JP6490451B2 - Leakage prevention device for flange joints - Google Patents

Description

  The present invention relates to an apparatus for preventing fluid leakage at a flange joint portion 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 aging. In Patent Documents 1 and 2 by the present applicant, an apparatus as shown in FIG. 7 is proposed as a technique for preventing such fluid leakage or for preventing fluid leakage that has already occurred. ing. The device 101 includes a packing 103 wound around the outer periphery of the flange joint portion, and an annular fixing metal fitting 104 attached via the packing 103. 1 and 2 can be referred to as a front view and a side view of the apparatus.

  The fixture 104 has divided portions at a plurality of locations in the circumferential direction, and a fastener composed of a bolt and a nut is attached to each of the divided portions. When the fastener is tightened, the fixing bracket 104 is reduced in diameter and the packing 103 is pressed against the flange joint portion 10. The packing 103 includes three protrusions protruding toward the inner peripheral side, and a protrusion 132 positioned at the center of the packing 103 closes a gap between the flanges, and protrusions 133 and 134 positioned on both sides thereof are flanges 111 and 112. It adheres to the outer peripheral surface of

  By the way, in this apparatus 101, when the diameter of the fixing metal fitting 104 is reduced, the protrusions 133 and 134 are deformed so as to escape to the outside, and the adhesion to the outer peripheral surfaces of the flanges 111 and 112 is weakened to prevent fluid leakage. The effect may be reduced. In particular, in the divided portion, as shown by a broken line in FIG. 5, such deformation toward the outside of the packing was remarkable. Further, in this case, if the adhesion between the protrusions 133 and 134 is to be improved, the fastener must be tightened more strongly, and the torque at the time of work increases, leading to deterioration in workability.

Design Registration No. 1305825 JP 2013-204636 A

  This invention is made | formed in view of the said situation, The objective can suppress the deformation | transformation to the outer side of the packing accompanying the diameter reduction of a fixing metal fitting, and can prevent the fall of the leak prevention effect and the deterioration of workability | operativity. An object of the present invention is to provide a leakage preventing device for a flange joint.

  The above object can be achieved by the present invention as described below. That is, the flange joint leakage prevention device according to the present invention includes a packing wound around the outer periphery of the flange joint portion of the fluid pipe, and an annular fixing bracket mounted on the outer periphery side of the flange joint portion via the packing. In the leakage preventing device for a flange joint portion, the packing includes a belt-like main body extending in the circumferential direction and a plurality of protrusions protruding from the main body toward the inner peripheral side, and the plurality of protrusions are flanges. A protrusion that protrudes outward from the side protrusion at both ends in the width direction of the main body, including a center protrusion that closes a gap between the center protrusion and a side protrusion that is formed on both sides of the center protrusion and closely contacts the outer peripheral surface of the flange. The part is provided. By providing such a projecting portion on the main body, deformation to the outside of the packing due to the reduced diameter of the fixing bracket is suppressed, and as a result, it is possible to prevent a decrease in leakage prevention effect and a deterioration in workability. .

  It is preferable that each of the center protrusion and the side protrusion has a semicircular cross-sectional shape. According to such a configuration, the force concentrates on the tip of the curved protrusion, so that the gap between the flanges is properly closed by the center protrusion without increasing the torque during the operation, and the outer peripheral surface of the flange. The side protrusion can be strongly adhered. In addition, since the center of the semicircular shape in the cross-sectional shape of the center protrusion and the side protrusion is located on the inner peripheral side with respect to the center of the thickness of the packing, deformation to the outside of the packing can be more effectively suppressed.

  It is preferable that the inner peripheral surface of the protruding portion is inclined toward the inner peripheral side toward the center of the packing. According to such a configuration, the side protrusion is difficult to be deformed so as to escape to the outside, so that the deformation of the packing to the outside can be more effectively suppressed.

  The division in which the fixing bracket has divided portions at a plurality of locations in the circumferential direction, and a plurality of divided pieces constituting the fixing bracket are connected by a fastener attached to the divided portion and are abutted with each other at the dividing portion. One of the end portions of the piece 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 tooth are mutually connected. It is preferable that a complementary shape to be fitted is formed, and the center of the side protrusion is disposed inside the center of the side tooth. According to such a configuration, since the side teeth are located on the outer side with respect to the side protrusion, it is difficult to deform the side protrusion so that it escapes outward, and deformation of the packing to the outside can be more effectively suppressed.

  What has the slit formed in the outer periphery of the said main body is preferable. Since the cross-sectional area of the packing is reduced due to the formation of the slit, the deformation to the outside of the packing can be reduced.

Front view of the leakage prevention device attached to the flange joint Side view of the leakage prevention device of FIG. AA sectional view of FIG. Cross section of packing Side view showing enlarged division Sectional drawing which shows other embodiment of a leakage prevention apparatus Sectional view showing a conventional leakage 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 flange-joined to each other. In the flange joint portion 10, a pair of flanges 11 and 12 formed at the ends of the water pipes P <b> 1 and P <b> 2 are fastened by the fixing tool 20. The fasteners 20 are attached to a plurality of locations in the circumferential direction (four locations in the present embodiment). As shown in FIG. 3, an annular gasket 13 is interposed between the pair of flanges 11 and 12, but the present invention is not limited to this. Further, a gap 14 is formed between the flanges 11 and 12 and opens toward the outer peripheral side (radially outer side).

  The fixing tool 20 includes a bolt 21 inserted through the bolt holes of the flanges 11 and 12, and nuts 22 and 23 screwed into the bolt 21, and the flanges 11 and 12 are sandwiched between 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 fixing tool 20 includes a seal member 24 that seals between the nut 23 and the flange 11, a frame 25 formed of a material (for example, metal) harder than the seal member 24, the nut 22, and the flange 12. And a sealing material 26 for sealing between the two. The seal material 24 is formed with a fin portion that enters the bolt hole.

  In such a flange joint portion 10 of a water pipe, when the flanges are separated due to an external force such as an earthquake or due to aging, water may leak from the gap 14. Therefore, in order to prevent water leakage or to prevent water leakage that has already occurred, the leakage prevention device 1 is attached. If the flanges are separated from each other, water leakage from the bolt holes of the flanges 11 and 12 is a concern, but in the present embodiment, such bolt holes are provided by the fixing tool 20 provided with the sealing materials 24 and 26. Can prevent and stop water leakage.

  The leakage prevention device 1 includes a packing 3 wound around the outer periphery of the flange joint portion 10 and an annular fixing fitting 4 attached to the outer periphery 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 inner side). The plurality of protrusions include a center protrusion 32 that closes the gap 14 between the flanges, and side protrusions 33 and 34 that are formed on both sides of the center protrusion 32 and closely contact the outer peripheral surface of the flanges 11 and 12. It extends continuously in the direction. The packing 3 is formed of an elastic material such as rubber. In order to facilitate the distinction on the drawings, the packing 3 is drawn in FIGS.

  The fixing bracket 4 has divided portions 41 at a plurality of locations in the circumferential direction (two locations in the present embodiment), and a plurality (two in the present embodiment) of the divided pieces 4A and 4B constituting the fixing bracket 4 are: It is connected by a fastener 42 attached to the dividing portion 41. By fastening the fastener 42, the diameter of the fixing bracket 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 an extending portion 43 that protrudes in the left-right direction in FIG. 1 from the end portions of the divided pieces 4A and 4B in the circumferential direction.

  In this leakage prevention device 1, protrusions 35 that protrude 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. Since the projecting portion 35 is provided on the main body 31, the side projections 33 and 34 do not escape to the outside when the fixing bracket 4 is reduced in diameter even in the divided portion 41. The outward deformation of the packing 3 clamped between the outer peripheral surface and the inner peripheral surface of the fixture 4 can be suppressed, and as a result, the leakage prevention effect can be prevented and the workability can be prevented from deteriorating.

  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 35 is formed on the outside thereof. Has been. In addition, the fixing bracket 4 is provided with a pair of inner flanges 44 projecting toward the inner peripheral side, and these are disposed at both ends in the width direction of the projecting portion 35 so as to sandwich the main body 31. The protruding portion 35 is opposed to the inner flange 44 with a minute gap, and even when the main body 31 bulges outward as the diameter of the fixing bracket 4 is reduced, the amount of deformation is small.

  The protrusions included in the packing 3 preferably have a cross-sectional shape with the tip curved in a convex shape. For example, a shape in which the upper surface of the trapezoid is curved in a convex shape is conceivable. In the present embodiment, the protrusions 32 to 34 have a semicircular cross-sectional shape, and according to this, the force concentrates on the tip of the curved protrusion, so that the center protrusion is not increased without increasing the torque during operation. The side protrusions 33 and 34 can be tightly adhered to the outer peripheral surfaces of the flanges 11 and 12 while the gap between the flanges is appropriately closed by 32. The curved tip of the center protrusion 32 faces the opening of the gap 14 and abuts the edges of the flanges 11 and 12 so that both sides of the tip close the opening of the gap 14. The curved tips of the side protrusions 33 and 34 are in contact with the outer peripheral surfaces of the flanges 11 and 12, respectively.

  As shown in FIG. 4, in this packing 3, semicircular centers C <b> 32 to C <b> 34 in the cross-sectional shapes of the center protrusion 32 and the side protrusions 33 and 34 are positioned on the inner peripheral side from the center of the thickness T of the packing 3. Thereby, the deformation | transformation to the outer side of the packing 3 can be suppressed effectively. The center protrusion 32 has a semicircular radius of curvature larger than the side protrusions 33 and 34, and the protrusion amount 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 protrusion 32 and the side protrusions 33 and 34, even when the packing 3 is strongly clamped, the adjacent protrusions are prevented from interfering with each other. Each protrusion can be properly adhered to the outer peripheral surface of the twelve.

  Moreover, in this packing 3, the inner peripheral surface of the protrusion part 35 inclines toward the inner peripheral side toward the center of the packing 3 in the width direction. According to such a configuration, when the fastener 42 is tightened to reduce the diameter of the fixing bracket 4, the side protrusions 33 and 34 are difficult to be deformed so as to escape to the outside, and deformation of the packing 3 to the outside is more effective. Can be suppressed. Moreover, the thickness of the protrusion part 35 is larger than the half (namely, T / 2) of the thickness T of the packing 3, and this is advantageous when suppressing the deformation | transformation to the outer side of the packing 3. FIG.

  FIG. 5 shows the dividing portion 41 in an enlarged manner, and corresponds to the broken line portion of FIG. In the present embodiment, center teeth 51 that pass through the center of the packing 3 are provided on one of the ends of the divided pieces 4A and 4B that are butted against each other in the divided portion 41, and the other is disposed on both sides of the center teeth 51. Side teeth 52 and 53 are provided, and the center tooth 51 and the side teeth 52 and 53 have a complementary shape. The degree of engagement (degree of engagement) varies depending on the diameter of the flanges 11 and 12 and the tightening of the fastener 42.

  The center CL33, 34 of the side protrusions 33, 34 is disposed inside the center CL52, 53 of the side teeth 52, 53, respectively. According to such a configuration, since the side teeth 52 and 53 are positioned on the outer side with respect to the side protrusions 33 and 34, the side protrusions 33 and 34 are deformed so as to escape outward when the diameter of the fixing bracket 4 is reduced. It becomes difficult to carry out and the deformation | transformation to the outer side of the packing 3 can be suppressed more effectively. The center CL32 of the center protrusion 32 coincides with the center CL51 of the center tooth 51, but these may be slightly shifted.

  In the example of FIG. 6, a slit 36 is formed on the outer periphery of the main body 31 of the packing 3. By reducing the cross-sectional area of the packing 3 with such slits 36, the deformation of the packing 3 toward the outside can also be reduced. Since the slit 36 is formed at a position avoiding the protrusion 32 in the width direction of the packing 3, the thickness of the packing 3 at the formation position of the protrusion 32 is ensured, and the function of sealing the gap 14 is hindered. Absent. The slit 36 preferably extends 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 is exemplified as a fluid pipe, but the present invention is not limited to this, and the present invention can be applied to a fluid pipe used for various liquids other than water, 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 Leakage prevention apparatus 3 Packing 4 Fixing metal fitting 4A Division | segmentation piece 4B Division | segmentation piece 10 Flange joint part 11 Flange 12 Flange 14 Crevice 31 Main body 32 Center protrusion 33 Side protrusion 34 Side protrusion 35 Projection part 36 Slit 41 Split part 42 Fastener 51 Center tooth 52 side teeth 53 side teeth P1 water pipe (an example of a fluid pipe)
P2 water pipe (an example of a fluid pipe)

Claims (5)

In a leakage preventing device for a flange joint comprising: a packing wound around the outer periphery of a flange joint portion of a fluid pipe; and an annular fixing fitting attached to the outer periphery of the flange joint portion via the packing;
The packing includes a belt-like main body extending in the circumferential direction, and a plurality of protrusions protruding from the main body toward the inner peripheral side, and the plurality of protrusions includes a center protrusion that closes a gap between flanges; Including side protrusions formed on both sides of the center protrusion and in close contact with the outer peripheral surface of the flange,
Protruding portions protruding outward from the side protrusions are provided at both ends in the width direction of the main body ,
The fixing bracket has divided portions at a plurality of locations in the circumferential direction, and a plurality of divided pieces constituting the fixing bracket are connected by a fastener attached to the divided portion,
Of the end portions of the divided pieces that are butted against each other in the divided portion, one side is provided with a center tooth that passes through the center of the packing, and the other is provided with side teeth that are disposed on both sides of the center tooth, The center teeth and the side teeth have a complementary shape that fits each other,
The flange joint leakage preventing device, wherein a center of the side protrusion is disposed on an inner side than a center of the side teeth .   The leakage prevention device for a flange joint according to claim 1, wherein each of the center protrusion and the side protrusion has a semicircular cross-sectional shape.   The leakage preventing device for a flange joint according to claim 2, wherein the center of the semicircular shape in the cross-sectional shape of the center protrusion and the side protrusion is located on the inner peripheral side with respect to the center of the thickness of the packing.   The leakage preventing device for a flange joint according to any one of claims 1 to 3, wherein an inner peripheral surface of the protruding portion is inclined toward an inner peripheral side toward a center of the packing. The leak prevention apparatus of the flange joint part of any one of Claims 1-4 in which the slit is formed in the outer periphery of the said main body.

Images