JP2011179552A - Piping repairing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piping repairing method for easily repairing damage at any section of piping. <P>SOLUTION: When a fluid leaks from a damage point 2 of the piping 1, an escape pipe 3 having an inflow port 3a and an outflow port 3b is arranged outside the piping 1 so that the inflow port 3a faces the damage point 2. Then, a clearance between the escape pipe 3 and the piping 1 is blocked with an uncured curable repairing material 4 so that all of the fluid leaking from the damage point 2 to outside the piping 1 is made to flow through the escape pipe 3. When the curable repairing material 4 is hardened, the outflow port 3b is sealed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a pipe repairing method for repairing damage caused to a pipe carrying a pressure fluid in a state where pressure is applied to the pipe.

  A conventional tube breakage emergency sealer includes an attachment plate having an attachment surface suitable for attaching to the outer surface of the tube, a sealing material provided along the periphery of the attachment surface, and an anti-attachment surface of the attachment plate It has a radiation pipe erected on the side, a shut-off valve provided on the radiation pipe, and a belt for pressing and fixing the attachment plate against the outer surface of the pipe (for example, see Patent Document 1).

  Further, in the conventional pressure fluid leakage closing method, a cap-like contact member having a discharge nozzle is disposed at the leakage portion. And a contact member is hold | maintained with the discharge nozzle opened, and the joining surface is adhere | attached on piping outer surface. Thereafter, the discharge nozzle is closed, and the contact member is tightly bound to the pipe (for example, see Patent Document 2).

JP-A-9-229289 Japanese Patent Laid-Open No. 61-127996

  In the conventional pipe repairing method as described above, a splicing plate or a cap-shaped abutting member having a splicing surface along the outer surface of the pipe is used. When it is determined in advance, it is easy to apply, but when it is applied to a branched portion of a pipe or a bent portion having a small curvature radius, it is necessary to prepare a member suitable for each shape, and it is difficult to manufacture the member.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to obtain a pipe repair method capable of easily repairing damage at any location of the pipe.

  The pipe repair method according to the present invention includes a step of disposing an escape pipe having an inlet and an outlet outside the pipe so that the inlet faces the damaged portion, and an uncured state between the relief pipe and the pipe. And a step of passing all of the fluid leaking out of the pipe from the damaged portion through the escape pipe, a step of hardening the hardenable repair material, and a step of closing the escape pipe.

  The pipe repairing method of the present invention allows the fluid leaking from the damaged part to escape with the pipe, and prevents the curable repair material in the uncured state from being deformed by pressure, while closing the space between the pipe and the pipe to make it hardenable. Since the relief pipe is closed after the repair material is hardened, the pipe can be repaired without using a contact plate or the like along the pipe shape of the damaged part, and damage to any part of the pipe can be easily repaired.

It is explanatory drawing which shows the cross section when the piping repair method by Embodiment 1 of this invention is applied to the straight pipe part of piping in order of a process. It is explanatory drawing which shows a cross section when the piping repair method of Embodiment 1 is applied to the branch part of piping in order of a process. It is explanatory drawing which shows the cross section when the piping repair method of Embodiment 1 is applied to the outer periphery of the bending part of piping in order of a process. It is sectional drawing which shows the state in the middle of repair when the piping repair method of Embodiment 1 is applied to the inner periphery of the bending part of piping. It is sectional drawing which shows the state after repair when the piping repair method by Embodiment 2 of this invention is applied to the straight pipe part of piping. It is explanatory drawing which shows the cross section when the pipe repair method by Embodiment 3 of this invention is applied to the straight pipe part of piping in order of a process. It is sectional drawing which shows the state after repair when the piping repair method by Embodiment 4 of this invention is applied to the straight pipe part of piping. It is a block diagram which shows the evaluation test apparatus of the piping repair method of Embodiment 3,4. It is a table | surface which shows the test result by the apparatus of FIG.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is an explanatory view showing the sections in order of steps when the pipe repair method according to Embodiment 1 of the present invention is applied to a straight pipe portion of a pipe. As shown in FIG. 1 (a), when the fluid leaks from the damaged portion 2 of the pipe 1, as shown in FIG. 1 (b), an escape pipe (bypass pipe) having an inlet 3a and an outlet 3b. 3 is arranged outside the pipe 1 so that the inlet 3a faces the damaged portion 2.

  Thereafter, the internal pressure of the pipe 1 is not dropped to zero, and the fluid is leaking, and the curable repair material is in an uncured state between the escape pipe 3 and the pipe 1 as shown in FIG. (Sealing material) 4 is closed and all of the fluid leaking from the damaged portion 2 to the outside of the pipe 1 is released and passed through the pipe 3. That is, all of the fluid leaking from the damaged portion 2 is discharged to the outside through the escape pipe 3.

  When the curable repair material 4 is cured (or solidified) and has resistance to the pipe pressure, the outlet 3b is sealed and the escape pipe 3 is closed (closed pipe or Sealed tube). In the example of FIG. 1, a metal escape pipe 3 is used, and the outlet 3b is sealed by caulking the escape pipe 3 with a pinch-off tool or the like.

  In such a pipe repair method, the fluid leaking from the damaged portion 2 is escaped by the escape pipe 3, and the curable repair material 4 in an uncured state is not deformed by pressure, while the relief pipe 3 and the pipe 1 are not deformed. Since the outlet 3b is sealed after the curable repair material 4 is hardened, the pipe can be repaired without using a contact plate or the like along the pipe shape of the damaged part 2, and damage to any part of the pipe 1 can be prevented. It can be repaired easily.

  Further, the relief pipe 3 need not be fitted to the shape of the pipe 1 as long as it can be closed, and therefore can be used as a common member for different pipe shapes and is efficient.

  Furthermore, since the damaged part 2 can be repaired in a state where pressure is applied, it is suitable for repairing a pipe 1 through which a gas flows, such as a chlorofluorocarbon refrigerant pipe.

  Furthermore, since the outlet 3b is sealed by caulking the escape pipe 3, the escape pipe 3 can be configured to be compact and lightweight, thereby improving workability and reducing costs.

  Here, as the escape pipe 3, it is preferable to use a low pressure loss pipe having a sufficient diameter with respect to the damaged portion 2 so that the curable repair material 4 before hardening does not deform when leaking the leak fluid. By using the escape pipe 3 with such a small pressure loss, the uncured hardening between the escape pipe 3 and the pipe 1 can be achieved without bringing the end of the escape pipe 3 into contact with the pipe 1 as shown in FIG. It can be easily closed with the sex repair material 4. Therefore, even when it is difficult to make the escape pipe 3 contact the pipe 1, the damaged portion 2 can be repaired easily. Of course, the end of the escape pipe 3 may be brought into contact with the pipe 1 if possible.

  Hereinafter, an example in which the pipe repair method according to the first embodiment is applied to a portion other than the straight pipe portion will be described. FIG. 2 is an explanatory view showing sections in order of steps when the pipe repair method of the first embodiment is applied to a branch portion of the pipe. As shown in FIG. 2 (a), when the fluid leaks from the damaged portion 2 generated at the corner of the 90-degree T-shaped portion of the pipe 1, the inlet 3a is damaged as shown in FIG. 2 (b). The escape pipe 3 is arranged outside the pipe 1 so as to face 2.

  Thereafter, as shown in FIG. 2C, the space between the escape pipe 3 and the pipe 1 is closed with an uncured curable repair material 4, and all of the fluid leaking from the damaged portion 2 to the outside of the pipe 1 is removed. Pass through escape tube 3. Thereafter, when the curable repair material 4 is cured, the outlet 3b is sealed as shown in FIG.

  As described above, according to the pipe repair method of the first embodiment, the damaged portion 2 can be easily repaired even when the branch portion of the pipe 1 is damaged. On the other hand, in the conventional pipe repair method in which the plate is applied to the outer periphery of the pipe, the plate becomes an obstacle and it is difficult to repair the branch portion.

  FIG. 3 is an explanatory diagram showing sections in order of steps when the pipe repair method of the first embodiment is applied to the outer periphery of a bent part of a pipe. As shown in FIG. 3A, when the fluid leaks from the damaged portion 2 generated on the outer periphery of the bent portion of the pipe 1, the inlet 3a faces the damaged portion 2 as shown in FIG. The escape pipe 3 is arranged outside the pipe 1 as described above.

  Thereafter, as shown in FIG. 3 (c), the space between the escape pipe 3 and the pipe 1 is closed with an uncured curable repair material 4, and all of the fluid leaking out of the pipe 1 from the damaged portion 2 is removed. Pass through escape tube 3. Thereafter, when the curable repair material 4 is cured, the outlet 3b is sealed as shown in FIG.

  As described above, according to the pipe repair method of the first embodiment, the damaged portion 2 can be easily repaired even when the outer periphery of the bent portion of the pipe 1 is damaged.

  FIG. 4 is a cross-sectional view showing a state in the middle of repair when the pipe repair method of the first embodiment is applied to the inner periphery of the bent part of the pipe. When the fluid leaks from the damaged portion 2 generated in the inner periphery of the bent portion of the pipe 1, the escape pipe 3 is arranged outside the pipe 1 so that the inlet 3 a faces the damaged portion 2. Thereafter, the space between the escape pipe 3 and the pipe 1 is closed with an uncured curable repair material 4, and all of the fluid leaking from the damaged portion 2 to the outside of the pipe 1 is passed through the escape pipe 3 (the state shown in FIG. 4). ). Thereafter, when the curable repair material 4 is cured, the outlet 3b is sealed.

  As described above, according to the pipe repair method of the first embodiment, even when the inner periphery of the bent portion of the pipe 1 is damaged, the escape pipe 3 is inserted inside the bent portion to It can be repaired easily.

  Here, as the curable repair material 4, it is preferable to use a solvent-free material having adhesion to the escape pipe 3 and the pipe 1. For example, a curable resin such as an epoxy resin, a urethane resin, or an acrylate resin, or a hot-melt type resin such as polyolefin or polyamide is applicable as the curable repair material 4.

  However, if the viscosity in the uncured state is low, the self-shape cannot be maintained, and sealing in an appropriate shape becomes impossible. Therefore, the curable repair material 4 has a putty shape that is not fluid in the uncured state. Or a clay-like thing is preferable.

  When an epoxy resin is used as the curable repair material 4, it is preferable to use a type that cures through a putty-like or clay-like state by mixing two components (for example, two liquids) immediately before use.

  Further, when a hot melt type resin is used as the curable repair material 4, it is necessary to select a resin that has a high melt viscosity and quickly cools and hardens. Specifically, the hot melt resin preferably has a viscosity at the time of melting of 5 Pa · s or more.

  Since such a hot melt resin is remelted by heating, the repaired portion can be easily removed. For this reason, the hot-melt resin is suitable for the case where the damaged portion 2 is repaired immediately, and then the curable repair material 4 and the escape pipe 3 are removed and permanent repair is performed by brazing or the like.

  Further, when selecting a material for the curable repair material 4, the elastic modulus after curing is also an important factor. That is, if the elastic modulus of the curable repair material 4 is low, the curable repair material 4 may be deformed by losing the fluid pressure in the pipe 1 and may not function as the repair material. For this reason, it is preferable that the tensile elasticity modulus after hardening of the curable repair material 4 is 30 MPa or more.

Embodiment 2. FIG.
Next, FIG. 5 is a cross-sectional view showing a state after repair when the pipe repair method according to Embodiment 2 of the present invention is applied to a straight pipe portion of the pipe. For example, when the damaged part 2 covers a wide range or the amount of leak gas is large, and when it is impossible to deal with a single escape pipe 3, a plurality of escape pipes 3 can be used as shown in FIG. It can be dealt with. Repair methods other than the number of escape pipes 3 are the same as those in the first embodiment.

  As described above, by increasing or decreasing the number of the escape pipes 3 in accordance with the state of the damaged portion 2, it is possible to respond flexibly on site.

Embodiment 3 FIG.
Next, FIG. 6 is explanatory drawing which shows the cross section when the piping repair method by Embodiment 3 of this invention is applied to the straight pipe part of piping in order of a process. The pipe repair method of the third embodiment is the same as that of the first embodiment until the step of closing the space between the escape pipe 3 and the pipe 1 with the curable repair material 4. Thereafter, in the third embodiment, a liquid coating material (adhesive substance) 5 is further applied on the curable repair material 4. That is, as shown in FIG. 6A, the surface of the curable repair material 4 is coated with a coating material 5 having a viscosity lower than that of the curable repair material 4. And as shown in FIG.6 (b), the outflow port 3b is sealed.

  As the coating material 5, for example, a low-viscosity curable resin or a solvent volatile coating material is used. Moreover, it is preferable that the tensile elasticity modulus of the coating material 5 is 0.1 GPa or more. Those softer than that may be deformed by the pressure in the pipe 1 and cannot be sealed.

  In such a pipe repair method, since the surface of the curable repair material 4 is coated with the low-viscosity coating material 5, even if a minute gap or a pinhole is formed in the curable repair material 4, fluid leakage is prevented. It can prevent more reliably. In particular, when a material having low adhesiveness or a material having high viscosity is used as the curable repair material 4, voids or gaps may be formed in the curable repair material 4 and the airtightness may be reduced. Airtightness can be enhanced by the material 5.

  In the third embodiment, only one escape pipe 3 is used. However, as shown in the second embodiment, even when a plurality of escape pipes 3 are used, the coating material 5 is coated to form the embodiment. The same effect as 3 can be obtained.

Embodiment 4 FIG.
Next, FIG. 7 is a cross-sectional view showing a state after repair when the pipe repair method according to Embodiment 4 of the present invention is applied to a straight pipe portion of the pipe. In this example, the outlet 3b is sealed by operating the sealing device 6 using the escape pipe 3 in which the sealing device 6 such as a cock or a valve is provided in advance. Other repair methods are the same as those in the third embodiment.

  In such a pipe repair method, the outlet 3b can be easily and more reliably sealed. Even if a leak occurs after the tube is closed, it can be repaired easily by opening the sealing device 6 again.

  In addition, you may attach the sealing device 6 of Embodiment 4 to the escape pipe | tube 3 of Embodiment 1,2.

Verification of Effect FIG. 8 is a block diagram showing an evaluation test apparatus for the pipe repair method according to the third and fourth embodiments, and FIG. 9 is a table showing test results by the test apparatus of FIG. In this evaluation test, the effect of air-conditioning piping on CFC gas leakage was verified.

  In the figure, the CFC gas in the CFC cylinder 11 is supplied to the small storage tank 12. Pressure is applied to the sample 10 to be evaluated by the small storage tank 12. When an initial pressure (3.5 MPa in this case) is applied to the sample 10, the front gas is transferred from the front cylinder 11 to the small storage tank 12 so that the pressure in the small storage tank 12 becomes 3.5 MPa, and then the front cylinder is used. 11 valve is closed and the sample 10 side valve is opened.

  A pressure sensor 13 is connected between the sample 10 and the small storage tank 12. The pressure sensor 13 generates a signal corresponding to the pressure in the sample 10. A data logger (recorder) 14 is connected to the pressure sensor 13. The data logger 14 obtains the pressure in the sample 10 based on the signal from the pressure sensor 13, and records / holds the data. A personal computer 15 is connected to the data logger 14.

  As Sample 10, Samples A to D and Comparative Sample A were used as shown in the table of FIG. In the sample A, a hole (pseudo-damaged portion) is provided in a straight pipe (length: about 150 mm) as in FIGS. In the sample B, holes are provided at the corners of the T-shaped tube as in FIG. In the sample C, a hole is provided on the outer periphery of the bent tube as in FIG. In the sample D, a hole is provided in the inner periphery of the bent tube, as in FIG. As in the case of Sample A, Comparative Sample A is a straight pipe provided with holes.

  Samples A to D and comparative sample A were all φ1 / 2 inch (12.7 mm) copper tubes, and the diameter of each hole was φ50 μm. Further, in Samples A to D and Comparative Sample A, the ends other than the end connected to the small storage tank 12 (two locations in Sample B) were sealed.

  The evaluation test is performed for each of the samples A to D and the comparative sample A when the hole is not repaired (“unrepaired” in FIG. 6) and when the hole is repaired (“after repair” in FIG. 6). Later, the degree of pressure decrease (leak state) was examined.

  In the evaluation test “after repair” of samples A to D, the hole was repaired by the same method as in the third and fourth embodiments while applying a pressure of 3.5 MPa. Furthermore, in the evaluation test “after repair” of comparative sample A, the hole was repaired with a commercially available repair kit (butyl rubber tape + urethane tape) while applying a pressure of 3.5 MPa.

  As the curable repair material 4, an epoxy putty (Repair Putty made by New Pig Corporation) was used. Further, as the coating material 5, a room temperature curing epoxy adhesive (Cemedine High Super 5 manufactured by Cemedine) was used. Further, the coating material 5 was coated on the surface of the curable repair material 4 and the boundary surface between the curable repair material 4 and the pipe 1 with a thickness of about 1 mm.

  As the escape pipe 3, a welded pipe having a φ3.2 mm copper pipe and a φ1 / 4 inch (6.35 mm) copper pipe was used. The lengths of the copper tubes after welding were 30 mm and 10 mm, respectively.

  As a result of performing such an evaluation test, a large pressure drop is observed after 24 hours in the unrepaired samples A to D, but in the samples A to D that have been repaired as in the third and fourth embodiments, 24 The initial pressure was maintained after time. In Samples A to D that were repaired as in Embodiments 3 and 4, the initial pressure was maintained even after 211 hours. That is, according to the pipe repair method of the third and fourth embodiments, repair is possible not only in the straight pipe but also in the branching portion and the bending portion, and the pressure drop due to the gas leak at the repaired portion is not seen, and excellent repair is performed. Proven to have performance.

  On the other hand, in Comparative Sample A repaired with a commercially available repair kit, the pressure dropped to a level close to unrepaired after 24 hours. Note that the difference in pressure after 24 hours in the unrepaired samples A to D is considered to be due to the difference in the pressure loss of the hole depending on the position of the hole.

  1 piping, 2 damaged parts, 3 relief pipes, 4 curable repair material, 5 coating material, 6 sealing device.

Claims (6)

A step of disposing an escape pipe having an inflow port and an outflow port outside the pipe so that the inflow port faces the damaged portion;
The step of closing the space between the escape pipe and the pipe with an uncured curable repair material, and passing all of the fluid leaking out of the pipe from the damaged portion through the escape pipe,
A pipe repairing method comprising: curing the curable repair material; and closing the escape pipe.   2. The pipe repair method according to claim 1, wherein the curable repair material is an epoxy resin of a type that cures through a putty-like or clay-like state by mixing two components immediately before use.   2. The pipe repair according to claim 1, wherein the curable repair material is a remeltable hot-melt type thermoplastic resin, and the viscosity of the curable repair material upon melting is 5 Pa · s or more. Method.   The pipe repair method according to any one of claims 1 to 3, wherein the relief pipe is closed by caulking the relief pipe.   4. The escape pipe according to claim 1, wherein the escape pipe is provided with a sealing device in advance, and the relief pipe is closed by operating the sealing device. 5. Piping repair method.   The method further comprises a step of coating the surface of the curable repair material with a coating material having a viscosity lower than that of the curable repair material after the space between the escape pipe and the pipe is filled with the curable repair material. The piping repair method according to any one of claims 1 to 5.

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