JP2019019867A - Leak prevention device - Google Patents

Abstract

To provide a leak prevention device capable of obtaining a sufficient seal strength for preventing leak against a fluid pressure inside of a flange joint.SOLUTION: A leak prevention device comprises at least a leak prevention member 4 which includes a seal part for sealing over an outer periphery of a pair of flanges 3 and 3 and is elastically deformable, and a mounting part 5 including a seat part 58 in which the leak prevention member 4 is accommodated, and externally fitted to the pair of flanges 3 and 3. The seal part of the leak prevention member 4 includes: a first expansion part 48 which is inserted into a clearance gap between opposed faces 3b and 3b of the pair of flanges 3 and 3 in a sealed state so as to be abutted to the opposed faces 3b and 3b; and second expansion parts 49 and 49 which are continued via groove parts 401 and 401 at both sides holding the first expansion part 48 therebetween in a tube axis direction, expanded at an outer diameter side of the first expansion part 48, and abutted to outer peripheral surfaces 3c and 3c of the flanges 3 and 3.SELECTED DRAWING: Figure 6

Description

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

  Conventional leak prevention devices that prevent leakage of flange joints have deteriorated due to long-term corrosion of flange joints of piping members such as existing fluid pipes and valves, or unexpected external forces such as earthquakes have occurred. When there is a risk of fluid leakage, this is a device that prevents leakage in an uninterrupted state. The leakage preventing member is disposed along the outer peripheral surface of the flange, and is fitted on the flange by accommodating the leakage preventing member. There is an attachment member that prevents leakage by sealing over the outer peripheral surface of the flange joint (see, for example, Patent Document 1).

Japanese Patent Laying-Open No. 2006-161054 (5th page, FIG. 3)

  However, in Patent Document 1, a packing as a leakage preventing member is disposed on a pair of flanges facing each other and in contact with the outer peripheral surfaces of the pair of flanges. However, since it is the outer peripheral surface edge near the opposing surface of the flange and the linear region along the outer peripheral surface, it is not possible to obtain a sealing force to counteract the fluid pressure inside the pipe, and the fluid flows between the opposing surfaces of the flange. There is a problem of causing 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 spanned by these flanges is the expected sealing function The risk of leaking without being able to fulfill is increased.

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

In order to solve the above-mentioned problem, the leakage preventing apparatus of the present invention is
A leakage prevention device that seals over the outer periphery of a flange joint in which a pair of opposed flanges are connected in a sealing manner, and prevents leakage in the flange joint,
A leakage preventing member having a sealing portion that seals the outer periphery of the pair of flanges and elastically deformable; and a mounting member that has a seat portion that accommodates the leakage preventing member and is fitted on the pair of flanges. At least,
The sealing portion of the leakage preventing member bulges in an inner diameter direction, and a first bulging portion that is inserted in a sealing manner so as to abut on the opposing surfaces in a gap between the opposing surfaces of the pair of flanges, and the first A second bulging portion that is connected to both sides of the bulging portion in the tube 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 preventing member is elastically deformed as the mounting member that accommodates the leakage preventing member is externally fitted to the flange, and the first bulging portion is interposed between the opposing surfaces of the flange. By inserting while obtaining the reaction force in the direction, the second bulges on both sides are positioned in the tube axis direction, and these second bulges are obtained in the radial direction on the outer peripheral surface of each flange. In order to abut, the first bulging portion and the second bulging portions on both sides connected through the groove portion can each independently obtain a sufficient sealing force to counteract the pressure of the internal fluid and prevent leakage. In addition, the mounting member can be easily installed simply by accommodating the leakage preventing member and fitting it onto the flange.

The seat portion of the outer fitting member has a side wall sandwiching the leakage prevention member in the tube axis direction, and a gap serving as a clearance 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 second bulge portion comes into contact with the outer peripheral surface of the flange following the insertion of the first bulge portion into the gap between the opposing surfaces of the flange in the inner diameter direction, the leakage preventing member is It can be elastically deformed with a clearance formed in the tube axis direction as a clearance.

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

The leakage preventing member has a divided structure divided in the circumferential direction.
According to this feature, the leakage preventing member divided in the circumferential direction can be easily sealed from the outer diameter side to the outer periphery of the flange joint.

The end portions in the circumferential direction where the leakage preventing members are joined to each other have a pair of concavo-convex shapes that can be fitted to each other.
According to this feature, the end portions can be positioned relative to each other by fitting the end portions having a pair of concave and convex shapes of the leakage preventing member divided in the circumferential direction.

The end portions in the circumferential direction of the leakage preventing members that are joined to each other have a pair of opposed surfaces that are inclined with respect to the radial direction.
According to this feature, the end portions of the leakage prevention members divided in the circumferential direction are fitted on the inner diameter side by being externally fitted by the mounting member in a state where the opposed surfaces inclined with respect to the radial direction are opposed to each other. In addition to generating a pressing force in the inner diameter direction with respect to the one leakage preventing member having the opposing surface, it is possible to increase the area of the opposing surface, so that the sealing performance between the end portions can be improved.

The mounting member includes a fastening member that fastens the mounting member on the outer diameter side of the circumferential ends of the leakage prevention members that are joined to each other.
According to this feature, the fastening member is fastened by the fastening member on the outer diameter side of the circumferential end portion of the leakage preventing member, and this fastening force is applied to the circumferential end portion of the leakage preventing member to provide a sealing property. Can be improved.

(A) is front sectional drawing which shows the fluid pipe | tube with which the leak prevention apparatus was attached, (b) is a side view similarly. (A) is the partially broken view which looked at the structure of the attachment member from the front, (b) is an AA arrow directional view, (c) is BB sectional drawing, (d) is CC sectional drawing. . (A) is a front view which shows the structure of packing, (b) is DD sectional drawing, (c) is EE sectional enlarged view. It is the partially broken view which looked at a mode that the existing volt | bolt nut was replaced | exchanged for the volt | bolt nut provided with the sealing performance from the side. It is the partially broken figure which looked at the state where the division body was temporarily installed in the flange joint from the front. 5A is a cross-sectional view taken along the line F-F in FIG. 5, FIG. 5B is a side cross-sectional view illustrating a state in which the mounting member has been reduced in the inner diameter direction from the state illustrated in FIG. 5A, and FIG. It is a sectional side view which shows the state which the member diameter-reduced further in the internal diameter direction. 5A is a cross-sectional view taken along the line H-H in FIG. 5, FIG. 5B is a side cross-sectional view illustrating a state in which the mounting member is reduced in the inner diameter direction from the state illustrated in FIG. 5A, and FIG. It is a sectional side view which shows the state which the member diameter-reduced further in the internal diameter direction. (A) is front sectional drawing which shows the state which attachment members adjoined in the circumferential direction, (b) is a front sectional view which shows the state in which attachment members adjoined further in the circumferential direction from the state of (a). (A) (b) is explanatory drawing which shows the form which applied the leak prevention apparatus to the flange connected in the state which the position shift generate | occur | produced in radial direction. (A)-(c) is the schematic which shows the modification of an attachment member. (A) (b) is the schematic which shows the modification of packing.

  EMBODIMENT OF THE INVENTION The form for implementing the leak prevention apparatus which concerns on this invention is demonstrated below based on an Example.

  The leakage preventing apparatus according to the embodiment will be described with reference to FIGS. Hereinafter, the front side of the sheet of FIG. 1A will be described as the front side (front side) of the leakage preventing apparatus.

  As shown in FIGS. 1A and 1B, reference numerals 1A and 1B denote existing fluid pipes that transport fluid from the upstream side to the downstream side, and are connected to the fluid pipes 1A and 1B, respectively. Flanges 3 and 3 (see FIG. 4) are provided and connected by bolts, nuts 7, 7,... A leakage prevention device 2 is sealed and attached to the flange joint 3A over the outer periphery of the flange joint 3A, thereby preventing leakage in the flange joint 3A. In this embodiment, the fluid in the fluid pipe is clean water. However, the fluid is not limited to clean water in this embodiment. For example, industrial water, agricultural water, sewage, or a gas-liquid mixture of gas, gas, and liquid. It does not matter.

  As shown in FIG. 1, the fluid pipes 1A and 1B are made of ductile cast iron, are formed in a substantially circular shape in cross section, and have an inner peripheral surface covered with an epoxy resin layer 1a. The fluid pipe according to the present invention may be made of metal such as cast iron or steel, concrete, vinyl chloride, polyethylene, or polyolefin. 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 the like, or an appropriate material may be coated on the inner peripheral surface of the fluid pipe with powder coating.

  Next, the structure of the leakage preventing apparatus 2 will be described with reference to FIGS. As shown in FIG. 1, the leakage prevention device 2 includes divided bodies 2A, 2A,... Divided into three in the circumferential direction of the flange joint 3A in this embodiment by bolts, nuts 6, 6,. Each divided body 2 </ b> A includes a packing 4 (leakage prevention member) and an attachment member 5. The leakage prevention device 2 is not limited to three divisions, and may be divided into two or four or more predetermined numbers.

  As shown in FIG. 2, the attachment member 5 is made of ductile cast iron, and has a main body portion 5A having an arc shape extending in the circumferential direction in a front view, and connection portions 51 and 52 provided at both ends of the main body portion 5A. It is equipped with. As will be described later, the connection portions 51 and 52 are used when connecting to adjacent mounting members 5.

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

  Further, a groove portion 58 is formed on the inner diameter side of the main body portion 5A so as to open in the inner diameter direction over the circumferential direction, and forms a concave shape in cross-sectional view. Specifically, as shown in FIG. 2C in particular, the main body portion 5A includes an outer diameter wall portion 5a extending in the tube axis direction (front-rear direction), and an inner diameter from both ends of the outer diameter wall portion 5a in the tube axis direction. It is comprised from the side wall parts 5b and 5b extended in the direction, and the part enclosed by the outer-diameter wall part 5a and the side wall parts 5b and 5b is the groove part 58. FIG.

  Step portions 51 a and 52 a in which the groove portion 58 expands in the outer diameter direction are formed at the longitudinal ends of the attachment member 5. Further, the mounting member 5 is provided with two projecting wall portions 59 and 59 projecting in the inner diameter direction on the outer side in the tube axis direction of the side wall portions 5b and 5b.

  As shown in FIG. 3, the packing 4 is composed of an elastic member made of styrene butadiene rubber in the present embodiment, and has a main body portion 4 </ b> A that extends in the circumferential direction in a front view and forms an arc shape, Connection portions 41 and 42 provided at outer diameter portions at both ends in the circumferential direction. The connecting portions 41 and 42 are used when connecting to the adjacent packing 4 as will be described later. The packing may be a member having elasticity, and may be, for example, nitrile rubber, ethylene propylene rubber, fluorine rubber, 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 incline in the outer diameter direction from one end portion of the main body portion 4A. And 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 4A. The other connecting portion 42 has a rising piece 44 that rises in the outer diameter direction from the other end of the main body portion 4A, and the main body so as to incline from the substantially central portion of the rising piece 44 toward the inner diameter direction. And 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 and 44, substantially rectangular recesses 43a and 44a are formed that are recessed in the circumferential direction. Moreover, the recessed parts 45 and 46 recessed in the circumferential direction are formed in each end surface of the connection parts 41 and 42, respectively.

  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 a base portion 47 fitted into the groove portion 58 of the mounting member 5 as will be described later. A first bulging portion 48 bulging from the center of the base portion 47 in the inner diameter direction in the circumferential direction, and a circumferential direction in the inner diameter direction so as to sandwich the first bulging portion 48 from the base portion 47 in the tube axis direction. And second bulging portions 49 and 49 that bulge over. On both sides of the base portion 47 in the tube axis direction, concave portions 47a and 47a are formed over the circumferential direction. In addition, the 1st bulging part 48 and the 2nd bulging parts 49 and 49 function as a sealing part sealed over the outer periphery of the flanges 3 and 3 so that it may mention later.

  Further, groove portions 401, 401 are formed along the circumferential direction between the first bulging portion 48 and the second bulging portions 49, 49, and the radial dimension L1 of the first bulging portion 48 is shown. (Dimension between the outer peripheral end of the main body portion 4A and the inner peripheral end of the first bulging portion 48) is a radial dimension L2 of the second bulging portions 49, 49 (the outer peripheral end of the main body portion 4A and the second bulging portion). 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 heads (tip portions on the inner diameter side) of the second bulging portions 49 and 49 are divided into two forks by grooves 402 and 402 extending in the circumferential direction.

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

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

  When attaching the leakage preventing device 2 to the flange joint 3A, first, as shown in FIG. 4, existing bolts and nuts 7 ', 7',... For connecting the flanges 3 and 3 of the fluid pipes 1A and 1B are connected. Remove and replace bolts and nuts 7, 7, ... with high sealing performance one by one or several. The bolt and nut 7 is composed of a bolt 7a and a cap nut 7b. Between the head 7c of the bolt 7a and the flange 3 of the fluid pipe 1A, and between the cap nut 7b and the flange 3 of the fluid pipe 1B. Is provided with seal rings 7d, 7d. Thereby, it can prevent leaking from the bolt holes 3a, 3a,.

  In this embodiment, the form using the bolt 7a having the head 7c has been described. However, the present invention is not limited to this. For example, a bolt 7a and a nut may be used, a seal washer may be interposed, It is also possible to use a screw or a bolt of a partial screw, and attach nuts to both ends of the bolt via seal washers.

  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 divided 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 FIG. 5, the split 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 another adjacent mounting member 5. It arrange | positions on the outer periphery of 3A of couplings. In addition, 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 tube axis direction, the divided bodies 2A, 2A,. The work of temporarily installing on the outer periphery of is easy.

  As shown in FIGS. 6A and 7A, in a state where the divided bodies 2A, 2A,... Are temporarily installed on the outer periphery of the flange joint 3A, the first bulging portion 48 and the second The bulging portions 49, 49 are not in contact with the outer peripheral surface of the flange joint 3A.

  Next, in a state where the divided bodies 2A, 2A,... Are arranged on the outer periphery of the flange joint 3A, they are connected by bolts, nuts 6, 6,. Is fixed to the flange joint 3A (see FIG. 1).

  As shown in FIGS. 6 (b) and 7 (b), when the nuts 2A, 2A,... Are temporarily installed on the outer periphery of the flange joint 3A, the bolts and nuts 6, 6,. 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 opposing surfaces 3b, 3b of the flanges 3, 3. Specifically, since the width of the first bulging portion 48 in the tube axis direction is larger than the separation width of the flanges 3 and 3, the opposing surfaces 3b and 3b and the outer peripheral surfaces 3c and 3c of the flanges 3 and 3 The first bulging portion 48 is inserted into the gap between the opposing surfaces 3b and 3b of the flanges 3 and 3 while being in pressure contact with the formed edge portion. Therefore, a portion of the first bulging portion 48 that is on the outer diameter side of the edge portion (a portion that is 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). It is inserted into the gap between the opposing surfaces 3b and 3b of the flanges 3 and 3 (while obtaining force), and the second bulges 49 and 49 on both sides are positioned in the tube axis direction accordingly. At this time, as shown in FIGS. 5 and 6, the first bulging portion 48 on the circumferential end side leads and is inserted into the gap between the opposing surfaces 3 b and 3 b of the flanges 3 and 3. The positioning is preferably performed while reducing the tightening force of the bolts and nuts 6, 6.

  At this time, the second bulging portions 49 and 49 are configured independently of the first bulging portion 48 via the groove portion 401 and are not yet in contact with the outer peripheral surfaces 3c and 3c of the flanges 3 and 3. Further, only the first bulging portion 48 can be deeply immersed between the opposing surfaces 3b and 3b of the flanges 3 and 3 while being elastically deformed.

  As shown in FIG. 8 (a), when the bolts and nuts 6, 6,... Are tightened from the state where the divided bodies 2A, 2A,. 4 and 4 connection portions 41 and 42 (end portions in the circumferential direction) approach each other, but the end portion in the circumferential direction of one packing 4 has a convex shape, and the end in the circumferential direction of another adjacent packing 4 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 packing 4 adjacent to each other slide. Since the mounting members 5 and 5 are present on the outer diameter side of the packings 4 and 4, the packings 4 and 4 are restricted from moving to the outer diameter side. When the inclined surface 42a of the other adjacent packing 4 slides, the one packing 4 is guided by the inclined surface 42a of the adjacent other packing 4 and pressed in the inner diameter direction.

  Then, as shown in FIGS. 6C and 7C, when the bolts and nuts 6, 6,... Are further tightened, the first bulging portion 48 is formed on the opposing surfaces 3b, 3b of the flanges 3, 3. Further inserted into the gap, the second bulging portions 49, 49 are brought into pressure contact with the outer peripheral surfaces 3c, 3c of the flanges 3, 3 to complete the fixing of the leakage preventing device 2 to the flange joint 3A. At this time, the groove portions 401, 401 between the first bulging portion 48 and the second bulging portions 49, 49 and the groove portions 402, 402 of the second bulging portions 49, 49 are the first bulging portion 48 and the second bulging portion 48, respectively. It becomes flat by functioning as a clearance for elastic deformation of the bulging portions 49, 49.

  Further, as shown in FIG. 8 (b), the connecting portion 41 of one packing 4 and the connecting portion 42 of the other packing 4 are in pressure contact, and the packings 4, 4,. . Further, as described above, the rising pieces 43 and 44 are provided with the recesses 43a and 44a, and the both ends of the main body 4A are provided with the recesses 45 and 46. When 41 and the connecting portion 42 of the other packing 4 are in pressure contact, the recesses 43a and 44a and the recesses 45 and 46 are elastically deformed as a clearance for the packings 4 and 4, so that the bolts and nuts 6, 6,. The torque required when tightening can be reduced.

  In addition, in the state where the connection part 41 of one packing 4 and the connection part 42 of the other packing 4 are in pressure contact with each other, a slight gap is formed in the concave parts 43a, 44a and the concave parts 45, 46, so Even if an internal fluid enters between the portion 41 and the connecting portion 42, it is accommodated 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 the gaps between the opposing surfaces 3b, 3b of the flanges 3, 3 and the edge portion, and the second bulging portions 49, 49 can prevent the flanges 3, 3 from being sealed. The outer peripheral surfaces 3c, 3c can be sealed. That is, since the sealing region is formed in a planar shape from the opposing 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 to the flanges 3 and 3. In other words, since the first bulging portion 48 seals in a planar shape between the opposing 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 conventionally provided. High sealing performance can be exhibited compared to the sealed form.

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

  In addition, as described above, the first bulging portion 48 and the second bulging portions 49, 49 are independent of each other by 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 a positional deviation occurs in the radial direction or in a state where there is a dimensional difference in the radial direction, The first bulging portion 48 can be pressed between the opposed surfaces 31b and 32b of the flanges 31 and 32 without being inclined in the axial direction, and the second bulging portions 49 and 49 are outer peripheral surfaces of the flanges 31 and 32. It can be press-contacted to 31c and 32c.

  Furthermore, the elastic deformation allowance of the second bulging portion 49 that is in pressure contact with 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 is in pressure contact with the flange 31 that is displaced in the inner diameter direction. However, since not only the recessed portion 47a on the second bulging portion 49 side in pressure contact with the flange 32 but also the recessed portion 47a on the second bulging portion 49 side in pressure contact with the flange 31, it is possible to escape the flanges 31 and 32. The pressure contact force of the 2nd bulging part 49 and 49 with respect to the outer peripheral surfaces 31c and 32c can be substantially equalized.

  Further, the first bulging portion 48 is inserted between the opposing surfaces 3b, 3b of the flanges 3, 3 while obtaining a reaction force in the tube axis direction, so that the second bulging portions 49, 49 on both sides are in the tube axis direction. Therefore, the second bulging portions 49, 49 can be suitably pressed (sealed) against the outer peripheral surfaces 3c, 3c of the flanges 3, 3.

  When the second bulging portions 49 and 49 are in pressure contact with the outer peripheral surfaces 3c and 3c of the flanges 3 and 3, the second bulging portions 49 and 49 are elastic with the clearances S and S as clearances. Deform. According to this, when the 2nd bulging parts 49 and 49 are press-contacted to the outer peripheral surfaces 3c and 3c of the flanges 3 and 3, the 2nd bulging parts 49 and 49 are elastically deformed and the groove part 58 of the attachment member 5 is provided. Therefore, it is possible to prevent the pressure contact force on the outer peripheral surfaces 3c and 3c of the second bulging portions 49 and 49 from being lowered and to improve the sealing performance.

  Further, since the gaps S and S are the recesses 47a and 47a formed on the outer surface of the rubber packing 4 in the tube axis direction, the gaps S and S can be easily formed, and the packing 4 is reduced in weight. Since the degree of freedom of deformation of the packing 4 is increased, an elastic repulsive force is generated while improving the workability, and the leakage preventing power is exhibited corresponding to the 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, the packings 4, 4,... And the mounting members 5, 5,... (Divided bodies 2A, 2A,...) Divided in the circumferential direction are used from the outer diameter side to the outer periphery of the flange joint 3A. Can be easily sealed.

  Moreover, the edge part (connection part 41, 42) of the circumferential direction where the adjacent packings 4 and 4 are mutually connected has a pair of uneven | corrugated shape which can mutually be fitted. According to this, the end portions (connecting portions 41, 42) are fitted to each other by fitting the end portions (connecting portions 41, 42) having a pair of concave and convex shapes of the packings 4, 4 divided in the circumferential direction. They can be positioned relative to each other.

  Further, when 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 another adjacent mounting member 5, so that the divided body 2A, 2A,... Are prevented from relatively moving in the tube axis direction (see FIG. 1B).

  Moreover, the edge part (connection part 41, 42) of the circumferential direction joined to the adjacent packings 4 and 4 has a pair of inclined surface 41a, 42a inclined with respect to the radial direction. In this way, when the bolts and nuts 6, 6,... Are tightened in a state where the divided bodies 2A, 2A,... Are arranged on the outer periphery of the flange joint 3A, the inclined surface 41a of the one packing 4 becomes the other. The seal 4 is guided and slid by the inclined surface 42a to generate a pressing force in the inner diameter direction, and the contact area between the inclined surfaces 41a and 42a can be increased, so that the sealing performance between the end portions is improved. be able to.

  The mounting members 5 and 5 include fastening member bolts and nuts 6 and 6 that fasten the mounting members 5 and 5 on the outer diameter side of the end portions in the circumferential direction of the packings 4 and 4. By doing in this way, the fastening members 5 and 5 are fastened by the bolts and nuts 6 and 6 on the outer diameter side of the end portions in the circumferential direction of the packings 4 and 4. The sealability can be improved by giving to the end in the circumferential direction.

  Moreover, there are the following as modifications of the attachment member. As shown in FIG. 10A, the projecting wall portions 590 and 590 are provided with screw holes 590a and 590a penetrating in the tube axis direction, and bolts 8 and 8 are provided outside the screw holes 590a and 590a. Can be screwed in. According to this, when the leakage prevention device 2 is fixed to the flange joint 3A, the bolts 8 and 8 are screwed to sandwich the flanges 3 and 3 in the tube axis direction so that the leakage prevention device 2 is moved in the tube axis direction. Since the movement can be restricted, it is possible to prevent the leakage prevention device 2 from moving in the tube axis direction and thus preventing the sealing performance from being lowered.

  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 in the flange joint 3A while abutting against the flange 3 on one side with the protruding wall portion 591 ′ not provided with the screw hole 590a as a guide, and the leakage prevention device 2 can be attached to the flange 3A. When the bolt 8 is screwed into the screw hole 590a when fixed to the joint 3A, the flanges 3 and 3 are sandwiched between the bolt 8 and the protruding wall portion 591 'so that the leakage preventing device 2 is connected to the pipe. Movement in the axial direction can be restricted.

  Moreover, in the said Example, although the recessed part 47a, 47a was provided in the side surface of the pipe axis direction of the packing 4, the escape allowance of the packing 4 elastically deformed between the side wall parts 5b, 5b of the attachment member 5 was illustrated. For example, as shown in FIG. 10C, the side walls 500b and 500b of the attachment member 500 may be provided with recesses 500c and 500c.

  Moreover, in the said Example, the packing 4 illustrated the form which the head part (front-end | tip part of an internal diameter side) of the 2nd bulging parts 49 and 49 is divided into the forked shape by the groove parts 402 and 402 extended in the circumferential direction. However, as shown in FIG. 11A, for example, a packing 410 having second bulging portions 491 and 491 in which the groove portions 402 and 402 are not provided (the head portion is not divided) may be used. ), A packing 420 having second bulging portions 492 and 492 in which a plurality of groove portions 402 are provided (the head portion is divided into a plurality of portions) may be used.

  Although the embodiments of the present invention have been described with reference to the drawings, the specific configuration is not limited to these embodiments, and modifications and additions within the scope of the present invention are included in the present invention. It is.

  In the said Example, although the base 47 of the packing 4 was press-fitted and installed with respect to the groove part 58 of the attachment member 5, this invention is not limited to this, For example, in the groove part 58 of the attachment member 5, On the other hand, the base 47 of the packing 4 may be bonded with an adhesive or the like.

  Moreover, in the said Example, the flanges 3 and 3 are substantially circular shape by the front view, However, This invention is not limited to this, For example, like the joined part of a polygonal flange or 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 (opposite surface)
47a Concave portion 48 First bulge portion (sealing portion)
49 Second bulging part (sealing part)
58 Groove (seat)
401 Groove S S Gap

Claims (7)

A leakage prevention device that seals over the outer periphery of a flange joint in which a pair of opposed flanges are connected in a sealing manner, and prevents leakage in the flange joint,
A leakage preventing member having a sealing portion that seals the outer periphery of the pair of flanges and elastically deformable; and a mounting member that has a seat portion that accommodates the leakage preventing member and is fitted on the pair of flanges. At least,
The sealing portion of the leakage preventing member bulges in an inner diameter direction, and a first bulging portion that is inserted in a sealing manner so as to abut on the opposing surfaces in a gap between the opposing surfaces of the pair of flanges, and the first A second bulging portion that is connected to both sides of the bulging portion in the tube 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; Leakage prevention device characterized by that.   The seat portion of the outer fitting member has a side wall sandwiching the leakage prevention member in the tube axis direction, and a gap serving as a clearance for the leakage prevention member that is elastically deformed between the leakage prevention member and the side wall. The leakage prevention device according to claim 1, wherein a portion is formed.   The leakage prevention device according to claim 2, wherein the gap is a recess formed on an outer surface of the leakage prevention member.   The leakage prevention device according to claim 1, wherein the leakage prevention member has a divided structure divided in a circumferential direction.   The leakage prevention device according to claim 4, wherein end portions of the leakage prevention members that are joined to each other in the circumferential direction have a pair of concave and convex shapes that can be fitted to each other.   The leakage prevention device according to claim 4 or 5, wherein the end portions of the leakage prevention members that are joined to each other in the circumferential direction have a pair of opposed surfaces that are inclined with respect to the radial direction.   The said attachment member is equipped with the fastening member which fastens this attachment member by the outer-diameter side of the edge part of the circumferential direction joined to the said leakage prevention member mutually, The Claim 4 thru | or 6 characterized by the above-mentioned. Leakage prevention device.

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