JP2018071074A - Drain piping using existing pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide drain piping using an existing pipe capable of attaining the life-prolongation by preventing dissimilar metal contact corrosion.SOLUTION: The damage of a cast iron flexible joint 4 due to the dissimilar metal contact corrosion is prevented by inserting an annular first insulation packing 50 between an upper end flange part 20 of a stainless steel sleeve 2 and an abutting face 41 provided at the deep end of a downward receptacle 40 of the cast iron flexible joint 4 to thereby avoid the contact of an upper face of the flange part 20 with the abutting face 41. Also, the damage of the cast iron flexible joint 4 due to the dissimilar metal contact corrosion is prevented by providing an annular second insulation packing 51 covering an outer periphery of the flange part 20 to thereby avoid the contact of the outer peripheral face of the flange part 20 with an inner peripheral face of the downward receptacle 40. Furthermore, a third insulation packing 53 insulating dissimilar metals is inserted in a fastening mechanism 45 to prevent the damage of the fastening mechanism 45 and the cast iron flexible joint 4 due to the dissimilar metal contact corrosion.SELECTED DRAWING: Figure 1

Description

  The present invention relates to drainage pipes that use existing pipes, and more particularly, to drainage pipes that use existing pipes that can prevent contact corrosion of different metals.

  In a multi-story apartment house (high-rise house), existing drainage pipes extend from the roof to the residential drainage on each floor and extend to, for example, drainage grooves on the ground. In order to shorten the construction period and keep the construction costs low when renewing this aging drain pipe over time, the existing pipe made by reusing the remaining cut portion of the steel pipe left from the existing drain pipe was used. A drainage pipe is provided (see, for example, Patent Document 1). This drain pipe is shown in FIGS.

  FIG. 4 is an explanatory view showing the basic structure of the existing drainage pipe. In this figure, the existing drainage pipes 100 that pass through the residential areas of each floor and pass through the slab S are indicated by broken lines bl1 and bl2. The steel pipe 101 above the broken line bl2 and the existing joint 102 and the steel pipe 101 below the broken line bl1 and the existing joint 102 are removed, and the upper end faces the residential area above the slab S. The short pipe 1 which consists of the cutting | disconnection residual member of the existing steel pipe which faced the living area below the slab S is ensured. In addition, scales and other foreign matters adhering to the inner surface of the tube wall of the short tube 1 are removed by cleaning the tube.

  A stainless steel cylindrical sleeve 2 shown in FIG. 5 has a first annular gap 3 (see FIG. 6) and is inserted into the short tube 1 from above. The sleeve 2 is provided with a flange portion 20 having an enlarged diameter substantially equal to the outer diameter of the short tube 1 at the upper end thereof, and is inserted into the short tube 1 with a fit continuously immediately below the flange portion 20. The first annular gap between the straight portion 21 that is formed, the guide portion 22 that is an upward-diameter taper that is continuous immediately below the straight portion 21, and the inner surface of the short tube 1 that is continuous immediately below the guide portion 22. 3, and a flange portion 20 is suspended from the upper end of the short pipe 1 via an annular holding packing 24 made of synthetic rubber, and a lower end portion of the main portion 23. The vicinity of the upper side protrudes below the short tube 1 as an extension 23a.

  On the upper side of each short pipe 1, as shown in FIG. 6, the upper end portion of the short pipe 1 including the flange portion 20 of the sleeve 2 and the annular holding packing 24 is secondly connected to the downward receiving port 40 of the cast iron flexible joint 4. The flexible joint 4 is inserted into each short pipe 1 in a state where the upper surface of the flange portion 20 of the sleeve 2 is brought into contact with the butting surface 41 provided at the back end of the downward receiving port 40. It is connected.

  Below each short pipe 1, as shown in FIG. 7, the cast iron flexible joint 4A similar to the cast iron flexible joint 4 is used, and the lower end portion of the short pipe 1 is the upward receiving port 40A of the flexible joint 4A. Is inserted with a third annular gap 5A, and the lower end of the short pipe 1 is brought into contact with the butting surface 41A provided at the back end of the upward receiving port 40A. It is connected.

  As shown in FIG. 8, on the upper side of each short pipe 1, the lower end portion of the newly installed standpipe 7 is inserted and connected to the upward receiving port 40 </ b> A (see FIG. 6) of the flexible joint 4. On the lower side, the upper end portion of the newly installed standpipe 7 is inserted and connected to the downward receiving port 40 (see FIG. 7) of the flexible joint 4A. That is, by connecting the short pipe 1 on the ceiling side in which the sleeves 2 and 2 are inserted in the residential area of each floor and the short pipe 1 on the floor side to the new stand pipe 7 through the flexible joints 4 and 4A. Each of the sleeves 2 and 2 is connected to each other to constitute a drainage pipe 10 utilizing an existing pipe. In addition, the illustration of the water distribution pipe which guides the waste_water | drain from drainage sources, such as a bathhouse and a washroom, to this drain piping 10 is abbreviate | omitted.

  However, in the drainage pipe 10 using the existing pipe, as shown in FIG. 6, the upper surface of the flange portion 20 at the upper end of the stainless steel sleeve 2 is a butting surface 41 provided at the far end of the downward receiving port 40 in the cast iron flexible joint 4. Therefore, the cast iron flexible joint 4 is damaged by the contact corrosion of different metals. Further, if a minute relative eccentricity occurs between the axis of the short pipe 1 including the sleeve 2 and the axis of the flexible joint 4 due to an earthquake or aged deterioration, or a relative inclination occurs in each axis due to the bending, The outer peripheral surface of the flange portion 20 comes into contact with the inner surface of the downward receiving port 40 of the cast iron flexible joint 4, and the cast iron flexible joint 4 is damaged by the dissimilar metal contact corrosion. Further, the drainage pipe (sewage) flowing down the drainage pipe 10 utilizing the existing pipe passes through the fourth annular gap 3A and the first annular gap 3 shown in FIG. When the distance between the inner circumference of the sleeve 2 and the outer circumference of the straight portion 21 of the sleeve 2 is reached, the short tube 1 and the straight portion 21 come into contact with each other in the electrolyte (in the drainage). The upper end is damaged.

  On the other hand, there is a drainage pipe 10 that utilizes existing pipes shown in FIGS. 9 to 12 as a drainage pipe that utilizes existing pipes that are conventionally known. The drain pipe 10 will be described with the same reference numerals assigned to the same or corresponding parts as the drain pipe 10 utilizing the existing pipe of Patent Document 1.

  The drainage pipe 10 utilizing the existing pipe shown in FIG. 9 is a cut remaining member of the existing steel pipe provided through the slabs S partitioning the residential area of each floor and positioning the upper and lower ends near each slab S. As shown in FIGS. 10 and 11, the short pipe 1 and the flange portion 20 provided at the upper end portion and having a diameter approximately equal to the outer diameter of the short pipe 1 have an outer diameter of the short pipe 1 and the flange portion. It is made of synthetic rubber slightly smaller than 20 and is suspended and held at the upper end of each short pipe 1 via an annular holding packing 24 and is inserted into each short pipe 1 from above with a first annular gap 3. And a stainless steel sleeve 2 in which an extending portion 23a is extended below each short tube 1. As with the sleeve 2 of the above-mentioned Patent Document 1, the sleeve 2 has a straight portion 21 inserted into the short pipe 1 with a fitting structure that is continuous immediately below the flange portion 20, and an upward direction that is directly below the straight portion 21. The guide portion 22 is formed of a taper having an enlarged diameter, and has a long main portion 23 that is continuous immediately below the guide portion 22 and that forms the first annular gap 3 with the inner surface of the short tube 1.

  On the upper side of each short pipe 1, the upper end portion of the short pipe 1 including the flange portion 20 of the sleeve 2 and the annular holding packing 24 has the second annular gap 5 in the downward receiving port 40 of the cast iron flexible joint 4. The flexible joint 4 is connected to each short pipe 1 by bringing the upper surface of the flange portion 20 of the sleeve 2 into contact with the butting surface 41 provided at the back end of the downward receiving port 40. This connection state is obtained by elastically deforming the annular lock packing 6 made of synthetic rubber fitted near the upper end portion of the short tube 1 by fastening of the fastening mechanism 45 provided on the flexible joint 4 side. It is held by pressing it strongly against the outer periphery.

  Specifically, the fastening mechanism 45 includes a lower flange portion 42 projecting radially outward at a lower end portion of the downward receiving port 40, and a lower flange portion 42 that is externally fitted to the short pipe 1 to freely move in the axial direction. The lower flange 43 is opposed to each other on the lower side, and the lower flange portion 42 and the loose flange 43 are connected to each other, and a fastening member 44 made of steel or stainless steel bolts and nuts. Therefore, the lock packing 6 is compressed in the axial direction by fastening of the fastening member 44, and the inner periphery thereof is strongly elastically pressed against the outer periphery of the short tube 1, so that the relative movement in the axial direction between the downward receiving port 40 and the short tube 1 is achieved. The upper end of each short tube 1 is flexible in a state in which a minute relative eccentricity and a minute relative inclination between the axis of the short tube 1 including the sleeve 2 and the axis of the flexible joint 4 can be allowed. A joint 4 is connected.

  Below each short pipe 1, as shown in FIGS. 10 and 12, the upper end of the newly established pipe 7 has a fourth annular gap 3 </ b> A and an extension 23 a of the sleeve 2 is inserted. The lower end of the short pipe 1 and the upper end of the vertical pipe 7 are inserted and connected to the cast iron union joint 9 in a state of being opposed to each other. As a result, the first annular gap 3 and the fourth annular gap 3A communicate with each other. The newly established pipe 7 is composed of a steel pipe 7b having a resin lining layer 7a formed on the inner surface. The outer diameter of the short pipe 1 and the outer diameter of the newly established pipe 7 are set to be equal, and the thickness of the newly established pipe 7 is set to be slightly larger than the thickness of the short pipe 1.

  On the upper side of each short pipe 1, the lower end portion of the newly established pipe 7 is inserted into the upward receiving port 40A of the flexible joint 4 with the third annular gap 5A and the upward receiving port 40A as shown in FIG. The flexible joint 4 is connected to each vertical pipe 7 by bringing the lower end of the vertical pipe 7 into contact with the butting surface 41A provided at the back end of the vertical pipe 7. This connection state is obtained by elastically deforming the annular lock packing 6 made of synthetic rubber fitted near the lower end portion of the vertical pipe 7 by fastening of a fastening mechanism 45A provided on the flexible joint 4 side. It is held by pressing it strongly against the outer periphery. The fastening mechanism 45A includes an upper flange portion 42A that projects radially outward at the upper end of the upward receiving port 40A, and a loosely-fitted outer tube 7 that is axially movable and faces the upper flange portion 42A on the upper side. The flange 43A and the upper flange portion 42A are composed of a fastening member 44A made of steel or stainless steel bolts and nuts that connect the loose flange 43A. Accordingly, the lock packing 6 is compressed in the axial direction by fastening the fastening member 44A, and the inner periphery thereof is strongly elastically pressed against the outer periphery of the upright tube 7, whereby the upward movement of the upward receiving port 40A and the upright tube 7 in the axial direction. And the flexible joint 4 is connected to the upper end of each vertical pipe 7 in a state where a slight relative eccentricity and a slight relative inclination between the axis of the vertical pipe 7 and the axis of the flexible joint 4 can be allowed. Is done.

  As shown in FIGS. 10 and 12, the cast iron union joint 9 includes a cylindrical main body 90 and a fastening mechanism 92 provided on the outer peripheral side of the upper and lower ends (both ends in the axial direction) of the cylindrical main body 90. 93 and an elastic lock packing 94 made of a synthetic rubber that is elastically deformed and reduced in diameter by fastening of the fastening mechanisms 92 and 93, and is elastically restored to a natural state and released in diameter by releasing the fastening of the fastening mechanisms 92 and 93. 95.

  The cylindrical main body 90 includes an insertion passage 91 that vertically penetrates with a uniform inner diameter slightly larger than the outer diameter of the short pipe 1 and the standpipe 7, and the fastening mechanism 92 is an upper end portion of the cylindrical main body 90. The upper flange portion 92a projecting radially outward, the loose flange 92b facing each other on the upper side of the upper flange portion 92a, and the bolts and nuts made of steel or stainless steel connecting both the upper flange portion 92a and the loose flange 92b. The fastening mechanism 93 is composed of a lower flange portion 93a projecting radially outward at the lower end portion of the cylindrical main body portion 90 and a lower side of the lower flange portion 93a. Loose flange 93b to be connected, and a bolt or nut made of steel or stainless steel that connects both the lower flange portion 93a and the loose flange 93b. It is composed of a composed clamping member 93c.

  The annular lock packing 94 is attached to the short pipe 1 in a state of being interposed between an upward-diameter tapered surface formed at the upper end opening of the insertion passage 91 in the cylindrical main body 90 and the lower surface of the loose flange 92b. The externally fitted annular lock packing 95 is interposed between a downwardly enlarged taper surface formed at the lower end opening of the insertion passage 91 in the cylindrical main body 90 and the lower surface of the loose flange 93b. The lock packings 94 and 95 are fitted into the vertical pipe 7 so that the inner diameters of the lock packings 94 and 95 are in a natural state when the fastening mechanisms 92 and 93 are released from the loose state, and come into gentle contact with the outer peripheral surfaces of the short pipe 1 and the vertical pipe 7. The size is set to allow advancement and retreat.

  Therefore, in the residential area of each floor, first, the lower end portion of the short pipe 1 and the upper end portion of the vertical pipe 7 are respectively inserted into the insertion passage 91 of the union joint 9, and the lower end of the short pipe 1 and the upper end of the vertical pipe 7 are Are placed close to each other.

  Here, the lock packing 94 is compressed in the axial direction by fastening of the fastening member 92 c in the fastening mechanism 92, and the inner periphery thereof is strongly elastically pressed against the outer periphery of the short tube 1, whereby the union joint 9 and the short tube 1 are connected. A union joint at the lower end of each short pipe 1 in a state in which relative movement in the axial direction is impossible and a minute relative eccentricity and a minute relative inclination between the axis of the short pipe 1 and the union joint 9 can be allowed. 9 is connected. At the same time, the lock packing 95 is compressed in the axial direction by fastening of the fastening member 93c in the fastening mechanism 93, and the inner circumference thereof is strongly elastically pressed against the outer circumference of the vertical pipe 7, whereby the shaft of the union joint 9 and the vertical pipe 7 is The union joints 9 are connected to the upper ends of the vertical pipes 7 in a state in which the relative movement in the directions is impossible and a minute relative eccentricity and a slight relative inclination between the axis of the vertical pipes 7 and the axis of the union joints 9 can be allowed. Connect.

  On the other hand, the fastening member 44A of the flexible joint 4 is unscrewed and the upward receiving port 40A of the flexible joint 4 is opened in a state in which the loose flange 43A and the lock packing 6 are respectively fitted in the vicinity of the lower end portion of the vertical pipe 7. In this state, the lower end portion is inserted into the upward receiving port 40A of the flexible joint 4 while the standing tube 7 is appropriately elastically bent, and the lower end thereof is brought into contact with the butting surface 41A. Subsequently, the lock piping 6 and the loose flange 43A are lowered, the fastening member 44A is assembled, the fastening mechanism 45A is restored, and the fastening member 44A is fastened, whereby the drain pipe 10 utilizing the existing pipe shown in FIG. Composed. Moreover, in the residential area of each floor, the downstream end part of the distribution pipe P which guides the waste_water | drain from drainage sources (illustration omitted), such as a bathhouse and a washroom, is connected to the waste_water | drain inflow port 46 provided in the flexible joint 4. FIG. .

  However, even in the drainage pipe 10 using the existing pipe, as shown in FIG. 11, the upper surface of the flange portion 20 at the upper end of the stainless steel sleeve 2 is provided at the back end of the downward receiving port 40 in the cast iron flexible joint 4. Therefore, the cast iron flexible joint 4 is damaged by the different metal contact corrosion. Further, if a minute relative eccentricity occurs between the axis of the short pipe 1 including the sleeve 2 and the axis of the flexible joint 4 due to an earthquake or aged deterioration, or a relative inclination occurs in each axis due to the bending, The outer peripheral surface of the flange portion 20 comes into contact with the inner surface of the downward receiving port 40 of the cast iron flexible joint 4, and the cast iron flexible joint 4 is damaged by the dissimilar metal contact corrosion. Further, the waste water (sewage) flowing down the drain pipe 10 passes through the fourth annular gap 3A and the first annular gap 3 shown in FIG. 12, and the short pipe 1 having the fitting structure shown in FIG. When it reaches between the inner periphery and the outer periphery of the straight portion 21 in the sleeve 2, the short tube 1 and the straight portion 21 come into contact with each other in the electrolyte (in the drainage), and the dissimilar metal contact corrosion is promoted, and the upper end of the short tube 1 is reached. The part is damaged.

  Further, a fifth annular gap 5B is formed between the inner peripheral surface of the loose flange 43 and the outer peripheral surface of the short pipe 1 in FIG. . However, if a minute relative eccentricity occurs between the axis of the short pipe 1 and the axis of the flexible joint 4 due to an earthquake or aged deterioration, or a relative inclination occurs in each axis due to bending, the outer peripheral surface of the short pipe 1 becomes loose. It contacts the inner surface of the flange 43. This is the path of electrolyte (drainage) → flexible joint 4 → downward receiving port 40 → lower flange portion 42 → clamping member 44 → loose flange 43 → short pipe 1 → sleeve 2 → electrolyte (drainage). An electric closed circuit including the mechanism 45 in the path is formed, current flows from the flexible joint 4 to the sleeve 2, and electrons flow from the flexible joint 4 → the downward receiving port 40 → the lower flange portion 42 → the clamping member 44 → loose. It flows along the route of flange 43 → short pipe 1 → sleeve 2. As a result, the flexible joint 4 is ionized and dissolved in the electrolyte (drainage) to cause a state where corrosion is accelerated. That is, dissimilar metal contact corrosion occurs between the sleeve 2 and the flexible joint 4.

Japanese Patent No. 3677481

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a drainage pipe using an existing pipe that achieves a life extension by preventing the contact corrosion of dissimilar metals.

In order to achieve the above-mentioned object, the drainage pipe using the existing pipe according to the present invention is provided by penetrating each slab partitioning the residential area for each floor and positioning the upper and lower ends near each slab. In addition, the short pipe formed by the remaining cut portion of the existing steel pipe and the first annular gap are inserted into the respective short pipes from above, and the flange portion provided at the upper end is connected to each of the short pipes via the annular holding packing. A stainless steel sleeve suspended from the upper end of the tube,
On the upper side of each short pipe, the upper end portion of the short pipe including the flange portion of the sleeve and the annular holding packing is inserted into the downward receiving port of the flexible joint made of a metal different from the sleeve with a second annular gap, And the flexible joint is fastened and connected to each short pipe by a fastening mechanism by bringing the flange part into contact with the butting surface provided at the back end of the downward receiving port,
On the lower side of each short pipe, the lower end of the short pipe and the upper end of the newly established pipe are inserted and connected to the union joint in a state of facing each other,
The lower end portion of the vertical pipe is a drainage pipe using an existing pipe inserted and connected to the upward receiving port of the flexible joint.
An annular first insulating packing that insulates dissimilar metals is interposed between the flange portion of the sleeve and a butting surface provided at the back end of the downward receiving port of the flexible joint. Yes.

  According to the drainage pipe using the existing pipe having the above-described configuration, the annular first insulating packing allows contact between the upper surface of the upper end flange portion of the stainless steel sleeve and the butted surface of the lower end of the cast iron flexible joint. Therefore, it is possible to prevent the cast iron flexible joint from being damaged by the contact corrosion of different metals and to extend the life of the drainage pipe using the existing pipe.

  The drainage pipe using the existing pipe according to the present invention includes an annular second insulating packing that covers the outer periphery of the flange portion of the sleeve. According to this, even if a minute relative eccentricity occurs between the axis of the short pipe including the sleeve and the axis of the cast iron flexible joint due to an earthquake or aged deterioration, or the relative inclination occurs in each axis due to the bending, The second insulation packing prevents contact between the outer peripheral surface of the upper end flange portion of the stainless steel sleeve and the inner surface of the downward receiving port of the cast iron flexible joint, so that damage to the cast iron flexible joint due to dissimilar metal contact corrosion is avoided. It is possible to prevent and contribute to the extension of the life of drainage pipes using existing pipes.

  In the drainage pipe using the existing pipe according to the present invention, a third insulating packing for insulating between different metals is interposed in the fastening mechanism. According to this, since the formation of an electrical closed circuit including the fastening mechanism in the path is hindered, the cast iron flexible joint is caused by the dissimilar metal contact corrosion between the stainless steel sleeve and the cast iron flexible joint in the electrolyte (drainage). It is possible to contribute to the achievement of the extension of the life of drainage pipes utilizing existing pipes.

  In the drainage pipe using the existing pipe according to the present invention, an annular fourth insulating packing for insulating between dissimilar metals is interposed between the fastening mechanism and the short pipe. This also prevents the formation of an electrical closed circuit including the fastening mechanism in the path, so that the cast iron flexible joint is caused by dissimilar metal contact corrosion between the stainless steel sleeve and the cast iron flexible joint in the electrolyte (drainage). It is possible to contribute to the achievement of the extension of the life of drainage pipes utilizing existing pipes.

  In the drainage pipe using the existing pipe according to the present invention, an annular shut-off packing for blocking drainage into the first annular gap is sandwiched between the upper end of the vertical pipe and the lower end of the short pipe in the union joint. Is retained. According to this, it is possible to prevent drainage (sewage) flowing down in the drainage pipe from entering the first annular gap. Therefore, contact between the sleeve and the short pipe in the electrolyte (under drainage) can be avoided, and damage to the short pipe due to dissimilar metal contact corrosion can be prevented, contributing to the extension of the life of the drain pipe using the existing pipe. It becomes possible to do.

  According to the drainage pipe using the existing pipe of the present invention, it becomes possible to prevent the contact corrosion of different metals and to extend the life.

It is a longitudinal cross-sectional view of the principal part in one Embodiment of the drain piping using the existing pipe | tube which concerns on this invention. It is a longitudinal cross-sectional view which expands and partially shows one Embodiment of the interposed structure of a 1st insulating packing, a 2nd insulating packing, a 3rd insulating packing, and a 3rd insulating packing. It is a longitudinal cross-sectional view which expands and partially shows one Embodiment of interruption | blocking packing and its interposition structure. It is explanatory drawing of existing drainage piping removal. It is explanatory drawing of the state which penetrated the sleeve to the short pipe which remains as an existing pipe. It is an expanded sectional view which shows the connection structure of the upper end part of a short pipe including the flange part of a flexible joint and a sleeve in a 1st prior art example, and a standing pipe lower end part. It is an expanded sectional view which shows the connection structure of the flexible joint in the 1st prior art example, the lower end part of a short pipe, and a standing pipe upper end part. It is explanatory drawing of the drain piping which utilized the existing pipe | tube of a 1st prior art example. It is explanatory drawing of the drain piping which utilized the existing pipe of the 2nd prior art example. It is a longitudinal cross-sectional view of the principal part in a 2nd prior art example. It is a longitudinal cross-sectional view of a portion corresponding to FIG. 2 in a second conventional example. It is a longitudinal cross-sectional view of a portion corresponding to FIG. 3 in the second conventional example.

Hereinafter, preferred embodiments of drainage pipes utilizing existing pipes according to the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view of a main part in an embodiment of a drainage pipe using an existing pipe according to the present invention, and FIG. 2 is a diagram illustrating the first insulating packing, the second insulating packing, the third insulating packing, and the fourth insulating packing. FIG. 3 is an enlarged longitudinal sectional view partially showing an embodiment of the blocking packing and its interposition structure. FIG.
Note that the same parts as those in the second conventional example described with reference to FIGS.

  As shown in FIG. 1 and FIG. 2, the drainage pipe 10 utilizing the existing pipe according to the present invention is provided on the upper surface of the flange portion 20 of the stainless steel sleeve 2 and the back end of the downward receiving port 40 in the cast iron flexible joint 4. An annular first insulating packing 50 made of synthetic rubber that insulates different metals is interposed between the provided butting surface 41 and the outer periphery of the flange portion 20 and the outer periphery of the annular holding packing 24. A second insulating packing 51 made of synthetic rubber and covering the outer periphery of the upper end of the short tube 1 is provided in a form extending downwardly in the second annular gap 5.

  In the present embodiment, a structure in which the first insulating packing 50 and the second insulating packing 51 are integrally formed is used. Specifically, the first insulating packing 50 is formed of an annular body having a substantially square cross section, the upper surface of which is elastically contacted with the abutting surface 41, and the lower surface thereof is elastically contacted with the upper surface of the flange portion 20 of the stainless steel sleeve 2. The insulating packing 51 is formed in a skirt-like shape that extends downward from the outer peripheral edge of the first insulating packing 50 and extends downwardly into the second annular gap 5, and covers the outer periphery of the flange portion 20 at its upper end. In addition, the outer periphery of the annular holding packing 24 and the upper end portion of the short tube 1 and the vicinity thereof are covered with a portion below the upper end portion.

  According to the drainage pipe 10 utilizing the existing pipe having the above-described configuration, the annular first insulating packing 50 allows the upper surface of the upper end flange portion 20 of the stainless steel sleeve 2 and the back end 40 of the cast iron flexible joint 4 to be located at the back end. Since contact with the abutting surface 41 is avoided, it is possible to prevent damage to the cast iron flexible joint 4 due to contact corrosion of different metals and to extend the life of the drainage pipe 10 using existing pipes.

  In addition, even if a minute relative eccentricity occurs between the axis of the short pipe 1 including the sleeve 2 and the axis of the cast iron flexible joint 4 due to an earthquake or deterioration over time, or the relative inclination occurs in each axis due to bending, The second insulation packing 51 prevents at least the contact between the outer peripheral surface of the upper end flange portion 20 of the stainless steel sleeve 2 and the inner surface of the downward receiving port 40 of the cast iron flexible joint 4, so that it is made of cast iron due to contact corrosion of different metals. It is possible to prevent damage to the flexible joint 4 and contribute to the achievement of the life extension of the drainage pipe 10 using the existing pipe.

  On the other hand, in the drainage pipe 10 using the existing pipe according to the present invention, the fastening mechanism 45 is provided with a third insulating packing 53 that insulates different metals. The third insulating packing 53 in the present embodiment includes an upper sleeve 53A and a lower sleeve 53B made of synthetic resin. The upper sleeve 53A includes a large-diameter portion 53a1 that opens upward, and a small-diameter cylindrical portion 53a2 that extends continuously downward from the large-diameter portion 53a1, and the lower sleeve 53B includes a flange portion 53b1. A small-diameter cylindrical portion 53b2 that is provided on the upper side of the flange portion 53b1 and extends vertically upward. Therefore, first, the small diameter cylindrical portion 53a2 of the upper sleeve 53A is inserted from the upper side into the bolt insertion hole of the lower flange portion 42, and the large diameter portion 53a1 is seated on the upper surface of the lower flange portion 42, and then the lower sleeve. The small diameter cylindrical portion 53b2 of 53B is inserted into the bolt insertion hole of the loose flange 43 from below and the flange portion 53b1 is seated on the lower surface of the loose flange 43, and then a fastening member made of steel or stainless steel bolts and nuts. Tighten with 44.

  In this case, a minute relative eccentricity is generated between the axis of the short pipe 1 and the axis of the cast iron flexible joint 4 due to an earthquake or aged deterioration, or a relative inclination is generated in each axis due to the bending. Even if a part of the outer peripheral surface of 1 comes into contact with the radially inner surface of the loose flange 43, the insulating action of the third insulating packing 53 prevents the formation of the electrical closed circuit including the fastening mechanism 45 described above in the path. Achieved life extension of drainage pipe 10 utilizing existing pipes by preventing damage to cast iron flexible joints 4 due to different metal contact corrosion between stainless steel sleeve 2 and cast iron flexible joints 4 in electrolyte (drainage) It becomes possible to contribute to.

  The drainage pipe 10 utilizing the existing pipe according to the present invention is loose with a part of the outer peripheral surface of the short pipe 1 even if the fourth insulating gap 54 made of synthetic rubber is interposed in the fifth annular gap 5B. Since contact with the inner surface of the flange 43 is avoided and formation of the electrical closed circuit including the fastening mechanism 45 described above in the path is prevented, the stainless steel sleeve 2 and the cast iron flexible in the electrolyte (drainage) are prevented. It is possible to prevent damage to the cast iron flexible joint 4 due to the different metal contact corrosion with the joint 4 and to contribute to the life extension of the drainage pipe 10 using the existing pipe.

  As shown in FIG. 3, a synthetic rubber-made annular shut-off packing 52 is sandwiched and held in the union joint 9 between the upper end of the vertical pipe 7 and the lower end of the short pipe 1. The annular shut-off packing 52 includes an annular fitting portion 52a having a downward concave cross section, and an annular tongue piece 52b that is continuous with the inner peripheral wall of the annular fitting portion 52a and extends downward in the radial direction. With the portion 52a fitted on the upper end of the standpipe 7, the inner peripheral edge of the annular tongue piece 52b elastically contacts the outer periphery of the main portion 23 of the sleeve 2, and the first annular gap 3 and the fourth annular gap Communication with 3A is blocked.

  According to this, it is possible to prevent the drainage (sewage) flowing down in the drainage pipe 10 utilizing the existing pipe from entering the first annular gap 3 through the fourth annular gap 3A. Thereby, the contact in the electrolyte (in the waste water) of the fitting part between the straight portion 21 and the short tube 1 in the sleeve 2 shown in FIG. 2 is avoided, and the short tube 1 is prevented from being damaged by different metal contact corrosion. It becomes possible to contribute to the achievement of the life extension of the drainage pipe 10 using the existing pipe. Further, if the sleeve 2 is inserted into the short tube 1 with a resin tape (not shown) wound around the outer periphery of the straight portion 21 in advance, contact between the straight portion 21 and the short tube 1 can be avoided. Therefore, the effect of preventing the contact corrosion of different metals can be further enhanced.

  In addition, although the said embodiment demonstrated the example which integrally molded the 1st insulating packing 50 and the 2nd insulating packing 51, even if it shape | molds the 1st insulating packing 50 and the 2nd insulating packing 51 separately, respectively. Good.

  The drainage pipe 10 utilizing the existing pipe according to the present invention is not limited only to the above-described embodiment, and can be structurally modified as long as it does not depart from the spirit and technical idea thereof.

  The drainage pipe using the existing pipe of the present invention is useful for shortening the construction period and reducing the cost and constructing the drainage pipe when renewing the existing drainage pipe in a multi-story apartment building (high-rise house) over time. is there.

DESCRIPTION OF SYMBOLS 1 Short pipe 2 Sleeve 20 Flange part 21 Straight part 23a Extension part 24 Annular holding packing 3 First annular gap 4 Flexible joint 40 Downward receiving port 40A Upward receiving port 41 Butting surface 5 Second annular gap 7 Standing pipe (newly installed) Vertical pipe)
9 Union joint 10 Drainage pipe 50 utilizing existing pipe 50 Annular first insulating packing 51 Annular second insulating packing 52 Annular shut-off packing 53 Third insulating packing 54 Annular fourth insulating packing

Claims (5)

A short pipe consisting of a remaining cut portion of an existing steel pipe that passes through each slab that divides the residential area of each house into each floor and positions the upper and lower ends near each slab, and has a first annular gap A stainless steel sleeve that is inserted into each short pipe from above and a flange portion provided on the upper end is suspended and held on the upper end of each short pipe via an annular holding packing,
On the upper side of each short pipe, the upper end portion of the short pipe including the flange portion of the sleeve and the annular holding packing is inserted into the downward receiving port of the flexible joint made of a metal different from the sleeve with a second annular gap, And the flexible joint is fastened and connected to each short pipe by a fastening mechanism by bringing the flange part into contact with the butting surface provided at the back end of the downward receiving port,
On the lower side of each short pipe, the lower end of the short pipe and the upper end of the newly established pipe are inserted and connected to the union joint in a state of facing each other,
The lower end portion of the vertical pipe is a drainage pipe using an existing pipe inserted and connected to the upward receiving port of the flexible joint.
An annular first insulating packing for insulating between dissimilar metals is interposed between the flange portion of the sleeve and a butting surface provided at the back end of the downward receiving port of the flexible joint. Drainage piping using existing pipes. In the drainage pipe using the existing pipe described in claim 1,
A drainage pipe using an existing pipe provided with an annular second insulating packing covering the outer periphery of the flange portion of the sleeve. In the drainage pipe using the existing pipe described in claim 1 or claim 2,
A drainage pipe using an existing pipe in which a third insulating packing for insulating different metals is interposed in the fastening mechanism. In the drainage pipe using the existing pipe according to any one of claims 1 to 3,
A drainage pipe using an existing pipe in which an annular fourth insulating packing for insulating between dissimilar metals is interposed between the fastening mechanism and the short pipe. In the drainage pipe using the existing pipe according to any one of claims 1 to 4,
A drainage pipe using an existing pipe in which an annular shut-off packing for blocking drainage intrusion into the first annular gap is sandwiched and held between an upper end of a vertical pipe and a lower end of a short pipe in the union joint.

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