Plate-equipped pipeline and method for constructing plate-equipped pipeline

Abstract

To provide a pipeline and its construction method easy in construction management.SOLUTION: In a pipeline 100 with a plate including a pipeline 10, and a conductive plate 20 disposed on the pipeline 10 and connected with a conductor wire L, the pipeline 10 and the conductive plate 20 are mounted via an adhesive agent A. Between the pipeline 10 and the conductive plate 20, a proximity part where the distance between the pipeline 10 and the conductive plate 20 is comparatively short and a remote part where the distance between the pipeline 10 and the conductive plate 20 is comparatively long are formed by the adhesive agent A.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a plate-equipped pipeline and a method for constructing a plate-equipped pipeline. [Background technology]

[0002] A conventionally known wired pipeline includes a pipeline and a wire connected to the pipeline. For example, Patent Document 1 below discloses a structure of this type of wired pipeline, in which a conductive plate with a wire welded thereto is attached to the pipeline via an adhesive made of a mixture of epoxy resin and conductive powder and granules. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6785126 Summary of the Invention [Problem to be solved by the invention]

[0004] In the conventional pipeline with conductors, the conductive plate is assumed to have a shape that conforms to the outer surface of the pipeline, i.e., a curvature that is equal to the outer surface of the pipeline, but the outer diameter of the pipeline is selected appropriately depending on the application. For this reason, it was expected that conductive plates with curvatures that matched the outer diameter of the pipeline would be used appropriately, but there was an issue that managing the types would become complicated.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and has as its object to provide a plate-equipped pipeline and a construction method therefor that facilitate construction management. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention proposes the following means. The plate-equipped pipeline of the present invention comprises a pipeline and a conductive plate that is placed on the pipeline and to which a conductor is connected, wherein the pipeline and the conductive plate are attached via an adhesive, and the adhesive forms between the pipeline and the conductive plate a close portion where the pipeline and the conductive plate are relatively close to each other, and a remote portion where the pipeline and the conductive plate are relatively far from each other.

[0007] According to this invention, the adhesive portion between the pipeline and the conductive plate includes a close portion where the pipeline and the conductive plate are relatively close to each other, and a remote portion where the pipeline and the conductive plate are relatively far from each other. This structure is realized, for example, when the pipeline and the conductive plate have different curvatures. In other words, even if there is only one type of conductive plate shape, it can be applied to multiple types of pipelines. This makes it easier to manage the construction of the conductive plate.

[0008] When the pipeline and the conductive plate are attached with the adhesive, the adhesive is concentrated in a remote area between the pipeline and the conductive plate, which makes it easier for the adhesive to be placed between the pipeline and the conductive plate, thereby improving the adhesive strength.

[0009] Generally, when a conductive plate is bonded to a pipeline, the adhesive-coated conductive plate is pressed against the pipeline. At this time, any adhesive that does not fit into the area between the pipeline and the conductive plate due to the remote section will leak out from the remote section. By visually inspecting this, it is possible to confirm that sufficient adhesive has been applied to the remote section. This also improves visibility during construction management.

[0010] Furthermore, by attaching the pipeline and the conductive plate with an adhesive, the pipeline can be attached without being affected by temperature changes, compared to when the pipeline and the conductive plate are attached by welding. However, when the pipeline and the conductive plate are welded together, the surface of the pipeline is heated. This can cause thermal stress in the pipeline and affect surface treatments such as anti-corrosion treatments on the surface of the pipeline. Furthermore, if the pipeline is already installed and is filled with contents such as gas, the heat generated during welding can heat the contents of the pipeline. Attaching the pipeline and the conductive plate with an adhesive can prevent the above-mentioned problems from occurring.

[0011] The size of the remote portion may be less than 2 mm.

[0012] According to this invention, the size of the remote portion is less than 2 mm. Here, if the size of the remote portion is 2 mm or more, the adhesive strength between the pipeline and the conductive plate is reduced, and sufficient strength cannot be obtained. In other words, by making the remote portion less than 2 mm, the adhesive strength of the adhesive can be fully exerted. Therefore, it is possible to ensure greater adhesive strength.

[0013] The curvature of the surface of the conductive plate that contacts the pipeline may also be equivalent to the outer diameter of a 150A pipe specified in JIS G3452:2019.

[0014] According to this invention, the curvature of the surface of the conductive plate that contacts the pipeline corresponds to the outer diameter of a 150A pipe as specified in JIS G3452:2019. As a result, when assuming a pipeline of 100A to 600A, the size of the remote section can be made less than 2 mm regardless of the nominal diameter of the pipeline. Therefore, by setting the curvature of the conductive plate to 150A, a plate-equipped pipeline can be constructed using a single type of conductive plate in the range of 100A to 600A.

[0015] The conductive plate may have a dimension in the circumferential direction of the pipeline of 30 mm or more and 40 mm or less.

[0016] According to this invention, the dimension of the conductive plate in the circumferential direction of the pipeline is 30 mm or more and 40 mm or less. Assuming a 100 A to 600 A pipeline, the curvature of the surface of the conductive plate that contacts the pipeline corresponds to the outer diameter of a 150 A pipe specified in JIS G3452:2019. Furthermore, by having the dimension of the conductive plate in the circumferential direction of the pipeline be 30 mm or more and 40 mm or less, it is possible to more reliably ensure that the size of the remote portion is less than 2 mm regardless of the nominal diameter of the pipeline. Therefore, the adhesive strength between the conductive plate and the pipeline can be ensured while minimizing the size of the conductive plate.

[0017] The curvature of the surface of the conductive plate that contacts the pipeline may also be equivalent to the outer diameter of a 65A pipe specified in JIS G3452:2019.

[0018] According to this invention, the curvature of the surface of the conductive plate that contacts the pipeline corresponds to the outer diameter of a 65A pipe as specified in JIS G3452:2019. As a result, when assuming a pipeline of 50A to 80A, the size of the remote section can be made less than 2 mm regardless of the pipeline's nominal diameter. Therefore, by setting the curvature of the conductive plate to 65A, a plate-equipped pipeline can be constructed using a single type of conductive plate in the range of 50A to 80A.

[0019] The conductive plate may have a dimension in the circumferential direction of the pipeline of 20 mm or more and 30 mm or less.

[0020] According to this invention, the dimension of the conductive plate in the circumferential direction of the pipeline is 20 mm or more and 30 mm or less. Assuming a 50 A to 80 A pipeline, the curvature of the surface of the conductive plate that contacts the pipeline corresponds to the outer diameter of a 65 A pipe as specified in JIS G3452:2019. Furthermore, by having the dimension of the conductive plate in the circumferential direction of the pipeline be 20 mm or more and 30 mm or less, it is possible to more reliably ensure that the size of the remote portion is less than 2 mm regardless of the nominal diameter of the pipeline. Therefore, the adhesive strength between the conductive plate and the pipeline can be ensured while minimizing the size of the conductive plate.

[0021] The adhesive may be a mixture of acrylic resin and conductive powder particles.

[0022] According to this invention, the adhesive is a mixture of acrylic resin and conductive powder and granular material. When comparing acrylic resin with epoxy resin, acrylic resin has superior water resistance and moisture resistance compared to epoxy resin. Therefore, by using acrylic resin as the adhesive, the water resistance and moisture resistance of the adhesive can be improved. Therefore, this configuration can be applied even in environments where condensation occurs in exposed pipes or moisture from the soil penetrates into buried pipes.

[0023] In addition, acrylic resins have a faster curing rate than epoxy resins, which shortens the time required to hold the conductive plate in the pipeline until the adhesive hardens, further improving workability.

[0024] The volume of the conductive powder particles in the adhesive may be 10% or more and 30% or less of the volume of the adhesive.

[0025] According to this invention, the volume of the conductive powder particles in the adhesive is between 10% and 30% of the adhesive, which makes it possible to achieve both the adhesive strength of the adhesive and the conductivity between the conductive plate and the pipeline bonded by the adhesive.

[0026] The proximal portion may be located at both ends of the conductive plate in the circumferential direction, and the distal portion may be located at a central portion of the conductive plate in the circumferential direction.

[0027] According to this invention, the adjacent portions are located at both ends of the circumferential direction of the conductive plate. In other words, when the conductive plate is brought into contact with the pipeline, both ends of the conductive plate come into contact with the pipeline. This makes it possible to stabilize the conductive plate compared to when the adjacent portions are located at the center of the circumferential direction of the conductive plate. This can further contribute to improving workability.

[0028] Furthermore, the remote portion is located at the center of the conductive plate in the circumferential direction, which makes it easier for the adhesive to remain between the conductive plate and the pipeline when the conductive plate is applied with adhesive and brought into contact with the pipeline, thereby contributing to improved adhesive strength.

[0029] Furthermore, a method for installing a plate-equipped pipeline according to the present invention includes: an attachment step of attaching a conductive plate of a common shape to a pipeline having an outer diameter equivalent to 100A or more as specified in JIS G3452:2019; and an application step of applying an adhesive to a surface of the conductive plate that contacts the pipeline before the attachment step, wherein the surface of the conductive plate that contacts the pipeline has a shape such that, when the conductive plate and the outer peripheral surface of the pipeline come into contact, a gap of less than 2 mm is formed unevenly between the conductive plate and the outer peripheral surface of the pipeline, and in the attachment step, for at least a part of the pipeline having the outer diameter, proximate portions that are relatively close to the pipeline are formed at both ends of the conductive plate in the circumferential direction of the pipeline, while a remote portion that is relatively far from the pipeline is formed in the center of the conductive plate in the circumferential direction, and the conductive plate is pressed against the pipeline via the adhesive while being supported by the proximate portions.

[0030] The method may further include an attachment step of attaching a conductive plate of a common shape to a pipeline having an outer diameter equivalent to 80A or less as specified in JIS G3452:2019, and an application step of applying an adhesive to a surface of the conductive plate that contacts the pipeline before the attachment step, wherein the surface of the conductive plate that contacts the pipeline has a shape such that a gap of less than 2 mm is formed unevenly between the conductive plate and the outer peripheral surface of the pipeline when the conductive plate and the outer peripheral surface of the pipeline come into contact, and in the attachment step, for at least a part of the pipeline having the outer diameter, proximal portions that are relatively close to the pipeline are formed at both ends of the conductive plate in the circumferential direction of the pipeline, and distal portions that are relatively far from the pipeline are formed in the center of the conductive plate in the circumferential direction, and the conductive plate is pressed against the pipeline via the adhesive while being supported by the proximal portions.

[0031] According to this invention, in the pipeline having at least a portion of the outer diameter, the attaching step presses the conductive plate against the pipeline via an adhesive while the conductive plate is supported on the pipeline by the adjacent portions located at both ends in the circumferential direction of the conductive plate. This allows the operation of pressing the conductive plate against the pipeline to be performed stably, thereby contributing to improved workability. [Effects of the Invention]

[0032] According to the present invention, it is possible to provide a plate-equipped pipeline and a construction method therefor that facilitate construction management. [Brief explanation of the drawings]

[0033] [Figure 1] 1 is a schematic diagram of a pipeline with plates according to the present invention; FIG. [Figure 2] FIG. 2 is a perspective view of the conductive plate shown in FIG. [Figure 3]1 is a first example of a case in which the conductive plate according to the present embodiment is attached to a pipeline. [Figure 4] 10 is a second example of a case in which the conductive plate according to the present embodiment is attached to a pipeline. DETAILED DESCRIPTION OF THE INVENTION

[0034] Hereinafter, a plate-equipped pipeline according to one embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the plate-equipped pipeline 100 includes a pipeline 10, a conductive plate 20, and a connection portion 30.

[0035] The pipeline 10 is a pipe made of a conductive metal. More specifically, a steel pipe is preferable. The pipeline 10 may be installed, for example, underground or underwater, or on land or on a structure. The pipeline 10 thus installed may serve as a water pipe, a drainage pipe, a gas pipe, or the like, depending on the installation location and purpose. Furthermore, the outer surface of the pipeline 10 may be subjected to a surface treatment such as an anti-corrosion coating depending on the purpose.

[0036] In this embodiment, the size of the pipeline 10 is one whose nominal diameter is 100A to 600A or 50A to 80A as specified in JIS G3452:2019. The nominal diameter need not be limited to the nominal diameter of the above standards. For example, the pipeline 10 may have a nominal diameter according to JIS G3457, JIS G3454, API standards, or other standards. In this embodiment, when a description is made that the nominal diameter is 100A or more or 80A or less, it is not limited to the above-mentioned JIS G3452, but also includes a range corresponding to the nominal diameter in other standards. In the following, the direction parallel to the central axis of the pipeline 10 is referred to as the axial direction. The direction perpendicular to the central axis of the pipeline 10 is referred to as the radial direction. The circumferential direction is the circumferential direction of the outer surface of the pipeline in a cross section perpendicular to the central axis of the pipeline 10. The following describes a state in which the pipeline 10 is installed sideways so that the central axis extends horizontally.

[0037] The conductive plate 20 is disposed on the pipeline 10, and the conductive wire L is connected to the conductive plate 20 via the connection portion 30. The conductive plate 20 is made of a conductive metal material. The pipeline 10 and the conductive plate 20 may be made of the same material or different materials.

[0038] The conductive plate 20 has an arc shape in a cross section perpendicular to the axial direction, and a rectangular shape along the axial direction in a plan view. The arc shape is formed at least on the surface of the conductive plate 20 that contacts the pipeline 10. Furthermore, when the size of the pipeline 10 is 100 A to 600 A, the curvature of the arc shape preferably corresponds to the outer diameter of a pipe having a nominal diameter of 150 A as specified in JIS G3452:2019. In other words, when the surface of the conductive plate 20 that contacts the pipeline 10 is brought into contact with a pipe having a nominal diameter of 150 A, the conductive plate 20 is preferably shaped so that there is no gap between the conductive plate 20 and the outer peripheral surface of the pipe.

[0039] Alternatively, when the size of the pipeline 10 is 50 A to 80 A, the curvature of the arc shape preferably corresponds to the outer diameter of a pipe having a nominal diameter of 65 A as specified in JIS G3452:2019. In other words, when the surface of the conductive plate 20 that contacts the pipeline 10 is brought into contact with a pipe having a nominal diameter of 65 A, the conductive plate 20 is preferably shaped so that there is no gap between the conductive plate 20 and the outer peripheral surface of the pipe.

[0040] Furthermore, the circumferential dimension of the rectangular shape of the conductive plate 20 is preferably 30 mm or more and 40 mm or less when the curvature of the conductive plate 20 is equivalent to 150 A. It is preferably 20 mm or more and 30 mm or less when the curvature of the conductive plate 20 is equivalent to 65 A. Within the above range, the size of the remote portion G2, described below, can be 2 mm or less. The axial dimension of the rectangular shape can be selected arbitrarily, but is preferably about 50 mm. There is no particular upper limit to the axial dimension of the rectangular shape, provided that it does not impede construction, and it may be 50 mm or more. The conductive plate 20 formed as described above may be formed by cutting out a metal tube having the above curvature, or may be formed by processing a flat plate into a curved surface.

[0041] The pipeline 10 and the conductive plate 20 are preferably attached via an adhesive A. The adhesive A according to this embodiment is preferably a mixture of an acrylic resin and conductive powder and granules. Examples of suitable acrylic resins include 3M's acrylic adhesives "DP8405NS Green" and "DP8805NS Green." Iron powder is preferably used as the conductive powder and granules. The volume of the conductive powder and granules in the adhesive A is preferably 10% to 30%, and more preferably 20%. Hereinafter, the region between the pipeline 10 and the conductive plate 20, i.e., the region where the pipeline 10 and the conductive plate 20 are attached by the adhesive A, will be referred to as the adhesive portion G.

[0042] The adhesive portion G between the pipeline 10 and the conductive plate 20 includes a proximal portion G1 and a distal portion G2. As described above, the adhesive portion G is attached by the adhesive A. In other words, the proximal portion G1 and the distal portion G2 are formed between the pipeline 10 and the conductive plate 20 by the adhesive A.

[0043] The proximity portion G1 is a portion of the adhesive portion G where the distance between the pipeline 10 and the conductive plate 20 is relatively short. The remote portion G2 is a portion of the adhesive portion G where the distance between the pipeline 10 and the conductive plate 20 is relatively long. In the proximity portion G1, the distance between the pipeline 10 and the conductive plate 20 is closer than in the remote portion G2. Specifically, for example, the proximity portion G1 is a portion where the distance between the pipeline 10 and the conductive plate 20 is 0 mm to 0.5 mm. In other words, the pipeline 10 and the conductive plate 20 may be in contact with each other in the proximity portion G1. In this case, the contacting portion may be referred to as the proximity portion G1.

[0044] In contrast, the area where the distance between the pipeline 10 and the conductive plate 20 is 0.5 mm or more is defined as the remote area G2. In other words, the area other than the proximal area G1 in the adhesive area G is defined as the remote area G2. Furthermore, if the pipeline 10 and the conductive plate 20 are in contact with each other in the proximal area G1, the area other than the contacting area may be defined as the remote area G2. In this embodiment, the size of the remote portion G2, i.e., the distance between the pipeline 10 and the conductive plate 20, is preferably less than 2 mm, and more preferably 1 mm or less (details will be described later). The relationship between the close portion G1 and the remote portion G2 in the adhesive portion G will be described below.

[0045] As described above, the pipeline 10 according to this embodiment has a nominal diameter of 100 A to 600 A or 50 A to 80 A. In contrast, the conductive plate 20 according to this embodiment has an arc-shaped curvature formed on the surface that contacts the pipeline 10 that corresponds to an outer diameter of 150 A when the nominal diameter of the pipeline 10 is 100 A to 600 A, and corresponds to an outer diameter of 65 A when the nominal diameter of the pipeline 10 is 50 A to 80 A. When the conductive plate 20 is attached to the pipeline 10, two states are created as shown in FIGS.

[0046] That is, when the curvature of the arc shape of the conductive plate 20 is smaller than the curvature of the outer peripheral surface of the pipeline 10, i.e., when the radius of curvature is large, the proximal portion G1 is located at one location other than the end of the conductive plate 20 in the circumferential direction, and the distal portions G2 are located on both sides of the proximal portion G1 in the circumferential direction, as shown in Fig. 3. In other words, in the adhesive portion G, the distal portion G2 is located on both end sides (outside) of the conductive plate 20 in the circumferential direction, and the proximal portion G1 is located at a location other than both end portions of the conductive plate 20 in the circumferential direction.

[0047] Table 1 shown below summarizes the size (gap) of the remote portion G2 occurring between the pipeline 10 and the conductive plate 20 (terminal plate) when the arcuate curvature of the conductive plate 20 (terminal plate) having a circumferential dimension (plate width) of 30 mm is set to be equivalent to 600 A, as an example, and when the conductive plate 20 is flat for comparison. Specifically, the table summarizes the size of the remote portion G2 occurring between the conductive plate 20 according to the above-mentioned conditions and the pipeline 10 when the nominal diameter (pipe diameter) of the pipeline 10 is 100 A to 600 A.

[0048] [Table 1]

[0049] In contrast, when the curvature of the arc shape of the conductive plate 20 is larger than the curvature of the outer peripheral surface of the pipeline 10, i.e., when the radius of curvature is small, as shown in Fig. 4, the proximal portion G1 is located at both ends of the conductive plate 20 in the circumferential direction, and the remote portion G2 is located toward the center of the conductive plate 20. In other words, in the adhesive portion G, the remote portion G2 is located at a position other than both ends of the conductive plate 20 in the circumferential direction.

[0050] Table 2 below shows a summary of the size (gap) of the remote portion G2 occurring between the conductive plate 20 (terminal plate) and the pipeline 10 when the arcuate curvature of the conductive plate 20 (terminal plate) having a circumferential dimension (plate width) of 30 mm is set to be equivalent to 100 A, 150 A, 200 A, and 300 A. Specifically, the table shows the size of the remote portion G2 occurring between the conductive plate 20 according to the above-mentioned conditions and the pipeline 10 when the nominal diameter (pipe diameter) of the pipeline 10 is 100 A to 600 A.

[0051] [Table 2]

[0052] Table 3 shown below summarizes the size (gap) of the remote portion G2 occurring between the conductive plate 20 (terminal plate) and the pipeline 10 when the arcuate curvature of the conductive plate 20 (terminal plate) with a circumferential dimension (plate width) of 20 mm is set to equivalent to 50 A, 65 A, and 80 A. Specifically, the table summarizes the size of the remote portion G2 occurring between the conductive plate 20 according to the above-mentioned conditions and the pipeline 10 when the nominal diameter (pipe diameter) of the pipeline 10 is 50 A to 80 A.

[0053] [Table 3]

[0054] As shown in Table 1, when the curvature of the arc-shaped conductive plate 20 is equivalent to 600 A, the size of the remote portion G2 is smaller than when the conductive plate 20 is flat. It is also found that the size of the remote portion G2 is 2 mm or less in all combinations.

[0055] As shown in Table 2, when the diameter of the pipeline 10 and the curvature of the conductive plate 20 are equal, the size of the remote portion G2 is 0 mm. When the diameter of the pipeline 10 is larger than the curvature of the conductive plate 20, the size of the remote portion G2 is larger. When the diameter of the pipeline 10 is smaller than the curvature of the conductive plate 20, the size of the remote portion G2 is smaller. Alternatively, as shown in Table 2, the size of the remote portion G2 is a negative value. When the size of the remote portion G2 is negative, the nominal diameter of the pipeline 10 is smaller than the arc-shaped curvature of the conductive plate 20, and therefore the relationship between the remote portion G2 and the proximal portion G1 is as shown in Figure 3, i.e., the remote portion G2 is located on both ends (outside) of the conductive plate 20 in the circumferential direction.

[0056] In all of the combinations in Tables 1, 2, and 3, the size of the remote portion G2 is less than 2 mm. When standardizing the shape of the conductive plate 20, it is preferable to select a combination that results in a number of intermediate values ​​for the value of the remote portion G2, rather than using extreme values. Looking at Table 2, when the curvature of the conductive plate 20 is equivalent to 150 A or 200 A, the size of the remote portion G2 is 1 mm or less in all combinations. Therefore, assuming a pipeline 10 of 100 A to 600 A, it is preferable that the curvature of the conductive plate 20 is equivalent to 150 A or 200 A, and the plate width is 30 mm.

[0057] Furthermore, among the combinations shown in Table 3, many combinations result in an intermediate value for the remote section G2 when the curvature of the conductive plate 20 is equivalent to 65 A. Therefore, assuming a pipeline 10 of 50 A to 80 A, it is preferable that the curvature of the conductive plate 20 is 65 A and the plate width is 20 mm.

[0058] 3 and 4, the state shown in Fig. 4, i.e., the state where the remote portion G2 is located between the close portion G1, is easier to install (the reason will be described later). Therefore, in this embodiment, it is best for the arc-shaped curvature of the conductive plate 20 to be equivalent to 150A. Below, the workability of installing the conductive plate 20 in the cases shown in Fig. 3 and 4 will be compared.

[0059] When the conductive plate 20 is attached to the pipeline 10, the conductive plate 20, to which adhesive A has been applied, is pressed against the surface of the pipeline 10. At this time, as shown in Figure 3, if the proximal portion G1 is located between the distal portion G2, the position of the proximal portion G1 may be biased to one side in the circumferential direction depending on how the force pressing the conductive plate 20 is applied. This makes it difficult to hold the conductive plate 20 stably until the adhesive A hardens.

[0060] In contrast, as shown in Figure 4, when the remote portion G2 is located between the proximal portions G1, when the conductive plate 20 is pressed against the pipeline 10, the position of the conductive plate 20 is likely to be stable because the pressing force is received by the proximal portions G1 located at both ends in the circumferential direction. Therefore, the conductive plate 20 can be easily and stably held until the adhesive A hardens. For the above reasons, the case where the remote portion G2 is located between the proximal portions G1 is easier to work than the case where the proximal portions G1 are located between the remote portions G2.

[0061] Furthermore, when the conductive plate 20 is pressed against the pipeline 10, two proximal portions G1 come into contact with the pipeline 10. This makes the size of the distal portion G2 constant. In contrast, as shown in FIG. 3, if the distal portion G2 is located on both ends of the conductive plate 20 in the circumferential direction, the position of the proximal portion G1 is unstable, and the distal portions G2 located on both sides of the proximal portion G1 may not have the same size. Even in this case, if the maximum size of the distal portion G2 is 2 mm or less, the distal portion G2 can be fixed without affecting its strength.

[0062] As described above, when the curvature is equivalent to 150 A and 200 A, the size of the remote section G2 is less than 2 mm in all combinations shown in Table 2. Therefore, assuming a pipeline 10 of 100 A to 600 A, conductive plates 20 with curvatures equivalent to either 150 A or 200 A are applicable. Considering workability, it is more preferable to apply 150 A, which has the most combinations that result in the state shown in Figure 4.

[0063] Next, the optimal size of the remote portion G2 being less than 2 mm was investigated by the following verification. Specifically, for adhesive A according to this embodiment, a tensile test was conducted using test pieces bonded with a 3M acrylic adhesive "DP8405NS Green" mixed with reduced iron powder at a ratio of 20%. The test pieces described below were curved plates or solid pipes, and the conditions according to this embodiment were reproduced as follows. The results of the above test are shown in Table 4.

[0064] [Table 4]

[0065] Condition 1 in Table 4 used a curved plate with a curvature equivalent to 150 A on the conductive plate 20 side (terminal side) and a real pipe with a nominal diameter of 100 A on the pipeline 10 side (steel pipe side). This resulted in the state shown in Fig. 3, i.e., a state in which the remote portion G2 (gap) occurred on the end side in the circumferential direction, and the size of the remote portion G2 was 0.63 mm. In condition 2, a curved plate with a curvature equivalent to 150 A was used on the conductive plate 20 side (terminal side), and a curved plate with a curvature equivalent to 600 A was used on the pipeline 10 side (steel pipe side). This resulted in the state shown in Fig. 4, i.e., a state in which the remote portion G2 (gap) occurred on the circumferential center side, and the size of the remote portion G2 was 1 mm. In condition 3, a curved plate with a curvature equivalent to 600 A was used on the conductive plate 20 side (terminal side), and a curved plate with a curvature equivalent to 150 A was used on the pipeline 10 side (steel pipe side). This resulted in the state shown in Fig. 4, i.e., a state in which the remote portion G2 (gap) occurred on the circumferential center side, and the size of the remote portion G2 was 1 mm. In condition 4, a flat plate was used as the conductive plate 20 side (terminal side) and a real pipe with a nominal diameter of 100 A was used as the pipeline 10 side (steel pipe side). This resulted in the state shown in Fig. 3, i.e., a state in which a remote portion G2 (gap) occurred on the circumferential end side, and the size of the remote portion G2 was 2 mm. The size of the remote portion G2 (gap) for each of the above conditions is a calculated value obtained by calculation using the dimensions of the components related to each of the above conditions. Therefore, depending on the components used in each experiment, the size of G2 in the actual installation state may differ from the calculated value. However, such an error is a maximum of about ±0.1 mm, which can be ignored in the following discussion. In conditions 1 and 4, a conductor L (cable) was attached by thermite welding to the side of the conductive plate 20 that was not in contact with the pipeline 10, and the tensile load was measured by pulling the conductor L.

[0066] The conductor L is connected to the pipeline 10 via a connection part 30 or a conductive plate 20. This establishes electrical continuity with the pipeline 10 and ensures cathodic protection. The conductor L may be, for example, a 600 V single-core cable coated with an insulating material such as cross-linked polyethylene. The conductor L may be configured to be used as a path for passing current for cathodic protection, or as a lead wire for measuring the state of cathodic protection. In these cases, the conductor L is used for a long period of time while remaining electrically connected to the pipeline 10.

[0067] The standard for the tensile load of the adhesive joint G related to the conditions of the tensile test was determined after the following consideration. That is, the diameter of the conductor L was set to 38 mm, which is the largest diameter of the conductor L generally used for cathodic protection. 2Since the tensile load performance of the conductor L is 9 kN, if the tensile load when the conductive plate 20 is pulled exceeds 9 kN, it can be determined that the adhesive strength is equivalent to the tensile strength of the conductor L. For this reason, the tensile load standard was set at 9 kN, and if it exceeds this, it was determined that the required tensile load performance is met.

[0068] Tensile tests were carried out under each of the above conditions as follows. The number of samples under each condition was n=3, and the tensile load results are shown in Table 4. First, the tensile load was measured using a measuring machine for conditions 2 and 3. The results were 11.32 kN for condition 2 and 22.82 kN for condition 3, confirming that both met the required conditions. Note that, as shown in Table 4, these values ​​were the minimum values ​​for n=3 samples.

[0069] Regarding condition 1, in all of the three samples (n=3), the welded portion of the conductor L attached to the conductive plate 20 broke before the adhesive portion G between the conductive plate 20 and the pipeline 10 broke. Regarding condition 4, of the three samples (n=3), in sample 2, the welded portion of the conductor L attached to the conductive plate 20 broke before the adhesive portion G between the conductive plate 20 and the pipeline 10, as in condition 1. In sample 1, the adhesive portion G broke before the conductor L.

[0070] In Conditions 1 and 4, the conductor L is welded to the conductive plate 20 by thermite welding. When the cable wire is directly attached to the terminal plate by thermite welding, the weld strength is slightly lower than the tensile strength of the cable. Even considering this condition, the tensile load at the time of breakage of the welded portion of the cable was 9 kN or more, so it was determined that the practical load condition was met and there was no problem. In the sample in which the adhesive G broke under Condition 4, the load at the time of breakage was the same as that of other welded portions, so it was determined that the practical strength condition was met and there was no problem.

[0071] Furthermore, even when the thickness of adhesive A is 1 mm or more but less than 2 mm, it was confirmed that the tensile load is equivalent to that when the conductor L is directly attached to the conductive plate 20 by thermite welding. Therefore, it was confirmed that the remote portion G2 of less than 2 mm is sufficient for practical strength. Based on this result and the relationship between the size of the remote portion G2 resulting from the relationship between the curvatures of the conductive plate 20 and the pipeline 10 described above, it was determined that the size of the remote portion G2 is optimally less than 2 mm. In addition, since the pass / fail criteria for tensile strength may differ depending on the client, in order to be able to satisfy a variety of actual operations (pass / fail criteria) without relying solely on the pass / fail criteria for tensile strength, which may change, in the embodiments of the present invention, it is preferable to make the thickness less than 2 mm, except for the 2 mm condition where the adhesive joint broke in some results.

[0072] As shown in FIG. 2, the connection part 30 is a flat plate provided in an electrically conductive state on the surface of the conductive plate 20 that does not face the pipeline 10. The connection part 30 is preferably welded to the conductive plate 20. Also, as shown in FIG. 2, the connection part 30 has a mounting hole 31. The mounting hole 31 is a hole used when fixing the conductor L to the connection part 30 with a bolt. This allows the conductor L to be electrically connected to the conductive plate 20 and the pipeline 10. The conductive plate 20 and the connection part 30 may be made of the same material or different materials.

[0073] Although the structure in which the conductor L is connected to the conductive plate 20 via the connection portion 30 has been described above, the present invention is not limited to this. For example, the conductor L may be directly attached by thermite welding or the like to the surface of the conductive plate 20 that does not face the pipeline 10. When the conductor L is attached by thermite welding, it is preferable that the surface of the contact portion where the conductor L is attached is flat, as shown in Figures 3 and 4.

[0074] (Construction method of pipeline with plates) Next, a description will be given of a method for constructing the plate-equipped pipeline 100 according to this embodiment. The construction method includes a coating step and an attachment step. The application process is a process of applying adhesive A to the surface of the conductive plate 20 that contacts the pipeline 10 before the attachment process described below. A sufficient amount of adhesive A is applied so that no gaps are formed between the conductive plate 20 and the pipeline 10. Specifically, it is preferable to apply enough adhesive A so that when the conductive plate 20 coated with adhesive A is attached to the pipeline 10, the adhesive A leaks out from between the conductive plate 20 and the pipeline 10.

[0075] The mounting process is a process of mounting the conductive plate 20 to the pipeline 10. In the mounting process, a common conductive plate 20 is mounted to pipelines 10 having different nominal diameters. For a pipeline 10 having an outer diameter with a curvature smaller than the arc-shaped curvature of the conductive plate 20, proximal portions G1 are formed at both ends of the conductive plate 20 in the circumferential direction of the pipeline 10. On the other hand, a distal portion G2 is formed at the center of the conductive plate 20 in the circumferential direction. In this case, the surface of the conductive plate 20 that contacts the pipeline 10 is shaped so that a gap of less than 2 mm is formed unevenly between the conductive plate 20 and the outer peripheral surface of the pipeline 10 when the conductive plate 20 and the outer peripheral surface of the pipeline 10 come into contact. Furthermore, when the remote portion G2 is formed at the center of the conductive plate 20 in the circumferential direction, the conductive plate 20 is attached by pressing it against the pipeline 10 via adhesive A while the conductive plate 20 is supported on the pipeline 10 by the proximal portion G1.

[0076] As described above, in the plate-equipped pipeline 100 according to this embodiment, the adhesive portion G between the pipeline 10 and the conductive plate 20 includes a close portion G1 where the pipeline 10 and the conductive plate 20 are relatively close to each other, and a remote portion G2 where the pipeline 10 and the conductive plate 20 are relatively far from each other. This structure is realized, for example, when the pipeline 10 and the conductive plate 20 have different curvatures. In other words, even if the conductive plate 20 has only one type of shape, it can be applied to multiple types of pipelines 10. This facilitates construction management of the conductive plate 20.

[0077] When the pipeline 10 and the conductive plate 20 are attached via the adhesive A, the adhesive A is concentrated in the remote portion G2 between the pipeline 10 and the conductive plate 20. This makes it easier for the adhesive A to be disposed between the pipeline 10 and the conductive plate 20. This improves the adhesive strength of the adhesive A.

[0078] Generally, when adhering the conductive plate 20 to the pipeline 10, the conductive plate 20 coated with adhesive A is pressed against the pipeline 10. At this time, any adhesive A that does not fit into the area between the pipeline 10 and the conductive plate 20 created by the remote portion G2 flows out from the remote portion G2. By visually checking this, it can be confirmed that a sufficient amount of adhesive A has been applied to the remote portion G2. This also improves visibility during construction management.

[0079] Furthermore, by attaching the pipeline 10 and the conductive plate 20 with adhesive A, the pipeline 10 can be attached without being affected by temperature changes, compared to when the pipeline 10 and the conductive plate 20 are attached by welding. Here, when the pipeline 10 and the conductive plate 20 are welded together, the surface of the pipeline 10 is heated. This may cause thermal stress in the pipeline 10 or affect surface treatments such as anti-corrosion treatments on the surface of the pipeline 10. Furthermore, if the pipeline 10 is an existing pipeline filled with contents such as gas, the heat generated during welding may heat the contents of the pipeline 10. By attaching the pipeline 10 and the conductive plate 20 with adhesive A, the above-mentioned problems can be prevented.

[0080] Furthermore, the size of the remote portion G2 is less than 2 mm. If the size of the remote portion G2 were 2 mm or more, the adhesive strength between the pipeline 10 and the conductive plate 20 by the adhesive A would be reduced, and sufficient strength would not be obtained. In other words, by making the remote portion G2 less than 2 mm, the adhesive strength of the adhesive A can be fully exerted. Therefore, greater adhesive strength can be ensured.

[0081] Furthermore, the curvature of the surface of the conductive plate 20 that contacts the pipeline 10 corresponds to the outer diameter of a 150A pipe as specified in JIS G3452:2019. As a result, when a pipeline 10 of 100A to 600A is assumed, the size of the remote section G2 can be made less than 2 mm regardless of the nominal diameter of the pipeline 10. Therefore, by setting the curvature of the conductive plate 20 to 150A, a plate-equipped pipeline 100 can be configured using one type of conductive plate 20 in the range of 100A to 600A.

[0082] Furthermore, the dimension of the conductive plate 20 in the circumferential direction of the pipeline 10 is 30 mm or more and 40 mm or less. Assuming a pipeline 10 of 100 A to 600 A, the curvature of the surface of the conductive plate 20 that contacts the pipeline 10 corresponds to the outer diameter of a 150 A pipe specified in JIS G3452:2019. In addition, the dimension of the conductive plate 20 in the circumferential direction of the pipeline 10 of 30 mm or more and 40 mm or less can more reliably ensure that the size of the remote section G2 is less than 2 mm regardless of the nominal diameter of the pipeline 10. Therefore, the adhesive strength between the conductive plate 20 and the pipeline 10 can be ensured while minimizing the size of the conductive plate 20.

[0083] Furthermore, the curvature of the surface of the conductive plate 20 that contacts the pipeline 10 corresponds to the outer diameter of a 65A pipe as specified in JIS G3452:2019. As a result, when a pipeline 10 of 50A to 80A is assumed, the size of the remote section G2 can be made less than 2 mm regardless of the nominal diameter of the pipeline 10. Therefore, by setting the curvature of the conductive plate 20 to 65A, a plate-equipped pipeline 100 can be constructed using one type of conductive plate 20 in the range of 50A to 80A.

[0084] Furthermore, the dimension of the conductive plate 20 in the circumferential direction of the pipeline 10 is 20 mm or more and 30 mm or less. Assuming a 50 A to 80 A pipeline 10, the curvature of the surface of the conductive plate 20 that contacts the pipeline 10 corresponds to the outer diameter of a 65 A pipe specified in JIS G3452:2019. In addition, the dimension of the conductive plate 20 in the circumferential direction of the pipeline 10 of 20 mm or more and 30 mm or less can more reliably ensure that the size of the remote section G2 is less than 2 mm regardless of the nominal diameter of the pipeline 10. Therefore, the adhesive strength between the conductive plate 20 and the pipeline 10 can be ensured while minimizing the size of the conductive plate 20.

[0085] Furthermore, adhesive A is a mixture of acrylic resin and conductive powder and granules. When comparing acrylic resin with epoxy resin, acrylic resin has superior water resistance and moisture resistance properties compared to epoxy resin. Therefore, by using acrylic resin for adhesive A, the water resistance and moisture resistance of adhesive A can be improved. Therefore, this configuration can be applied even in environments where condensation occurs in exposed pipes or moisture from the soil penetrates into buried pipes.

[0086] In addition, acrylic resin has a faster hardening speed than epoxy resin, which reduces the time required to hold the conductive plate 20 to the pipeline 10 until the adhesive A hardens, thereby contributing to improved workability.

[0087] Furthermore, the volume of the conductive powder particles in adhesive A is 10% or more and 30% or less of adhesive A. This makes it possible to achieve both the adhesive strength of adhesive A and the conductivity between the conductive plate 20 and the pipeline 10 bonded by adhesive A.

[0088] Furthermore, the proximity portions G1 are located at both circumferential ends of the conductive plate 20. In other words, when the conductive plate 20 is brought into contact with the pipeline 10, both ends of the conductive plate 20 come into contact with the pipeline 10. This makes it possible to stabilize the conductive plate 20 compared to when the proximity portion G1 is located in the circumferential center of the conductive plate 20. This can further contribute to improved workability.

[0089] Furthermore, the remote portion G2 is located at the center in the circumferential direction of the conductive plate 20. This makes it easier for adhesive A to remain between the conductive plate 20 and the pipeline 10 when adhesive A is applied to the conductive plate 20 and brought into contact with the pipeline 10, thereby contributing to improved adhesive strength.

[0090] In addition, in the attachment process, the conductive plate 20 is pressed against the pipeline 10 via the adhesive A in a state where the conductive plate 20 is supported on the pipeline 10 by the proximity portions G1 located at both circumferential ends of the conductive plate 20. This allows the work of pressing the conductive plate 20 against the pipeline 10 to be performed stably, thereby contributing to improved work.

[0091] The technical scope of the present invention is not limited to the embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, the conductive plate 20 and the connection portion 30 may be attached with an adhesive A. Furthermore, the shape of the conductive plate 20 on the side in contact with the pipeline 10 does not have to be curved. It is sufficient to ensure that the gap between the pipeline 10 and the conductive plate 20 is less than 2 mm. For example, it may be flat, or its cross section may be V-shaped or U-shaped.

[0092] In addition, within the scope of the spirit of the present invention, the components in the above-described embodiments may be replaced with well-known components as appropriate, and the above-described modifications may be combined as appropriate. [Explanation of symbols]

[0093] 10 Pipeline 20 Conductive Plate 100 Pipelines with Plates A adhesive G1 Proximal G2 Remote Unit L conductor

Claims

1. A plate-equipped pipeline comprising a pipeline and a conductive plate disposed on the pipeline and connected to a conductor, the pipeline and the conductive plate are attached to each other via an adhesive; Between the pipeline and the conductive plate: a proximal portion and a distal portion are formed by the adhesive; the proximity portion is closer to the pipeline than the remote portion; The adhesive is electrically conductive. Pipeline with plates.

2. A plate-equipped pipeline comprising a pipeline and a conductive plate disposed on the pipeline and connected to a conductor, the pipeline and the conductive plate are attached to each other via an adhesive; Between the pipeline and the conductive plate: a proximal portion and a distal portion are formed by the adhesive; the proximity portion is closer to the pipeline than the remote portion; The proximal portion is in contact with the pipeline. Pipeline with plates.

3. The size of the remote portion is less than 2 mm.

3. A pipeline with plates according to claim 1 or 2.

4. The curvature of the surface of the conductive plate that contacts the pipeline corresponds to the outer diameter of a 150A pipe specified in JIS G3452:2019. A pipeline with plates according to any one of claims 1 to 3.

5. The conductive plate has a circumferential dimension of 30 mm or more and 40 mm or less.

5. A pipeline with plates according to claim 4.

6. The curvature of the surface of the conductive plate that contacts the pipeline corresponds to the outer diameter of a 65A pipe specified in JIS G3452:2019. A pipeline with plates according to any one of claims 1 to 3.

7. The conductive plate has a circumferential dimension of 20 mm or more and 30 mm or less. A pipeline with plates according to claim 6.

8. The adhesive is a mixture of an acrylic resin and conductive powder particles. A pipeline with plates according to any one of claims 1 to 7.

9. The volume of the conductive powder particles in the adhesive is 10% or more and 30% or less of the volume of the adhesive. A pipeline with plates according to claim 8.

10. the proximal portions are located at both ends of the conductive plate in the circumferential direction, and the distal portions are located at the central portion of the conductive plate in the circumferential direction. A pipeline with plates according to any one of claims 1 to 9.

11. An attachment process of attaching a conductive plate of a common shape to a pipeline having an outer diameter equivalent to 100A or more as specified in JIS G3452:2019; a coating step of coating a conductive adhesive on a surface of the conductive plate that contacts the pipeline before the attaching step; Equipped with a surface of the conductive plate that contacts the pipeline has a shape such that, when the conductive plate and the outer peripheral surface of the pipeline come into contact, a gap of less than 2 mm is formed unevenly between the conductive plate and the outer peripheral surface of the pipeline; In the attaching step, For the pipeline having at least a portion of the outer diameter, the conductive plate has proximal portions formed at both ends of the conductive plate in a circumferential direction of the pipeline, and a distal portion formed at a center of the conductive plate in the circumferential direction; the proximity portion is closer to the pipeline than the remote portion; The conductive plate is pressed against the pipeline via the adhesive while the conductive plate is supported on the pipeline by the adjacent portion. Construction method for pipelines with plates.

12. An attachment process of attaching a conductive plate of a common shape to a pipeline having an outer diameter equivalent to 100A or more as specified in JIS G3452:2019; an application step of applying an adhesive to a surface of the conductive plate that contacts the pipeline before the attachment step; Equipped with a surface of the conductive plate that contacts the pipeline has a shape such that, when the conductive plate and the outer peripheral surface of the pipeline come into contact, a gap of less than 2 mm is formed unevenly between the conductive plate and the outer peripheral surface of the pipeline; In the attaching step, For the pipeline having at least a portion of the outer diameter, the conductive plate has proximal portions formed at both ends of the conductive plate in a circumferential direction of the pipeline, and a distal portion formed at a center of the conductive plate in the circumferential direction; the proximity portion is closer to the pipeline than the remote portion; the conductive plate is pressed against the pipeline via the adhesive in a state in which the proximal portion is in contact with the pipeline and the conductive plate is supported on the pipeline by the proximal portion. Construction method for pipelines with plates.

13. An attachment process of attaching a conductive plate having a common shape to a pipeline having an outer diameter of 80A or less as specified in JIS G3452:2019; a coating step of coating a conductive adhesive on a surface of the conductive plate that contacts the pipeline before the attaching step; Equipped with a surface of the conductive plate that contacts the pipeline has a shape such that, when the conductive plate and the outer peripheral surface of the pipeline come into contact, a gap of less than 2 mm is formed unevenly between the conductive plate and the outer peripheral surface of the pipeline; In the attaching step, For the pipeline having at least a portion of the outer diameter, the conductive plate has proximal portions formed at both ends of the conductive plate in a circumferential direction of the pipeline, and a distal portion formed at a center of the conductive plate in the circumferential direction; the proximity portion is closer to the pipeline than the remote portion; The conductive plate is pressed against the pipeline via the adhesive while the conductive plate is supported on the pipeline by the adjacent portion. Construction method for pipelines with plates.

14. An attachment process of attaching a conductive plate having a common shape to a pipeline having an outer diameter of 80A or less as specified in JIS G3452:2019; an application step of applying an adhesive to a surface of the conductive plate that contacts the pipeline before the attachment step; Equipped with a surface of the conductive plate that contacts the pipeline has a shape such that, when the conductive plate and the outer peripheral surface of the pipeline come into contact, a gap of less than 2 mm is formed unevenly between the conductive plate and the outer peripheral surface of the pipeline; In the attaching step, For the pipeline having at least a portion of the outer diameter, the conductive plate has proximal portions formed at both ends of the conductive plate in a circumferential direction of the pipeline, and a distal portion formed at a center of the conductive plate in the circumferential direction; the proximity portion is closer to the pipeline than the remote portion; the conductive plate is pressed against the pipeline via the adhesive in a state in which the proximal portion is in contact with the pipeline and the conductive plate is supported on the pipeline by the proximal portion. Construction method for pipelines with plates.

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