 49, 49 are arranged on the inner diameter side of the mounting member 5. Further, gaps S and S are formed by recesses 47a and 47a between the side wall portions 5b and 5b and the second bulging portions 49 and 49 in a natural state before elastic deformation, which will be described later.

Next, the procedure for attaching the leakage prevention device 2 to the flange joint 3A will be described with reference to FIGS. 4 to 8. Here, a mode in which the leakage prevention device 2 is attached to the existing fluid pipes 1A and 1B buried in the ground will be illustrated.

When attaching the leakage prevention device 2 to the flange joint 3A, first, as shown in FIG. 4, the existing bolts / nuts 7', 7', ... Remove and replace one or several bolts, nuts 7, 7, ... with high sealing performance. The bolt / nut 7 is composed of a bolt 7a and a bag nut 7b, and is between the head portion 7c of the bolt 7a and the flange 3 of the fluid pipe 1A, and between the bag nut 7b and the flange 3 of the fluid pipe 1B. The seal rings 7d and 7d are arranged in the. As a result, it is possible to prevent leakage from the bolt holes 3a, 3a, ... Of the flanges 3, 3.

In this embodiment, the embodiment in which the bolt 7a having the head portion 7c is used has been described, but the present invention is not limited to this. For example, a bolt 7a and a nut may be used and a seal washer may be interposed, and both screws or all of them may be used. A screw or a bolt of a part of a screw may be used, and nuts may be attached to both ends of the bolt via a seal washer.

Next, as described above, the packing 4 is fitted into the groove 58 of each mounting member 5 to form the divided bodies 2A, 2A, .... Then, as shown in FIG. 5, the split bodies 2A, 2A, ... Are arranged on the outer periphery of the flange joint 3A (temporary installation). At this time, as shown on the right side of the paper surface of FIG. 5, the divided bodies 2A, 2A, ... Are flanged in a state where the protruding piece 55 of one mounting member 5 is aligned with the concave groove 57 of the other adjacent mounting member 5. It is arranged on the outer periphery of the joint 3A. As shown in FIG. 7, by arranging the protruding wall portions 59, 59 of the mounting member 5 so as to sandwich both sides of the flange joint 3A in the pipe axial direction, the split bodies 2A, 2A, ... Are arranged in the flange joint 3A. It is easy to temporarily install it on the outer circumference of the.

As shown in FIGS. 6A and 7A, when the split bodies 2A, 2A, ... Are temporarily installed on the outer periphery of the flange joint 3A, the first bulging portions 48 and the second of the packing 4 are provided. The bulging portions 49, 49 are not in contact with the outer peripheral surface of the flange joint 3A.

Next, with the split bodies 2A, 2A, ... Arranged on the outer periphery of the flange joint 3A, they are connected by bolts, nuts 6, 6, ..., And the bolts, nuts 6, 6, ... Are tightened to prevent leakage device 2. Is fixed to the flange joint 3A (see FIG. 1).

As shown in FIGS. 6B and 7B, when the split bodies 2A, 2A, ... Are temporarily installed on the outer periphery of the flange joint 3A, the bolts, nuts 6, 6, ... Are tightened. The mounting member 5 moves (reduces the diameter) in the inner diameter direction, and first, the first bulging portion 48 that bulges most in the inner diameter direction is inserted into the gap between the facing surfaces 3b, 3b of the flanges 3, 3. Specifically, since the width of the first bulging portion 48 in the pipe axis direction is larger than the separation width of the flanges 3 and 3, the facing surfaces 3b and 3b of the flanges 3 and 3 and the outer peripheral surfaces 3c and 3c The first bulging portion 48 is pressure-welded to the formed edge portion and inserted into the gap between the facing surfaces 3b and 3b of the flanges 3 and 3. Therefore, the portion of the first bulging portion 48 on the outer diameter side of the edge portion (the portion not inserted into the gap between the facing surfaces 3b and 3b) is elastically deformed in the tube axis direction (reverse in the tube axis direction). (While obtaining a force), the flanges 3 and 3 are inserted into the gaps between the facing surfaces 3b and 3b, and the second bulging portions 49 and 49 on both sides are positioned in the pipe axial direction accordingly. At this time, as shown in FIGS. 5 and 6, the first bulging portion 48 on the end side in the circumferential direction leads and is inserted into the gap between the facing surfaces 3b and 3b of the flanges 3 and 3. , Bolts and nuts 6, 6 are preferably positioned while reducing the tightening force.

At this time, the second bulging portions 49, 49 are formed independently of the first bulging portion 48 via the groove portion 401, and do not yet come into contact with the outer peripheral surfaces 3c, 3c of the flanges 3, 3. , Only the first bulging portion 48 can be elastically deformed and deeply immersed between the facing surfaces 3b and 3b of the flanges 3 and 3.

Further, as shown in FIG. 8A, when the bolts / nuts 6, 6, ... Are temporarily installed on the outer periphery of the flange joint 3A after the split bodies 2A, 2A, ... Are temporarily installed, the adjacent packings are tightened. The connecting portions 41 and 42 (ends in the circumferential direction) of 4 and 4 approach each other, but the peripheral end portion of one packing 4 has a convex shape, and the circumferential end of another adjacent packing 4 is formed. Since the portions have a concave shape, they are unevenly fitted and positioned, and the inclined surface 41a of one packing 4 and the inclined surface 42a of the other adjacent packing 4 slide with each other. Since the mounting members 5 and 5 are present on the outer diameter side of the packings 4 and 4, the movement of the packings 4 and 4 to the outer diameter side is restricted. When the inclined surface 42a of the other adjacent packing 4 slides, one packing 4 is guided by the inclined surface 42a of the other adjacent packing 4 and pressed in the inner diameter direction.

Then, as shown in FIGS. 6 (c) and 7 (c), when the bolts / nuts 6, 6, ... The second bulging portions 49, 49 are further inserted into the gap, and the second bulging portions 49, 49 are pressed against the outer peripheral surfaces 3c, 3c of the flanges 3, 3 to complete the fixing of the leakage prevention device 2 to the flange joint 3A. At this time, the groove portions 401, 401 between the first bulge portion 48 and the second bulge portions 49, 49 and the groove portions 402, 402 of the second bulge portions 49, 49 are the first bulge portion 48 and the second bulge portion 48 and the second. It becomes flat by functioning as an escape allowance for elastic deformation of the bulging portions 49 and 49.

Further, as shown in FIG. 8B, the connecting portion 41 of one packing 4 and the connecting portion 42 of the other packing 4 are pressure-welded, and the packings 4, 4, ... Are continuously sealed in the circumferential direction. .. Further, as described above, the rising pieces 43 and 44 are provided with recesses 43a and 44a, and the recesses 45 and 46 are provided at both ends of the main body 4A, and the connecting portions of one packing 4 are provided. When the 41 and the connecting portion 42 of the other packing 4 are pressed against each other, the recesses 43a, 44a and the recesses 45, 46 are elastically deformed as relief allowances for the packings 4, 4, and thus the bolts, nuts 6, 6, ... The torque required when tightening can be reduced.

Further, in a state where the connecting portion 41 of one packing 4 and the connecting portion 42 of the other packing 4 are in pressure contact with each other, a slight gap is formed in the recesses 43a and 44a and the recesses 45 and 46, so that the connection is made. Even if the internal fluid enters between the portion 41 and the connecting portion 42, the internal fluid is stored in the gap, and the internal fluid can be prevented from leaking to the outside.

As described above, the first bulging portion 48 can seal between the facing surfaces 3b and 3b of the flanges 3 and 3 and the edge portion, and the second bulging portions 49 and 49 can seal the flanges 3 and 3. The outer peripheral surfaces 3c and 3c of the above can be sealed. That is, since the sealing region is formed in a planar shape from the facing surfaces 3b and 3b of the flanges 3 and 3 to the outer peripheral surfaces 3c and 3c, it is possible to prevent leakage against the fluid pressure inside the flange joint 3A. Sufficient sealing force can be obtained, and the mounting member 5 can be easily installed only by accommodating the packing 4 and fitting it on the flanges 3 and 3. In other words, since the first bulging portion 48 seals in a planar shape between the facing surfaces 3b and 3b of the flanges 3 and 3 and the edge portion, only the edge portion of the flanges 3 and 3 is sealed as in the conventional case. Higher sealing performance can be exhibited as compared with the sealed form.

Further, the first bulging portion 48 is in pressure contact between the facing surfaces 3b and 3b of the flanges 3 and 3 in the pipe axis direction, and the second bulging portions 49 and 49 are the outer peripheral surfaces 3c of the flanges 3 and 3. Pressurize 3c in the radial direction. That is, since the first bulging portion 48 and the second bulging portions 49, 49 are independent of each other, it is possible to counter the pressure of the internal fluid from various directions.

Further, as described above, in the first bulging portion 48 and the second bulging portion 49, 49, the first bulging portion 48 and the second bulging portion 49, 49 are independent of each other due to the groove portions 401, 401. Therefore, for example, as shown in FIG. 9, even if the flanges 31 and 32 are connected to each other in a state where the position is displaced in the radial direction or a dimensional difference in the radial direction, the mounting member 5 is connected to the pipe. The first bulging portion 48 can be pressure-contacted between the facing surfaces 31b and 32b of the flanges 31 and 32 without tilting in the axial direction, and the second bulging portions 49 and 49 can be brought into contact with the outer peripheral surfaces of the flanges 31 and 32. It can be pressure-welded to 31c and 32c.

Further, the elastic deformation allowance of the second bulging portion 49 that presses against the flange 32 that is displaced in the outer diameter direction is larger than the elastic deformation allowance of the second bulging portion 49 that presses against the flange 31 that is displaced in the inner diameter direction. However, since it can be released not only to the recess 47a on the second bulging portion 49 side that is in pressure contact with the flange 32 but also to the recess 47a on the second bulging portion 49 side that is in pressure contact with the flange 31, the flanges 31 and 32 The pressure contact force of the second bulging portions 49, 49 with respect to the outer peripheral surfaces 31c, 32c can be made substantially equal.

Further, the first bulging portion 48 is inserted between the facing surfaces 3b, 3b of the flanges 3, 3 while obtaining a reaction force in the pipe axial direction, so that the second bulging portions 49, 49 on both sides are inserted in the pipe axial direction. The second bulging portions 49, 49 can be suitably pressed (sealed) with respect to the outer peripheral surfaces 3c, 3c of the flanges 3, 3.

Further, when the second bulging portions 49, 49 are in a state of being pressed against the outer peripheral surfaces 3c, 3c of the flanges 3, 3, the second bulging portions 49, 49 are elastic with the gaps S, S as an escape allowance. Deform. According to this, when the second bulging portions 49, 49 are pressed against the outer peripheral surfaces 3c, 3c of the flanges 3, 3, the second bulging portions 49, 49 are elastically deformed and the groove portion 58 of the mounting member 5 is formed. Since it is possible to prevent the second bulging portions 49 and 49 from protruding to the outside, it is possible to prevent the pressure contact force of the second bulging portions 49 and 49 from decreasing to the outer peripheral surfaces 3c and 3c and improve the sealing performance.

Further, since the gaps S and S are recesses 47a and 47a formed on the outer surface of the rubber packing 4 in the pipe axis direction, not only the gaps S and S can be easily formed, but also the packing 4 is reduced in weight. In addition, since the degree of deformation of the packing 4 is increased, elastic repulsive force is generated while improving workability, and leakage prevention force is exhibited corresponding to flanges 3 and 3 of various diameters and shapes. be able to.

Further, the packings 4, 4, ... And the mounting members 5, 5, ... Have a divided structure divided in the circumferential direction. According to this, using packings 4, 4, ... And mounting members 5, 5, ... (Divided bodies 2A, 2A, ...) Divided in the circumferential direction, the flange joint 3A extends from the outer diameter side to the outer circumference. Can be easily sealed.

Further, the peripheral end portions (connecting portions 41, 42) of the adjacent packings 4 and 4 connected to each other have a pair of concave-convex shapes that can be fitted to each other. According to this, the ends (connecting portions 41, 42) are fitted to each other by fitting the ends (connecting portions 41, 42) having a pair of uneven shapes of the packings 4 and 4 divided in the circumferential direction. Can be positioned with each other.

Further, in the state where the leakage prevention device 2 is fixed to the flange joint 3A, the protruding piece 55 of one mounting member 5 is inserted into the concave groove 57 of the other adjacent mounting member 5, so that the split body 2A, 2A, ... Are prevented from moving relative to each other in the pipe axis direction (see FIG. 1 (b)).

Further, the peripheral end portions (connecting portions 41, 42) of the adjacent packings 4 and 4 joined to each other have a pair of inclined surfaces 41a and 42a inclined with respect to the radial direction. By doing so, when the bolts, nuts 6, 6, ... With the split bodies 2A, 2A, ... Arranged on the outer periphery of the flange joint 3A, the bolts / nuts 6, 6, ... The packing 4 is guided by the inclined surface 42a and slides to generate a pressing force in the inner diameter direction, and the contact area of the inclined surfaces 41a and 42a can be widened, so that the sealing performance between the ends thereof is improved. be able to.

Further, the mounting members 5 and 5 include fastening member bolts and nuts 6 and 6 for fastening the mounting members 5 and 5 on the outer diameter side of the peripheral end of the packings 4 and 4. By doing so, by fastening the mounting members 5 and 5 on the outer diameter side of the circumferential end of the packings 4 and 4 with the bolts and nuts 6 and 6, this fastening force is applied to the packings 4 and 4. It can be applied to the end portion in the circumferential direction to improve the sealing property.

Further, there are the following modifications of the mounting member. As shown in FIG. 10A, the protruding wall portions 590 and 590 are provided with screw holes 590a and 590a penetrating in the pipe axis direction, and bolts 8 and 8 are outside the screw holes 590a and 590a. It is possible to screw in from. According to this, when the leakage prevention device 2 is fixed to the flange joint 3A, the flanges 3 and 3 are sandwiched in the pipe axis direction by screwing the bolts 8 and 8, and the leakage prevention device 2 moves in the pipe axis direction. Since the movement can be restricted, it is possible to prevent the possibility that the leakage prevention device 2 moves in the pipe axis direction and the sealing property is deteriorated.

Further, as shown in FIG. 10B, a screw hole 590a may be provided only in the protruding wall portion 591 on one side. According to this, the leakage prevention device 2 can be temporarily installed on the flange joint 3A while abutting the flange 3 on one side with the protruding wall portion 591'without the screw hole 590a as a guide, and the leakage prevention device 2 can be mounted on the flange. When fixed to the joint 3A, by screwing the bolt 8 into the screw hole 590a, the flanges 3 and 3 are sandwiched between the bolt 8 and the protruding wall portion 591'in the pipe axis direction, and the leakage prevention device 2 becomes a pipe. It is possible to regulate the movement in the axial direction.

Further, in the above embodiment, the embodiment in which the recesses 47a and 47a are provided on the side surface of the packing 4 in the pipe axial direction is illustrated, but the relief allowance of the packing 4 elastically deformed between the packing 4 and the side wall portions 5b and 5b of the mounting member 5. As long as the gap portion S is provided, for example, as shown in FIG. 10C, recesses 500c and 500c may be provided in the side wall portions 500b and 500b of the mounting member 500.

Further, in the above embodiment, the packing 4 exemplifies a form in which the heads (tips on the inner diameter side) of the second bulging portions 49, 49 are divided into two branches by the groove portions 402, 402 extending in the circumferential direction. However, for example, as shown in FIG. 11A, the packing 410 may have the second bulging portions 491 and 491 without providing the groove portions 402 and 402 (the head is not divided), or may be a packing 410 having the second bulging portions 491 and 491, or FIG. 11 (b). ), The packing 420 may have a second bulging portion 492, 492 in which a plurality of groove portions 402 are provided (the head is divided into a plurality of portions).

Although examples of the present invention have been described above with reference to the drawings, the specific configuration is not limited to these examples, and any changes or additions within the scope of the gist of the present invention are included in the present invention. Is done.

In the above embodiment, the embodiment in which the base portion 47 of the packing 4 is press-fitted and installed in the groove portion 58 of the mounting member 5 is illustrated, but the present invention is not limited to this, and for example, the groove portion 58 of the mounting member 5 is used. On the other hand, the base 47 of the packing 4 may be adhered with an adhesive or the like.

Further, in the above embodiment, the flanges 3 and 3 have a substantially circular shape in front view, but the present invention is not limited to this, for example, a polygonal flange or a joint portion between a valve lid and a valve box. It may be applied to a substantially diamond-shaped flange.

1A, 1B Fluid pipe 2 Leakage prevention device 2A Split body 3 Flange 3A Flange joint 3b Opposing surface 3c Outer peripheral surface 4 Packing (leakage prevention member)
5 Mounting member 5b Side wall (side wall)
6 Bolts and nuts (fastening members)
31, 32 Flange 41a, 42a Inclined surface (opposing surface)
47a Recess 48 1st bulge (sealing)
49 Second bulge (sealed part)
58 Groove (seat)
401 Groove S gap

Claims (4)

A leak prevention device that seals a pair of facing flanges over the outer periphery of a flange joint that is hermetically connected to prevent leakage in the flange joint.
The pair of flanges have a leak-preventing member having a sealing portion that seals the outer periphery of the pair of flanges and having a split structure that is elastically deformable and divided in the circumferential direction, and a seat portion that accommodates the leak-preventing member. It is provided with at least a mounting member made of a divided body that is externally fitted and divided in the circumferential direction.
The sealing portion of the leakage prevention member fitted to each of the divided bodies bulges in the inner diameter direction in a natural state before elastic deformation, and abuts the facing surface in the gap between the facing surfaces of the pair of flanges. The first bulge, which is inserted in a sealed shape, and the first bulge are integrally connected to the first bulge via grooves on both sides of the first bulge in the direction of the tube axis, and are in a natural state before elastic deformation. bulging in the outer diameter side than the first bulging portion, have a, a second bulge abuts the outer peripheral surface of said flange, said both sides of the first bulging portion in the axial direction of the tube The head portion of the second bulging portion is divided into two parts by a groove portion extending in the circumferential direction, and the seat portion of the mounting member has a side wall that sandwiches the leakage prevention member in the pipe axis direction. Leakage prevention is characterized in that the outer surface of the leakage prevention member is formed with a recess as a gap portion that is elastically deformed between the leakage prevention member and the side wall and serves as an escape allowance for the leakage prevention member. Device. The leakage prevention device according to claim 1 , wherein the peripheral ends of the leakage prevention members joined to each other have a pair of uneven shapes that can be fitted to each other. The leak prevention device according to claim 1 or 2 , wherein the peripheral ends of the leak prevention members joined to each other have a pair of facing surfaces inclined in the radial direction. The attachment member according to any one of claims 1 to 3 , wherein the attachment member includes a fastening member for fastening the attachment member on the outer diameter side of the peripheral end portions of the leakage prevention member to be joined to each other. Leakage prevention device.

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