JP2019090542A - Leakage prevention device of flange joint part - Google Patents

Abstract

To provide a leakage prevention device of a flange joint part which can inhibit a packing from being deformed to the outer side by diameter reduction of a fixing bracket to prevent deterioration of leakage prevention effect and deterioration of workability.SOLUTION: A leakage prevention device 1 includes: a packing 3 disposed at an outer periphery of a flange joint part 10; and an annular fixing bracket 4 which is attached to the outer periphery side of the flange joint part 10 through the packing 3. The packing 3 includes: a belt-like body 31 extending in a circumferential direction; and multiple protrusions protruding from the body 31 to the inner periphery side. The multiple protrusions includes: a center protrusion 32 which closes a gap between flanges; and side protrusions 33, 34 which are formed at both sides of the center protrusion 32 and adhere to outer peripheral surfaces of the flanges 11, 12. A protrusion amount of the center protrusion 32 is larger than protrusion amounts of the side protrusions 33, 34.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an apparatus for preventing fluid leakage at a flange joint of a fluid pipe.

  In the flange joint portion of the fluid pipe, fluid may leak from the gap between the flanges due to an external force such as an earthquake or the influence of deterioration. In Patent Documents 1 and 2 of the applicant of the present invention, a device as shown in FIG. 7 is proposed as a method for preventing such fluid leakage or for preventing or stopping fluid leakage that has already occurred. ing. The device 101 includes a packing 103 wound around the outer periphery of the flange joint, and an annular fixing fitting 104 mounted via the packing 103. 1 and 2 can also be referred to as a front view and a side view of this device.

  The fixing bracket 104 has divided portions at a plurality of circumferential positions, and a fastener formed of a bolt and a nut is attached to each of the divided portions. When the fastener is tightened, the diameter of the fixing fitting 104 is reduced and the packing 103 is pressed against the flange joint portion 10. The packing 103 is provided with three projections that project toward the inner peripheral side, and the projection 132 located at the center among them closes the gap between the flanges, and the projections 133 and 134 located on both sides thereof are the flanges 111 and 112. Close contact with the outer peripheral surface of

  By the way, in this device 101, when the diameter of the fixing bracket 104 is reduced, the projections 133 and 134 are deformed so as to escape outward, and the adhesion to the outer peripheral surface of the flanges 111 and 112 is weakened to prevent fluid leakage. The effect was sometimes reduced. Particularly in the divided portion, as shown by a broken line in FIG. 5, such outward deformation of the packing was remarkable. Further, in this case, if it is intended to improve the adhesion of the protrusions 133 and 134, the fastener must be tightened more strongly, which causes the deterioration of workability because the torque at the time of operation increases.

Design registration No. 1305825 JP, 2013-204636, A

  The present invention has been made in view of the above-mentioned circumstances, and its object is to suppress the deformation of the packing to the outside due to the diameter reduction of the fixing bracket and to prevent the deterioration of the leakage preventing effect and the deterioration of the workability. An object of the present invention is to provide a leak prevention device for a flange joint.

  The above object can be achieved by the present invention as described below. That is, the leakage preventing apparatus of the flange joint portion according to the present invention includes: a packing disposed on an outer periphery of the flange joint portion of the fluid pipe; and an annular fixing fitting mounted on the outer peripheral side of the flange joint portion via the packing. And the packing includes a belt-like main body extending in the circumferential direction and a plurality of protrusions protruding toward the inner circumferential side from the main body, the plurality of protrusions being A center projection that closes a gap between the flanges and a side projection formed on both sides of the center projection and in close contact with the outer peripheral surface of the flange, wherein the amount of projection of the center projection is larger than the amount of projection of the side projections It is. According to such a configuration, the gap can be easily closed by the center projection, and the torque for bringing the side projections into close contact with the outer peripheral surface of the flange can be reduced. Therefore, the deformation of the packing to the outside due to the diameter reduction of the fixing bracket is suppressed. As a result, it is possible to prevent the deterioration of the leakage prevention effect and the deterioration of the workability.

  It is preferable that each of the center protrusion and the side protrusion have a semicircular cross-sectional shape. According to this configuration, the force is concentrated on the tip of the curved projection, so that the gap between the flanges is appropriately closed by the center projection without increasing the torque during operation. The side projections can be tightly attached. Further, since the center of the semicircle in the cross-sectional shape of the center protrusion and the side protrusion is positioned on the inner peripheral side of the center of the thickness of the packing, the deformation of the packing to the outside can be more effectively suppressed.

  It is preferable that the inner circumferential surface of the projecting portion be inclined toward the inner circumferential side toward the center of the packing. According to this configuration, since the side protrusion is less likely to be deformed so as to escape outward, the deformation of the packing to the outside can be more effectively suppressed.

  The fixture has split portions at multiple locations in the circumferential direction, and the multiple split pieces that make up the fix fixture are connected by fasteners attached to the split portions, and the splits are butted against one another by the split portions Among the end portions of the piece, one is provided with a center tooth passing through the center of the packing, and the other is provided with side teeth disposed on both sides of the center tooth, and the center tooth and the side teeth are mutually It is preferable that the fitting has a complementary shape, and the center of the side projection is disposed inside the center of the side tooth. According to this configuration, since the side teeth are positioned outward with respect to the side protrusion, the side protrusion is less likely to be deformed so as to escape outward, and deformation of the packing to the outside can be more effectively suppressed.

  It is preferable that a slit is formed on the outer periphery of the main body. Since the cross-sectional area of the packing is reduced by the formation of the slits, the outward deformation of the packing can be reduced.

Front view of leak prevention device attached to flange joint Side view of the leak prevention device of FIG. 1 A-A sectional view of FIG. 1 Cross section of packing Side view showing the divided part in an enlarged manner Sectional view showing another embodiment of the leakage prevention apparatus Sectional view showing a conventional leak prevention device

  Embodiments of the present invention will be described with reference to the drawings.

  1 and 2 show a flange joint portion 10 in which water pipes P1 and P2, which are fluid pipes, are flanged to each other. In the flange joint portion 10, the pair of flanges 11 and 12 formed at the ends of the water pipes P1 and P2 are fastened by the fastener 20. The fasteners 20 are attached to a plurality of circumferential locations (four locations in this embodiment). As shown in FIG. 3, although the annular gasket 13 is interposed between a pair of flanges 11 and 12, it is not restricted to this. Further, between the flanges 11 and 12, a gap 14 opened toward the outer peripheral side (radially outer side) is formed.

  The fastener 20 includes a bolt 21 inserted into the bolt holes of the flanges 11 and 12, and nuts 22 and 23 screwed to the bolt 21. The flanges 11 and 12 are held by the pair of nuts 22 and 23. doing. The bolt 21 is composed of a double screw bolt, and the nut 23 is composed of a cap nut (cap nut). Furthermore, the fastener 20 includes a seal 24 for sealing between the nut 23 and the flange 11, a frame 25 formed of a material (for example, metal) harder than the seal 24, a nut 22 and the flange 12. And a sealing material 26 for sealing between them. The seal member 24 is formed with a fin portion which enters the bolt hole.

  In the flange joint portion 10 of such a water pipe, when the flanges are separated due to an external force such as an earthquake or the influence of deterioration, the water may leak from the gap 14. Therefore, the leakage prevention device 1 is attached in order to prevent leakage or prevent the existing leakage. In the case where the flanges are separated from each other, water leakage from the bolt holes of the flanges 11 and 12 is also a concern, but in the present embodiment, such bolt holes are formed by the fastener 20 provided with the sealing members 24 and 26. Can prevent and stop water leakage from water.

  The leak prevention device 1 includes a packing 3 wound around the outer periphery of the flange joint portion 10 and an annular fixing fitting 4 mounted on the outer peripheral side of the flange joint portion 10 via the packing 3. The packing 3 includes a belt-shaped main body 31 extending in the circumferential direction, and a plurality of (three in the present embodiment) protrusions protruding from the main body 31 toward the inner peripheral side (radially inward). The plurality of protrusions include a center protrusion 32 closing the gap 14 between the flanges, and side protrusions 33 and 34 formed on both sides of the center protrusion 32 and in close contact with the outer peripheral surfaces of the flanges 11 and 12, respectively. It extends continuously in the direction. The packing 3 is formed of an elastic material such as rubber. In order to make distinction on a drawing easy, the packing 3 is colored and drawn in FIG.

  The fixing bracket 4 has dividing portions 41 at a plurality of circumferential locations (two locations in the present embodiment), and a plurality of (two in the present embodiment) split pieces 4A and 4B constituting the securing bracket 4 It is connected by the fastener 42 attached to the division part 41. By tightening the fastener 42, the diameter of the fixing fitting 4 is reduced, and the packing 3 is pressed against the flange joint portion 10. The fastener 42 is composed of a bolt and a nut, and the bolt is inserted into the extending portion 43 protruding in the left and right direction in FIG. 1 from the end of the divided pieces 4A and 4B in the circumferential direction.

  In the leakage prevention device 1, protrusions 35 protruding outward from the side protrusions 33 and 34 are provided at both ends in the width direction of the main body 31 of the packing 3. By providing such a projecting portion 35 in the main body 31, the side protrusions 33 and 34 do not escape to the outside when the diameter of the fixing metal fitting 4 is reduced in the divided portion 41, too. The deformation to the outside of the packing 3 clamped between the outer peripheral surface and the inner peripheral surface of the fixing bracket 4 is suppressed, and as a result, it is possible to prevent the leakage prevention effect and the workability from being deteriorated.

  In the present embodiment, as shown in FIG. 3, the width W2 (see FIG. 4) of the packing 3 is larger than the width W1 of the joined flanges 11 and 12, and the protruding portion is formed by the protruding portion 35. It is done. Further, the fixing bracket 4 is provided with a pair of inner flanges 44 projecting to the inner peripheral side, and they are disposed at both ends in the width direction of the projecting portion 35 so as to sandwich the main body 31. The protrusion 35 faces the inner flange 44 with a minute gap, and the amount of deformation is small even when the main body 31 bulges outward with the diameter reduction of the fixing bracket 4.

  The protrusion of the packing 3 preferably has a cross-sectional shape in which the tip is curved in a convex shape, and for example, a shape in which a trapezoidal upper surface is curved in a convex shape can be considered. In the present embodiment, since the protrusions 32 to 34 have a semicircular cross-sectional shape, the force acts on the tip of the curved protrusion in a concentrated manner, so that the center protrusion can be obtained without increasing the working torque. The side protrusions 33 and 34 can be strongly adhered to the outer peripheral surfaces of the flanges 11 and 12 while appropriately closing the gap between the flanges 32. The curved tip of the center projection 32 faces the opening of the gap 14, and both sides of the tip abut the edges of the flanges 11 and 12 so as to close the opening of the gap 14. The curved tips of the side protrusions 33 and 34 abut on the outer peripheral surfaces of the flanges 11 and 12, respectively.

  As shown in FIG. 4, in the packing 3, semicircular centers C32 to C34 in the cross-sectional shape of the center projection 32 and the side projections 33 and 34 are respectively located on the inner peripheral side of the center of the thickness T of the packing 3. Thereby, the deformation to the outside of packing 3 can be controlled effectively. The center protrusion 32 has a semicircular radius of curvature larger than that of the side protrusions 33 and 34, and the amount of protrusion is relatively large. Therefore, the gap 14 can be easily closed by the center protrusion 32, and the torque for bringing the side protrusions 33 and 34 into close contact with the outer peripheral surfaces of the flanges 11 and 12 can be reduced. Since the flat portion 37 is formed between the center projection 32 and the side projections 33 and 34, interference between adjacent projections is suppressed even when the packing 3 is strongly pressed. Each protrusion can be made to adhere appropriately to the outer peripheral surface of 12.

  Further, in the packing 3, the inner peripheral surface of the protruding portion 35 is inclined toward the inner peripheral side toward the center of the packing 3 in the width direction. According to this configuration, when the fastener 42 is tightened to reduce the diameter of the fixing bracket 4, the side protrusions 33, 34 are less likely to be deformed so as to escape outward, and the deformation of the packing 3 is more effective. Can be suppressed. Further, the thickness of the projecting portion 35 is larger than half (that is, T / 2) of the thickness T of the packing 3, which is advantageous in suppressing the deformation of the packing 3 to the outside.

  FIG. 5 is an enlarged view of the dividing portion 41, and corresponds to the broken line in FIG. In this embodiment, center teeth 51 passing through the center of the packing 3 are provided on one of the end portions of the divided pieces 4A and 4B which are abutted against each other by the divided portion 41, and disposed on both sides of the center teeth 51 on the other. Side teeth 52, 53 are provided, and the center teeth 51 and the side teeth 52, 53 have complementary shapes in which they are fitted to each other. The degree of engagement (degree of engagement) changes depending on the diameter dimensions of the flanges 11 and 12 and the tightening of the fastener 42.

  The central CLs 33 and 34 of the side protrusions 33 and 34 are disposed inward of the central CLs 52 and 53 of the side teeth 52 and 53, respectively. According to such a configuration, the side teeth 52, 53 are positioned closer to the outer side with respect to the side protrusions 33, 34, so that the side protrusions 33, 34 deform so as to escape outward when the fixing fitting 4 is contracted. It becomes difficult to do so, and the deformation of the packing 3 to the outside can be suppressed more effectively. The center CL 32 of the center projection 32 coincides with the center CL 51 of the center tooth 51, but these may be slightly offset.

  In the example of FIG. 6, a slit 36 is formed on the outer periphery of the main body 31 of the packing 3. Also by reducing the cross-sectional area of the packing 3 by the slits 36, the deformation of the packing 3 to the outside can be reduced. Since the slit 36 is formed at a position avoiding the projection 32 in the width direction of the packing 3, the thickness of the packing 3 at the location where the projection 32 is formed is secured, and the function of sealing the gap 14 interferes. Absent. The slits 36 preferably extend continuously in the circumferential direction. Moreover, although the slit 36 is extended in the thickness direction of the packing 3, it is not restricted to this.

  In the present embodiment, a water pipe has been described as an example of the fluid pipe, but the invention is not limited thereto. The present invention can be applied to a fluid pipe used for various liquids other than water and fluids such as gas.

  The present invention is not limited to the embodiment described above, and various improvements and modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 leak prevention device 3 packing 4 fixing bracket 4A split piece 4B split piece 10 flange joint portion 11 flange 12 flange 14 gap 31 main body 32 center protrusion 33 side protrusion 34 side protrusion 35 protrusion 36 slit 41 split portion 42 fastener 51 center tooth 52 side teeth 53 side teeth P1 water pipe (example of fluid pipe)
P2 water pipe (an example of fluid pipe)

Claims (7)

A leak prevention device for a flange joint portion, comprising: a packing disposed on an outer periphery of a flange joint portion of a fluid pipe; and an annular fixing fitting mounted on an outer peripheral side of the flange joint portion via the packing.
The packing includes a belt-shaped main body extending in a circumferential direction, and a plurality of protrusions protruding toward the inner peripheral side from the main body, and the plurality of protrusions form a center protrusion closing a gap between the flanges; And side protrusions formed on both sides of the center protrusion and in close contact with the outer peripheral surface of the flange,
The leakage prevention device for a flange joint portion characterized in that the protrusion amount of the center protrusion is larger than the protrusion amount of the side protrusion.   The leak prevention device of the flange joint part according to claim 1 which a tip of said center projection intrudes into a crevice between said flanges, and closes said crevice. Each of the center protrusion and the side protrusion has a semicircular cross-sectional shape,
The flange joint portion leakage prevention device according to claim 1 or 2, wherein the semicircular radius of curvature of the center projection is larger than the semicircular radius of curvature of the side projection. The fixing metal fitting is provided with a pair of inner flanges disposed on both ends in the width direction of the packing so as to protrude to the inner peripheral side and sandwich the main body,
The leak prevention device of the flange joint part according to any one of claims 1 to 3, wherein the main body has a gap and faces the inner flange.   The leak prevention device of the flange joint part of any one of Claims 1-4 in which the flat part is formed between the said center protrusion and the said side protrusion.   The protrusion part which protruded outside the said side protrusion is provided in the width direction both ends of the said main body, The thickness of the said protrusion part is larger than half of the thickness of the said packing. Leakage prevention device for flange joint as described in.   The leak prevention device of the flange joint part according to any one of claims 1 to 6, wherein the inner peripheral surface of the packing is inclined toward the inner peripheral side from the both widthwise ends of the packing toward the center of the packing. .

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