Pipe inspection method

Abstract

To provide a piping inspection method for specifying a part where a water leakage hole exists in piping without visually observing the piping.SOLUTION: An injecting step of injecting fluorescent liquids having fluorescent colors different from each other into a pipe through a plurality of inlets of the pipe; and a specifying step of specifying a partial pipe in which a water leak hole is present among a plurality of partial pipes included in the pipe based on a fluorescent color of a fluorescent liquid leaking from the water leak hole of the pipe, the fluorescent color of the fluorescent liquid leaking from the water leakage hole of the pipe is the fluorescent color of the fluorescent liquid injected into the pipe via any one of the inlets, or the fluorescent color of the fluorescent liquid obtained by mixing a plurality of fluorescent liquids injected into the pipe via a plurality of inlets.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a piping inspection method. [Background technology]

[0002] The water supply or sewage pipes installed in buildings may develop leak holes due to aging, etc. In such cases, the water leaking from the leak hole may reach the floor of the structure below the pipe, the ceiling of the structure below, or the ceiling or walls of the room, causing severe damage.

[0003] When a plumber is contacted by a resident, he or she will repair the leak, but before that, the plumber must stop the water flow and drain the water, and then identify the location of the leak.

[0004] However, the pipes are arranged in a narrow, dark, and obstructed space between the floor of the building frame and the floor of the room, and the leak holes are small, so it is difficult for plumbers to find the leak holes by visually inspecting the pipes. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-250116 Summary of the Invention [Problem to be solved by the invention]

[0006] Patent Document 1 discloses a method for inspecting a building for leaks using a plurality of luminescent test liquids with different luminescent colors. This method makes it possible to grasp the correspondence between the defect location (the location where rainwater has entered) and the seepage location based on the luminescent color. Furthermore, this method also makes it possible to confirm the merging of intrusion routes when seepage of the luminescent test liquid from only one location is confirmed and the luminescent color is a mixture of colors. However, it is difficult to determine the route taken within the building by the luminescent test liquid to reach the seepage location from the defect location.

[0007] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a pipe inspection method for identifying a portion of a pipe where a water leak hole exists without visually inspecting the pipe. [Means for solving the problem]

[0008] According to the present invention, there is provided a piping inspection method, which includes an injection step of injecting fluorescent liquid into a piping via a plurality of inlets of the piping, each fluorescent liquid having a different fluorescent color from the other inlets, and an identification step of identifying a partial piping among a plurality of partial piping included in the piping in which a leak hole is present, based on the fluorescent color of the fluorescent liquid leaking from a leak hole in the piping, wherein the fluorescent color of the fluorescent liquid leaking from a leak hole in the piping is the fluorescent color of the fluorescent liquid injected into the piping via any one of the inlets, or the fluorescent color of the fluorescent liquid obtained by mixing the plurality of fluorescent liquids injected into the piping via the plurality of inlets. [Effects of the Invention]

[0009] According to the present invention, it is possible to identify a portion of a pipe where a water leakage hole exists without visually inspecting the pipe. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1A is a schematic cross-sectional view of a house in which a piping inspection method according to an embodiment of the present invention is carried out, and FIG. 1B is a schematic perspective view showing a piping system installed in the house. [Figure 2]1 is a flowchart illustrating a piping inspection method according to an embodiment of the present invention. [Figure 3] 3 is a flowchart showing details of the partial pipe identification process shown in FIG. 2. [Figure 4] FIG. 1 is a diagram for explaining Examples 1 and 2. [Figure 5] FIG. 10 is a diagram for explaining a third embodiment. [Figure 6] FIG. 10 is a diagram for explaining a fourth embodiment. [Figure 7] FIG. 10 is a diagram for explaining a fifth embodiment. [Figure 8] FIG. 10 is a diagram for explaining a sixth embodiment. [Figure 9] FIG. 10 is a diagram for explaining a seventh embodiment. [Figure 10] FIG. 13 is a diagram for explaining an eighth embodiment. [Figure 11] FIG. 13 is a diagram for explaining Example 9. DETAILED DESCRIPTION OF THE INVENTION

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0012] [First embodiment] FIG. 1(a) is a schematic cross-sectional view of a building in which pipes to be inspected for water leaks are installed. The building is assumed to be, for example, a high-rise apartment building or a medium- or low-rise apartment building, but it may also be a detached house. The part indicated by reference numeral 101 corresponds to a column or wall of the building frame. The part indicated by reference numeral 102 corresponds to a floor of the building frame. Reference numeral 102a indicates the floor of the building frame, and reference numeral 102b indicates the ceiling of the building frame. Reference numeral 104 indicates the wall of a room 103, reference numeral 105 indicates the floor of the room, and reference numeral 106 indicates the ceiling of the room.

[0013] FIG. 1(b) is a conceptual perspective view showing a piping set and the like arranged in the area indicated by the dashed frame 107 in FIG. 1(a) (the area sandwiched between the floor 102a of the building frame and the floor 105 of the room).

[0014] The sewerage piping sets include a normal sewage piping set 111 and a sewage piping set 112. The piping set 111 is for draining water from the kitchen plumbing, the bath plumbing, the washroom and washing machine plumbing, the bath plumbing, etc. The piping set 112 is for draining sewage from the toilet plumbing.

[0015] FIG. 4(a) is a diagram for explaining a piping inspection method to be described later, and shows a piping set 111 in a schematic manner.

[0016] 1(b) and 4(a), the piping set 111 has a plurality of partial pipes S1 to S7. Wastewater flows into the partial pipe S1 through a drain outlet E1. Wastewater flows into the partial pipe S2 through a drain outlet E2. Wastewater flows into the partial pipe S4 through a drain outlet E4. Wastewater flows into the partial pipe S6 through a drain outlet E6.

[0017] Partial pipes S1 and S2 join together at joint J3 to form partial pipe S3. Partial pipes S3 and S4 join together at joint J5 to form partial pipe S5. Partial pipes S5 and S6 join together at joint J7 to form partial pipe S7. The outlet of partial pipe S7 is connected to pipe 115 that extends vertically along a column or wall of the building structure.

[0018] Here, the joints J3, J5, and J7 may be independent of the partial pipes, or may be part of any of the partial pipes. For example, the partial pipes S1, S3, S5, and S7 may be one partial pipe, and the partial pipes S2, S4, and S6 may be connected to the side of this single pipe. Even in this case, the partial pipes S1, S3, S5, and S7 still conceptually exist.

[0019] Sewage flows into the pipe S8 included in the pipe set 112 via a drain outlet E8. The pipe S8 communicates with a pipe 116 that extends vertically along a pillar or wall of the building frame.

[0020] Although not shown in FIG. 1(b), the drain outlet (not shown) of bathtub 113 and the drain outlet (not shown) of washing area 114 of the bath correspond to any of drain outlets E1 to E6.

[0021] 1(a) and 1(b) show a state in which a leak hole has occurred in piping set 111 or piping set 112, and liquid puddles 121, 122, 123, or 124 due to the water leak have occurred on floor 102a of the frame, ceiling 102b of the frame of the floor below, ceiling 106 of the room below, or the ceiling and wall of the room below. Based on the locations of liquid puddles 121, 122, 123, or 124, it is not possible to determine whether a water leak has occurred in piping set 111 or piping set 112. Furthermore, even if a water leak has occurred in piping set 111, it is not possible to determine which part of piping set 111 the leak hole is in based on the locations of liquid puddles 121, 122, 123, or 124. In the following explanation, the term "liquid puddle 121" refers to puddles 121, 122, 123, or 124, or any other puddle caused by a water leak, including puddles that are difficult to find. The explanation will be based on the premise that if fluorescent liquid leaks from any of the leak holes, puddle 121 will necessarily occur, and if fluorescent liquid does not leak from any of the leak holes, puddle 121 will certainly not occur.

[0022] A plumbing contractor who receives a report from a resident or the like who has discovered a water leak inspects the piping set 111 and the piping set 112 before repairing the water leak, and identifies the location of the leak hole in the pipe that is causing the water leak.

[0023] In this embodiment, the piping contractor inspects the piping set 111 using a piping inspection method in accordance with the flowcharts shown in Figures 2 and 3. However, this inspection may be performed by someone other than the piping contractor. For example, it may be performed by a person who specializes in inspection. In the following description, the piping set 111 will be simply referred to as piping 111, and the piping set 112 will be simply referred to as piping 112.

[0024] This piping inspection method includes an injection step (S203) of injecting fluorescent liquid having a different fluorescent color (e.g., red, green, and blue) for each inlet into the piping 111 through multiple inlets Ei (e.g., E1, E2, and E4) of the piping 111, and a partial piping identification process step (S206) of identifying a partial piping Sj (e.g., S1) among multiple partial piping Sk (e.g., S1 to S7) included in the piping 111 in which a leak hole Hj (e.g., H1) is present, based on the fluorescent color (e.g., red) of the fluorescent liquid leaking from the leak hole Hj (e.g., H1) in the piping 111.

[0025] When fluorescent liquid leaks from a leak hole Hj in the pipe 111, for example, a liquid pool 121 of fluorescent liquid is formed. A plumber irradiates the liquid pool 121 with a black light to confirm the fluorescent color of the fluorescent liquid.

[0026] 2, in S201, the plumbing contractor determines which drain outlets to pour fluorescent liquids of which fluorescent colors into the piping 111. Here, as will be described later, for example, the plumbing contractor determines that red fluorescent liquid, green fluorescent liquid, and blue fluorescent liquid are to be poured into the three upstream drain outlets out of the four drain outlets, respectively.

[0027] Next, in S202, the plumbing worker records the information, determined in S201, about which drain outlet the fluorescent liquid of which fluorescent color is to be poured into the pipe 111, as color allocation information in, for example, a workbook.

[0028] Next, in S203, the plumber pours fluorescent liquid having a fluorescent color determined based on the color assignment information into the pipe 111 from the drain outlet determined based on the color assignment information recorded in S201.

[0029] Next, in S204, the plumber checks whether the fluorescent liquid is leaking. Here, the plumber does not check by directly inspecting the pipe 111, but checks whether the fluorescent liquid is leaking, for example, based on whether a new puddle 121 of fluorescent liquid has appeared. Here, as described above, it is difficult to identify the position of the leak hole from the position where the puddle 121 of fluorescent liquid exists.

[0030] If it is confirmed in S204 that the fluorescent liquid is leaking, the plumbing worker checks the fluorescent color of the leaking fluorescent liquid in S205.

[0031] If it is confirmed in S204 that the fluorescent liquid is not leaking, the plumbing worker omits S205.

[0032] Next, in S206, the plumbing technician executes a partial pipe identification process. Here, the partial pipe identification process is basically a process for identifying a partial pipe where a water leak exists. This will be described later with reference to FIG. 3.

[0033] Next, in S207, the plumbing technician determines whether or not the partial piping was identified in S206.

[0034] If it is confirmed in S207 that the partial piping was identified in S206, the process ends. In this case, the piping contractor records the identification information of the partial piping that was identified in S206, which was executed immediately before, in, for example, a workbook.

[0035] If it is confirmed in S207 that a partial piping could not be identified in S206, the plumbing contractor determines in S208 which drain outlet and which color of fluorescent liquid will be poured into the piping 111 next time. Here, as will be described later, for example, the plumbing contractor determines that a red fluorescent liquid and a green fluorescent liquid will be poured into the two downstream drain outlets out of the four drain outlets, respectively.

[0036] If the result in S207 is NO, depending on the situation, the process may be interrupted without proceeding to S208. For example, if it is determined that there is a high probability that there are multiple leak holes, the process may be interrupted. Also, if it is not possible to narrow down the possibility to one partial pipe, but it is possible to narrow down the possibility to two partial pipes, the process may be interrupted.

[0037] Next, in S209, the plumbing worker records the information, determined in S208, about which drain outlet the fluorescent liquid of which fluorescent color is to be poured into the pipe 111, as color allocation information in, for example, a workbook.

[0038] Next, the liquid puddle 121 is wiped off so that it does not mix with the fluorescent liquid leaking from the pipe 111 in the next and subsequent steps. In addition to this, or instead of this, it is also possible to wait for a predetermined time, as this may cause the liquid puddle 121 to become smaller or disappear.

[0039] From S210, the process returns to S203, and the process from S203 is repeated.

[0040] Next, the partial pipe identification process (S206) will be described in detail with reference to FIG.

[0041] First, in S301, the plumbing worker acquires color allocation information. Here, as described above, the color allocation information is information about which drain outlets are to be used to pour fluorescent liquid of which color into the piping 111, and is recorded in, for example, a workbook in S202 or in S209, which was executed immediately before.

[0042] Next, in S302, the plumbing technician executes a process for uniquely identifying a partial pipe in which a leak hole exists, based only on the color allocation information and the fluorescent color of the leaking fluorescent liquid.

[0043] Next, in S303, the plumbing technician determines whether or not the partial pipe in which the leak hole exists has been uniquely identified in S302.

[0044] If it is confirmed in S303 that the partial piping in which the leak hole exists has been uniquely identified in S302, the plumbing contractor records the identification information of the partial piping in which the leak hole exists, which was identified in S302, for example, in a workbook, in S310, and concludes in S311 that the partial piping has been identified.

[0045] If it is confirmed in S303 that a section of piping in which a leak hole exists could not be uniquely identified in S302, the plumbing contractor obtains in S304 a list of sections of piping in which it has been uniquely confirmed that no leak holes exist (also called a "white list").

[0046] Here, a partial pipe that has been uniquely confirmed to have no leak holes is a partial pipe that falls under either (a) or (b) below.

[0047] (a) (a1) Since fluorescent liquid of a specified fluorescent color flows only in that partial piping, (a2) It is a partial pipe where the presence of a leak hole in the partial pipe can be confirmed only by the fact that the fluorescent color of the leaked fluorescent liquid is a predetermined fluorescent color. (a3) The fluorescent color of the leaked fluorescent liquid is a different fluorescent color, or the fluorescent liquid does not leak, so it cannot be confirmed. (b) (b1) A fluorescent liquid of a predetermined fluorescent color flows through the partial pipe and one or more other partial pipes. The fact that the fluorescent color of the leaked fluorescent liquid is the specified fluorescent color alone does not confirm the existence of a leak hole in that part of the pipe, (b2) The partial pipe can be confirmed to have a leak hole by deleting the partial pipe registered on the white list from two or more partial pipes that have been identified as candidates for a leak hole because the fluorescent color of the leaked fluorescent liquid is a predetermined fluorescent color. (b3) A portion of the piping where the fluorescent color of the leaked fluorescent liquid was a different fluorescent color, or where the fluorescent liquid did not leak and therefore could not be confirmed. Next, in S305, the plumbing technician executes a process of uniquely identifying a partial pipe having a leak hole based on the color allocation information, the fluorescent color of the leaking fluorescent liquid, and the white list.

[0048] Next, in S306, the plumbing technician determines whether or not the partial pipe in which the leak hole exists has been uniquely identified in S305.

[0049] If it is confirmed in S306 that the partial piping in which the leak hole exists has been uniquely identified in S305, the plumbing contractor records the identification information of the partial piping in which the leak hole exists, which was identified in S305, for example, in a workbook, in S310, and concludes in S311 that the partial piping has been identified.

[0050] If it is confirmed in S306 that the partial pipe in which the leak hole exists could not be uniquely identified in S305, the plumbing technician checks in S307 whether there is any partial pipe in which the presence of the leak hole could not be uniquely confirmed based on the fluorescent color of the fluorescent liquid leaking from the leak hole in the partial pipe.

[0051] If the plumber has a partial pipe that has not been uniquely identified as having a leak hole, the plumber adds such partial pipe to the whitelist in S308.

[0052] Next, in S309, the court concludes that the plumber failed to identify the partial pipe.

[0053] Next, the pipe inspection method will be explained using several examples. It is assumed that a resident or the like reports an actual water leak and that there is one leak hole in the pipe 111. This is because the probability of one leak hole occurring in a pipe is extremely low, and the probability of multiple leak holes occurring simultaneously in a pipe is even lower.

[0054] [Example 1] 4(a) and 4(b) are conceptual diagrams for explaining Example 1. In Example 1, first, as shown in FIG. 4(a), fluorescent liquids having red, green, and blue fluorescent colors are poured into the pipe 111 from three upstream drain outlets E1, E2, and E4, respectively, to inspect the pipe. Next, as shown in FIG. 4(b), fluorescent liquids having red and green fluorescent colors are poured into the pipe 111 from two downstream drain outlets E4 and E6, respectively, to inspect the pipe. The pipe inspection method shown in FIGS. 2 and 3 will be described with reference to FIGS. 4(a) and 4(b).

[0055] In S201, the plumbing contractor determines from which drain outlet a fluorescent liquid of which fluorescent color will be poured into the pipe 111. Here, as shown in Fig. 4(a), the plumbing contractor determines that a fluorescent liquid having a red fluorescent color will be poured into the pipe 111 from drain outlet E1, a fluorescent liquid having a green fluorescent color will be poured into the pipe 111 from drain outlet E2, and a fluorescent liquid having a blue fluorescent color will be poured into the pipe 111 from drain outlet E4.

[0056] Next, in S202, the plumbing worker records the information, determined in S201, about which drain outlet the fluorescent liquid of which fluorescent color is to be poured into the pipe 111, as color allocation information in, for example, a workbook.

[0057] Next, in S203, the plumber pours fluorescent liquid having a fluorescent color determined based on the color assignment information into the pipe 111 from the drain outlet determined based on the color assignment information recorded in S201.

[0058] In this case, fluorescent liquid having a red fluorescent color flows through partial pipe S1, fluorescent liquid having a green fluorescent color flows through partial pipe S2, fluorescent liquid having a yellow fluorescent color flows through partial pipe S3, fluorescent liquid having a blue fluorescent color flows through partial pipe S4, fluorescent liquid having a white fluorescent color flows through partial pipe S5, fluorescent liquid having a white fluorescent color flows through partial pipe S7, and fluorescent liquid does not flow through partial pipe S6.

[0059] Here, a fluorescent liquid having a yellow fluorescent color can be obtained by mixing a fluorescent liquid having a red fluorescent color with a fluorescent liquid having a green fluorescent color. Also, a fluorescent liquid having a white fluorescent color can be obtained by mixing a fluorescent liquid having a red fluorescent color with a fluorescent liquid having a green fluorescent color and a fluorescent liquid having a blue fluorescent color. Or, it can be said that a fluorescent liquid having a yellow fluorescent color can be obtained by mixing a fluorescent liquid having a yellow fluorescent color with a fluorescent liquid having a blue fluorescent color.

[0060] In Figure 4(a), drain outlet E6 into which fluorescent liquid is not poured and partial pipe H6 through which fluorescent liquid does not flow are marked with an "x". This also applies to other similar drawings referred to in the following explanation.

[0061] Next, in S204, the plumber checks whether the fluorescent liquid has leaked.

[0062] If a water leak hole H1 exists in the partial pipe S1, the fluorescent liquid having a red fluorescent color leaks out from the water leak hole H1, and for example, a liquid pool 121 of the fluorescent liquid having a red fluorescent color is formed on the floor 102a.

[0063] If a leak hole H2 exists in the partial pipe S2, the fluorescent liquid having a green fluorescent color leaks out from the leak hole H2, and for example, a liquid pool 121 of the fluorescent liquid having a green fluorescent color is formed on the floor 102a.

[0064] If a leak hole H3 exists in the partial pipe S3, the fluorescent liquid having a yellow fluorescent color leaks out from the leak hole H3, and for example, a liquid pool 121 of the fluorescent liquid having a yellow fluorescent color is formed on the floor 102a.

[0065] If a leak hole H4 exists in the partial pipe S4, the fluorescent liquid having a blue fluorescent color leaks out from the leak hole H4, and for example, a liquid pool 121 of the fluorescent liquid having a blue fluorescent color is formed on the floor 102a.

[0066] If a leak hole H5 exists in the partial pipe S5, the fluorescent liquid having a white fluorescent color leaks out from the leak hole H5, and for example, a liquid pool 121 of the fluorescent liquid having a white fluorescent color is formed on the floor 102a.

[0067] If a leak hole H7 exists in the partial pipe S7, the fluorescent liquid having a white fluorescent color leaks out from the leak hole H7, and for example, a liquid pool 121 of the fluorescent liquid having a white fluorescent color is formed on the floor 102a.

[0068] In the above six cases, a YES determination is made in S204, and the plumbing technician checks the fluorescent color of the fluorescent liquid that constitutes the liquid pool 121 in S205.

[0069] On the other hand, if a water leak hole H6 exists in the partial piping S6, no water leakage will occur. In this case, a NO determination is made in S204, and the plumbing worker is not required to check the fluorescent color of the liquid pool 121.

[0070] In this example, if the answer is NO in S204, it can be inferred by the process of elimination that there is a leak hole in partial pipe S6. In other words, if there is a leak hole in any of partial pipes S1 to S7, and fluorescent liquid is flowing through partial pipes S1 to S5 and S7 but no fluorescent liquid is leaking, this means that there are no leak holes in partial pipes S1 to S5 and S7, so by the process of elimination it can be inferred that there is a leak hole in partial pipe S6. Therefore, the inspection method may be ended here.

[0071] Next, the plumbing engineer executes a partial plumbing identification process (S206).

[0072] The partial pipe identification process (S206) will be described in detail with reference to FIG.

[0073] First, in S301, the plumbing worker acquires color allocation information, which is recorded in, for example, a workbook in S202.

[0074] Next, in S302, the plumbing technician executes a process for uniquely identifying a partial pipe in which a leak hole exists, based only on the color allocation information and the fluorescent color of the leaking fluorescent liquid.

[0075] Here, if a leak hole H1 exists in the partial piping S1, it is possible to uniquely identify that the leak hole H1 is located in the partial piping S1 using the color assignment information and the fluorescent color red of the leaking fluorescent liquid.

[0076] Furthermore, if a leak hole H2 exists in the partial pipe S2, it is possible to uniquely identify that the leak hole H2 is located in the partial pipe S2 based on the color assignment information and the green color of the leaking fluorescent liquid.

[0077] Furthermore, if a leak hole H3 exists in the partial pipe S3, it is possible to uniquely identify that the leak hole H3 is located in the partial pipe S3 based on the color assignment information and the yellow color of the leaking fluorescent liquid.

[0078] Furthermore, if a leak hole H4 exists in the partial pipe S4, it is possible to uniquely identify that the leak hole H4 is located in the partial pipe S4 based on the color assignment information and the blue color of the leaking fluorescent liquid.

[0079] In the above four cases, the determination in S303 is YES, and the plumbing contractor records the identification information of the partial piping identified in S302, for example, in a workbook, in S310, and concludes in S311 that the partial piping has been identified.

[0080] On the other hand, if there is a leak hole H5 in partial pipe S5 and if there is a leak hole H7 in partial pipe S7, it is possible to determine that the leak hole H5 is in partial pipe S5 or that the leak hole H7 is in partial pipe S7 based on the color assignment information and the white color of the leaking fluorescent liquid, but it is not possible to determine which is which.

[0081] In this case, the determination in S303 is NO, and in S304, the plumber acquires a whitelist. Next, in S305, the plumber executes a process to uniquely identify a section of piping where a leak hole exists based on the color assignment information, the fluorescent color of the leaking fluorescent liquid, and the whitelist. However, since the whitelist does not contain any sections of piping that have been uniquely confirmed to have no leak holes, S305 executed here is essentially the same as S302 executed immediately before. Therefore, the determination result in S306 is NO, just like the determination result in S303, and the plumber proceeds to S307 in the piping inspection method.

[0082] In S307, the plumber checks whether there is a partial pipe for which it has been uniquely confirmed that there is no leak hole. In this case, it has been uniquely confirmed that there is no leak hole in the partial pipes S1, S2, S3, and S4. Therefore, the determination in S307 is YES, and the plumber adds the partial pipes S1, S2, S3, and S4 to the whitelist in S308. Next, in S309, the plumber concludes that the partial pipe could not be identified.

[0083] Returning to Fig. 2, after S206, the process proceeds to S207. If a water leak hole H1 exists in the partial pipe S1, if a water leak hole H2 exists in the partial pipe S2, if a water leak hole H3 exists in the partial pipe S3, or if a water leak hole H4 exists in the partial pipe S4, the determination in S207 becomes YES, and the pipe inspection method ends.

[0084] On the other hand, if there is a leak hole H5 in the partial pipe S5, if there is a leak hole H6 in the partial pipe S6, or if there is a leak hole H7 in the partial pipe S7, the determination in S207 will be NO, and the plumbing technician will proceed with the inspection to S208.

[0085] If there is a leak hole H7 in the partial piping S7, it can be identified by the process of elimination. However, if there is no identification by the process of elimination and there is a leak hole H7 in the partial piping S7, the determination in S207 will be NO, and the plumbing technician will proceed to S208.

[0086] In S208, the plumbing contractor determines which drain outlet to pour the fluorescent liquid of which fluorescent color into the pipe 111.

[0087] In S208, the plumbing contractor determines from which drain outlet a fluorescent liquid of which fluorescent color will be poured into the pipe 111. Here, as shown in FIG. 4(b), the plumbing contractor determines that a fluorescent liquid having a red fluorescent color will be poured into the pipe 111 from drain outlet E4, and that a fluorescent liquid having a green fluorescent color will be poured into the pipe 111 from drain outlet E6. The reason for this determination is that it is necessary to check whether a leak hole exists in any of the partial pipes H5, H6, and H7.

[0088] Next, in S209, the plumbing worker records the information, determined in S208, about which drain outlet the fluorescent liquid of which fluorescent color is to be poured into the pipe 111, as color allocation information in, for example, a workbook.

[0089] Next, in S203, the plumber pours fluorescent liquid having a fluorescent color determined based on the color assignment information into the pipe 111 from the drain outlet determined based on the color assignment information recorded in S209.

[0090] In this case, fluorescent liquid having a red fluorescent color flows through partial pipe S4, fluorescent liquid having a red fluorescent color flows through partial pipe S5, fluorescent liquid having a green fluorescent color flows through partial pipe S6, and fluorescent liquid having a yellow fluorescent color flows through partial pipe S7. Fluorescent liquid does not flow through partial pipes S1 to S3.

[0091] Next, in S204, the plumber checks whether the fluorescent liquid has leaked.

[0092] Here, if a water leak hole H4 exists in the partial piping S4, a fluorescent liquid having a red fluorescent color will leak from the water leak hole H1, and for example, a puddle 121 of the fluorescent liquid having a red fluorescent color will occur on the floor 102a. However, in reality, if a water leak hole H4 exists in the partial piping S4, the piping inspection method has already been terminated with a YES determination in S207. Therefore, this situation will not be realized.

[0093] If a leak hole H5 exists in the partial pipe S5, the fluorescent liquid having a red fluorescent color leaks out from the leak hole H5, and for example, a liquid pool 121 of the fluorescent liquid having a red fluorescent color is formed on the floor 102a.

[0094] If a leak hole H6 exists in the partial pipe S6, the fluorescent liquid having a green fluorescent color leaks out from the leak hole H6, and for example, a liquid pool 121 of the fluorescent liquid having a green fluorescent color is formed on the floor 102a.

[0095] If a leak hole H7 exists in the partial pipe S7, the fluorescent liquid having a yellow fluorescent color leaks out from the leak hole H7, and for example, a liquid pool 121 of the fluorescent liquid having a yellow fluorescent color occurs on the floor 102a.

[0096] In reality, if a leak hole exists in any of the partial piping S5 to S7, the process proceeds to S204, which should be executed for the second time, via S209, and the determination in S204 is always YES.

[0097] In S205, the plumbing worker checks the fluorescent color of the fluorescent liquid that constitutes the liquid pool 121.

[0098] Next, the plumbing engineer executes a partial plumbing identification process (S206).

[0099] The partial pipe identification process (S206) will be described in detail with reference to FIG.

[0100] First, in S301, the plumbing worker acquires color allocation information, which is recorded in, for example, a workbook in S209.

[0101] Next, in S302, the plumbing technician executes a process for uniquely identifying a partial pipe in which a leak hole exists, based only on the color allocation information and the fluorescent color of the leaking fluorescent liquid.

[0102] Here, if a leak hole H6 exists in the partial piping S6, it is possible to uniquely identify that the leak hole H6 is located in the partial piping S6 based on the color assignment information and the green fluorescent color of the leaking fluorescent liquid.

[0103] Furthermore, if a leak hole H7 exists in the partial piping S7, it is possible to uniquely identify that the leak hole H7 is located in the partial piping S7 based on the color assignment information and the yellow color of the leaking fluorescent liquid.

[0104] In the above two cases, the determination in S303 is YES, and the plumbing contractor records the identification information of the partial piping identified in S302, for example, in a workbook, in S310, and concludes in S311 that the partial piping has been identified.

[0105] On the other hand, if there is a leak hole H5 in the partial pipe S5, it is possible to determine, based on the color assignment information and the color of the leaking fluorescent liquid, which is red, whether the leak hole H4 is in the partial pipe S4 or whether the leak hole H5 is in the partial pipe S5, but it is not possible to determine which it is.

[0106] In this case, the determination in S303 is NO, and the plumbing worker advances the piping inspection method to S304.

[0107] In S304, the plumbing contractor obtains a whitelist, which registers the partial pipes S1, S2, S3, and S4 as partial pipes that have been uniquely confirmed to have no leak holes.

[0108] In Figure 4(b), the partial piping registered in the whitelist is marked with a "☆" mark. This also applies to other similar figures referred to in the following explanation.

[0109] Next, in S305, the plumbing technician executes a process to uniquely identify the partial pipe where the leak hole exists based on the color assignment information, the fluorescent color of the leaking fluorescent liquid, and the white list. Here, the fluorescent color of the leaking fluorescent liquid is red, and it is not possible to determine whether the leak hole exists in partial pipe S4 or partial pipe S5 based on the fluorescent color alone. However, partial pipe S4 is registered in the white list as a pipe that has been uniquely confirmed to have no leak hole. Therefore, it is possible to uniquely identify partial pipe S5 where the leak hole H5 exists based on the color assignment information, the fluorescent color of the leaking fluorescent liquid (red), and partial pipe S4 registered in the white list.

[0110] Therefore, the determination result in S306 is YES, and the plumbing technician proceeds to S310 in the plumbing inspection method. In S310, the plumbing technician records the identification information of the partial pipe identified in S305, for example, in a workbook, and concludes in S311 that the partial pipe has been identified. Therefore, the determination result in S207 is YES, and the plumbing inspection method ends.

[0111] Below, only some of the main steps will be described.

[0112] 4(a), in the first piping inspection method, when fluorescent liquids having red, green, and blue fluorescent colors are respectively poured into the piping 111 from the three upstream drain outlets E1, E2, and E4 (S203), fluorescent liquid having red fluorescent color flows in the partial piping S1, fluorescent liquid having green fluorescent color flows in the partial piping S2, fluorescent liquid having yellow fluorescent color flows in the partial piping S3, fluorescent liquid having blue fluorescent color flows in the partial piping S4, fluorescent liquid having white fluorescent color flows in the partial piping S5, fluorescent liquid having white fluorescent color flows in the partial piping S7, and fluorescent liquid does not flow in the partial piping S6.

[0113] When the liquid pool 121 is inspected by irradiating it with black light and the fluorescent color is red, it can be uniquely identified that the water leakage hole H1 is present in the partial piping S1 (S302, S303: YES).

[0114] When the fluorescent color of the liquid pool 121 examined by irradiating it with black light is green, it can be uniquely identified that the water leakage hole H2 exists in the partial piping S2 (S302, S303: YES).

[0115] When the liquid pool 121 is inspected by irradiating it with black light and the fluorescent color is yellow, it can be uniquely identified that the water leakage hole H3 is present in the partial piping S3 (S302, S303: YES).

[0116] When the fluorescent color of the liquid pool 121 examined by irradiating it with black light is blue, it can be uniquely identified that the water leakage hole H4 is present in the partial piping S4 (S302, S303: YES).

[0117] Therefore, in these four cases, only the first pipe inspection method is performed.

[0118] On the other hand, if the fluorescent color of the puddle 121 examined by irradiating it with black light is white, it is determined that there is a leak hole H5 in the partial pipe S5 or a leak hole H7 in the partial pipe S7, but it is not possible to determine which it is (S302, S303: NO). Partial pipes are not registered in the white list. Therefore, even if the white list is referenced, it is not possible to determine whether there is a leak hole H5 in the partial pipe S5 or a leak hole H7 in the partial pipe S7 (S304, S305, S306: NO).

[0119] Here, based on the color assignment information and the structure of the pipe 111 (the connection relationship of the partial pipes), it is known that a fluorescent liquid having a white fluorescent color flows in the partial pipes S5 and S7. Therefore, when the fluorescent color of the liquid puddle 121 examined by irradiating it with a black light is white, it is known that it is not possible to identify whether the partial pipe in which the leak hole exists is the partial pipe S5 or the partial pipe S7. Therefore, when the fluorescent color of the liquid puddle 121 is white, the partial pipes S5 and S7 are not registered in the white list.

[0120] On the other hand, based on the color assignment information and the structure of the pipe 111 (the connection relationship of the partial pipes), it is known that the fluorescent liquid having a red fluorescent color flows only in the partial pipe S1. Therefore, when the fluorescent color of the liquid puddle 121 examined by shining a black light is white, it is possible to identify that the partial pipe in which the leak hole exists is not the partial pipe S1. Therefore, when the fluorescent color of the liquid puddle 121 is white, the partial pipe S1 is registered on the white list. Similarly, when the fluorescent color of the liquid puddle 121 is white, the partial pipes S2 to S4 are added to the white list. Therefore, when the fluorescent color of the liquid puddle 121 is white, the partial pipes S1 to S4 are added to the white list.

[0121] Furthermore, it is known that fluorescent liquid does not flow into partial pipe S6 based on the color assignment information and the structure of pipe 111 (the connection relationship of the partial pipes). Therefore, even if partial pipe S6 has a leak hole H6, it is not possible to identify the presence of leak hole H6 in partial pipe S6 based on the fluorescent color of liquid pool 121 examined by irradiating it with black light. Therefore, partial pipe S6 is not registered on the whitelist.

[0122] From the above, if the fluorescent color of the liquid pool 121 examined by irradiating it with black light is white, the partial pipes S1 to S4 are added to the white list (S308), as indicated by the star in FIG. 4(b).

[0123] If no water leak occurs, there should be a water leak hole i (i = 1 to 7) in one of the partial piping S1 to S7, but it can be confirmed that there is no water leak hole Hj (j = 1 to 5, 7) in any of the partial piping S1 to S5 and S7. Therefore, by a process of elimination, it is possible to identify that there is a water leak hole H6 in the partial piping S6. Therefore, if no water leak occurs, it is possible to perform only the first piping inspection method and then end the process.

[0124] However, because the presence of a water leak hole H6 in the partial pipe S6 has not been confirmed due to a water leak, a second pipe inspection method may be performed. In this case, a white list similar to that created when the fluorescent color of the liquid puddle 121 examined by shining a black light is white is created. In other words, for the partial pipes S1 to S4, where the presence of a water leak hole could have been identified if the liquid puddle 121 had occurred and its color had been red, green, yellow, or blue, but because the liquid puddle 121 did not occur, such identification was not possible, so the partial pipes S1 to S4 are added to the white list.

[0125] The plumbing technician performs the second piping inspection method if the fluorescent color of the fluorescent liquid that forms the liquid pool 121 is white in the first piping inspection method. The plumbing technician may also perform the second piping inspection method even if the liquid pool 121 does not form in the first piping inspection method.

[0126] 4(b), when fluorescent liquids having red and green fluorescent colors are poured into the pipe 111 from the two downstream drain outlets E4 and E6, respectively (S203), fluorescent liquid having red fluorescent color flows into the partial pipe S4, fluorescent liquid having red fluorescent color flows into the partial pipe S5, fluorescent liquid having green fluorescent color flows into the partial pipe S6, and fluorescent liquid having yellow fluorescent color flows into the partial pipe S7. Fluorescent liquid does not flow into the partial pipes S1 to S3.

[0127] When the fluorescent color of the liquid pool 121 examined by irradiating it with black light is green, it can be uniquely identified that the water leakage hole H6 is present in the partial piping S6 (S302, S303: YES).

[0128] When the fluorescent color of the liquid pool 121 examined by irradiating it with black light is yellow, it can be uniquely identified that the water leakage hole H7 exists in the partial piping S7 (S302, S303: YES).

[0129] Therefore, in these two cases, the partial pipe where the water leak hole exists can be identified without using the white list in the second pipe inspection method.

[0130] On the other hand, if the fluorescent color of the puddle 121 examined by irradiating it with black light is red, it is determined that there is a leak hole H4 in the partial pipe S4 or a leak hole H5 in the partial pipe S5, but it is not possible to identify which it is (S302, S303: NO). Therefore, a white list is obtained (S304). The partial pipes S1 to S4 are registered on the white list. Here, by excluding the partial pipe S4 registered on the white list from the partial pipes S4 and S5 that are candidates for the partial pipe having a leak hole, it is possible to identify that there is a leak hole H5 in the partial pipe S5 (S305, S306: YES).

[0131] Although this will result in wasted fluorescent liquid, fluorescent liquids of, for example, red, green, and blue fluorescent colors may be flowed into the pipe 111 from the drain outlets E2, E4, and E6 in the second inspection. Since it has been confirmed that there are no leak holes in the partial pipes S2 to S4, even in this case, fluorescent liquid will leak from a leak hole present in any of the partial pipes S5 to S7 in the second inspection.

[0132] [Example 2] In Example 1, when steps S203 and after are re-executed, as shown in Fig. 4(b), fluorescent liquids having red fluorescent color and fluorescent liquids having green fluorescent color are poured from drain outlets E4 and E6, respectively, but fluorescent liquid having blue fluorescent color is not used, and fluorescent liquid having blue fluorescent color is not produced either.

[0133] Therefore, at the same time as re-executing steps from S203, a water leak inspection can be performed on the partial pipe S8 included in the pipe 112 using a fluorescent liquid having a blue fluorescent color, as shown in Fig. 4(c). For example, if a puddle 121 of fluorescent liquid having a blue fluorescent color appears on the floor, it can be detected that there is a water leak hole in the partial pipe S8.

[0134] Also, at the same time as re-executing steps from S203, fluorescent liquid having a blue fluorescent color is sprayed onto the washing area 114, as shown in FIG. 4(d). For example, if a puddle 121 of fluorescent liquid having a blue fluorescent color appears on the floor 102a of the building frame, it can be detected that there is a hole or crack in the washing area 114 that could be the cause of a water leak. In this case, care is taken to prevent the fluorescent liquid having a blue fluorescent color from entering the piping 111 from the drain outlet provided in the washing area 114. This is a water leak inspection that does not go through the piping 111.

[0135] Note that the above "simultaneous" does not mean strictly simultaneous. It is not used in the sense that they must be simultaneous, but rather that it is okay if they are simultaneous. For example, a time included in a predetermined period (for example, several minutes to several tens of minutes) centered on the time when S203 is performed is included in "simultaneous."

[0136] [Example 3] 5(a) and 5(b) are conceptual diagrams for explaining Example 3. In Example 3, first, as shown in FIG. 5(a), fluorescent liquids having red and green fluorescent colors are poured into the pipe 111 from two upstream drain outlets E1 and E2, respectively, to inspect the pipe. Then, as shown in FIG. 5(b), fluorescent liquids having red, green, and blue fluorescent colors are poured into the pipe 111 from three downstream drain outlets E2, E4, and E6, respectively, to inspect the pipe. The pipe inspection method shown in FIGS. 2 and 3 will be described with reference to FIGS. 5(a) and 5(b).

[0137] In S201, the plumbing contractor determines from which drain outlet a fluorescent liquid of which fluorescent color will be poured into the pipe 111. Here, as shown in Fig. 5(a), the plumbing contractor determines that a fluorescent liquid having a red fluorescent color will be poured into the pipe 111 from drain outlet E1, and that a fluorescent liquid having a green fluorescent color will be poured into the pipe 111 from drain outlet E2.

[0138] Next, in S202, the plumbing worker records the information, determined in S201, about which drain outlet the fluorescent liquid of which fluorescent color is to be poured into the pipe 111, as color allocation information in, for example, a workbook.

[0139] Next, in S203, the plumber pours fluorescent liquid having a fluorescent color determined based on the color assignment information into the pipe 111 from the drain outlet determined based on the color assignment information recorded in S201.

[0140] In this case, fluorescent liquid having a red fluorescent color flows through partial pipe S1, fluorescent liquid having a green fluorescent color flows through partial pipe S2, fluorescent liquid having a yellow fluorescent color flows through partial pipe S3, fluorescent liquid having a yellow fluorescent color flows through partial pipe S5, and fluorescent liquid having a yellow fluorescent color flows through partial pipe S7.

[0141] No fluorescent liquid flows through the partial pipes S4 and S6.

[0142] Next, in S204, the plumber checks whether the fluorescent liquid has leaked.

[0143] If a water leak hole H1 exists in the partial pipe S1, the fluorescent liquid having a red fluorescent color leaks out from the water leak hole H1, and for example, a liquid pool 121 of the fluorescent liquid having a red fluorescent color is formed on the floor 102a.

[0144] If a leak hole H2 exists in the partial pipe S2, the fluorescent liquid having a green fluorescent color leaks out from the leak hole H2, and for example, a liquid pool 121 of the fluorescent liquid having a green fluorescent color is formed on the floor 102a.

[0145] If a leak hole H3 exists in the partial pipe S3, the fluorescent liquid having a yellow fluorescent color leaks out from the leak hole H3, and for example, a liquid pool 121 of the fluorescent liquid having a yellow fluorescent color is formed on the floor 102a.

[0146] If a leak hole H5 exists in the partial pipe S5, the fluorescent liquid having a yellow fluorescent color leaks out from the leak hole H5, and for example, a liquid pool 121 of the fluorescent liquid having a yellow fluorescent color is formed on the floor 102a.

[0147] If a leak hole H7 exists in the partial pipe S7, the fluorescent liquid having a yellow fluorescent color leaks out from the leak hole H7, and for example, a liquid pool 121 of the fluorescent liquid having a yellow fluorescent color occurs on the floor 102a.

[0148] In the above five cases, a YES determination is made in S204, and the plumbing technician checks the fluorescent color of the fluorescent liquid that constitutes the liquid pool 121 in S205.

[0149] On the other hand, if there is a water leak hole H4 in the partial pipe S4 or if there is a water leak hole H6 in the partial pipe S6, no water leak will occur. In this case, the determination in S204 is NO, and the plumbing worker will not need to check the fluorescent color of the liquid pool 121.

[0150] Next, the plumbing engineer executes a partial plumbing identification process (S206).

[0151] The partial pipe identification process (S206) will be described in detail with reference to FIG.

[0152] First, in S301, the plumbing worker acquires color allocation information, which is recorded in, for example, a workbook in S202.

[0153] Next, in S302, the plumbing technician executes a process for uniquely identifying a partial pipe in which a leak hole exists, based only on the color allocation information and the fluorescent color of the leaking fluorescent liquid.

[0154] Here, if a leak hole H1 exists in the partial piping S1, it is possible to uniquely identify that the leak hole H1 is located in the partial piping S1 using the color assignment information and the fluorescent color red of the leaking fluorescent liquid.

[0155] Furthermore, if a leak hole H2 exists in the partial pipe S2, it is possible to uniquely identify that the leak hole H2 is located in the partial pipe S2 based on the color assignment information and the green color of the leaking fluorescent liquid.

[0156] In the above two cases, the determination in S303 is YES, and the plumbing contractor records the identification information of the partial piping identified in S302, for example, in a workbook, in S310, and concludes in S311 that the partial piping has been identified.

[0157] On the other hand, if there is a leak hole H3 in partial pipe S3, if there is a leak hole H5 in partial pipe S5, or if there is a leak hole H7 in partial pipe S7, it is possible to determine from the color assignment information and the yellow color of the leaking fluorescent liquid that leak hole H3 is in partial pipe S3, that leak hole H5 is in partial pipe S5, or that leak hole H7 is in partial pipe S7, but it is not possible to determine which it is.

[0158] In this case, the determination in S303 is NO, and in S304, the plumber acquires a whitelist. Next, in S305, the plumber executes a process to uniquely identify a section of piping where a leak hole exists based on the color assignment information, the fluorescent color of the leaking fluorescent liquid, and the whitelist. However, since the whitelist does not contain any sections of piping that have been uniquely confirmed to have no leak holes, S305 executed here is essentially the same as S302 executed immediately before. Therefore, the determination result in S306 is NO, just like the determination result in S303, and the plumber proceeds to S307 in the piping inspection method.

[0159] In S307, the plumbing technician checks whether any new partial pipes have been created in which it has not been possible to uniquely identify the presence of a leak hole.

[0160] Here, the presence of a leak hole in the partial pipe S1, which could have been uniquely confirmed by the red fluorescent liquid, could not be confirmed, and the presence of a leak hole in the partial pipe S2, which could have been uniquely confirmed by the green fluorescent liquid, could not be confirmed, leading to S307. Therefore, the partial pipes S1 and S2 are partial pipes in which the presence of a leak hole could not be uniquely confirmed. Therefore, the determination in S307 is YES, and the plumbing contractor adds the partial pipes S1 and S2 to the whitelist.

[0161] The plumber then concludes that he failed to identify the partial plumbing under S309.

[0162] Returning to Fig. 2, after S206, the process proceeds to S207. If a water leakage hole H1 exists in the partial piping S1 and if a water leakage hole H2 exists in the partial piping S2, the determination in S207 becomes YES, and the piping inspection method ends.

[0163] On the other hand, if a water leakage hole Hn (n=3 to 7) exists in any of the partial piping S3 to S7, the determination in S207 is NO, and the plumbing technician proceeds to the inspection in S208.

[0164] In S208, the plumbing contractor determines which drain outlet to pour the fluorescent liquid of which fluorescent color into the pipe 111.

[0165] In S208, the plumbing contractor determines which drain outlet to pour fluorescent liquid of which fluorescent color into the pipe 111. Here, as shown in FIG. 5(b), the plumbing contractor determines that fluorescent liquid having a red fluorescent color will be poured into the pipe 111 from drain outlet E2, fluorescent liquid having a green fluorescent color will be poured into the pipe 111 from drain outlet E4, and fluorescent liquid having a blue fluorescent color will be poured into the pipe 111 from drain outlet E6. The reason for making such determinations is that it is necessary to check which of the partial pipes H3 to H7 has a leak hole.

[0166] Next, in S209, the plumbing worker records the information, determined in S208, about which drain outlet the fluorescent liquid of which fluorescent color is to be poured into the pipe 111, as color allocation information in, for example, a workbook.

[0167] Next, in S203, the plumber pours fluorescent liquid having a fluorescent color determined based on the color assignment information into the pipe 111 from the drain outlet determined based on the color assignment information recorded in S209.

[0168] In this case, fluorescent liquid having a red fluorescent color flows through partial pipe S2, fluorescent liquid having a red fluorescent color flows through partial pipe S3, fluorescent liquid having a green fluorescent color flows through partial pipe S4. Also, fluorescent liquid having a yellow fluorescent color flows through partial pipe S5, fluorescent liquid having a blue fluorescent color flows through partial pipe S6, fluorescent liquid having a white fluorescent color flows through partial pipe S7. No fluorescent liquid flows through partial pipe S1.

[0169] Next, in S204, the plumber checks whether the fluorescent liquid has leaked.

[0170] Here, if a leak hole H2 exists in the partial piping S2, fluorescent liquid having a red fluorescent color will leak from the leak hole H2, and for example, a puddle 121 of fluorescent liquid having a red fluorescent color will occur on the floor 102a. However, in reality, if a leak hole H2 exists in the partial piping S2, the piping inspection method has already been terminated with a YES determination in S207. Therefore, this will not occur.

[0171] If a leak hole H3 exists in the partial pipe S3, the fluorescent liquid having a red fluorescent color leaks out from the leak hole H3, and for example, a liquid pool 121 of the fluorescent liquid having a red fluorescent color is formed on the floor 102a.

[0172] If a leak hole H4 exists in the partial pipe S4, the fluorescent liquid having a green fluorescent color leaks out from the leak hole H5, and for example, a pool 121 of the fluorescent liquid having a green fluorescent color is formed on the floor 102a.

[0173] If a leak hole H5 exists in the partial pipe S5, the fluorescent liquid having a yellow fluorescent color leaks out from the leak hole H5, and for example, a liquid pool 121 of the fluorescent liquid having a yellow fluorescent color is formed on the floor 102a.

[0174] If a leak hole H6 exists in the partial pipe S6, the fluorescent liquid having a blue fluorescent color leaks out from the leak hole H6, and for example, a liquid pool 121 of the fluorescent liquid having a blue fluorescent color is formed on the floor 102a.

[0175] If a leak hole H7 exists in the partial pipe S7, the fluorescent liquid having a white fluorescent color leaks out from the leak hole H7, and for example, a liquid pool 121 of the fluorescent liquid having a white fluorescent color is formed on the floor 102a.

[0176] In reality, if a leak hole exists in any of the partial piping S3 to S7, the process proceeds to S204, which should be executed for the second time, via S209, and the determination in S204 is always YES.

[0177] In S205, the plumbing worker checks the fluorescent color of the fluorescent liquid that constitutes the liquid pool 121.

[0178] Next, the plumbing engineer executes a partial plumbing identification process (S206).

[0179] The partial pipe identification process (S206) will be described in detail with reference to FIG.

[0180] First, in S301, the plumbing worker acquires color allocation information, which is recorded in, for example, a workbook in S209.

[0181] Next, in S302, the plumbing technician executes a process for uniquely identifying a partial pipe in which a leak hole exists, based only on the color allocation information and the fluorescent color of the leaking fluorescent liquid.

[0182] Here, if a leak hole H4 exists in the partial piping S4, it is possible to uniquely identify that the leak hole H4 is located in the partial piping S4 by the color assignment information and the green fluorescent color of the leaking fluorescent liquid.

[0183] If a water leak hole H5 exists in the partial pipe S5, it is possible to uniquely identify that the water leak hole H5 is located in the partial pipe S5 based on the color assignment information and the yellow fluorescent color of the leaking fluorescent liquid.

[0184] If a water leak hole H6 exists in the partial pipe S6, it is possible to uniquely identify that the water leak hole H6 is located in the partial pipe S6 based on the color assignment information and the blue fluorescent color of the leaking fluorescent liquid.

[0185] If a water leak hole H7 exists in the partial pipe S7, it is possible to uniquely identify that the water leak hole H7 is located in the partial pipe S7 based on the color assignment information and the white color of the leaking fluorescent liquid.

[0186] In the above four cases, the determination in S303 is YES, and the plumbing contractor records the identification information of the partial piping identified in S305, for example, in a workbook in S302, and concludes in S311 that the partial piping has been identified.

[0187] On the other hand, if there is a leak hole H3 in the partial pipe S3, it is possible to determine, based on the color assignment information and the color of the leaking fluorescent liquid, which is red, whether the leak hole H2 is in the partial pipe S2 or whether the leak hole H3 is in the partial pipe S3, but it is not possible to determine which it is.

[0188] In this case, the determination in S303 is NO, and the plumbing worker advances the piping inspection method to S304.

[0189] In S304, the plumbing contractor obtains the whitelist. The whitelist contains the partial pipes S1 and S2 as parts of the pipe that have been uniquely confirmed to have no leak holes. In Figure 5(b), the partial pipes registered on the whitelist are marked with a "☆".

[0190] Next, in S305, the plumbing technician executes a process to uniquely identify the partial pipe where the leak hole exists based on the color assignment information, the fluorescent color of the leaking fluorescent liquid, and the white list. Here, the fluorescent color of the leaking fluorescent liquid is red, and it is not possible to determine whether the leak hole exists in partial pipe S2 or partial pipe S3 based on the fluorescent color alone. However, partial pipe S2 is registered in the white list as a partial pipe where it has been uniquely confirmed that there is no leak hole. Therefore, it is possible to uniquely identify partial pipe S3 where the leak hole H3 exists based on the color assignment information, the fluorescent color of the leaking fluorescent liquid (red), and partial pipe S2 registered in the white list.

[0191] Therefore, the determination result in S306 is YES, and the plumbing technician proceeds to S310 in the plumbing inspection method. In S310, the plumbing technician records the identification information of the partial pipe identified in S305, for example, in a workbook, and concludes in S311 that the partial pipe has been identified. Therefore, the determination result in S207 is YES, and the plumbing inspection method ends.

[0192] Below, only some of the main steps will be described.

[0193] 5(a), when fluorescent liquids having red and green fluorescent colors are poured into the pipe 111 from the two upstream drain outlets E1 and E2, respectively (S203), fluorescent liquid having red fluorescent color flows in the partial pipe S1, fluorescent liquid having green fluorescent color flows in the partial pipe S2, fluorescent liquid having yellow fluorescent color flows in the partial pipe S3, fluorescent liquid having yellow fluorescent color flows in the partial pipe S5, fluorescent liquid having yellow fluorescent color flows in the partial pipe S7. No fluorescent liquid flows in the partial pipes S4 and S6.

[0194] When the liquid pool 121 is inspected by irradiating it with black light and the fluorescent color is red, it can be uniquely identified that the water leakage hole H1 is present in the partial piping S1 (S302, S303: YES).

[0195] When the fluorescent color of the liquid pool 121 examined by irradiating it with black light is green, it can be uniquely identified that the water leakage hole H2 exists in the partial piping S2 (S302, S303: YES).

[0196] Therefore, in these two cases, only the first pipe inspection method is carried out.

[0197] On the other hand, if the fluorescent color of the puddle 121 examined by irradiating it with black light is yellow, it is determined that there is a leak hole H3 in the partial pipe S3, a leak hole H5 in the partial pipe S5, or a leak hole H7 in the partial pipe S7, but it is not possible to determine which one it is (S302, S303: NO). Partial pipes are not registered in the whitelist. Therefore, even if the whitelist is referenced, it is not possible to determine whether there is a leak hole H3 in the partial pipe S3, a leak hole H5 in the partial pipe S5, or a leak hole H7 in the partial pipe S7 (S304, S305, S306: NO).

[0198] Here, based on the color assignment information and the structure of the pipe 111 (the connection relationship of the partial pipes), it is known that a fluorescent liquid having a yellow fluorescent color flows in the partial pipes S3, S5, and S7. Therefore, when the fluorescent color of the liquid pool 121 examined by irradiating it with a black light is yellow, it is known that it is impossible to identify whether the partial pipe in which the leak hole exists is the partial pipe S3, the partial pipe S5, or the partial pipe S7. Therefore, when the fluorescent color of the liquid pool 121 is yellow, the partial pipes S3, S5, and S7 are not registered in the whitelist.

[0199] On the other hand, based on the color assignment information and the structure of the pipe 111 (the connection relationship of the partial pipes), it is known that the fluorescent liquid having a red fluorescent color flows only in the partial pipe S1. Therefore, when the fluorescent color of the liquid puddle 121 examined by shining a black light is yellow, it is possible to identify that the partial pipe in which the leak hole exists is not the partial pipe S1. Therefore, when the fluorescent color of the liquid puddle 121 is yellow, the partial pipe S1 is registered on the white list. Similarly, when the fluorescent color of the liquid puddle 121 is yellow, the partial pipe S2 is added to the white list. Therefore, when the fluorescent color of the liquid puddle 121 is yellow, the partial pipes S1 and S2 are added to the white list.

[0200] Furthermore, based on the color assignment information and the structure of the pipe 111 (the connection relationship of the partial pipes), it is known that the fluorescent liquid will not flow into the partial pipes S4 and S6. Therefore, even if there is a leak hole H4 in the partial pipe S4, it is not possible to identify the presence of the leak hole H4 in the partial pipe S4 based on the fluorescent color of the liquid pool 121 examined by shining a black light on it. The same is true for the partial pipe H6. Therefore, the partial pipes S4 and S6 are not registered on the whitelist.

[0201] From the above, if the fluorescent color of the liquid pool 121 examined by irradiating it with black light is yellow, the partial pipes S1 and S2 are added to the white list (S308), as indicated by the star in FIG. 5(b).

[0202] If no water leakage occurs, there should be a leak hole i (i = 1 to 7) in one of the partial pipes S1 to S7, but it can be confirmed that there is no leak hole Hj (j = 1 to 3, 5, 7) in any of the partial pipes S1 to S3, S5, and S7. Therefore, even if the elimination method is used, it is not possible to determine whether there is a leak hole H4 in the partial pipe S4 or whether there is a leak hole H6 in the partial pipe S6.

[0203] Even when no water leak occurs, a white list similar to that created when the fluorescent color of the liquid puddle 121 examined by shining a black light on it is yellow is created. In other words, for the pipe sections S1 and S2, where the existence of a water leak hole could have been identified if the liquid puddle 121 had occurred and its color had been red or green, but since the liquid puddle 121 did not occur, such identification was not possible, and so the pipe sections S1 and S2 are added to the white list.

[0204] The piping technician performs the second piping inspection method if the fluorescent color of the fluorescent liquid that forms the liquid pool 121 is yellow in the first piping inspection method. The piping technician also performs the second piping inspection method if the liquid pool 121 does not occur in the first piping inspection method.

[0205] 5(b), in the second piping inspection method, when fluorescent liquids having red, green, and blue fluorescent colors are poured into the piping 111 from the three downstream drain outlets E2, E4, and E6, respectively (S203), fluorescent liquid having red fluorescent color flows in the partial piping S2, fluorescent liquid having red fluorescent color flows in the partial piping S3, fluorescent liquid having green fluorescent color flows in the partial piping S4, fluorescent liquid having yellow fluorescent color flows in the partial piping S5, fluorescent liquid having blue fluorescent color flows in the partial piping S6, and fluorescent liquid having white fluorescent color flows in the partial piping S7. No fluorescent liquid flows in the partial piping S1.

[0206] When the fluorescent color of the liquid pool 121 examined by irradiating it with black light is green, it can be uniquely identified that the water leakage hole H4 is present in the partial piping S4 (S302, S303: YES).

[0207] When the fluorescent color of the liquid pool 121 examined by irradiating it with black light is yellow, it can be uniquely identified that the water leakage hole H5 exists in the partial piping S5 (S302, S303: YES).

[0208] When the fluorescent color of the liquid pool 121 examined by irradiating it with black light is blue, it can be uniquely identified that the water leakage hole H6 is present in the partial piping S6 (S302, S303: YES).

[0209] When the fluorescent color of the liquid pool 121 examined by irradiating it with black light is white, it can be uniquely identified that the water leakage hole H7 exists in the partial piping S7 (S302, S303: YES).

[0210] Therefore, in these four cases, it is possible to identify a partial pipe where a water leak hole exists without using a white list in the second pipe inspection method.

[0211] On the other hand, if the fluorescent color of the puddle 121 examined by irradiating it with black light is red, it is determined that there is a leak hole H2 in the partial pipe S2 or a leak hole H3 in the partial pipe S3, but it is not possible to identify which it is (S302, S303: NO). Therefore, a white list is obtained (S304). The partial pipes S1 and S2 are registered on the white list. Here, by excluding the partial pipe S2 registered on the white list from the partial pipes S2 and S3 that are candidates for the partial pipe having a leak hole, it is possible to identify that there is a leak hole H3 in the partial pipe S3 (S305, S306: YES).

[0212] [Example 4] 6(a) and 6(b) are conceptual diagrams for explaining Example 4. In Example 4, in a first pipe inspection method, as shown in FIG. 6(a), fluorescent liquids having red, green, and blue fluorescent colors are poured into the pipe 111 from three downstream drain outlets E2, E4, and E6, respectively, to inspect the pipe. Then, as necessary, a second pipe inspection method is performed. In the second pipe inspection method, as shown in FIG. 6(b), fluorescent liquids having red and green fluorescent colors are poured into the pipe 111 from two upstream drain outlets E1 and E2, respectively, to inspect the pipe. In Example 4, the pipe inspection method described with reference to FIGS. 2 and 3 is also performed, as in Examples 1 and 3. Therefore, detailed descriptions of each step are omitted, and only some steps will be described.

[0213] 6(a), in the first piping inspection method, when fluorescent liquids having red, green, and blue fluorescent colors are respectively poured into the piping 111 from the three downstream drain outlets E2, E4, and E6 (S203), fluorescent liquid having red fluorescent color flows in the partial piping S2, fluorescent liquid having red fluorescent color flows in the partial piping S3, fluorescent liquid having green fluorescent color flows in the partial piping S4, fluorescent liquid having yellow fluorescent color flows in the partial piping S5, fluorescent liquid having blue fluorescent color flows in the partial piping S6, and fluorescent liquid having white fluorescent color flows in the partial piping S7. No fluorescent liquid flows in the partial piping S1.

[0214] When the fluorescent color of the liquid pool 121 examined by irradiating it with black light is green, it can be uniquely identified that the water leakage hole H4 is present in the partial piping S4 (S302, S303: YES).

[0215] When the fluorescent color of the liquid pool 121 examined by irradiating it with black light is yellow, it can be uniquely identified that the water leakage hole H5 exists in the partial piping S5 (S302, S303: YES).

[0216] When the fluorescent color of the liquid pool 121 examined by irradiating it with black light is blue, it can be uniquely identified that the water leakage hole H6 is present in the partial piping S6 (S302, S303: YES).

[0217] When the fluorescent color of the liquid pool 121 examined by irradiating it with black light is white, it can be uniquely identified that the water leakage hole H7 exists in the partial piping S7 (S302, S303: YES).

[0218] Therefore, in these four cases, only the first pipe inspection method is performed.

[0219] On the other hand, if the fluorescent color of the liquid pool 121 examined by irradiating it with black light is red, it is determined that there is a leak hole H2 in the partial pipe S2 or a leak hole H3 in the partial pipe S3, but it is not possible to identify which it is (S302, S303: NO). The whitelist does not register any partial pipes for which it has not been possible to uniquely confirm the presence of a leak hole. Therefore, even if the whitelist is referenced, it is not possible to identify whether there is a leak hole H2 in the partial pipe S2 or a leak hole H3 in the partial pipe S3 (S304, S305, S306: NO).

[0220] Here, based on the color assignment information and the structure of the pipe 111 (the connection relationship of the partial pipes), it is known that a fluorescent liquid having a red fluorescent color flows in the partial pipes S2 and S3. Therefore, when the fluorescent color of the liquid pool 121 examined by irradiating it with a black light is red, it is known that it is not possible to identify whether the partial pipe in which the leak hole exists is the partial pipe S2 or the partial pipe S3. Therefore, when the fluorescent color of the liquid pool 121 is red, the partial pipes S2 and S3 are not registered in the whitelist.

[0221] On the other hand, based on the color assignment information and the structure of the pipe 111 (the connection relationship of the partial pipes), it is known that fluorescent liquid having a green fluorescent color flows only in partial pipe S4. Therefore, when the fluorescent color of the liquid puddle 121 examined by shining a black light is red, it is possible to identify that the partial pipe in which the leak hole exists is not partial pipe S4. Therefore, when the fluorescent color of the liquid puddle 121 is red, partial pipe S4 is registered on the white list. Similarly, when the fluorescent color of the liquid puddle 121 is red, partial pipes S5 to S7 are added to the white list.

[0222] Furthermore, based on the color assignment information and the structure of the pipe 111 (the connection relationship of the partial pipes), it is known that the fluorescent liquid will not flow into the partial pipe S1. Therefore, even if there is a leak hole H1 in the partial pipe S1, it is not possible to identify the existence of the leak hole H1 in the partial pipe S1 based on the fluorescent color of the liquid pool 121 examined by irradiating it with a black light. Therefore, the partial pipe S1 is not registered on the whitelist.

[0223] From the above, if the fluorescent color of the liquid pool 121 examined by irradiating it with black light is red, the partial piping S4 to S7 is added to the white list (S308), as indicated by the star in FIG. 6(b).

[0224] If no water leak occurs, a leak hole i (i = 1 to 7) should exist in one of the partial pipes S1 to S7. However, it can be confirmed that a leak hole Hj (j = 2 to 7) does not exist in any of the partial pipes S2 to S7. Therefore, by process of elimination, it is possible to identify the existence of a leak hole H1 in the partial pipe S1. Therefore, in this case, only the first pipe inspection method is performed, and a second pipe inspection method does not need to be performed. However, just to be sure, a second pipe inspection method may be performed. In this case, a white list similar to that created when the fluorescent color of the liquid puddle 121 inspected by irradiating it with black light is red is created. In other words, for the partial pipes S4 to S7, if a liquid puddle 121 had occurred and its color had been green, yellow, blue, or white, the existence of a leak hole could have been identified. However, because the liquid puddle 121 did not exist, such identification was not possible, and therefore the partial pipes S4 to S7 are added to the white list.

[0225] The piping technician performs the second piping inspection method if the fluorescent color of the fluorescent liquid that forms the liquid pool 121 is red in the first piping inspection method. The piping technician may also perform the second piping inspection method if the liquid pool 121 does not occur in the first piping inspection method.

[0226] 6(b), in the second piping inspection method, when fluorescent liquids having red and green fluorescent colors are poured into the piping 111 from the two upstream drain outlets E1 and E2, respectively (S203), fluorescent liquid having red fluorescent color flows in the partial piping S1, fluorescent liquid having green fluorescent color flows in the partial piping S2, fluorescent liquid having yellow fluorescent color flows in the partial piping S3, fluorescent liquid having yellow fluorescent color flows in the partial piping S5, fluorescent liquid having yellow fluorescent color flows in the partial piping S7. No fluorescent liquid flows in the partial piping S4 and S6.

[0227] When the liquid pool 121 is inspected by irradiating it with black light and the fluorescent color is red, it can be uniquely identified that the water leakage hole H1 is present in the partial piping S1 (S302, S303: YES).

[0228] When the fluorescent color of the liquid pool 121 examined by irradiating it with black light is green, it can be uniquely identified that the water leakage hole H2 exists in the partial piping S2 (S302, S303: YES).

[0229] Therefore, in these two cases, the partial pipe where the water leak hole exists can be identified without using the white list in the second pipe inspection method.

[0230] On the other hand, if the fluorescent color of the puddle 121 examined by irradiating it with black light is yellow, it is determined that there is a leak hole H3 in the partial pipe S3, a leak hole H5 in the partial pipe S5, or a leak hole H7 in the partial pipe S7, but it is not possible to identify which one it is (S302, S303: NO). Therefore, a white list is obtained (S304). The partial pipes S4 to S7 are registered on the white list. Here, by excluding the partial pipes S5 and S7 registered on the white list from the partial pipes S3, S5, and S7 that are candidates for the partial pipe having a leak hole, it is possible to identify that there is a leak hole H3 in the partial pipe S3 (S305, S306: YES).

[0231] [Example 5] 7(a) and 7(b) are conceptual diagrams for explaining Example 5. In Example 5, in a first pipe inspection method, as shown in FIG. 7(a), fluorescent liquids having red and green fluorescent colors are poured into the pipe 111 from two downstream drain outlets E4 and E6, respectively, to inspect the pipe. Then, as necessary, a second pipe inspection method is performed. In the second pipe inspection method, as shown in FIG. 7(b), fluorescent liquids having red, green, and blue fluorescent colors are poured into the pipe 111 from three upstream drain outlets E1, E2, and E4, respectively, to inspect the pipe. In Example 5, the pipe inspection method described with reference to FIGS. 2 and 3 is also performed, as in Examples 1 and 3. Therefore, detailed descriptions of each step are omitted, and only some steps will be described.

[0232] 7(a), when fluorescent liquids having red and green fluorescent colors are poured into the pipe 111 from the two downstream drain outlets E4 and E6, respectively (S203), fluorescent liquid having red fluorescent color flows into the partial pipe S4, fluorescent liquid having red fluorescent color flows into the partial pipe S5, fluorescent liquid having green fluorescent color flows into the partial pipe S6, and fluorescent liquid having yellow fluorescent color flows into the partial pipe S7. Fluorescent liquid does not flow into the partial pipes S1 to S3.

[0233] When the fluorescent color of the liquid pool 121 examined by irradiating it with black light is green, it can be uniquely identified that the water leakage hole H6 is present in the partial piping S6 (S302, S303: YES).

[0234] When the fluorescent color of the liquid pool 121 examined by irradiating it with black light is yellow, it can be uniquely identified that the water leakage hole H7 exists in the partial piping S7 (S302, S303: YES).

[0235] Therefore, in these two cases, only the first pipe inspection method is carried out.

[0236] On the other hand, if the fluorescent color of the liquid pool 121 examined by irradiating it with black light is red, it is determined that there is a leak hole H4 in the partial pipe S4 or a leak hole H5 in the partial pipe S5, but it is not possible to identify which it is (S302, S303: NO). The whitelist does not register any partial pipes for which it has not been possible to uniquely confirm the presence of a leak hole. Therefore, even if the whitelist is referenced, it is not possible to identify whether there is a leak hole H4 in the partial pipe S4 or a leak hole H5 in the partial pipe S5 (S304, S305, S306: NO).

[0237] Here, based on the color assignment information and the structure of the pipe 111 (the connection relationship of the partial pipes), it is known that a fluorescent liquid having a red fluorescent color flows in the partial pipes S4 and S5. Therefore, when the fluorescent color of the liquid pool 121 examined by irradiating it with a black light is red, it is known that it is not possible to identify whether the partial pipe in which the leak hole exists is the partial pipe S2 or the partial pipe S3. Therefore, when the fluorescent color of the liquid pool 121 is red, the partial pipes S4 and S5 are not registered in the whitelist.

[0238] On the other hand, based on the color assignment information and the structure of the pipe 111 (the connection relationship of the partial pipes), it is known that fluorescent liquid having a green fluorescent color flows only in the partial pipe S6. Therefore, when the fluorescent color of the liquid puddle 121 examined by shining a black light is red, it is possible to identify that the partial pipe in which the leak hole exists is not the partial pipe S6. Therefore, when the fluorescent color of the liquid puddle 121 is red, the partial pipe S6 is registered on the white list. Similarly, when the fluorescent color of the liquid puddle 121 is red, the partial pipe S7 is added to the white list. Therefore, when the fluorescent color of the liquid puddle 121 is red, the partial pipes S6 and S7 are added to the white list.

[0239] Furthermore, based on the color assignment information and the structure of the pipe 111 (the connection relationship of the partial pipes), it is known that the fluorescent liquid will not flow from the partial pipes S1 to S3. Therefore, even if there is a leak hole Hi (i = 1 to 3) in any of the partial pipes S1 to S3, it is not possible to identify the existence of the leak hole Hi (i = 1 to 3) in any of the partial pipes S1 to S3 based on the fluorescent color of the liquid pool 121 examined by irradiating it with black light. Therefore, the partial pipes S1 to S3 are not registered on the whitelist.

[0240] From the above, if the fluorescent color of the liquid pool 121 examined by irradiating it with black light is red, the partial pipes S6 and S7 are added to the white list (S308), as indicated by the star in FIG. 7(b).

[0241] If no water leak occurs, a leak hole i (i = 1 to 7) should exist in one of the partial pipes S1 to S7. However, it can be confirmed that a leak hole Hj (j = 2 to 7) does not exist in any of the partial pipes S4 to S7. Therefore, by process of elimination, it is possible to identify that a leak hole Hi (i = 1 to 3) exists in one of the partial pipes S1 to S3. However, it is not possible to identify which of these three partial pipes S1 to S3 has a leak hole. In this case, a white list similar to that for the case where the fluorescent color of the liquid puddle 121 examined by irradiating it with a black light is red is created. In other words, for partial pipes S6 and S7, if a liquid puddle 121 had occurred and its color had been green or yellow, it would have been possible to identify the existence of a leak hole. However, because no liquid puddle 121 exists, such identification was not possible. Therefore, partial pipes S6 and S7 are added to the white list.

[0242] The piping technician performs the second piping inspection method if the fluorescent color of the fluorescent liquid that forms the liquid pool 121 is red in the first piping inspection method. The piping technician also performs the second piping inspection method if the liquid pool 121 does not occur in the first piping inspection method.

[0243] 7(b), in the second piping inspection method, when fluorescent liquids having red, green, and blue fluorescent colors are respectively poured into the piping 111 from the two upstream drain outlets E1, E2, and E4 (S203), fluorescent liquid having red fluorescent color flows in the partial piping S1, fluorescent liquid having green fluorescent color flows in the partial piping S2, fluorescent liquid having yellow fluorescent color flows in the partial piping S3, fluorescent liquid having blue fluorescent color flows in the partial piping S4, fluorescent liquid having white fluorescent color flows in the partial piping S5, fluorescent liquid having white fluorescent color flows in the partial piping S7, and fluorescent liquid having white fluorescent color flows in the partial piping S6.

[0244] When the liquid pool 121 is inspected by irradiating it with black light and the fluorescent color is red, it can be uniquely identified that the water leakage hole H1 is present in the partial piping S1 (S302, S303: YES).

[0245] When the fluorescent color of the liquid pool 121 examined by irradiating it with black light is green, it can be uniquely identified that the water leakage hole H2 exists in the partial piping S2 (S302, S303: YES).

[0246] When the liquid pool 121 is inspected by irradiating it with black light and the fluorescent color is yellow, it can be uniquely identified that the water leakage hole H3 is present in the partial piping S3 (S302, S303: YES).

[0247] When the fluorescent color of the liquid pool 121 examined by irradiating it with black light is blue, it can be uniquely identified that the water leakage hole H4 is present in the partial piping S4 (S302, S303: YES).

[0248] Therefore, in these four cases, it is possible to identify a partial pipe where a water leak hole exists without using a white list in the second pipe inspection method.

[0249] On the other hand, if the fluorescent color of the puddle 121 examined by irradiating it with black light is white, it is determined that there is a leak hole H5 in the partial pipe S5 or a leak hole H7 in the partial pipe S7, but it is not possible to identify which it is (S302, S303: NO). Therefore, a white list is obtained (S304). The partial pipes S6 and S7 are registered on the white list. Here, by excluding the partial pipe S7 registered on the white list from the partial pipes S5 and S7 that are candidates for the partial pipe having a leak hole, it is possible to identify that there is a leak hole H5 in the partial pipe S5 (S305, S306: YES).

[0250] [Example 6] FIGS. 8(a), 8(b), and 8(c) are conceptual diagrams for explaining Example 6. In Example 6, in a first piping inspection method, as shown in FIG. 8(a), a piping inspection is performed by pouring fluorescent liquids having red and green fluorescent colors into the piping 111 from two upstream drain outlets E1 and E2, respectively. Then, a second piping inspection method is performed as needed. In the second piping inspection method, as shown in FIG. 8(b), a piping inspection is performed by pouring fluorescent liquids having red and green fluorescent colors into the piping 111 from two midstream drain outlets E2 and E4, respectively. Furthermore, a third piping inspection method is performed as needed. In the third piping inspection method, as shown in FIG. 8(c), a piping inspection is performed by pouring fluorescent liquids having red and green fluorescent colors into the piping 111 from two downstream drain outlets E4 and E6, respectively. In Example 6, the piping inspection method described with reference to FIGS. 2 and 3 is also performed, as in Examples 1 and 3. Therefore, detailed explanations of each step will be omitted, and only some of the steps will be explained.

[0251] 8(a), in the first piping inspection method, when fluorescent liquids having red and green fluorescent colors are poured into the piping 111 from the two upper drain outlets E1 and E2, respectively (S203), fluorescent liquid having red fluorescent color flows in the partial piping S1, fluorescent liquid having green fluorescent color flows in the partial piping S2, fluorescent liquid having yellow fluorescent color flows in the partial piping S3, fluorescent liquid having yellow fluorescent color flows in the partial piping S5, fluorescent liquid having yellow fluorescent color flows in the partial piping S7. Fluorescent liquid does not flow in the partial piping S4 and S6.

[0252] When the liquid pool 121 is inspected by irradiating it with black light and the fluorescent color is red, it can be uniquely identified that the water leakage hole H1 is present in the partial piping S1 (S302, S303: YES).

[0253] When the fluorescent color of the liquid pool 121 examined by irradiating it with black light is green, it can be uniquely identified that the water leakage hole H2 exists in the partial piping S2 (S302, S303: YES).

[0254] Therefore, in these two cases, only the first pipe inspection method is carried out.

[0255] On the other hand, if the fluorescent color of the puddle 121 examined by irradiating it with black light is yellow, it is determined that there is a leak hole H3 in the partial pipe S3, a leak hole H5 in the partial pipe S5, or a leak hole H7 in the partial pipe S7, but it is not possible to determine which one it is (S302, S303: NO). No partial pipes are registered in the whitelist. Therefore, even if the whitelist is referenced, it is not possible to determine whether there is a leak hole H3 in the partial pipe S3, a leak hole H5 in the partial pipe S5, or a leak hole H7 in the partial pipe S7 (S304, S305, S306: NO).

[0256] Here, based on the color assignment information and the structure of the pipe 111 (the connection relationship of the partial pipes), it is known that a fluorescent liquid having a yellow fluorescent color flows in the partial pipes S3, S5, and S7. Therefore, when the fluorescent color of the liquid pool 121 examined by irradiating it with a black light is yellow, it is known that it is impossible to identify whether the partial pipe in which the leak hole exists is the partial pipe S3, the partial pipe S5, or the partial pipe S7. Therefore, when the fluorescent color of the liquid pool 121 is yellow, the partial pipes S3, S5, and S7 are not registered in the whitelist.

[0257] On the other hand, based on the color assignment information and the structure of the pipe 111 (the connection relationship of the partial pipes), it is known that the fluorescent liquid having a red fluorescent color flows only in the partial pipe S1. Therefore, when the fluorescent color of the liquid puddle 121 examined by shining a black light is yellow, it is possible to identify that the partial pipe in which the leak hole exists is not the partial pipe S1. Therefore, when the fluorescent color of the liquid puddle 121 is yellow, the partial pipe S1 is registered on the white list. Similarly, when the fluorescent color of the liquid puddle 121 is yellow, the partial pipe S2 is added to the white list. Therefore, when the fluorescent color of the liquid puddle 121 is yellow, the partial pipes S1 and S2 are added to the white list.

[0258] Furthermore, based on the color assignment information and the structure of the pipe 111 (the connection relationship of the partial pipes), it is known that the fluorescent liquid will not flow into the partial pipes S4 and S6. Therefore, even if there is a leak hole Hi (i = 4, 6) in either of the partial pipes S4 and S6, it is not possible to identify the existence of the leak hole Hi (i = 4, 6) in either of the partial pipes S4 and S6 based on the fluorescent color of the liquid pool 121 examined by irradiating it with black light. Therefore, if the fluorescent color of the liquid pool 121 is yellow, the partial pipes S4 and S6 will not be registered on the whitelist.

[0259] From the above, if the fluorescent color of the liquid pool 121 examined by irradiating it with black light is yellow, the partial pipes S1 and S2 are added to the white list (S308), as indicated by the star in FIG. 8(b).

[0260] If no water leak occurs, a leak hole i (i = 1 to 7) should exist in one of the partial pipes S1 to S7. However, it can be confirmed that a leak hole Hi (i = 1 to 3, 5, 7) does not exist in any of the partial pipes S1 to S3, S5, and S7. Therefore, by process of elimination, it is possible to identify that a leak hole Hi (i = 4, 6) exists in one of the partial pipes S4 and S6. However, it is not possible to identify which of these two partial pipes S4 and S6 has a leak hole. In this case, a white list similar to that for the case where the fluorescent color of the liquid puddle 121 examined by irradiating it with a black light is yellow is created. In other words, for the partial pipes S1 and S2, where a leak hole would have been identified if a liquid puddle 121 had occurred and its color had been red or green, the liquid puddle 121 did not occur, and therefore such identification was not possible. Therefore, the partial pipes S1 and S2 are added to the white list.

[0261] The piping technician performs the second piping inspection method if the fluorescent color of the fluorescent liquid that forms the liquid pool 121 is yellow in the first piping inspection method. The piping technician also performs the second piping inspection method if the liquid pool 121 does not occur in the first piping inspection method.

[0262] 8(b), in the second piping inspection method, when fluorescent liquids having red and green fluorescent colors are poured into the piping 111 from two midstream drain outlets E2 and E4, respectively (S203), fluorescent liquid having red fluorescent color flows in partial piping S2, fluorescent liquid having red fluorescent color flows in partial piping S3, fluorescent liquid having green fluorescent color flows in partial piping S4, fluorescent liquid having yellow fluorescent color flows in partial piping S5, and fluorescent liquid having yellow fluorescent color flows in partial piping S7. No fluorescent liquid flows in partial piping S1 and S6.

[0263] When the fluorescent color of the liquid pool 121 examined by irradiating it with black light is green, it can be uniquely identified that the water leakage hole H4 is present in the partial piping S4 (S302, S303: YES).

[0264] Therefore, in this case, it is possible to identify a portion of the pipe where a water leak hole exists without using a white list in the second pipe inspection method.

[0265] On the other hand, if the fluorescent color of the puddle 121 examined by irradiating it with black light is red, it is determined that there is a leak hole H2 in the partial pipe S2 or a leak hole H3 in the partial pipe S3, but it is not possible to identify which it is (S302, S303: NO). Therefore, a white list is obtained (S304). The partial pipes S1 and S2 are registered on the white list. Here, by excluding the partial pipe S2 registered on the white list from the partial pipes S2 and S3 that are candidates for the partial pipe having a leak hole, it is possible to identify that there is a leak hole H3 in the partial pipe S3 (S305, S306: YES).

[0266] Furthermore, if the fluorescent color of the puddle 121 examined by irradiating it with black light is yellow, it is determined that there is a leak hole H5 in the partial pipe S5 or a leak hole H7 in the partial pipe S7, but it is not possible to identify which it is (S302, S303: NO). Therefore, a white list is obtained (S304). The partial pipes S1 and S2 are registered in the white list, but neither the partial pipes S5 nor S7 are registered. Therefore, even if the white list is referenced, it is not possible to identify whether there is a leak hole H5 in the partial pipe S5 or a leak hole H7 in the partial pipe S7 (S305, S306: NO).

[0267] Here, based on the color assignment information and the structure of the pipe 111 (the connection relationship of the partial pipes), it is known that a fluorescent liquid having a yellow fluorescent color flows in the partial pipes S5 and S7. Therefore, when the fluorescent color of the liquid pool 121 examined by irradiating it with a black light is yellow, it is known that it is not possible to identify whether the partial pipe in which the leak hole exists is the partial pipe S5 or the partial pipe S7. Therefore, when the fluorescent color of the liquid pool 121 is yellow, the partial pipes S5 and S7 are not registered on the whitelist.

[0268] On the other hand, based on the color assignment information and the structure of the pipe 111 (the connection relationship of the partial pipes), it is known that the fluorescent liquid having a green fluorescent color flows only in the partial pipe S4. Therefore, when the fluorescent color of the liquid pool 121 examined by irradiating it with a black light is yellow, it is possible to identify that the partial pipe in which the leak hole exists is not the partial pipe S4. Therefore, when the fluorescent color of the liquid pool 121 is yellow, the partial pipe S4 is registered on the white list.

[0269] Furthermore, based on the color assignment information and the structure of the pipe 111 (the connection relationship of the partial pipes), it is known that fluorescent liquid having a red fluorescent color flows in the partial pipes S2 and S3. It is also known that the partial pipes S1 and S2 are registered on the white list. Therefore, based on the color assignment information, the structure of the pipe 111 (the connection relationship of the partial pipes), and the white list, if a puddle 121 of fluorescent liquid having a red fluorescent color is formed, it is known that it is possible to identify that there is a leak hole H3 in the partial pipe S3. Therefore, if the fluorescent color of the puddle 121 examined by irradiating it with a black light is yellow, it is possible to identify that the partial pipe in which the leak hole exists is not the partial pipe S3. Therefore, if the fluorescent color of the puddle 121 is yellow, the partial pipe S3 is registered on the white list.

[0270] Furthermore, based on the color assignment information and the structure of the pipe 111 (the connection relationship of the partial pipes), it is known that the fluorescent liquid will not flow into the partial pipes S1 and S6. Therefore, even if there is a leak hole Hi (i = 1, 6) in either the partial pipes S1 or S6, it is not possible to determine whether there is a leak hole Hi (i = 4, 6) in either the partial pipes S1 or S6 based on the fluorescent color of the liquid puddle 121 examined by irradiating it with black light. However, the partial pipe S1 has already been registered on the whitelist. Therefore, if the fluorescent color of the liquid puddle 121 is yellow, it can be confirmed that there is no leak hole H6 in the partial pipe S6. Therefore, if the fluorescent color of the liquid puddle 121 is yellow, the partial pipe S6 may be registered on the whitelist. The following description will be given assuming that the partial pipe S6 is registered on the whitelist.

[0271] Therefore, if the fluorescent color of the liquid pool 121 is yellow, the partial pipes S3, S4, and S6 are registered on the whitelist (S308). Here, the partial pipes S1 and S2 have already been registered on the whitelist. Therefore, if the fluorescent color of the liquid pool 121 is yellow, the partial pipes that have already been registered on the whitelist are the partial pipes S1, S2, S3, S4, and S6, as indicated by ☆ in Figure 8(c).

[0272] If no water leak occurs, there should be a leak hole i (i = 1 to 7) in one of the partial pipes S1 to S7, but it can be confirmed that there is no leak hole Hj (j = 2 to 5, 7) in any of the partial pipes S2 to S5 and S7. Therefore, by a process of elimination, it can be determined that there is a leak hole Hi (i = 4, 6) in either the partial pipes S1 or S6. Here, the partial pipe S1 is registered on the whitelist. Therefore, it can be determined that there is a leak hole H6 in the partial pipe S6.

[0273] If the fluorescent color of the fluorescent liquid forming the liquid pool 121 is yellow in the second pipe inspection method, the plumbing worker performs the third pipe inspection method.

[0274] 8(c), when fluorescent liquids having red and green fluorescent colors are poured into the pipe 111 from the two downstream drain outlets E4 and E6, respectively (S203), fluorescent liquid having red fluorescent color flows into the partial pipe S4, fluorescent liquid having red fluorescent color flows into the partial pipe S5, fluorescent liquid having green fluorescent color flows into the partial pipe S6, and fluorescent liquid having yellow fluorescent color flows into the partial pipe S7. Fluorescent liquid does not flow into the partial pipes S1 to S3.

[0275] When the fluorescent color of the liquid pool 121 examined by irradiating it with black light is yellow, it can be uniquely identified that the water leakage hole H7 exists in the partial piping S7 (S302, S303: YES).

[0276] Therefore, in this case, it is possible to identify the partial pipe where a water leak hole exists without using a white list in the third pipe inspection method.

[0277] On the other hand, if the fluorescent color of the puddle 121 examined by irradiating it with black light is red, it is determined that there is a leak hole H4 in the partial pipe S4 or a leak hole H5 in the partial pipe S5, but it is not possible to identify which it is (S302, S303: NO). Therefore, a white list is obtained (S304). The partial pipes S1 to S4 and S6 are registered on the white list. Here, by excluding the partial pipe S4 registered on the white list from the partial pipes S4 and S5 that are candidates for the partial pipe having a leak hole, it is possible to identify that there is a leak hole H5 in the partial pipe S5 (S305, S306: YES).

[0278] In the third piping inspection method, if the fluorescent color of the liquid puddle 121 inspected by irradiating it with black light is green, it can be uniquely identified that there is a water leak hole H6 in the partial piping S6 (S302, S303: YES). However, if there is a water leak hole H6 in the partial piping S6, it has already been identified in the second piping inspection method as described above.

[0279] [Example 7] FIGS. 9(a), 9(b), and 9(c) are conceptual diagrams for explaining Example 7. In Example 7, in a first piping inspection method, as shown in FIG. 9(a), fluorescent liquids having red and green fluorescent colors are poured into the piping 111 from two downstream drain outlets E4 and E6, respectively, to inspect the piping. Then, a second piping inspection method is performed as needed. In the second piping inspection method, as shown in FIG. 9(b), fluorescent liquids having red and green fluorescent colors are poured into the piping 111 from two midstream drain outlets E2 and E4, respectively, to inspect the piping. Furthermore, a third piping inspection method is performed as needed. In the third piping inspection method, as shown in FIG. 9(c), fluorescent liquids having red and green fluorescent colors are poured into the piping 111 from two upstream drain outlets E1 and E2, respectively, to inspect the piping. In Example 7, the piping inspection method described with reference to FIGS. 2 and 3 is also performed, as in Examples 1 and 3. Therefore, detailed explanations of each step will be omitted, and only some of the steps will be explained.

[0280] 9(a), when fluorescent liquids having red and green fluorescent colors are poured into the pipe 111 from the two lower drain outlets E4 and E6, respectively (S203), fluorescent liquid having red fluorescent color flows into the partial pipe S4, fluorescent liquid having green fluorescent color flows into the partial pipe S5, fluorescent liquid having green fluorescent color flows into the partial pipe S6, and fluorescent liquid having yellow fluorescent color flows into the partial pipe S7. Fluorescent liquid does not flow into the partial pipes S1 to S3.

[0281] When the fluorescent color of the liquid pool 121 examined by irradiating it with black light is green, it can be uniquely identified that the water leakage hole H6 is present in the partial piping S6 (S302, S303: YES).

[0282] When the fluorescent color of the liquid pool 121 examined by irradiating it with black light is yellow, it can be uniquely identified that the water leakage hole H7 exists in the partial piping S7 (S302, S303: YES).

[0283] Therefore, in these two cases, only the first pipe inspection method is carried out.

[0284] On the other hand, if the fluorescent color of the liquid pool 121 examined by irradiating it with black light is red, it is determined that there is a leak hole H4 in the partial pipe S4 or a leak hole H5 in the partial pipe S5, but it is not possible to determine which it is (S302, S303: NO). No partial pipes are registered in the whitelist. Therefore, even if the whitelist is referenced, it is not possible to determine whether there is a leak hole H4 in the partial pipe S4 or a leak hole H5 in the partial pipe S5 (S304, S305, S306: NO).

[0285] Here, based on the color assignment information and the structure of the pipe 111 (the connection relationship of the partial pipes), it is known that a fluorescent liquid having a red fluorescent color flows in the partial pipes S4 and S5. Therefore, when the fluorescent color of the liquid pool 121 examined by irradiating it with a black light is red, it is known that it is not possible to identify whether the partial pipe in which the leak hole exists is partial pipe S4 or partial pipe S5. Therefore, when the fluorescent color of the liquid pool 121 is red, partial pipes S4 and S5 are not registered in the whitelist.

[0286] On the other hand, based on the color assignment information and the structure of the pipe 111 (the connection relationship of the partial pipes), it is known that fluorescent liquid having a green fluorescent color flows only in the partial pipe S6. Therefore, when the fluorescent color of the liquid puddle 121 examined by shining a black light is red, it is possible to identify that the partial pipe in which the leak hole exists is not the partial pipe S6. Therefore, when the fluorescent color of the liquid puddle 121 is red, the partial pipe S6 is registered on the white list. Similarly, when the fluorescent color of the liquid puddle 121 is red, the partial pipe S7 is added to the white list. Therefore, when the fluorescent color of the liquid puddle 121 is red, the partial pipes S6 and S7 are added to the white list.

[0287] Furthermore, based on the color assignment information and the structure of the pipe 111 (the connection relationship of the partial pipes), it is known that the fluorescent liquid will not flow from the partial pipes S1 to S3. Therefore, even if there is a leak hole Hi (i = 1 to 3) in any of the partial pipes S1 to S3, it is not possible to identify the existence of the leak hole Hi (i = 1 to 3) in any of the partial pipes S1 to S3 based on the fluorescent color of the liquid pool 121 examined by irradiating it with black light. Therefore, the partial pipes S1 to S3 are not registered on the whitelist.

[0288] From the above, if the fluorescent color of the liquid pool 121 examined by irradiating it with black light is red, the partial pipes S6 and S7 are added to the white list (S308), as indicated by the star in FIG. 9(b).

[0289] If no water leak occurs, a leak hole i (i = 1 to 7) should exist in one of the partial pipes S1 to S7, but it can be confirmed that a leak hole Hi (i = 4 to 7) does not exist in any of the partial pipes S4 to S7. Therefore, by process of elimination, it is possible to identify that a leak hole Hi (i = 1 to 3) exists in one of the partial pipes S1 to S3. However, it is not possible to identify which of these three partial pipes S1 to S3 has a leak hole. In this case, a white list similar to that for the case where the fluorescent color of the liquid puddle 121 examined by irradiating it with a black light is red is created. In other words, for partial pipes S6 and S7, if a liquid puddle 121 had occurred and its color had been green or yellow, the existence of a leak hole could have been identified. However, because no liquid puddle 121 exists, such identification was not possible, and therefore partial pipes S6 and S7 are added to the white list.

[0290] The piping technician performs the second piping inspection method if the fluorescent color of the fluorescent liquid that forms the liquid pool 121 is red in the first piping inspection method. The piping technician also performs the second piping inspection method if the liquid pool 121 does not occur in the first piping inspection method.

[0291] 9(b), in the second piping inspection method, when fluorescent liquids having red and green fluorescent colors are poured into the piping 111 from two midstream drain outlets E2 and E4, respectively (S203), fluorescent liquid having red fluorescent color flows in partial piping S2, fluorescent liquid having red fluorescent color flows in partial piping S3, fluorescent liquid having green fluorescent color flows in partial piping S4, fluorescent liquid having yellow fluorescent color flows in partial piping S5, and fluorescent liquid having yellow fluorescent color flows in partial piping S7. No fluorescent liquid flows in partial piping S1 and S6.

[0292] When the fluorescent color of the liquid pool 121 examined by irradiating it with black light is green, it can be uniquely identified that the water leakage hole H4 is present in the partial piping S4 (S302, S303: YES).

[0293] Therefore, in this case, it is possible to identify a portion of the pipe where a water leak hole exists without using a white list in the second pipe inspection method.

[0294] On the other hand, if the fluorescent color of the puddle 121 examined by irradiating it with black light is yellow, it is determined that there is a leak hole H5 in the partial pipe S5 or a leak hole H7 in the partial pipe S7, but it is not possible to identify which it is (S302, S303: NO). Therefore, a white list is obtained (S304). The partial pipes S6 and S7 are registered on the white list. Here, by excluding the partial pipe S7 registered on the white list from the partial pipes S5 and S7 that are candidates for the partial pipe having a leak hole, it is possible to identify that there is a leak hole H5 in the partial pipe S5 (S305, S306: YES).

[0295] Furthermore, if the fluorescent color of the puddle 121 examined by irradiating it with black light is red, it is determined that there is a leak hole H2 in the partial pipe S2 or a leak hole H3 in the partial pipe S3, but it is not possible to identify which it is (S302, S303: NO). Therefore, a white list is obtained (S304). The partial pipes S6 and S7 are registered in the white list, but neither the partial pipes S2 nor S3 are registered. Therefore, even if the white list is referenced, it is not possible to identify whether there is a leak hole H2 in the partial pipe S2 or a leak hole H3 in the partial pipe S3 (S305, S306: NO).

[0296] Here, based on the color assignment information and the structure of the pipe 111 (the connection relationship of the partial pipes), it is known that a fluorescent liquid having a red fluorescent color flows in the partial pipes S2 and S3. Therefore, when the fluorescent color of the liquid pool 121 examined by irradiating it with a black light is red, it is known that it is not possible to identify whether the partial pipe in which the leak hole exists is the partial pipe S2 or the partial pipe S3. Therefore, when the fluorescent color of the liquid pool 121 is red, the partial pipes S2 and S3 are not registered in the whitelist.

[0297] On the other hand, based on the color assignment information and the structure of the pipe 111 (the connection relationship of the partial pipes), it is known that the fluorescent liquid having a green fluorescent color flows only in the partial pipe S4. Therefore, if the fluorescent color of the liquid pool 121 examined by irradiating it with a black light is red, it can be determined that the partial pipe in which the leak hole exists is not the partial pipe S4. Therefore, if the fluorescent color of the liquid pool 121 is red, the partial pipe S4 is registered on the white list.

[0298] Furthermore, based on the color assignment information and the structure of the pipe 111 (the connection relationship of the partial pipes), it is known that fluorescent liquid having a yellow fluorescent color flows through the partial pipes S5 and S7. It is also known that the partial pipes S6 and S7 are registered on the white list. Therefore, based on the color assignment information, the structure of the pipe 111 (the connection relationship of the partial pipes), and the white list, if a puddle 121 of fluorescent liquid having a yellow fluorescent color is formed, it is known that it is possible to identify that there is a leak hole H5 in the partial pipe S5. Therefore, if the fluorescent color of the puddle 121 examined by irradiating it with a black light is red, it is possible to identify that the partial pipe in which the leak hole exists is not the partial pipe S5. Therefore, if the fluorescent color of the puddle 121 is red, the partial pipe S5 is registered on the white list.

[0299] Furthermore, based on the color assignment information and the structure of the pipe 111 (the connection relationship of the partial pipes), it is known that the fluorescent liquid will not flow into the partial pipes S1 and S6. Therefore, even if there is a leak hole Hi (i = 1, 6) in either the partial pipes S1 or S6, it is not possible to determine whether there is a leak hole Hi (i = 4, 6) in either the partial pipes S1 or S6 based on the fluorescent color of the liquid puddle 121 examined by shining a black light. However, the partial pipe S6 has already been registered on the whitelist. Therefore, if the fluorescent color of the liquid puddle 121 is red, it can be confirmed that there is no leak hole H1 in the partial pipe S1. Therefore, if the fluorescent color of the liquid puddle 121 is red, the partial pipe S1 may be registered on the whitelist. The following description will be given assuming that the partial pipe S1 is registered on the whitelist.

[0300] Therefore, if the fluorescent color of the liquid pool 121 is red, the partial pipes S1, S4, and S5 are registered on the whitelist (S308). Here, the partial pipes S6 and S7 have already been registered on the whitelist. Therefore, if the fluorescent color of the liquid pool 121 is red, the partial pipes that have already been registered on the whitelist are the partial pipes S1, S4, S5, S6, and S7, as indicated by ☆ in Figure 9(c).

[0301] If no water leak occurs, there should be a leak hole i (i = 1 to 7) in one of the partial pipes S1 to S7, but it can be confirmed that there is no leak hole Hj (j = 2 to 5, 7) in any of the partial pipes S2 to S5 and S7. Therefore, by a process of elimination, it can be determined that there is a leak hole Hi (i = 4, 6) in either the partial pipes S1 or S6. Here, the partial pipe S6 is registered on the whitelist. Therefore, it can be determined that there is a leak hole H1 in the partial pipe S1.

[0302] If the fluorescent color of the fluorescent liquid forming the liquid pool 121 is red in the second pipe inspection method, the plumbing worker performs the third pipe inspection method.

[0303] 9(c), in the third piping inspection method, when fluorescent liquids having red and green fluorescent colors are poured into the piping 111 from the two upstream drain outlets E1 and E2, respectively (S203), fluorescent liquid having red fluorescent color flows in the partial piping S1, fluorescent liquid having green fluorescent color flows in the partial piping S2, fluorescent liquid having yellow fluorescent color flows in the partial piping S3, fluorescent liquid having yellow fluorescent color flows in the partial piping S5, fluorescent liquid having yellow fluorescent color flows in the partial piping S7. No fluorescent liquid flows in the partial piping S4 and S6.

[0304] When the fluorescent color of the liquid pool 121 examined by irradiating it with black light is green, it can be uniquely identified that the water leakage hole H2 exists in the partial piping S2 (S302, S303: YES).

[0305] Therefore, in this case, it is possible to identify the partial pipe where a water leak hole exists without using a white list in the third pipe inspection method.

[0306] On the other hand, if the fluorescent color of the puddle 121 examined by irradiating it with black light is yellow, it is determined that there is a leak hole H3 in the partial pipe S3, a leak hole H5 in the partial pipe S5, or a leak hole H7 in the partial pipe S7, but it is not possible to identify which one it is (S302, S303: NO). Therefore, a white list is obtained (S304). The partial pipes S1 and S4 to S7 are registered on the white list. Here, by excluding the partial pipes S5 and S7 registered on the white list from the partial pipes S3, S5, and S7 that are candidates for the partial pipe having a leak hole, it is possible to identify that there is a leak hole H5 in the partial pipe S3 (S305, S306: YES).

[0307] In the third piping inspection method, if the fluorescent color of the liquid pool 121 inspected by irradiating it with black light is red, it can be uniquely identified that there is a water leak hole H1 in the partial piping S1 (S302, S303: YES). However, if there is a water leak hole H1 in the partial piping S1, it has already been identified in the second piping inspection method as described above.

[0308] [Example 8] 10(a) and 10(b) are conceptual diagrams for explaining Example 8. In Example 8, in a first piping inspection method, as shown in FIG. 10(a), fluorescent liquids having red, green, and blue fluorescent colors are poured into the piping 131 from three drain outlets Ea, Ec, and Ee, respectively, to inspect the piping. Then, as necessary, a second piping inspection method is performed. In the second piping inspection method, as shown in FIG. 10(b), fluorescent liquids having red, green, and blue fluorescent colors are poured into the piping 131 from three drain outlets Ee, Eg, and Ei, which are shifted two outlets downstream, to inspect the piping 131. Thereafter, the piping inspection method is continued in the same manner as necessary, while shifting the drain outlets through which the fluorescent liquids are poured into the piping 131 by two outlets downstream at a time.

[0309] In the first pipe inspection method, as shown in FIG. 10(a), if the fluorescent color of the fluorescent liquid leaking from pipe 131 is green, yellow, or blue, partial pipe Sc, Sd, or Se can be uniquely identified as the partial pipe having a leak hole, respectively.

[0310] If the fluorescent color of the fluorescent liquid leaking from the pipe 131 is white or if no fluorescent liquid leaks from the pipe 131, it is not possible to identify the partial pipe where the leak hole is located. In these cases, a second pipe inspection method is carried out.

[0311] In the second pipe inspection method, as shown in FIG. 10(b), if the fluorescent color of the fluorescent liquid leaking from the pipe 131 is red, green, yellow, or blue, partial pipe Sf, Sg, Sh, or Si can be uniquely identified as the partial pipe having a leak hole, respectively. Note that partial pipe Sf is identified by utilizing the fact that partial pipe Se is registered in the whitelist. Also, related to this, if partial pipe Se has a leak hole, the second pipe inspection method is not executed.

[0312] To independently check for the presence of a leak hole Hf in the partial pipe Sf without using a white list, fluorescent liquids having red, green, and blue fluorescent colors are poured into the drain outlets Ec, Ee, and Eg, respectively, and it is checked whether a yellow fluorescent liquid leaks. Alternatively, fluorescent liquids having red, blue, and green fluorescent colors may be poured into the drain outlets Ec, Ee, and Eg, respectively, and it is checked whether a magenta fluorescent liquid leaks. Alternatively, fluorescent liquids having green, blue, and red fluorescent colors may be poured into the drain outlets Ec, Ee, and Eg, respectively, and it is checked whether a cyan fluorescent liquid leaks. Any colors may be selected as the three colors, but it is preferable to select three colors so that the fluorescent color of the fluorescent liquid flowing through the partial pipe Sf can be easily distinguished from the fluorescent colors flowing through other partial pipes.

[0313] To independently check whether there is a leak hole Hg in the partial pipe Sg without using a white list, fluorescent liquids having red and green fluorescent colors are poured into the drain outlets Ee and Eg, respectively, and it is checked whether the fluorescent liquid having green fluorescent color leaks. Alternatively, fluorescent liquids having blue and green fluorescent colors may be poured into the drain outlets Ee and Eg, respectively, and it is checked whether the fluorescent liquid having green fluorescent color leaks. Any colors may be selected as the two colors, but it is preferable to select two colors so that the fluorescent color of the fluorescent liquid flowing through the partial pipe Sg can be easily distinguished from the fluorescent colors flowing through other partial pipes.

[0314] [Example 9] 11(a) and 11(b) are conceptual diagrams for explaining Example 9. In Example 9, in a first piping inspection method, as shown in FIG. 11(a), fluorescent liquids having red, green, and blue fluorescent colors are poured into the piping 131 from three drain outlets Ee, Eg, and Ei, respectively, to inspect the piping. Then, as necessary, a second piping inspection method is performed. In the second piping inspection method, as shown in FIG. 11(b), fluorescent liquids having red, green, and blue fluorescent colors are poured into the piping 131 from three drain outlets Ea, Ec, and Ee, which are shifted two outlets upstream, to inspect the piping 131. Thereafter, the piping inspection method is continued as necessary, while shifting the drain outlets through which the fluorescent liquids are poured into the piping 131 downstream by two outlets at a time. Note that the partial piping Hj is assumed to be the most downstream partial piping.

[0315] In the first pipe inspection method, as shown in Figure 11(a), if the fluorescent color of the fluorescent liquid leaking from pipe 131 is green, yellow, blue, or white, partial pipe Sg, Sh, Si, or Sj can be uniquely identified as the partial pipe having a leak hole, respectively.

[0316] If the fluorescent color of the fluorescent liquid leaking from the pipe 131 is red, or if no fluorescent liquid leaks from the pipe 131, it is not possible to identify the portion of the pipe where the leak hole is located. In these cases, a second pipe inspection method is carried out.

[0317] In the second pipe inspection method, as shown in Fig. 11(b), when the fluorescent color of the fluorescent liquid leaking from the pipe 131 is green, yellow, blue, or white, partial pipes Sc, Sd, Se, or Sf can be uniquely identified as the partial pipe having a leak hole, respectively. Note that partial pipes Sh and Sj are registered in the white list to identify partial pipe Sf.

[0318] [Other embodiments] In the above embodiment, red and green are mixed first to produce yellow, and then yellow and blue are mixed to produce white, but this order may be reversed. For example, red and blue may be mixed first to produce magenta, and then magenta and green may be mixed to produce white. Alternatively, green and blue may be mixed first to produce cyan, and then cyan and red may be mixed to produce white.

[0319] If it is possible to determine that a leak hole exists in any of the n partial pipes, operation may be performed without narrowing down the search any further. For example, in the example shown in Figure 4(a), if the fluorescent color of the leaking fluorescent liquid is white, it can be determined that a leak hole exists in partial pipe S5 or S7, but operation may be performed without narrowing down the search any further.

[0320] It is conceivable to pour four or more different fluorescent liquids of different colors into a pipe through separate drains. However, even if the leak hole exists in a different section of the pipe, fluorescent liquids with similar near-white fluorescent colors will leak out. This is particularly noticeable in downstream sections of the pipe, where fluorescent liquids of various colors are mixed. In such cases, it becomes difficult to identify the section of the pipe where the leak hole exists based on the fluorescent color of the leaking fluorescent liquid. Therefore, in the above embodiment, the number of colors is limited to three, assuming that the colors will be distinguished visually. However, if the color spectrum distribution can be determined using, for example, a spectroscope or a measuring device capable of spectrum analysis, this limitation is eliminated.

Claims

1. an injection step of injecting fluorescent liquids having different fluorescent colors into the piping through a plurality of inlets of the piping; an identifying step of identifying a partial pipe having the leak hole among a plurality of partial pipes included in the pipe based on the fluorescent color of the fluorescent liquid leaking from the leak hole of the pipe; and the fluorescent color of the fluorescent liquid leaking from the leak hole in the piping is the same as the fluorescent color of the fluorescent liquid injected into the piping via any one of the inlets, or the fluorescent color of the fluorescent liquid obtained by mixing a plurality of fluorescent liquids injected into the piping via a plurality of the inlets; Piping inspection methods.

2. In the identifying step, information regarding which partial pipes the fluorescent liquid having which fluorescent color flows through is referenced. The piping inspection method according to claim 1 .

3. Information regarding which partial pipe the fluorescent liquid having which fluorescent color flows through is obtained based on information regarding which inlet of the pipe the fluorescent liquid having which fluorescent color is injected through into the pipe, information regarding which inlet of the pipe is the inlet of which partial pipe, and information regarding which partial pipe and which partial pipe merge into which partial pipe. The piping inspection method according to claim 2 .

4. the number of inlets through which the fluorescent liquid is injected into the piping is less than the number of inlets provided in the piping; In the injecting step, the fluorescent liquid is injected into the pipe without passing through some of the inlets of the pipe; The method further includes a second type identification step of identifying a partial pipe where the leak hole exists based on the fact that the fluorescent liquid does not leak from the leak hole of the pipe. The piping inspection method according to claim 1 .

5. the number of inlets through which the fluorescent liquid is injected into the piping is less than the number of inlets provided in the piping; re-executing the injection step and the identification step, while selecting a combination of inlets through which the fluorescent liquid is to be injected into the piping from a combination of inlets provided in the piping that is different from the combination in the injection step previously executed; The piping inspection method according to claim 1 .

6. If the partial pipe in which the leak hole exists cannot be identified in the first identification step, the method further includes a registration step of registering in a whitelist the partial pipe that could have been identified as the partial pipe in which the leak hole exists in the first identification step if the partial pipe actually has a leak hole, In the second identification step, a partial pipe in which the leak hole exists is identified among a plurality of partial pipes included in the pipe based on the fluorescent color of the fluorescent liquid leaking from the leak hole of the pipe or the fluorescent color of the fluorescent liquid leaking from the leak hole of the pipe and the white list. The piping inspection method according to claim 5.

7. a spraying step of spraying a fluorescent liquid having a fluorescent color different from the fluorescent colors of any of the fluorescent liquids injected into the pipes in the injecting step onto a portion of the building in which the pipes are installed that is suspected of having a water leak; a step of confirming whether or not fluorescent liquid having a fluorescent color different from the fluorescent colors of all of the fluorescent liquids injected into the piping in the injection step is leaking from a portion of the building suspected of having a water leak; Further comprising: The piping inspection method according to claim 1 .

8. The time when the spraying step is performed is included in a predetermined period centered on the time when the injection step is performed. The piping inspection method according to claim 7.

9. The fluorescent liquid leaking from the leak hole in the piping flows to the ceiling, wall, or floor of the building in which the piping is installed, and in the identifying step, the partial piping in which the leak hole exists is identified from among a plurality of partial pipings included in the piping, based on the fluorescent color of the fluorescent liquid that has flowed to the ceiling, wall, or floor. The piping inspection method according to claim 1 .

10. the first partial pipe and the second partial pipe merge into a third partial pipe; A piping inspection method for inspecting a piping having a configuration in which the third partial piping and the fourth partial piping join into a fifth partial piping, pouring a first fluorescent liquid having a first fluorescent color into the first partial pipe; pouring a second fluorescent liquid having a second fluorescent color into the second partial pipe; pouring a third fluorescent liquid having a third fluorescent color into the fourth partial pipe; inspecting whether or not there is a leak hole in the third partial pipe based on whether or not there is leakage of fluorescent liquid having a fluorescent color obtained by mixing the first fluorescent liquid and the second fluorescent liquid; Piping inspection methods.

11. inspecting whether or not there is a leak hole in the first partial pipe based on whether or not the fluorescent liquid having the first fluorescent color is leaking; The piping inspection method according to claim 10.

12. inspecting whether or not there is a leak hole in the second partial pipe based on whether or not the fluorescent liquid having the second fluorescent color is leaking; The piping inspection method according to claim 10.

13. inspecting whether or not there is a leak hole in the fourth partial pipe based on whether or not the fluorescent liquid having the third fluorescent color is leaking; The piping inspection method according to claim 10.

14. inspecting whether or not there is a leak hole in the fifth partial pipe based on whether or not there is leakage of fluorescent liquid having a fluorescent color obtained by mixing the first fluorescent liquid, the second fluorescent liquid, and the third fluorescent liquid; The piping inspection method according to claim 10.

15. A piping inspection method for inspecting a piping having a configuration in which a first partial piping and a second partial piping join a third partial piping, comprising: pouring a first fluorescent liquid having a first fluorescent color into the first partial pipe; pouring a second fluorescent liquid having a second fluorescent color into the second partial pipe; inspecting whether or not there is a leak hole in the third partial pipe based on whether or not there is leakage of fluorescent liquid having a fluorescent color obtained by mixing the first fluorescent liquid and the second fluorescent liquid; Piping inspection methods.

16. A piping inspection method for inspecting a piping having a configuration in which a first partial piping and a second partial piping join a third partial piping, comprising: pouring a first fluorescent liquid having a first fluorescent color into the first partial pipe; pouring a second fluorescent liquid having a second fluorescent color into the second partial pipe; Inspect whether there is a leak hole in the first partial pipe based on whether the fluorescent liquid containing the first fluorescent liquid leaks; Piping inspection methods.

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