JP6420108B2 - Piping connection method - Google Patents

Description

The present invention relates to a pipe, such as the discharge pipe of the pump to the pipe connection methods for connecting to the existing pipe.

  When installing the pump, it is necessary to strictly adjust not only the level and verticality of the rotating body such as the rotating shaft and impeller, but also the level and verticality of the impeller casing and discharge pipe in which the impeller is accommodated. It is said. This is to prevent the occurrence of abnormal vibration when the rotating body is rotating by stabilizing the installation state of the pump.

  When the discharge pipe of the pump installed in this way is connected to the existing piping of the pump station, the level and verticality of the existing piping may be shifted from the level and verticality of the discharge pipe. . For example, when the flange of the existing pipe is inclined with respect to the flange of the discharge pipe, the pump discharge pipe cannot be correctly connected to the existing pipe. Even when the distribution of the flange bolt holes of the existing pipe is deviated from the distribution center of the flange bolt holes of the discharge pipe, the flange of the discharge pipe cannot be correctly connected to the flange of the existing pipe. In the present specification, such a deviation in level and verticality of existing piping and a deviation in flange bolt holes are referred to as installation errors.

  As countermeasures against installation errors, conventionally, a short pipe is provided between the discharge pipe and the existing pipe, and the short pipe is processed so that the flange of the short pipe matches the flange of the existing pipe. Specifically, in a state where the flange of the short pipe is finely adjusted to match the flange of the existing pipe, the flange is temporarily welded to the short pipe at the site, and the short pipe with the flange temporarily welded is brought back to the factory. The welding of was completed. Such a short pipe is generally called “current pipe”.

  However, in such an existing pipe construction method, since the temporarily welded short pipe is brought back to the factory and regular welding is performed, the construction period of the pump is increased and the installation cost is increased. In particular, if the current pipe is a lining pipe with nylon coating or the like applied to the inner surface of the pipe, the coating can be performed only after the regular welding is completed, so the pump construction period will be greatly extended. .

  There is a method of absorbing an installation error by using a loose flange pipe as disclosed in Patent Document 1 instead of the current joint pipe. However, the loose flange pipe can absorb the displacement in the longitudinal direction of the pipe, but it is difficult to absorb the installation error such as the inclination of the flange surface and the displacement of the flange bolt hole. The loose flange tube uses a rubber seal member such as an O-ring. Therefore, when there is a large installation error, only a part of the seal member is deformed, so that it is difficult to ensure liquid tightness with the loose flange pipe.

  Patent Document 2 discloses a technique for connecting pipes in which installation errors have occurred using an expansion / contraction flexible pipe joint. However, this flexible expansion joint has a complicated structure and is very expensive. Therefore, when this expansion / contraction flexible pipe joint is employed, the economic effect is small. Moreover, the expansion-contraction flexible pipe joint of Patent Document 2 uses a rubber seal member such as a molded packing. Therefore, when there is a large installation error, only a part of the seal member is deformed, so that it is difficult to ensure liquid-tightness with the expansion / contraction flexible pipe joint described in Patent Document 2.

Japanese Patent No. 5306864 JP-A-5-164279

The present invention has been made in view of the above circumstances, and even if there is an installation error between the connected pipes, the pipe connection can connect the pipes only by on-site work and can ensure liquid tightness. an object of the present invention is to provide an mETHODS.

  One aspect of the present invention for solving the above-described problem is that the first pipe is connected to the second pipe so that the small-diameter flange portion of the first pipe and the flange of the second pipe face each other. Between the large-diameter flange portion of the first pipe and the flange of the second pipe, which are adjacent to the small-diameter flange section, and the flange of the second pipe. An elastic spacer is sandwiched between the first pipe and the large diameter flange portion and the flange of the second pipe in a state where the elastic spacer is sandwiched between the first pipe and the second pipe. A first pipe formed in the elastic spacer is formed by connecting a second pipe, attaching a rubber sheet to the inner surfaces of the first pipe and the second pipe so as to close an inner opening end of the gap. While injecting resin into the gap through the hole, After removing air from the gap through the second through hole formed in the elastic spacer, the gap is filled with resin, the resin in the gap is cured, and after the resin is cured, the rubber sheet And a piping connection method, wherein the elastic spacer is removed.

In a preferred aspect of the present invention, after removing the rubber sheet and the elastic spacer, between the cured resin and the small diameter flange portion, or between the cured resin and the flange of the second pipe. The sealing material is inserted.
In a preferred aspect of the present invention, the large-diameter flange portion is configured as an idle flange separated from the small-diameter flange portion.
In a preferred aspect of the present invention, the rubber sheet is pressed against the inner surfaces of the first pipe and the second pipe by a rubber sheet fixing jig after the rubber sheet is attached.

In a preferred aspect of the present invention, the first through hole is formed at a lowermost portion of the elastic spacer, and the second through hole is formed at an uppermost portion of the elastic spacer.
In a preferred aspect of the present invention, a hollow pipe is inserted into the first through hole and the second through hole.
In a preferred aspect of the present invention, the resin is an epoxy resin.
In a preferred aspect of the present invention, the first pipe is a short pipe connected to a discharge pipe of a pump, and the second pipe is an existing pipe arranged in a pump station.

One reference example of the present invention includes a small-diameter flange portion facing a flange of an existing pipe, a short pipe having a large-diameter flange section adjacent to the small-diameter flange section, and a gap between the small-diameter flange section and the flange of the existing pipe. And a fastening member that fastens the cured resin filled in the gap and the flange of the existing pipe and the flange of the existing pipe.

A preferred embodiment of the above reference example further includes a sealing material disposed between the cured resin and the small-diameter flange portion or between the cured resin and a flange of the existing pipe. .
In a preferred aspect of the above reference example, the large-diameter flange portion is configured as an idle flange separated from the small-diameter flange portion.
In a preferred embodiment of the above reference example , the cured resin is a cured epoxy resin.
In a preferred aspect of the above reference example, the short pipe extends horizontally.

  According to the present invention, even if there is an installation error between the first pipe (short pipe) and the second pipe (existing pipe), the gap between the small diameter flange portion and the flange of the second pipe is set. The installation error can be absorbed by the filled resin. Since the resin can be injected into the gap at the site where the piping is connected, the first piping can be connected to the second piping having an installation error with respect to the first piping in the field work. . Further, the cured resin is in close contact with the small-diameter flange portion and the flange of the second pipe. Therefore, since the cured resin achieves sealing of the fluid flowing in the first pipe and the second pipe, the liquid tightness of the connecting portion between the first pipe and the second pipe is ensured. Can do.

It is a schematic sectional drawing which shows an example of the vertical shaft pump provided with the pipe connected by the pipe connection method which concerns on one Embodiment of this invention. It is a schematic diagram which shows the state by which the 1st piping was arrange | positioned so that the flange of 1st piping might face the flange of 2nd piping. It is a schematic diagram which shows the state by which the large diameter flange part of 1st piping and the flange of 2nd piping were fastened by the fastening member. It is a schematic diagram which shows the state by which the rubber sheet was affixed on the inner surface of 1st piping and 2nd piping. It is the top view which showed an example of the rubber sheet fixing jig. It is the sectional view on the AA line of FIG. 4 before the clearance gap between the flange of 1st piping and the flange of 2nd piping is satisfy | filled with resin. It is the partial exploded perspective view which showed a mode that resin was inject | poured into a clearance gap from a hollow pipe. It is the sectional view on the AA line of FIG. 4 after the clearance gap between the flange of 1st piping and the flange of 2nd piping is satisfy | filled with resin. It is a schematic diagram which shows the connection part of 1st piping and 2nd piping after resin hardens | cures. It is a schematic diagram which shows the structure by which the large diameter flange part was integrally formed with the small diameter flange part. It is a schematic diagram which shows the sealing material pinched | interposed between hardened resin and a small diameter flange part. It is a flowchart for demonstrating one Embodiment of the piping connection method of this invention.

Hereinafter, embodiments of the pipe connection method and the pipe connection structure of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic cross-sectional view showing an example of a vertical shaft pump having pipes connected by a pipe connection method according to an embodiment of the present invention. The vertical shaft pump shown in FIG. 1 is connected to an impeller casing 1 having a suction bell mouth 1a and a pump bowl 1b, a suspension pipe 2 for suspending the impeller casing 1 in a suction water tank 30, and an upper end of the suspension pipe 2. The discharge curved pipe 3, the discharge pipe 4 connected to the discharge side of the discharge curved pipe 3, the impeller 10 accommodated in the impeller casing 1, the rotary shaft 15 to which the impeller 10 is fixed, and the rotary shaft And a driving machine 25 for rotating the motor 15. The discharge pipe 4 extends horizontally.

  The suspension pipe 2 extends downward through an insertion hole 7 formed in the pump installation floor 6 in the upper part of the suction water tank 30 into which water to be pumped flows, and a suspension base 8 provided at the upper end of the suspension pipe 2. To the pump installation floor 6. The rotating shaft 15 extends in the vertical direction through the discharge curved pipe 3, the suspension pipe 2, and the impeller casing 1. The rotating shaft 15 is rotatably supported by the underwater bearing 17, the intermediate bearing 18, and the outer bearing 19.

  The suction bell mouth 1a opens downward in the suction water tank 30, and the upper end of the suction bell mouth 1a is fixed to the lower end of the pump bowl 1b. The impeller 10 is fixed to the lower end of the rotating shaft 15, and the impeller 10 and the rotating shaft 15 rotate integrally. A plurality of guide vanes 16 are arranged on the secondary side (discharge side) of the impeller 10. These guide vanes 16 are fixed to the inner peripheral surface of the pump bowl 1b. The underwater bearing 17 that rotatably supports the rotating shaft 15 is accommodated in the pump bowl 1 b and is located above the impeller 10. Similarly, an intermediate bearing 18 that rotatably supports the rotary shaft 15 is accommodated in the suspension pipe 2, and an outer bearing 19 is fixed to the discharge curved pipe 3 outside the discharge curved pipe 3.

  The discharge pipe 4 is provided with a discharge valve 24. The discharge valve 24 is closed when the vertical pump drive unit 25 is not in operation, and is configured such that when the drive unit 25 is started, the discharge valve 24 is opened by a control unit (not shown). Yes. In the present embodiment, the discharge valve 24 is composed of an electric valve. The drive unit 25 and the discharge valve 24 are connected to a control unit (not shown), and the control unit controls the start and stop of the drive unit 25 and the opening / closing operation of the discharge valve 24.

  The discharge water tank 31 from which the water whose pressure has been increased by the rotation of the impeller 10 of the vertical shaft pump is discharged is provided with an existing pipe 51 that penetrates the wall surface 50 of the discharge water tank 31 and opens in the discharge water tank 31. A flap valve 23 as a backflow prevention valve for preventing a backflow of water from the discharge water tank 31 is provided at the discharge side end of the existing pipe 51. Since the existing pipe 51 is installed before the vertical pump is installed, an installation error has occurred with respect to the discharge pipe 4 of the vertical pump that is installed by strictly managing the level and verticality. There is a case. Therefore, in the present embodiment, a short pipe 40 is provided between the discharge pipe 4 and the existing pipe 51, and the short pipe 40 and the existing pipe 51 are connected by a pipe connection method described below to absorb installation errors. To do. As a result, the discharge pipe 4 can be connected to the existing pipe 51 via the short pipe 40.

  In the present embodiment, first, a short pipe (hereinafter referred to as a first pipe) 40 connected to the discharge pipe 4 of the pump and an existing pipe 51 (hereinafter referred to as a second pipe) arranged in the pump station. 2, the first pipe 40 is disposed so that the flange 41 of the first pipe 40 faces the flange 52 of the second pipe 51 as shown in FIG. 2. Both the first pipe 40 and the second pipe 51 extend horizontally. The flange 41 of the first pipe 40 includes a small diameter flange portion 43 facing the flange 52 of the second pipe 51 and a large diameter flange portion 44 having a larger diameter than the small diameter flange portion 43. The large diameter flange portion 44 is adjacent to the small diameter flange portion 43. The large diameter flange portion 44 is configured as an idle flange separated from the small diameter flange portion 43, and can move to some extent with respect to the small diameter flange portion 43.

  The surface of the small-diameter flange portion 43 that faces the flange 52 of the second pipe 51 constitutes a flange seal surface 43 a for preventing leakage of fluid flowing through the first pipe 40 and the second pipe 51. . Similarly, the surface of the flange 52 of the second pipe 51 that faces the small-diameter flange portion 43 is a flange seal surface 52a for preventing leakage of fluid flowing through the first pipe 40 and the second pipe 51. Configure. The outer diameter of the large diameter flange portion 44 is equal to the outer diameter of the flange 52 of the second pipe 51.

  Next, as shown in FIG. 3, the large-diameter flange portion 44 and the flange 52 of the second pipe 51 have a gap S between the small-diameter flange portion 43 and the flange 52 of the second pipe 51. The large-diameter flange portion 44 and the flange 52 of the second pipe 51 are fastened by the fastening member 54 with the elastic spacer 46 interposed therebetween. The elastic spacer 46 has an annular shape.

  The large diameter flange portion 44 is provided with a plurality of through holes 58 into which the fastening members 54 are inserted. The flange 52 and the elastic spacer 46 of the second pipe 51 are also provided with a plurality of through holes 59 and through holes 47 into which the fastening members 54 are inserted. The fastening member 54 includes a bolt 55 and a nut 56 that is screwed into the bolt 55. When the nut 56 is rotated in the tightening direction with the bolt 55 inserted into the through hole 58, the through hole 47, and the through hole 59, the large diameter flange portion 44 and the flange 52 of the second pipe 51 are fastened. . As a result, the first pipe 40 is connected to the second pipe 51.

  The elastic spacer 46 sandwiched between the large-diameter flange portion 44 and the flange 52 of the second pipe 51 is a seal at least a part of which is made of an elastic material. For example, the elastic spacer 46 is a sponge gasket. As the elastic spacer 46, a structure in which an annular spacer made of steel or a cured resin and an annular sponge gasket may be employed. In this case, the large-diameter flange portion 44 contacts the annular spacer, and the flange 52 of the second pipe 51 contacts the sponge gasket.

  The elastic spacer 46 is disposed so as to surround the small diameter flange portion 43. The elastic spacer 46 has a width (thickness) larger than the width (thickness) of the small diameter flange portion 43 so that a gap S is formed between the small diameter flange portion 43 and the flange 52 of the second pipe 51. As shown in FIG. 3, since the horizontality and verticality of the second pipe 51 are shifted from the horizontality and verticality of the first pipe 40, the upper width W1 of the gap S is equal to the lower width W2. Is different. For example, when the upper width W1 of the gap S is 10 mm, the lower width W2 of the gap S is 5 mm.

  Next, as shown in FIG. 4, the rubber sheet 61 is affixed to the inner surfaces of the first pipe 40 and the second pipe 51, and the inner opening end of the gap S is closed by the outer surface of the rubber sheet 61. The outer opening end of the gap S is closed by the elastic spacer 46 described above. The elastic spacer 46 and the rubber sheet 61 are provided in order to prevent a resin (described later) injected into the gap S from leaking out of the gap S. The rubber sheet 61 has a width wider than the width of the gap S formed between the small diameter flange portion 43 of the first pipe 40 and the flange 52 of the second pipe 51. The rubber sheet 61 has a thickness of 3 mm, for example. When the inner opening end of the gap S is closed over the entire circumference by the rubber sheet 61, the gap S is formed by the small diameter flange portion 43, the flange 52 of the second pipe, the elastic spacer 46, and the rubber sheet 61. It becomes a sealed space.

  After the rubber sheet 61 is pasted, the rubber sheet 61 is preferably pressed against the inner surfaces of the first pipe 40 and the second pipe 51 by a rubber sheet fixing jig. FIG. 5 is a plan view showing an example of the rubber sheet fixing jig 70. Hereinafter, the rubber sheet fixing jig 70 will be described with reference to FIG.

  A rubber sheet fixing jig 70 shown in FIG. 5 has an outer ring 71 that connects steel sheets in an annular shape, and an annular inner ring 72 that is arranged inside the outer ring 71. A plurality of inner ring bolt members 73 extend radially outward from the inner ring 72, and a plurality of outer ring bolt members 75 extend radially inward from the outer ring 71 corresponding to the position of the inner ring bolt member 73. The inner ring bolt member 73 and the outer ring bolt member 75 are provided with threads, and a length adjusting nut 74 is screwed onto these threads. Therefore, the inner ring bolt member 73 is connected to the corresponding outer ring bolt member 75 by the length adjusting nut 74.

  When the length adjusting nut 74 is turned in one direction, the thread of the inner ring bolt member 73 and the outer ring bolt member 75 is configured such that the distance between the inner ring bolt member 73 and the outer ring bolt member 75 extends. When the length adjusting nut 74 is turned in the reverse direction, the distance between the inner ring bolt member 73 and the outer ring bolt member 75 is reduced.

  By rotating the length adjusting nut 74 in the reverse direction so that the outer diameter of the outer ring 71 is smaller than the inner diameters of the first pipe 40 and the second pipe 51, the rubber sheet 61 is attached to the rubber sheet fixing jig 70. It can be carried to the position where it is affixed. The length adjusting nut 74 is rotated in the first pipe 40 and the second pipe 51 to increase the diameter of the outer ring 71, and the rubber sheet 61 is connected to the first pipe 40 and the second pipe by the outer peripheral surface of the outer ring 71. Press against the inner surface of the pipe 51.

  Thus, since the rubber sheet 61 is pressed against the inner surfaces of the first pipe 40 and the second pipe 51, even if high-pressure resin is injected into the gap S that is a sealed space, There is no leakage to the inner surface side of the pipe 40 and the second pipe 51. The rubber sheet fixing jig 70 is not limited to the example shown in FIG. For example, as the rubber sheet fixing jig 70, a water stop plug having an outer diameter substantially the same as the inner diameter of the first pipe 40 and the second pipe 51 may be used. Such a water stop plug is commercially available.

  6 is a cross-sectional view taken along the line AA of FIG. 4 before the resin is injected into the gap S. FIG. As shown in FIG. 6, a plurality of through holes 80 communicating with the gap S are provided in the elastic spacer 46. All the through holes 80 extend from the outer peripheral surface to the inner peripheral surface of the elastic spacer 46 and communicate with the gap S. In the embodiment shown in FIG. 6, two through holes 80 are provided in the uppermost part and the lowermost part of the annular elastic spacer 46. The resin is injected from a through hole 80 provided in the lowermost part, and the uppermost through hole 80 is used as an air vent hole.

  When the direction of the X-axis extending horizontally through the center point O of the elastic spacer 46 is 0 °, the two through holes 80 of the embodiment shown in FIG. 6 are at the 90 ° position and the 270 ° position. Is provided. Three or more through holes 80 may be provided. For example, the four through holes 80 may be provided at a 45 ° position, a 90 ° position, a 135 ° position, and a 270 ° position. Alternatively, six through holes 80 may be provided at a 45 ° position, a 90 ° position, a 135 ° position, a 225 ° position, a 270 ° position, and a 315 ° position.

  In any case, the resin is injected from the lowermost through hole 80 at a position of 270 °, and the other through holes 80 are used as an air vent hole and a resin filling confirmation hole. That is, when the resin flows out from the through hole 80, the operator can confirm that the resin has reached the position of the through hole 80. If three or more through-holes 80 are provided in this way, the position where the resin is poured into the gap S can be confirmed in order from the bottom, so that the resin can be reliably filled in the entire gap S. Become. Therefore, a highly reliable resin filling operation can be performed.

  Before the elastic spacer 46 is sandwiched between the large-diameter flange portion 44 and the flange 52 of the second pipe 51, a through hole 80 may be formed in the elastic spacer 46 in advance, or the elastic spacer 46 may be a large-diameter flange. The through hole 80 may be formed in the elastic spacer 46 while being sandwiched between the portion 44 and the flange 52 of the second pipe 51.

  FIG. 7 is a partially exploded perspective view showing a state in which resin is injected into the gap S from the hollow pipe 81 inserted into the through hole 80. In FIG. 7, illustration of the rubber sheet fixing jig 70 is omitted. 8 is a cross-sectional view taken along line AA of FIG. 4 after the gap S is filled with resin. As shown in FIGS. 7 and 8, it is preferable that a hollow pipe 81 is inserted into the through hole 80. For example, the resin 60 can be easily injected into the gap S through the hollow pipe 81 inserted into the through hole 80 located at a position of 270 °. Further, when the hollow pipe 81 is inserted into the through-hole 80 at the 45 ° position, the 90 ° position, the 135 ° position, the 225 ° position, and the 315 ° position, the resin causes the hollow pipe 81 to move. Since it flows out, the operator can easily and reliably check the filling of the resin 60. By bending the hollow pipe 81 after the resin 60 has flowed out and closing the flow path inside the resin, the resin can be easily prevented from flowing out of the hollow pipe 81.

  As shown in FIG. 7, the resin 60 is injected into the gap S by a filling machine 86 such as a grease gun connected to the hollow pipe 81 via a pipe 83. As described above, the resin 60 is injected from the hollow pipe 81 inserted into the through hole 80 at the lowest position of the elastic spacer 46 (that is, at a position of 270 °). The hollow pipe 81 inserted into the through hole 80 at the highest position of the elastic spacer 46 (that is, at a position of 90 °) is used as an air vent hole. Since the gap S is sealed by the small-diameter flange portion 43, the second pipe flange 52, the elastic spacer 46, and the rubber sheet 61 except for the through hole 80, the entire gap S can be filled with the resin 60. .

  The resin 60 filled in the gap S is, for example, a two-component type epoxy resin made of a mixture of a main agent and a curing agent. This epoxy resin cures over time. After the resin 60 is cured, the elastic spacer 46 and the rubber sheet 61 are removed. FIG. 9 is a schematic diagram showing a connection portion between the first pipe 40 and the second pipe 51 after the resin is cured. In FIG. 9, the elastic spacer 46 and the rubber sheet 61 are removed. As shown in FIG. 9, a cured resin 60 is sandwiched between the small diameter flange portion 43 and the flange 52 of the second pipe 51. In this way, the resin 60 having fluidity is filled in the gap S between the small diameter flange portion 43 and the flange 52 of the second pipe 51, and then the resin 60 is cured, thereby the first pipe 40. The resin 60 can absorb any installation error of the second pipe 51 with respect to.

  Since the resin 60 can be filled in the gap S at the site where the pipe is connected, the second pipe 51 having an installation error relative to the first pipe 40 is connected to the first pipe 40 in the field work. can do. Since the cured resin 60 is in close contact with the small-diameter flange portion 43 and the flange 52 of the second pipe 51, the cured resin 60 causes the fluid flowing in the first pipe 40 and the second pipe 51 to flow. A seal that prevents leakage can be achieved. Therefore, the liquid tightness of the connection part of the 1st piping 40 and the 2nd piping 51 is securable.

  In the above-described embodiment, the large diameter flange portion 44 is configured as an idle flange separated from the small diameter flange portion 43, and can rotate and tilt with respect to the small diameter flange portion 43. With such a configuration, even if the through hole 59 formed in the flange 52 of the second pipe 51 is displaced from the normal position, the through hole 58 of the large diameter flange portion 44 can be aligned with the position of the through hole 59. it can. Accordingly, the bolt 55 as the fastening member 54 can be inserted into the through hole 59 and the through hole 58 of the large diameter flange portion 44.

  When the installation error is small, the large diameter flange portion 44 may be formed integrally with the small diameter flange portion 43. FIG. 10 is a schematic view showing a configuration in which the large diameter flange portion 44 is formed integrally with the small diameter flange portion 43. When the installation error is small and the through hole 59 of the flange 52 of the second pipe 51 and the through hole 58 of the large diameter flange portion 44 are not greatly displaced, the flange 41 as shown in FIG. 10 can be used. it can. As the flange 41 in which the large-diameter flange portion 44 is formed integrally with the small-diameter flange portion 43, an RF flange defined in the JIS standard may be used.

  It may be necessary to disconnect the first pipe 40 from the second pipe 51 when removing the elastic spacer 46 or during maintenance of the vertical shaft pump. Further, it may be necessary to separate the first pipe 40 from the second pipe 51 in order to confirm the cured surface of the resin 60. However, since the cured resin 60 is bonded to the small diameter flange portion 43 and the flange 52 of the second pipe 51, it is difficult to separate the small diameter flange portion 43 or the flange 52 of the second pipe 51 from the resin 60. Sometimes.

  Therefore, before filling the gap S with the resin 60, the Teflon (registered trademark) is applied to the flange seal surface 43a of the small diameter flange portion 43 (that is, the contact surface with the resin 60 in the small diameter flange portion 43, see FIGS. 2 to 4). It is preferable to form a film in advance. The Teflon (registered trademark) film can be formed by spraying Teflon (registered trademark) spray on the flange seal surface 43a. Since the Teflon (registered trademark) film is not bonded to the resin 60, the small-diameter flange portion 43 can be easily separated from the resin 60.

  A Teflon (registered trademark) film may be formed on the flange seal surface 52a of the flange 52 of the second pipe 51 (that is, the contact surface of the flange 52 with the resin 60, see FIGS. 2 to 4). In this case, the resin 60 is bonded to the small diameter flange portion 43, while the flange 52 can be easily separated from the resin 60.

  Once the first pipe 40 is removed from the second pipe 51, a sealing material may be inserted between the flange seal surface from which the resin 60 has been peeled off and the resin 60 to ensure liquid tightness. preferable. For example, when the cured resin 60 is cut off from the flange seal surface 43 a of the small diameter flange portion 43, the sealing material is inserted between the cured resin 60 and the small diameter flange portion 43, and then the first pipe 40 The second pipe 51 is connected. Alternatively, when the cured resin 60 is separated from the flange seal surface 52 a of the flange 52 of the second pipe 51, a sealing material is inserted between the cured resin 60 and the flange 52 of the second pipe 51. After that, the first pipe 40 and the second pipe 51 are connected.

  FIG. 11 is a schematic diagram showing the sealing material 65 sandwiched between the cured resin 60 and the small diameter flange portion 43. The sealing material 65 is disposed between the cured resin 60 and the small diameter flange portion 43, and in this state, the flange 41 of the first pipe 40 and the flange 52 of the second pipe 51 are connected by the fastening member 54. . The sealing material 65 has a plurality of through holes through which the bolts 55 constituting the fastening member 54 are inserted. By inserting the bolts 55 into these through holes, the sealing material 65 is positioned. Therefore, working efficiency when the first pipe 40 and the second pipe 51 are connected by the fastening member 54 can be increased. The sealing material 65 is, for example, a rubber gasket, and a commercially available rubber gasket can be used.

  FIG. 12 is a flowchart for explaining an embodiment of the pipe connection method of the present invention. The flowchart of FIG. 12 shows an embodiment in which the small-diameter flange portion 43 is separated from the cured resin 60 after the resin 60 is cured in order to confirm the cured surface of the resin 60.

  First, the flange seal surface 43a of the small diameter flange portion 43 of the first pipe 40 and the flange seal surface 52a of the flange 52 of the second pipe 51 are cleaned using alcohol or the like (step 1). Next, a Teflon (registered trademark) coating is formed on the flange seal surface 43a of the small diameter flange portion 43 using a Teflon (registered trademark) spray (step 2). Next, the first pipe 40 is aligned with the second pipe 51 so that the flange 41 of the first pipe 40 faces the flange 52 of the second pipe 51 (step 3). Next, the elastic spacer 46 is sandwiched between the large diameter flange portion 44 and the flange 52 of the second pipe 51 so that a gap S is formed between the small diameter flange portion 43 and the flange 52 of the second pipe 51. (Step 4). Further, the hollow pipe 81 is inserted into the through hole 80 formed in the elastic spacer 46. The large diameter flange portion 44 and the flange 52 of the second pipe 51 are fastened by the fastening member 54 with the elastic spacer 46 sandwiched between the large diameter flange portion 44 and the flange 52 of the second pipe 51. (Step 5).

  Next, the rubber sheet 61 is affixed to the inner surfaces of the first pipe 40 and the second pipe 51, and the inner opening end of the gap S is closed by the rubber sheet 61 (step 6). After the rubber sheet 61 is pasted, the rubber sheet 61 is preferably pressed against the inner surfaces of the first pipe 40 and the second pipe 51 by the rubber sheet fixing jig 70. Next, a fluid epoxy resin 60 is prepared and packed in the filling machine 86 (step 7). And the epoxy resin 60 is inject | poured into the clearance gap S from the hollow pipe 81 inserted in the through-hole 80 provided in the lowest part of the elastic spacer 46 using the filling machine 86 (step 8). At this time, the hollow pipe 81 inserted into the through hole 80 provided at the uppermost portion of the elastic spacer 46 functions as an air vent hole. After confirming that the epoxy resin 60 flows out from the hollow pipe 81 inserted into the through hole 80 provided at the uppermost portion of the elastic spacer 46, the injection of the epoxy resin 60 is finished (step 9).

  With the gap S filled with the epoxy resin 60, the epoxy resin 60 is cured (step 10). After the epoxy resin 60 is cured, the rubber sheet 61 and the rubber sheet fixing jig 70 are removed (step 11). Next, the nut 56 is removed from the bolt 55, and the first pipe 40 is disconnected from the second pipe 51 (step 12). At this time, since the Teflon (registered trademark) film is formed on the flange surface 43 a of the small diameter flange portion 43, the small diameter flange portion 43 can be easily peeled off from the cured resin 60. At this time, the elastic spacer 46 is removed. Next, it is confirmed from the cured surface of the resin 60 whether or not the entire gap S is completely filled with the epoxy resin 60 (step 13). If the entire gap S is filled with the epoxy resin 60, the sealing material 65 is disposed between the small diameter flange portion 43 and the cured resin 60 (step 14), and the flange 41 of the first pipe 40 and the first The flange 52 of the second pipe 51 is connected by the fastening member 54 (step 15). Thereafter, a pressure test with a fluid is performed as necessary. This completes the pipe connection method of the present embodiment.

  In the embodiment described so far, the first pipe 40 and the second pipe 51 are configured as circular pipes having a circular cross section. However, the pipe connection method and the pipe connection structure of the present invention can be applied even when the first pipe 40 and the second pipe 51 are rectangular pipes having a rectangular cross section. In the case of a large-diameter pipe having a diameter of 2000 mm or more, it is often a rectangular pipe for the convenience of production. In the case of a large-diameter pipe, even a slight installation error causes a large shift at the flange end face. Therefore, the conventional loose flange short pipe cannot absorb the deviation of the flange end face. In addition, when the current joint pipe is temporarily welded on site, the welding work becomes large, and the burden on the operator is large. The pipe connection method and the pipe connection structure according to the present invention are very effective techniques because they can absorb a large shift without welding work on site.

  Moreover, although the above-mentioned embodiment demonstrated the example which applied the piping connection method and piping connection structure of this invention with respect to the discharge pipe 4 of a vertical shaft pump, this invention is not limited to this. For example, the present invention can be applied to a discharge pipe of a horizontal axis pump. In addition, the present invention can be applied to any pipe connection portion where an installation error that requires an existing pipe is generated.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims.

DESCRIPTION OF SYMBOLS 1 Impeller casing 1a Suction bell mouth 1b Pump bowl 2 Suspension pipe 3 Discharge curved pipe 4 Discharge pipe 6 Pump installation floor 7 Insertion hole 8 Installation base 10 Impeller 15 Rotating shaft 16 Guide vane 17 Underwater bearing 18 Intermediate bearing 19 Outer bearing 23 Backflow prevention valve 24 Discharge valve 25 Drive unit 30 Suction water tank 31 Discharge water tank 40 First piping (short pipe)
41 Flange 43 Small-diameter flange portion 43a Flange seal surface 44 Large-diameter flange portion 46 Elastic spacer 47 Through hole 50 Wall surface 51 Second piping (existing piping)
52 Flange 52a Flange seal surface 54 Fastening member 55 Bolt 56 Nut 58 Through hole 59 Through hole 60 Resin 61 Rubber sheet 65 Sealing material 70 Rubber sheet fixing jig 71 Outer ring 72 Inner ring 73 Inner ring bolt member 74 Length adjusting nut 75 Outer ring bolt member 80 Through-hole 81 Hollow pipe 83 Piping 86 Filling machine

Claims (8)

The first pipe is arranged with respect to the second pipe so that the small-diameter flange portion of the first pipe and the flange of the second pipe face each other,
There is a gap between the large-diameter flange portion of the first pipe adjacent to the small-diameter flange section and the flange of the second pipe, and between the small-diameter flange section and the flange of the second pipe. Insert an elastic spacer so that you can
In a state where the elastic spacer is sandwiched, the large-diameter flange portion and the flange of the second pipe are fastened together to connect the first pipe and the second pipe,
A rubber sheet is attached to the inner surfaces of the first pipe and the second pipe so as to close the inner opening end of the gap,
While injecting resin into the gap through the first through hole formed in the elastic spacer, the air is extracted from the gap through the second through hole formed in the elastic spacer, thereby filling the gap with resin. And
Curing the resin in the gap,
A pipe connection method, wherein the rubber sheet and the elastic spacer are removed after the resin is cured.   After removing the rubber sheet and the elastic spacer, a sealing material is inserted between the cured resin and the small-diameter flange portion, or between the cured resin and the flange of the second pipe. The pipe connection method according to claim 1.   The pipe connection method according to claim 1, wherein the large-diameter flange portion is configured as an idle flange separated from the small-diameter flange portion.   The rubber sheet is pressed against the inner surfaces of the first pipe and the second pipe by a rubber sheet fixing jig after the rubber sheet is attached. The pipe connection method according to one item.   5. The first through hole is formed at a lowermost part of the elastic spacer, and the second through hole is formed at an uppermost part of the elastic spacer. 6. The piping connection method described in 1.   A pipe connection method according to any one of claims 1 to 5, wherein a hollow pipe is inserted into the first through hole and the second through hole.   The pipe connection method according to any one of claims 1 to 6, wherein the resin is an epoxy resin. The first pipe is a short pipe connected to a discharge pipe of a pump;
The pipe connection method according to any one of claims 1 to 7, wherein the second pipe is an existing pipe disposed in a pump station.

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