JP2018081046A - Piping inspection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piping inspection method that hardly makes learning a state inside piping by transmission X ray partially inaccurate.SOLUTION: An X-ray film is exposed to a transmission X ray that passes through object piping, i.e. an inspection object. A corrosion state of the object piping is inspected on the basis of the X-ray film. A shield sheet is provided between the object piping and peripheral piping or the like, and thereby scattered X rays from the peripheral piping or the like are prevented from entering the X-ray film. A determination result of which type the object piping, i.e. the inspection object, is a first type (water supply system, hot-water supply system, or the like) or a second type (drain system or the like) and a determination result of whether or not a diameter of the object piping is equal to or more than a prescribed size are made necessary requirements to determine that a shield sheet will be provided.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a piping inspection method.

  Conventionally, as disclosed in Patent Document 1, there is a technique for grasping a corrosion state and the like inside a pipe by irradiating the pipe with X-rays and detecting the intensity of the X-ray transmitted through the pipe. For example, the X-ray film is exposed to X-rays transmitted through a pipe (hereinafter referred to as “transmitted X-rays”), and the X-ray film is developed to obtain the situation inside the pipe as an image on the film.

JP 2014-202603 A

  The present inventor has found that there is a case where an accurate situation inside the pipe cannot be partially grasped by detecting transmitted X-rays using an X-ray film or the like. For example, when an X-ray film exposed with transmitted X-rays is developed, a shadow may appear in the image on the film. In such a case, it is difficult to accurately grasp the corrosion state and the like inside the pipe in the shadowed portion.

  The purpose of the present invention is that it is not possible to partially grasp the accurate situation inside the pipe by transmitted X-rays, for example, the accurate situation of that part can be grasped by the shadow reflected in the image of the X-ray film by transmitted X-rays. The object is to provide a pipe inspection method that is unlikely to disappear.

  The present inventor has examined the cause of a phenomenon in which an accurate state inside the pipe cannot be partially grasped (hereinafter, referred to as the phenomenon), such as a shadow in the image of the X-ray film. In the following, it was considered that the problem was that X-rays scattered in the surrounding pipes and concrete walls (hereinafter referred to as “scattered X-rays”) enter the detector. In order to suppress the incidence of scattered X-rays to the detection unit, it is conceivable to provide a shielding means between the X-ray scattering source causing the phenomenon and the detection unit.

  However, scattered X-rays are generated in various ways depending on the surrounding conditions of the target pipe. Therefore, whether or not the phenomenon occurs also depends on the surrounding situation of the target pipe. In addition, when this phenomenon occurs, which equipment can be the cause of the scattering depends on the arrangement of the structures around the target pipe and the like. If it is necessary to determine whether or not to install shielding means based on the surrounding conditions of the target piping, it may take too much time and time to determine these according to various surrounding conditions. There is.

  Therefore, the present inventor, based on a number of piping inspections conducted in the past, what conditions are likely to cause the phenomenon and what are the main scattering sources that cause the phenomenon? I have studied earnestly. As a result, the present inventor has found that the ease of occurrence of the phenomenon depends not only on the surrounding situation of the target pipe but also on the situation of the target pipe itself. Specifically, this phenomenon is likely to occur when the target piping falls under a specific type, for example, when it falls under a water supply system, hot water supply system, etc., while the target piping falls under another type. For example, when it corresponds to a drainage system etc., it discovered that the said phenomenon did not occur easily. In addition, it was found that the diameter of the target piping was involved in the occurrence of the phenomenon. Specifically, it has been found that the phenomenon tends to occur as the diameter of the target pipe increases. Further, the present inventor has found that this phenomenon is likely to occur when other pipes are densely arranged around the target pipe or when a concrete wall is close to the target pipe. From this, it was found that the scattering source as the cause of the phenomenon was mainly another pipe around the target pipe or a concrete wall.

  The present invention based on the above is a method for inspecting the internal state of the target pipe by detecting the intensity of X-rays transmitted through the target pipe in a detection unit, and is a pipe installed around the target pipe A determining step for determining whether or not to provide a shielding means for shielding X-rays between at least one of the surrounding piping and the concrete wall installed around the target piping and the detection unit; In the determination step, when it is determined to provide the shielding means, it comprises a shielding step of providing the shielding means between at least one of the peripheral piping and the concrete wall and the detection unit, In the determination step, Whether the target pipe corresponds to the first type including the water supply system and the hot water supply system or the second type including the drainage system is determined according to the type of the target pipe. Results, and, at least one of a result of the diameter of the target pipe is determined to or greater than a predetermined size, the necessary condition for the decision of providing the shielding means.

  According to the present invention, the result of determining whether the target pipe is the first type or the second type according to the type of the pipe, and the result of determining whether the diameter of the pipe is greater than or equal to a predetermined size. One or more of them is a necessary condition for determining whether or not to provide shielding means. Whether the type of the target pipe is a water supply system, a hot water supply system, a drainage system, or the like is immediately and reliably determined based on the situation of the piping equipment. Therefore, it can be quickly and accurately determined whether the target pipe is the first type or the second type. Therefore, if the water supply system or hot water supply system where the phenomenon is likely to occur falls under the first type, and the drainage system where the phenomenon hardly occurs falls under the second type, the phenomenon is likely to occur. It is possible to quickly and accurately determine whether it is a type. In addition, the diameter of the target pipe can be easily grasped by actual measurement or confirmation of equipment data. As described above, the probability that the phenomenon occurs depends on the diameter of the target pipe. Therefore, based on the diameter of the target pipe, it is possible to quickly and accurately determine whether or not the phenomenon is likely to occur.

  As described above, according to the present invention, it is easy to determine whether or not to provide the shielding means easily and quickly without taking time and effort to closely examine the surrounding conditions of the piping. And it can make it difficult to produce the said phenomenon reliably by providing a shielding means between peripheral piping or a concrete wall, and a detection part.

  In the present invention, in the determining step, whether the target pipe corresponds to a first type including a water supply system and a hot water supply system or a second type including a drainage system depends on the type of the target pipe. It is preferable that both the result of determination and the result of determining whether or not the diameter of the target pipe is equal to or larger than a predetermined size are the necessary conditions. According to this, both the result of determining whether the target pipe is the first type or the second type according to the type of pipe and the result of determining whether the diameter of the pipe is a predetermined size or more are required. Condition. Therefore, the shielding means can be provided only when there is a high probability that the phenomenon occurs.

  Moreover, in this invention, you may fix the said shielding means to the said surrounding piping in the said shielding step. According to this, the shielding means is directly fixed to a highly probable structure serving as a scattering source. Therefore, the occurrence of the phenomenon can be directly suppressed.

  Further, in the present invention, the detection unit is an X-ray film, and in the shielding step, the peripheral pipe or the concrete wall is further behind a back surface that is a surface farther from the target pipe in the X-ray film. The shielding means may be arranged so as to shield scattered X-rays from the back toward the back surface. According to the knowledge of the present inventor, this phenomenon is likely to occur even in the situation where there is a concrete wall near the back of the X-ray film. That is, it is considered that a shadow is generated on the X-ray film by X-rays from the scattering source behind the X-ray film. According to the above, since the shielding means is disposed behind the X-ray film, the occurrence of the phenomenon in such a case can be effectively suppressed.

  Moreover, in this invention, the said detection part is an X-ray film, and the said shielding step irradiates X-rays to the said object piping, arrange | positioning the said X-ray film in the 1st position regarding the circumferential direction of the said object piping. And a second step of irradiating the target pipe with X-rays while disposing the X-ray film at a second position different from the first position in the circumferential direction of the target pipe. In at least one of the first and second strokes, shielding means for shielding X-rays may be provided between at least one of the peripheral piping and the concrete wall and the X-ray film. If the diameter of the target pipe is relatively large, it may be necessary to irradiate the target pipe with X-rays from various directions in a plurality of times as in the first and second steps. In such a case, since the X-rays are also irradiated around the target pipe in various directions, there is a high probability that scattered X-rays that cause the phenomenon occur around the target pipe. Therefore, in such a case, the technical significance of applying the present invention is high.

  Further, in the present invention, the detection unit is an X-ray film, and when the shielding means is provided in the shielding step, the X-ray from the peripheral piping or the concrete wall is thereby suppressed, An irradiation step of irradiating the X-ray film while allowing the X-ray from the X-ray generator to pass through the target pipe, and a brightness of a transmission image of the target pipe formed on the X-ray film after the irradiation step It is preferable to provide an inspection step for inspecting the corrosion state of the target pipe. If shadows appear, the brightness of the image will fluctuate, and the corrosion status of the target piping may not be acquired accurately. On the other hand, according to the above configuration, it is possible to inspect the corrosion status of the target pipe based on the brightness of the image of the X-ray film in which the occurrence of the phenomenon is suppressed, that is, the reflection of the shadow is suppressed. Therefore, it is easy to accurately acquire the corrosion status of the target piping.

  A pipe inspection method according to another aspect of the present invention is a method for inspecting the internal state of the target pipe by detecting the intensity of X-rays transmitted through the target pipe in a detection unit, Whether or not a shielding means for shielding X-rays is provided between at least one of a peripheral pipe that is a pipe installed in the periphery and a concrete wall installed around the target pipe and the detection unit. A decision step that is determined based on the conditions, and a shielding unit that provides the shielding unit between at least one of the peripheral pipe and the concrete wall and the detection unit when it is decided to provide the shielding unit in the determination step. In the determination step, the target pipe is either a first type including a water supply system and a hot water supply system or a second type including a drainage system. Among the plurality of conditions, at least one of a result of determining whether or not to match according to a type of the target pipe and a result of determining whether or not the diameter of the target pipe is equal to or larger than a predetermined size. Emphasize over other conditions.

  The pipe inspection method according to another aspect of the present invention is a result of determining whether the target pipe is the first type or the second type according to the type of the pipe and the diameter of the pipe in determining whether or not the shielding means is provided. One or more of the two results of determining whether or not is greater than or equal to a predetermined size is more important than other conditions. As described above, the determination of the first type or the second type and the determination of the diameter of the pipe can be performed easily and quickly as compared with the grasp of the surrounding situation of the pipe. Therefore, by placing importance on at least one of these conditions over other conditions, whether or not to provide a shielding means simply and quickly without taking time and effort to closely examine the surrounding conditions of the pipes, etc. Easy to make decisions. And it can make it difficult to produce the said phenomenon reliably by providing a shielding means between peripheral piping or a concrete wall, and a detection part.

  In another aspect of the present invention, placing importance on a condition among a plurality of conditions corresponds to, for example, determining a certain necessary condition before another necessary condition. For example, as a result of determining a certain condition, if it is determined that the condition for providing the shielding means is not satisfied, it is determined that the determination is made not to provide the shielding means without determining other conditions. In addition, when deciding whether or not to provide a shielding means by comprehensively judging a plurality of conditions, emphasizing a certain condition over other conditions means that the weight given to the determination by a certain condition is the weight of the other condition. Corresponding to larger. For example, when a score is set for each condition and a determination is made based on the total score, the score for a certain condition is made larger than the other conditions. Furthermore, setting a certain condition as a necessary condition and not setting another condition as a necessary condition also corresponds to placing importance on a certain condition over other conditions.

It is a top view which shows the condition of the X-ray generator in the piping inspection method which concerns on one Embodiment of this invention, the object piping used as inspection object, and its surrounding structure. The target piping, surrounding piping, and concrete walls are shown in a horizontal section. It is an example of the X-ray imaging of object piping. An example of developing an X-ray film with shadows is shown. It is a flowchart which shows the process of the piping inspection method in this embodiment. It is a top view which shows the condition which test | inspects object piping with a comparatively big diameter. The target pipe has a horizontal section.

  A pipe inspection method according to an embodiment of the present invention will be described with reference to FIGS. The piping inspection method according to the present embodiment relates to a method for inspecting the corrosion status of each piping included in piping equipment constructed in office buildings, schools, hotels, amusement facilities, and the like. Pipes to be inspected (hereinafter referred to as target pipes) are installed at various places in the piping equipment. The situation around the installation location varies depending on the facility and the position in the facility. FIG. 1 is an example of the target piping 11 and its surroundings. In FIG. 1, the target pipe 11 is along the vertical direction, and the pipes 12 and 13 and the concrete walls W1 and W2 exist in the vicinity thereof. The concrete wall W1 is behind the target pipe 11 when viewed from the X-ray generator 1. The concrete wall W2 is on the side of the target pipe 11 when viewed from the X-ray generator 1.

  In this pipe inspection method, the X-ray generator 1 is used. As shown in FIG. 1, X-rays are emitted from the X-ray generator 1 toward the target pipe 11. The time for irradiating the X-ray is appropriately adjusted according to the situation of the target pipe 11 such as the diameter of the target pipe 11, the nominal thickness of the pipe, the material, the presence of water in the pipe, and the like. Then, a transmission image of the target pipe 11 is acquired by detecting transmitted X-rays that have passed through the target pipe 11. In the present embodiment, the X-ray film 2 (detection unit) is disposed at a position where X-rays from the X-ray generator 1 pass through the target pipe 11. X-rays transmitted through the target pipe 11 expose the X-ray film 2. When the exposed X-ray film 2 is developed, a transmission image of the target pipe 11 appears on the X-ray film 2. A transmission image of the target pipe 11 appearing on the X-ray film 2 is captured by a scanner. Thereby, image data corresponding to the transmission image of the target pipe 11 is acquired. FIG. 2 is an example of a transmission image of the target pipe 11. The transmission image is an image corresponding to the thickness of each part of the target pipe 11. For example, the transmitted image is expressed in gray scale, and the brightness of each pixel indicates the intensity of the transmitted X-ray corresponding to that pixel. Specifically, the higher the lightness, the weaker the transmitted X-ray, and the lower the lightness, the stronger the transmitted X-ray. In this way, the thickness of the target pipe 11 is acquired based on the brightness of the transmission image. For this reason, the adjustment of the X-ray irradiation time is performed so that the brightness of the transmitted image appears moderately.

  In the present embodiment, the thickness of the target pipe 11 is derived based on the image data of the transmission image of the target pipe 11. For example, a location from which the thickness is derived (hereinafter referred to as a thickness derived location) and a reference location are set near the axis of the target pipe 11. As an example, the setting is made in the region indicated by R in FIG. Then, the ratio of the brightness value of the pixel corresponding to the thickness deriving location to the brightness value of the pixel corresponding to the reference location is calculated. Thereby, the ratio of the thickness at the thickness deriving location when the thickness at the reference location is set to 1 is obtained. Next, the thickness at the thickness deriving location is derived based on the assumption that the thickness at the reference location is equal to the nominal thickness value of the pipe. That is, the thickness is derived by (thickness of the thickness deriving location) = (nominal thickness value) * (thickness ratio).

  By the way, the present inventor has noticed that a shadow may partially appear on the X-ray film 2 on which the transmission image of the target pipe 11 is copied. FIG. 3 shows an example of development of the X-ray film 2 in which a shadow is reflected. In the X-ray film 2 of FIG. 3, a shadow is reflected at the right end. Thus, in the portion where the shadow is reflected, the brightness value in the transmission image of the target pipe 11 is shifted to a darker side than in the case where there is no shadow. Therefore, even if the thickness of the target pipe 11 is derived by the method as described above, the derived value may deviate from the actual thickness.

  The present inventor explained about the cause of the phenomenon in which a shadow is reflected in the image of the X-ray film 2 (hereinafter referred to as a shadow reflection phenomenon) in the peripheral equipment such as the pipe 12 and the concrete wall W1. It was considered that the problem was that scattered X-rays (hereinafter referred to as scattered X-rays) were incident on the X-ray film 2. In order to suppress the incidence of scattered X-rays on the X-ray film 2, it is conceivable to provide a shielding means between the X-ray scattering source and the X-ray film 2 that causes a shadow reflection phenomenon. The shielding means is, for example, a sheet including a thin plate made of a lead alloy. The blocking sheet 20 in FIG. 1 is one example.

  However, scattered X-rays are generated in various modes depending on the surrounding conditions of the target pipe 11. That is, it occurs in various manners depending on the presence or absence of adjacent peripheral pipes or concrete walls, their arrangement relationship, and the like. Therefore, whether or not the shadow reflection phenomenon occurs also depends on the surrounding situation of the target pipe 11. Also, which of the facilities can be the cause of the scattering depends on the arrangement of the structures around the target pipe 11 and the like. If the necessity of installing the blocking sheet 20 and the installation location are determined based only on the surrounding situation of the target pipe 11, it takes too much time and time to judge this according to various surrounding situations. There is a risk.

  Therefore, the present inventor, based on a large number of pipe inspections performed in the past, as to under what conditions the shadow reflection phenomenon is likely to occur, as a scattering source that causes the shadow reflection phenomenon I have intensively studied what the main ones are. As a result, the present inventor has found that the ease of occurrence of the phenomenon depends not only on the surrounding situation of the target pipe 11 but also on the situation of the target pipe 11 itself. Specifically, the shadow reflection phenomenon is likely to occur when the target pipe 11 corresponds to a specific type, for example, a case where the target pipe 11 corresponds to a water supply system, a hot water supply system, or the like. When it corresponds to another kind, for example, when it corresponds to a drainage system etc., it discovered that a shadow reflection phenomenon did not occur easily. Further, the present inventor has discovered that the diameter of the target pipe 11 is related to the occurrence of a shadow reflection phenomenon. Specifically, the present inventor has found that the larger the diameter of the target pipe 11, the more likely the shadow reflection phenomenon occurs. Further, when the target pipe 11 corresponds to the above-mentioned specific type, and other pipes such as the pipe 12 are dense around the target pipe 11 or a concrete wall is close to the target pipe 11, It was found that the phenomenon of reflection is likely to occur. From this, it was found that the scattering source as the cause of the shadow reflection phenomenon was mainly another pipe around the target pipe 11 or a concrete wall.

  The flow of the pipe inspection method according to the present embodiment based on the above knowledge will be described with reference to FIG. First, a preliminary survey is performed on the target pipe 11 and the surrounding situation (step S1; hereinafter simply referred to as S1). In the preliminary survey, the type of the target pipe 11 is grasped and the diameter thereof is measured, and the distance between the target pipe 11 and the surrounding pipe or concrete wall is measured. In grasping the type of the target pipe 11, it may be understood from the actual facility status whether the target pipe 11 corresponds to a water supply system, a hot water supply system, a drainage system, etc. You may grasp from.

  Next, it is determined whether the target pipe 11 corresponds to the first type or the second type according to Table 1 below (S2). The classification of the first type and the second type relates to the ease of occurrence of the shadow reflection phenomenon. Table 1 associates the types of piping such as a water supply system, a hot water supply system, and a water distribution system with the classification. As shown in Table 1, a water supply system and a hot water supply system in which a shadow reflection phenomenon is likely to occur are associated with the first type. Moreover, the drainage system in which the shadow reflection phenomenon does not easily occur is associated with the second type. And based on the kind of object piping 11 grasped | ascertained by S1, according to Table 1, it discriminate | determines alternatively whether the object piping 11 corresponds to either 1st type or 2nd type. When it is determined that the target pipe 11 is the second type, the process proceeds to step S6 without installing the blocking sheet 20. When it is determined that the target pipe 11 is the first type, it is determined whether or not the diameter of the target pipe 11 measured in S1 is equal to or larger than a predetermined value R (for example, 500 mm or larger) (S3). When it determines with the diameter of the object piping 11 being less than predetermined value R, it progresses to the step of S6, without installing the interruption | blocking sheet | seat 20. FIG. When it is determined that the diameter of the target pipe 11 is equal to or larger than the predetermined value R, it is determined whether or not the distance between the target pipe 11 and the surrounding pipe and the concrete wall is equal to or smaller than the predetermined value D (S4). The determination of S4 is based on the distance between the peripheral piping and the concrete wall (hereinafter referred to as a structure) and the target piping 11 acquired in S1. Of these structures, those having a distance from the target pipe 11 of a predetermined value D or less (for example, 2000 mm or less) are extracted. For example, when the distance between the pipe 12 and the concrete wall W1 is equal to or less than the predetermined value D and the distance between the pipe 13 and the concrete wall W2 exceeds the predetermined value D, the pipe 12 And the concrete wall W1 is extracted. If there is no structure whose distance from the target pipe 11 is equal to or less than the predetermined value D, the process proceeds to step S6 without installing the blocking sheet 20. When there is a structure whose distance from the target pipe 11 is equal to or less than the predetermined value D, the process proceeds to step S5 in which the blocking sheet 20 is installed.

  As described above, in S2 to S4, the target pipe 11 corresponds to the first type, the diameter of the target pipe 11 is equal to or larger than the predetermined value R, and the distance from the target pipe 11 is equal to or smaller than the predetermined value D. When there is a structure that is, the process proceeds to step S5 in which the blocking sheet 20 is installed. In other cases, that is, whether the target pipe 11 corresponds to the second type, the diameter of the target pipe 11 is determined to be less than the predetermined value R, or the distance from the target pipe 11 is equal to or less than the predetermined value D. If at least one of the structures does not exist, the process proceeds to step S6 without installing the blocking sheet 20. That is, the steps S2 to S4 correspond to the determination step in the present invention for determining whether or not to install the shielding means.

  In S5, the blocking sheet 20 is installed. The blocking sheet 20 is installed between the target pipe 11 and the structure whose distance from the target pipe 11 is equal to or less than the predetermined value D in S4. For example, when the distance between the pipe 12 and the target pipe 11 is equal to or less than the predetermined value D as described above, the blocking sheet 20 is installed at the position indicated by the arrow A in FIG. This position corresponds to a fixed position to the pipe 12. Further, as described above, when the distance between the concrete wall W1 and the target pipe 11 is equal to or less than the predetermined value D, the blocking sheet 20 is installed at a position indicated by an arrow B in FIG. This position corresponds to a position close to the back surface 2a of the X-ray film 2. The back surface 2 a is the surface farther from the target pipe 11 in the X-ray film 2.

  Next, the target pipe 11 is photographed (S6). That is, X-rays from the X-ray generator 1 are transmitted through the target pipe 11 and the X-ray film 2 is exposed to the transmitted X-rays (S6). Then, the exposed X-ray film 2 is developed, whereby a transmission image of the target pipe 11 appearing on the X-ray film 2 is captured by a scanner, and the target pipe 11 is based on the brightness value of the image data of the obtained transmission image. Is derived (S7). When the shielding sheet 20 is installed in S5, the shielding sheet 20 shields the X-ray film 2 from scattered X-rays from the pipe 12 and the concrete wall W1. Therefore, the shadow reflection phenomenon is difficult to occur. Even if S5 is not executed, it is a result of the decision not to install the blocking sheet 20 in S2 to S4. This determination is made when the probability of occurrence of a shadow reflection phenomenon is not high. As described above, the shadow reflection phenomenon hardly occurs both when S5 is executed and when it is not executed. Accordingly, it is easy to accurately derive the thickness of the target pipe 11 in S7.

  According to the present embodiment described above, based on the probability that a shadow reflection phenomenon will occur, by providing the shielding sheet 20 for a highly probable scattering source that causes the shadow reflection phenomenon, the shadow reflection phenomenon is reduced. Generation can be effectively suppressed. The reason is as follows. Whether the type of the target pipe 11 is a water supply system, a hot water supply system, a drainage system, etc., is immediately based on the actual situation of the piping equipment and materials even before the target pipe 11 is irradiated with X-rays. In addition, it is definitely found out. Therefore, based on the type of the target pipe 11 and Table 1, whether the target pipe 11 is the first type or the second type, that is, whether or not the type in which the shadow reflection phenomenon easily occurs is quickly and easily determined. Can be determined. Then, the fact that the target pipe 11 is the first type is one of the necessary conditions for determining the provision of the blocking sheet 20 (S2 → S3 in FIG. 4). Moreover, it is set as another one of the necessary conditions for determining to provide the blocking sheet 20 that the diameter of the target pipe 11 is equal to or greater than the predetermined value R (S3 → S4 in FIG. 4). When the target pipe 11 is the first type, as described above, there is a high probability that a shadow reflection phenomenon will occur. Further, when the diameter of the target pipe 11 is equal to or larger than the predetermined value R, as described above, there is a high probability that a shadow reflection phenomenon will occur. The diameter of the target pipe 11 can also be easily and quickly grasped based on actual measurement and data. Therefore, by setting these as the necessary conditions for determining that the blocking sheet 20 is to be provided, it is time and effort to carefully examine the structure and usage of the target pipe 11 in order to determine whether or not the shadow reflection phenomenon occurs. Even if it is not applied, it is possible to easily and appropriately evaluate the probability that a shadow reflection phenomenon will occur.

  Furthermore, the presence of a structure whose distance from the target pipe 11 is equal to or less than the predetermined value D is another necessary condition for determining the provision of the blocking sheet 20 (S4 → S5 in FIG. 4). On the other hand, if the surrounding structure is separated from the target pipe 11 by a certain amount, the shadow reflection phenomenon hardly occurs. Further, if only the distance between the target pipe 11 and the structure is measured, it is easier than examining these positional relationships. Therefore, by setting these as the necessary conditions for determining that the blocking sheet 20 is to be provided, it is time and effort to carefully examine the structure and usage of the target pipe 11 in order to determine whether or not the shadow reflection phenomenon occurs. Even if it is not applied, it is possible to easily and appropriately evaluate the probability that a shadow reflection phenomenon will occur. Note that the execution of S2 and S3 in FIG. 4 prior to S4 corresponds to the determination of S4 not being made based on the determination results of S2 and S3. That is, this corresponds to the fact that the determination conditions of S2 and S3 are more important than the determination condition of S4.

  Further, when the shadow reflection phenomenon occurs, as described above, the peripheral piping such as the pipe 12 and the concrete wall W1 are highly likely to cause the shadow reflection phenomenon. For this reason, the occurrence of the phenomenon can be effectively suppressed by providing a shielding means for the highly probable scattering source that causes the shadow reflection phenomenon.

  As described above, in the present embodiment, it is possible to determine whether or not to provide the blocking sheet 20 simply and quickly without taking time and effort to examine the structure and usage of the target pipe 11 closely. Then, by providing the blocking sheet 20 between the pipe 12 or the concrete wall W1 and the X-ray film 2, it is possible to reliably prevent the shadow reflection phenomenon.

(Modification)
The above is a description of a preferred embodiment of the present invention, but the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope described in the means for solving the problem. It is possible. Hereinafter, modified examples according to the above-described embodiment will be described. In addition, the same reference numerals as those described above are used for portions common to the above-described embodiment, and description thereof is omitted as appropriate.

  For example, in the above-described embodiment, the X-ray film 2 is used as an X-ray detection unit. However, other devices may be used as the detection unit. For example, an X-ray detector equipped with an image sensor using an X-ray photoelectric conversion element may be used.

  Further, in the above-described embodiment, the condition relating to the type of the target pipe 11, the condition relating to the size of the diameter, and the like are the necessary conditions for determining the provision of the blocking sheet 20. However, the above determination may be made by comprehensively judging these plural conditions. For example, a score is set for each of the condition whether the target pipe 11 is the first type or the second type, the condition whether the diameter of the target pipe 11 is greater than or equal to a predetermined value R, and other conditions. For each condition, an evaluation score is determined based on the set score. Then, the determined evaluation points are summed up for all conditions. For example, if the total evaluation score is equal to or greater than a predetermined value, it is determined that the blocking sheet 20 is provided, and if it is less than the predetermined value, it is determined that the blocking sheet 20 is not provided. At this time, for one or more of the two conditions of whether the target pipe 11 is the first type or the second type and whether the diameter of the target pipe 11 is equal to or larger than the predetermined value R, these 2 Set the score higher than the other conditions. Thereby, the influence which the evaluation score by at least one of two conditions has on the determination of whether to provide the blocking sheet 20 is larger than the evaluation score by other conditions. Accordingly, by calculating the evaluation score for at least one of the two conditions first, it becomes easy to quickly determine whether or not the total evaluation score is a predetermined value or more. In this way, by placing importance on at least one of the two conditions over the other conditions, it is easy to determine whether or not to provide the blocking sheet 20 easily and quickly.

  It should be noted that at least one of the above two conditions is a necessary condition for providing the blocking sheet 20, and the final decision is made based on the overall judgment including other conditions or the overall judgment based on other conditions. May be based. This case also corresponds to placing more importance on at least one of the two conditions than the other conditions.

  Further, in the above-described embodiment, the condition relating to the type of the target pipe 11 and the condition relating to the size of the diameter are set as the necessary conditions for determining the provision of the blocking sheet 20. In addition, the condition of the covering of the target pipe 11 may be a necessary condition. According to the knowledge of the present inventor, a shadow reflection phenomenon occurs even if the heat insulating material or a wire mesh for fixing and protecting the heat insulating material covers the target pipe 11 or the wet state of the heat insulating material. This is because the ease varies. Specifically, when there is a covering such as a heat insulating material, a shadow reflection phenomenon easily occurs. Also, the shadowing phenomenon tends to occur as the heat insulating material gets wet. Therefore, it is good also as a necessary condition for deciding to provide the interruption | blocking sheet | seat 20 that there exists a coating | covering and a heat insulating material is wet. Or it is good also as conditions of the comprehensive judgment for deciding whether to provide the interruption | blocking sheet | seat 20 that there exists a coating | cover and a heat insulating material is wet.

  Further, as shown in FIG. 5, when inspecting a target pipe 111 having a relatively large diameter, the target pipe is applied a plurality of times while changing the positions of the X-ray generator 1 and the X-ray film 2 in the circumferential direction of the target pipe 111. 111 may be X-rayed. In such a case, a series of imaging steps is performed because (b) the X-ray is irradiated in various directions around the target pipe 111 and (b) the diameter of the target pipe 111 is relatively large. This increases the possibility that shadows will appear in Therefore, the first step of imaging the target pipe 111 by placing the X-ray generator 1 at the position A1 and the X-ray film 2 at the position A2, and the X-ray film 1 at the position B1. The above-described S2 to S6 may be executed in at least one of the second step of imaging the target pipe 111 by arranging 2 at the position B2.

  Table 1 of the above-described embodiment describes the specific classification of the first type or the second type, but is limited to three types of water supply system, hot water supply system, and drainage system. For other various pipes such as a refrigeration system, an air conditioning system, and an oil supply system, the classification of the first type or the second type may be added to Table 1 based on experiments and experiences.

DESCRIPTION OF SYMBOLS 1 X-ray generator 2 X-ray film 11 Target piping 12, 13 Peripheral piping 20 Barrier sheet W, W1, W2 Concrete wall

The present invention based on the above is a method for inspecting the internal state of the target pipe by detecting the intensity of X-rays transmitted through the target pipe in a detection unit, and is a pipe installed around the target pipe A determining step for determining whether or not to provide a shielding means for shielding X-rays between at least one of the surrounding piping and the concrete wall installed around the target piping and the detection unit; When it is determined in the determining step that the shielding means is provided, the target pipe is irradiated with X-rays while the shielding means is provided between at least one of the peripheral pipe and the concrete wall and the detection unit. Inspecting the internal conditions of the piping, and if it is determined that the shielding means is not provided in the determining step, the peripheral piping and the concrete wall are reduced. Also it includes a inspection step of inspecting the condition of the inside of the target pipe is irradiated with X-rays to said subject the pipe without providing the shielding means between the one and the detection unit, in said determining step The result of determining whether the target pipe corresponds to the first type including the water supply system and the hot water supply system or the second type including the drainage system according to the type of the target pipe, and the diameter of the target pipe At least one of the results of determining whether or not is greater than or equal to a predetermined size is set as a necessary condition for determining to provide the shielding means.

Moreover, in this invention, you may fix the said shielding means to the said surrounding piping in the said test | inspection step. According to this, the shielding means is directly fixed to a highly probable structure serving as a scattering source. Therefore, the occurrence of the phenomenon can be directly suppressed.

Further, in the present invention, the detection unit is an X-ray film, and in the inspection step, the peripheral pipe or the concrete wall is further behind a back surface that is a surface far from the target pipe in the X-ray film. The shielding means may be arranged so as to shield scattered X-rays from the back toward the back surface. According to the knowledge of the present inventor, this phenomenon is likely to occur even in the situation where there is a concrete wall near the back of the X-ray film. That is, it is considered that a shadow is generated on the X-ray film by X-rays from the scattering source behind the X-ray film. According to the above, since the shielding means is disposed behind the X-ray film, the occurrence of the phenomenon in such a case can be effectively suppressed.

Moreover, in this invention, the said detection part is an X-ray film, and the said test | inspection irradiates X-rays to the said object piping, arrange | positioning the said X-ray film in the 1st position regarding the circumferential direction of the said object piping. And a second step of irradiating the target pipe with X-rays while disposing the X-ray film at a second position different from the first position in the circumferential direction of the target pipe. In at least one of the first and second steps , shielding means for shielding X-rays may be provided between at least one of the peripheral piping and the concrete wall and the X-ray film. If the diameter of the target pipe is relatively large, it may be necessary to irradiate the target pipe with X-rays from various directions in a plurality of times as in the first and second steps. In such a case, since the X-rays are also irradiated around the target pipe in various directions, there is a high probability that scattered X-rays that cause the phenomenon occur around the target pipe. Therefore, in such a case, the technical significance of applying the present invention is high.

In the present invention, the detection unit is an X-ray film, and when the shielding step is provided , the inspection step causes the X-ray to enter the X-ray film from the peripheral piping or the concrete wall. In the state in which the object pipe is transmitted, the irradiation step of irradiating the X-ray film while transmitting the target pipe, and the brightness of the transmission image of the target pipe formed on the X-ray film after the irradiation step It is preferable to include a corrosion state inspection step for inspecting the corrosion state of the target pipe based on the above. If shadows appear, the brightness of the image will fluctuate, and the corrosion status of the target piping may not be acquired accurately. On the other hand, according to the above configuration, it is possible to inspect the corrosion status of the target pipe based on the brightness of the image of the X-ray film in which the occurrence of the phenomenon is suppressed, that is, the reflection of the shadow is suppressed. Therefore, it is easy to accurately acquire the corrosion status of the target piping.

A pipe inspection method according to another aspect of the present invention is a method for inspecting the internal state of the target pipe by detecting the intensity of X-rays transmitted through the target pipe in a detection unit, Whether or not a shielding means for shielding X-rays is provided between at least one of a peripheral pipe that is a pipe installed in the periphery and a concrete wall installed around the target pipe and the detection unit. a determining step of determining based on the condition, if it is determined that providing the shielding means in said determining step, while providing the shielding means between at least one said detector of the peripheral pipes and the concrete wall When the target pipe is irradiated with X-rays to inspect the inside of the target pipe and it is determined that the shielding means is not provided in the determination step, And an inspection step of inspecting the condition of the inside of the target pipe is irradiated with X-rays to said subject the pipe without providing the shielding means between at least one said detector around the pipe and the concrete wall In the determination step, as a result of determining whether the target pipe corresponds to the first type including the water supply system and the hot water supply system or the second type including the drainage system according to the type of the target pipe, Further, at least one of the results of determining whether or not the diameter of the target pipe is greater than or equal to a predetermined size is more important than the other conditions among the plurality of conditions.

Claims (7)

A method of inspecting the internal situation of the target pipe by detecting the intensity of X-rays transmitted through the target pipe in a detection unit,
Whether to provide a shielding means for shielding X-rays between at least one of a peripheral pipe that is a pipe installed around the target pipe and a concrete wall installed around the target pipe and the detection unit A decision step to decide whether or not;
When it is determined that the shielding means is provided in the determining step, a shielding step of providing the shielding means between at least one of the peripheral piping and the concrete wall and the detection unit is provided,
In the determining step,
The result of determining whether the target pipe corresponds to the first type including the water supply system and the hot water supply system or the second type including the drainage system according to the type of the target pipe, and the diameter of the target pipe A pipe inspection method characterized in that at least one of the results of determining whether or not a predetermined size or more is a necessary condition for determining that the shielding means is provided. In the determining step,
The result of determining whether the target pipe corresponds to the first type including the water supply system and the hot water supply system or the second type including the drainage system according to the type of the target pipe, and the diameter of the target pipe The piping inspection method according to claim 1, wherein both of the results of determining whether or not the size is greater than or equal to a predetermined size are used as the necessary condition. In the shielding step,
The pipe inspection method according to claim 1 or 2, wherein the shielding means is fixed to the peripheral pipe. The detector is an X-ray film;
In the shielding step,
Disposing the shielding means so as to shield scattered X-rays from the peripheral piping or the concrete wall toward the back surface further behind the back surface, which is a surface far from the target piping in the X-ray film. The pipe inspection method according to any one of claims 1 to 3, wherein the pipe inspection method is characterized. The detector is an X-ray film;
The shielding step comprises:
A first step of irradiating the target pipe with X-rays while disposing the X-ray film at a first position with respect to a circumferential direction of the target pipe;
A second step of irradiating the target pipe with X-rays while disposing the X-ray film at a second position different from the first position with respect to the circumferential direction of the target pipe,
The shielding means for shielding X-rays is provided between at least one of the peripheral piping and the concrete wall and the X-ray film in at least one of the first and second steps. The piping inspection method according to any one of -4. The detector is an X-ray film;
When the shielding means is provided in the shielding step, the X-ray film is transmitted through the target pipe while the X-ray incident on the X-ray film from the peripheral pipe or the concrete wall is suppressed thereby. Irradiating with X-rays;
6. An inspection step for inspecting a corrosion state of the target pipe based on brightness and darkness of a transmission image of the target pipe formed on the X-ray film after the irradiation step. The piping inspection method according to any one of the above. A method of inspecting the internal situation of the target pipe by detecting the intensity of X-rays transmitted through the target pipe in a detection unit,
Whether to provide a shielding means for shielding X-rays between at least one of a peripheral pipe that is a pipe installed around the target pipe and a concrete wall installed around the target pipe and the detection unit A determination step for determining whether or not based on a plurality of conditions;
When it is determined that the shielding means is provided in the determining step, a shielding step of providing the shielding means between at least one of the peripheral piping and the concrete wall and the detection unit is provided,
In the determining step,
The result of determining whether the target pipe corresponds to the first type including the water supply system and the hot water supply system or the second type including the drainage system according to the type of the target pipe, and the diameter of the target pipe A pipe inspection method characterized in that at least one of the results of determining whether or not a predetermined size or more is more important than other conditions among the plurality of conditions.