Buffer materials, buffer control systems and methods, and program storage devices.

Abstract

The invention relates to the arrangement of an outer shear section (4-1, 4-2, 4-3, 4-4) in the unheld section (2-2) adjacent to the held section (2-1) held between flanges (16-1, 16-2), and the shape of the outer shear section changes due to the load applied to the held section. The shape of the outer shear section changing in response to the applied load is measured and the tightening of the shim is controlled based on the shape. Thus, the change in shape of the shim subjected to load between the flanges is directly observed and the observed results for controlling the shim tightening are used to improve the shim and the technique for controlling the shim.

Description

Gasket, its management method, system and program

[0001] The present disclosure relates to a gasket used, for example, for fastening piping systems, and a management technique for the gasket.

[0002] The tightening torque and bolt preload applied to the flanges by the bolts are traditionally used to tighten gaskets. The tightening torque and bolt preload provide information on the tightening of the bolts that fasten the flanges together.

[0003] Regarding the tightening of gaskets, a system is known that uses tightening surface pressure corresponding to the type of gasket and internal fluid, multiple tightening forces, information about the bolt, etc., in order to grasp the tightening torque (for example, Patent Document 1). Regarding the tightening of bolts, a system is known that converts strain generated in the bolt into data and visualizes the tightening state of the bolt (for example, Patent Document 2).

[0004] JP 2014-225219 A JP 2015-141345 A

[0005] The reason why bolt tightening torque and axial force values ​​are used to manage gasket tightening is that bolts are the means for tightening flanges, and the tightening force from the bolts can be easily determined by measuring bolt strain.

[0006] However, after carefully examining the relationship between the bolts, flanges, and gaskets, it was found that the bolt tightening force acts on the flange, and only indirectly on the gasket via the flange. In other words, the flange receives the load from the bolt tightening, and this load only acts on the gasket via the flange. The torque and axial force values ​​applied to the bolts are loads acting on part of the flange, and do not represent the surface pressure acting on the gasket.

[0007] For this reason, the following problems arise in managing the tightening of gaskets:

[0008] a) The torque and axial force values ​​obtained from the bolt are information about the bolt, and cannot be said to measure the surface pressure that the gasket receives.

[0009] b) In terms of the surface pressure that the gasket receives from the flange, the bolt torque value and axial force value are merely indirect information and serve only as a guide to the surface pressure.

[0010] c) The torque and axial force values ​​of the bolts are affected by the tightening conditions of the bolts and flanges, and this tendency to fluctuate cannot be ignored.

[0011] When gasket surface pressure is estimated using torque or axial force values ​​measured with a torque wrench or bolt axial force meter, the relationship between the surface pressure applied to the gasket (= estimated surface pressure) and the surface pressure actually received by the gasket (= actual surface pressure) is estimated surface pressure ≠ actual surface pressure, if the tightening condition of the bolts or flange is affected. Even if the measurement accuracy of the torque or axial force value is improved, the estimated surface pressure and the actual surface pressure of the gasket will not match. It is not possible to grasp the surface pressure received by the gasket.

[0012] Regarding this problem, the inventors have found that the change in shape of the gasket depends on the load applied between the flanges, and that observing this change in shape is useful for managing the tightening of the gasket. Patent Documents 1 and 2 do not disclose or suggest this problem. Furthermore, the configurations disclosed in Patent Documents 1 and 2 cannot solve this problem.

[0013] Therefore, based on the above-mentioned problems and findings, an object of the present disclosure is to directly observe changes in the shape of a gasket that is subjected to a load between flanges, and to use the observation results in managing the tightening of the gasket to improve gaskets and management techniques for the gaskets.

[0014] To achieve the above-mentioned objective, according to one aspect of the gasket disclosed herein, an outer cut is provided in a non-restrained portion adjacent to a restrained portion that is restrained between flanges, and the shape of the outer cut changes due to the load received by the restrained portion.

[0015] In order to achieve the above-mentioned object, according to one aspect of the management method of the present disclosure, the method includes the steps of: installing a gasket between flanges, the gasket having an outer cut whose shape changes under load; applying a load to the gasket constrained between the flanges; measuring the shape of the outer cut that has changed under the load; and managing the tightening of the gasket based on the shape.

[0016] In order to achieve the above object, according to one aspect of the management system of the present disclosure, it includes a measuring means for measuring the shape of the outer cut provided in the gasket, a management server for generating management information for managing the tightening between the flanges based on the shape, and an information presentation unit for presenting the management information.

[0017] In order to achieve the above-mentioned object, according to one aspect of the program of the present disclosure, the program is implemented by a computer, and the computer is provided with a function for acquiring shape information of an outer cut provided on a gasket that is constrained between flanges and subjected to load, a function for generating management information for managing the tightening of the gasket based on the shape information, and a function for presenting the management information.

[0018] According to the present invention, any of the following effects can be obtained.

[0019] (1) The load that the gasket receives from between the flanges causes strain in the gasket, and this strain can be made apparent as a change in the shape of the outer cut of the gasket, which can be visualized as a change in the shape of the outer cut and can be easily recognized.

[0020] (2) By observing the change in the shape of the outer cut, the load applied to the gasket can be easily determined without being affected by the tightening state of the bolts, allowing for proper tightening management of the gasket.

[0021] (3) If the load applied to the gasket can be estimated from the change in the shape of the outer cut, this load will be equivalent to the actual surface pressure the gasket receives from the flange, which will improve the accuracy of gasket management, such as fastening management and gasket life prediction.

[0022] (4) The shape change of the outer cut and the load estimated from this shape change directly reflect the tightening state of the gasket, unlike the bolt torque value or axial force value. Therefore, by observing such shape change and estimating the load, the accuracy of gasket management can be improved regardless of the skill of the worker.

[0023] Other objects, features, and advantages of the technology of the present disclosure will become more apparent by referring to the accompanying drawings and each embodiment.

[0024] 1A is a plan view showing a gasket according to the first embodiment, and B is an enlarged perspective view showing part IB of A. FIG. 1B is a view showing a flange fastening portion according to the first embodiment. FIG. 2B is a view showing a cross-sectional end surface taken along line III-III of FIG. 2. FIG. 1A is an enlarged view of an outer cut portion, and B is a view showing shape changes of the outer cut. FIG. 1B and B are views showing modified examples of the outer cut. FIG. 1C is a view showing a gasket management system according to the first embodiment. FIG. 1D is a view showing a gasket management database. FIG. 1A is a view showing a comparative example, and B is a view showing the settings of the shape observation unit. FIG. 1E is a view showing the relationship between shape changes and load in the comparative example. FIG. 1F is a view showing the relationship between shape changes and load in the example.

[0025] [First embodiment] Fig. 1A shows a gasket 2 according to a first embodiment. The configuration shown in the figure is an example, and the present disclosure is not limited to such a configuration. In Fig. 1, an X-axis, a Y-axis, and a Z-axis are also shown as an example.

[0026] The gasket 2 is a sheet gasket made of a material in which polytetrafluoroethylene (PTFE) and a filler are blended, for example. The gasket 2 may be made of a resin material or a rubber material other than PTFE.

[0027] A restrained portion 2-1 is set on the inner diameter side and a non-restrained portion 2-2 is set on the outer diameter side of this gasket 2. The restrained portion 2-1 is an area that comes into contact with the flanges 16-1 and 16-2 (FIGS. 2 and 3) and receives a load F from between the flanges 16-1 and 16-2. In contrast, the non-restrained portion 2-2 is an area that does not come into contact with the flanges 16-1 and 16-2.

[0028] Outer cuts 4-1, 4-2, 4-3, and 4-4 (hereinafter simply referred to as outer cuts 4 when no specific position is specified) are formed in the non-constraint portion 2-2. Each outer cut 4 is a cutout portion formed by partially cutting out the outermost edge of the gasket 2 to release it, and serves as a means for facilitating detection of changes in the shape of the gasket 2. Therefore, each outer cut 4 constitutes a shape observation portion for observing changes in the shape of the gasket 2 when a load F is applied to the constraint portion 2-1.

[0029] <Outer Cut 4> Figure 1B shows an enlarged view of the outer cut 4 located in part IB of Figure 1A. This outer cut 4 is a vertical groove cut from the periphery of the outermost edge of the gasket 2 toward the center by a fixed length L and opened to a width W, and this vertical groove penetrates the top and bottom surfaces of the gasket 2. Therefore, this outer cut 4 has a vertical surface portion 6 and opposing surface portions 8-1 and 8-2 within the non-restrained portion 2-2 of the gasket 2. The vertical surface portion 6 is exposed toward the periphery of the gasket 2, and opposing surface portions 8-1 and 8-2, each having a length L and a height D, face each other at a fixed width W. The height D is the thickness of the gasket 2 before deformation. In other words, the opening width between the opposing surface portions 8-1 and 8-2 of the outer cut 4 can be measured.

[0030] To detect changes in the shape of the gasket 2, the outer cuts 4 may be set at multiple locations on the gasket 2. It is preferable that the setting locations are uniform in order to avoid the influence of elastic interactions from the flanges 16-1 and 16-2 and to increase the accuracy of observing changes in shape. In this embodiment, the outer cuts 4 are set at four locations on the X-axis and Y-axis, allowing changes in shape to be observed over a wide range.

[0031] <Flange Fastening Portion 12> Fig. 2 shows a cutaway view of the flange fastening portion 12 including the gasket 2. This flange fastening portion 12 is an example, and the present disclosure is not limited to the configuration shown in Fig. 1 .

[0032] The flange fastening portion 12 includes a flange 16-1 on the pipeline 14-1 side, a flange 16-2 on the pipeline 14-2 side (FIG. 3), a gasket 2, a plurality of bolts 18, and nuts 20.

[0033] Flange 16-1 is integrally formed with the end surface of pipeline 14-1, and similarly, flange 16-2 is integrally formed with the end surface of pipeline 14-2. Flanges 16-1 and 16-2 have a larger diameter than pipelines 14-1 and 14-2, and a plurality of bolts 18 and nuts 20 are attached at predetermined angular intervals. A gasket 2 is installed between flanges 16-1 and 16-2, inside the bolts 18 and nuts 20. The gasket 2 constitutes a sealing member for flange fastening portion 12. Therefore, when each bolt 18 and nut 20 is tightened, a load F is applied to flanges 16-1 and 16-2, and the gasket 2 bears the load, thereby fastening and sealing pipelines 14-1 and 14-2.

[0034] The restraint portion 2-1 of the gasket 2 is sandwiched between the flanges 16-1 and 16-2 and is in contact with and restrained by the flanges 16-1 and 16-2. The non-restraint portion 2-2 protrudes around the restraint portion 2-1 and does not contact the flanges 16-1 and 16-2, i.e., is not restrained by the flanges 16-1 and 16-2. The restraint portion 2-1 receives a load F from the flanges 16-1 and 16-2 when the bolts 18 and nuts 20 are tightened. In contrast, the non-restraint portion 2-2 constitutes a free end that is not subjected to the load F.

[0035] When a load F is applied to the restraint portion 2-1 from the flanges 16-1 and 16-2, the load strain of the restraint portion 2-1 due to the load F spreads to the non-restraint portion 2-2 that is integral with the restraint portion 2-1, causing a change in shape in the outer cut 4. As a result, each outer cut 4 of the non-restraint portion 2-2 forms a site for observing the change in shape that appears in the gasket 2.

[0036] <Relationship between the restrained portion 2-1, non-restrained portion 2-2, and flanges 16-1, 16-2> Figure 3 shows a cross-sectional end surface taken along line III-III in Figure 2. The restrained portion 2-1 of the gasket 2 is sandwiched and restrained between the gasket seats 22 of the flanges 16-1, 16-2. In contrast, the non-restrained portion 2-2 protrudes into the gap 24 between the flanges 16-1, 16-2. The non-restrained portion 2-2 is integral with the restrained portion 2-1, is supported between the flanges 16-1, 16-2, and is a free end that protrudes into the gap 24. In other words, the non-restrained portion 2-2 is in a cantilever state.

[0037] Strain and deformation that occur in the restrained portion 2-1 when the load F is applied from the flanges 16-1 and 16-2 appear as a change in shape in the non-restrained portion 2-2. This change in shape can be easily observed by the outer cut 4. In other words, the change in shape of the gasket 2 that appears in the non-restrained portion 2-2 is strain or deformation caused by being pushed out from between the gasket seats 22, and represents the load that the restrained portion 2-1 of the gasket 2 receives from the flanges 16-1 and 16-2.

[0038] <Observation of Shape Change Due to Outer Cut 4> The outer cut 4 is formed to make strain occurring in the non-constrained portion 2-2 manifest as a noticeable shape change and facilitate its observation. As shown in Figure 4A, if the X axis is taken in the tangential direction of the gasket 2, the Y axis is taken at the center of the outer cut 4, and the Z axis is taken in the direction in which the load F is applied, when the load F is applied to the constrained portion 2-1 from the flanges 16-1 and 16-2, a shape change (= strain) occurs in the spacing direction between the flanges 16-1 and 16-2 and in a direction intersecting this spacing direction. This shape change includes a shape change in the circumferential direction of the gasket 2.

[0039] See FIG. 4B for the shape changes in the X-axis and Y-axis directions during this shape change. The non-constrained portion 2-2 expands radially, as indicated by arrows a and b. ΔY1 indicates the radial expansion of the non-constrained portion 2-2, and ΔY2 indicates the radial displacement of the vertical surface portion 6 of the outer cut 4. Accompanying this change, the width W of the vertical surface portion 6 expands to width W1, and the width W of the terminal ends of each opposing surface portion 8-1, 8-2 expands to width W2 (>W1). This shape change increases or decreases in proportion to the load F that the gasket 2 receives from the flanges 16-1, 16-2. While this example illustrates shape changes in the X- and Y-axes, it goes without saying that shape changes in the Z-axis and thickness directions also appear in the shape of the outer cut 4.

[0040] Therefore, the strain generated in the restrained portion 2-1 and the unrestrained portion 2-2 when the load F is applied from the flanges 16-1, 16-2 is amplified and manifested as a change in the shape of the outer cut 4, making it easy to observe.

[0041] <Modifications of outer cut 4> The outer cut 4 is not limited to the rectangular shape consisting of the vertical surface portion 6 and the opposing surface portions 8-1 and 8-2 shown in Fig. 1B. Figs. 5A and 5B show modifications of the outer cut 4. In Fig. 5, parts corresponding to those in Fig. 1B are given the same reference numerals.

[0042] As shown in Figure 5A, the outer cut 4 may be formed such that, except for the vertical surface 6, the opposing surface portions 8-1 and 8-2 are formed as non-parallel surfaces, forming a V-shaped cross section, or, for example, the vertical surface portion 6 may be formed as a curved surface, as shown in Figure 5B. Even in such a configuration, the change in shape that occurs in the non-constrained portion 2-2 when the load F is received by the constrained portion 2-1 can be easily observed from the outer cut 4.

[0043] It is also possible to install a sensor member made of metal or resin in the space of the outer cut 4 and detect the change in shape of the outer cut 4 from this sensor member.

[0044] <Control Process of Gasket 2> The control process of the gasket 2 is an example of a control method of the present disclosure. This control process includes a process S1 of generating the constrained portion 2-1 and the non-constrained portion 2-2, a process S2 of applying a load F, a process S3 of acquiring shape information, and a process S4 of presenting the shape information, etc. The numbers S1 to S4 attached to each process exemplify the order of the processes, and the terms used are used merely for convenience.

[0045] Step S1 of generating the constrained portion 2-1 and the non-constrained portion 2-2: When the gasket 2 is placed between the flanges 16-1 and 16-2, the portions of the gasket 2 that contact the flanges 16-1 and 16-2 become the constrained portion 2-1, and the portions of the gasket 2 that do not contact the flanges 16-1 and 16-2 become the non-constrained portion 2-2. In other words, the constrained portion 2-1 and the non-constrained portion 2-2 of the gasket 2 are generated by being placed between the flanges 16-1 and 16-2.

[0046] Load F application step S2: A load F is applied to the restrained portion 2-1 of the gasket 2, which is restrained by the flanges 16-1 and 16-2, by tightening the flanges 16-1 and 16-2. In response to this load F, strain occurs in the restrained portion 2-1 of the gasket 2, and a shape change occurs in the non-restrained portion 2-2.

[0047] Shape information acquisition step S3: The management server 30 (FIG. 6) receives the detection output of the strain sensor 28 and acquires shape information of the outer cut 4 regarding the shape change appearing in the non-restrained portion 2-2.

[0048] Step S4 of presenting shape information, etc.: The management server 30 generates presentation information including the shape information, and presents it by the information presenting unit 32 (FIG. 6).

[0049] Note that the shape information acquired in the shape information acquisition step S3 may be subjected to N-th order differentiation (multi-stage differentiation) to highlight change points in the shape information. If the results of this processing are reflected in the presented information in the presentation step S4, the change points in the shape information can be made clear.

[0050] <Gasket Management System 26> Figure 6 shows a gasket management system 26 for executing management processes by information processing. The configuration shown in Figure 6 is an example, and the present disclosure is not limited to such a configuration. In Figure 6, the same parts as in Figure 3 are assigned the same reference numerals.

[0051] The gasket management system 26 includes a strain sensor 28 , a management server 30 , and an information presentation unit 32 .

[0052] The strain sensor 28 measures the shape change appearing in the outer cut 4 of the gasket 2 and outputs a detection signal representing this shape change. This strain sensor 28 is an example of a means for detecting a shape change and converting it into an electrical signal. In addition to the strain sensor 28, a laser displacement meter, a camera, etc. may also be used as a shape change observation means. The laser displacement meter shines laser light on the outer cut 4, detects the shape change of the outer cut 4 by the reflected light, and observes the amount of change. The camera captures an image of the outer cut 4, and the management server 30 detects the strain appearing in the outer cut 4 by the number of pixels and obtains shape information corresponding to the strain.

[0053] The management server 30 is composed of a computer with communications capabilities. This management server 30 includes a processor 34, a memory unit 36, an input / output (I / O) unit 38, and a communications unit 40. The processor 34 executes the operating system (OS) and management programs stored in the memory unit 36 ​​to process information for gasket management. The memory unit 36 ​​includes a storage medium for storing the OS and management programs. A gasket management database (DB) 42 (FIG. 7) is stored in this memory unit 36. Under the control of the processor 34, the communications unit 40 interacts with a management terminal (not shown) to input and present information. The management terminal is also used to acquire shape information and write and read data to and from the gasket management DB 42.

[0054] Furthermore, the information presenting unit 32 presents management information including load information and judgment information associated with the shape information under the control of the management server 30 .

[0055] <Information processing of management server 30> Information processing of the management server 30 includes processes such as: a) inputting the detection output of the strain sensor 28; b) obtaining shape information of the outer cut 4; c) generating presentation information including the shape information; and d) presenting estimated information by the information presenting unit 32.

[0056] <Gasket Management DB 42> Fig. 7 shows an example of the gasket management DB 42. The gasket management DB 42 stores a gasket management file 44.

[0057] The gasket management file 44 includes a gasket information section 46, an outer cut information section 47, a time information section 48, a load information section 50, a strain sensor information section 52, a detection information section 54, a determination information section 56, and a history information section 58. The gasket information section 46 stores identification information of the gasket 2 as well as specification information for identifying the gasket 2.

[0058] The outer cut information section 47 stores outer cut information such as shapes representing the shapes of the outer cuts 4-1, 4-2, 4-3, and 4-4, their positions, sizes, etc.

[0059] The time information section 48 stores time information such as the measurement date and time.

[0060] The load information section 50 stores load information that indicates the load F applied to the gasket 2 from the flanges 16-1 and 16-2.

[0061] The strain sensor information section 52 stores sensor information including the type and identification information of the strain sensors 28 (=28-1, 28-2, 28-3, 28-4).

[0062] The detection information section 54 stores measurement information such as shape changes obtained from each outer cut 4 (=4-1, 4-2, 4-3, 4-4).

[0063] The determination information section 56 stores determination information that indicates the determination results of the measurement information of the outer cut 4 and load information estimated from this measurement information.

[0064] The history information section 58 stores history information such as acquisition of shape information.

[0065] <Effects of the First Embodiment> According to the first embodiment, any of the following effects can be obtained.

[0066] (1) Because the gasket 2 is provided with the outer cut 4, when the load F is applied to the restraint portion 2-1 from the flanges 16-1 and 16-2, the strain generated in the restraint portion 2-1 can be visualized as a change in shape of the outer cut 4 of the non-restraint portion 2-2. In other words, the change in shape corresponding to the load F can be easily observed from the outer cut 4.

[0067] (2) Shape information of the outer cut 4 is obtained from the detection output of each strain sensor 28 from the outer cut 4, and the load that the gasket 2 receives from the flanges 16-1 and 16-2 can be estimated from the change in shape.

[0068] (3) The strain of the gasket 2 can be observed by the change in shape of the outer cut 4, and the load being applied to the gasket 2 can be estimated from the change in shape without being affected by the tightening torque or axial force of the bolt 18, and the tightening state of the gasket 2 can be determined.

[0069] (4) The tightening state of the gasket 2 is not affected by the skill of the worker, and the control accuracy can be improved.

[0070] Second Embodiment A method for managing a gasket 2 according to a second embodiment includes an estimation step S5 using inflection point information in addition to the management step of the first embodiment.

[0071] In the estimation process S5 using inflection point information, the shape information including the shape changes that appear in the outer cut 4 includes inflection point information for a specific load (Figures 9 and 10), and the management server 30 can estimate the tightening state of the gasket 2 from the inflection points, i.e., the surface pressure that the gasket 2 receives from the flanges 16-1 and 16-2.

[0072] <Effects of the Second Embodiment> According to the second embodiment, any of the following effects can be obtained.

[0073] (1) The shape information can include inflection points as singular information of the load.

[0074] (2) By associating the load to be set with this inflection point and confirming the inflection point from the shape information, a specific load can be set.

[0075] (3) The load F, i.e., the surface pressure, that the gasket 2 receives can be estimated from the change in shape of the outer cut 4, making it possible to easily set and adjust the load on the gasket 2.

[0076] An example of the gasket 2 of the present disclosure will be described together with a comparative example. <Comparative Example> Fig. 8A shows a gasket 2 according to a comparative example. In this comparative example, the restraining portion 2-1 and the non-restraining portion 2-2 are set concentrically with the same or nearly the same width, and unlike the example, no outer cut 4 is provided.

[0077] 8B, in this comparative example, shape observation units 60-1, 60-2, 60-3, and 60-4 are set at positions corresponding to the outer cut 4 in the embodiment. The shape observation units 60-1, 60-2, 60-3, and 60-4 are arranged at angular intervals of a central angle of 90 degrees in the non-restraint portion 2-2.

[0078] <Examples> Table 1 shows the shapes of the outer cuts 4 of the gaskets 2 according to the examples, the measurement results, and the like.

[0079]

[0080] Table 1 shows the shape, shape change, and load for the comparative example (= no outer cut) and the example (= with outer cut). The comparative example did not have an outer cut 4. The example had an outer cut 4 with a width W1 of 1 mm and a length L1 of 3 mm.

[0081] In the comparative example, an inflection point load of 140 kN was obtained from the circumferential strain, and no minimum point load was obtained. Similarly, in the example, an inflection point load of 125 kN was obtained from the circumferential strain, and it was confirmed that a change occurred in the opening width of the outer cut 4.

[0082] <Inflection Point Information in Shape Change> Figure 9 shows the relationship between shape change and load, with the horizontal axis representing load [kN] and the vertical axis representing strain. Figure 9 shows the measured values ​​of the shape change occurring in the gasket 2 according to the comparative example, measured by the strain sensor 28, using angles of 0 (deg), 45 (deg), and 90 (deg) as parameters. m1 represents the deformation of the gasket 2 in the 0 (deg) direction (the circumferential direction of the gasket 2), m2 represents the deformation of the gasket 2 in the 45 (deg) direction, and m3 represents the deformation in the 90 (deg) direction (the thickness direction of the gasket 2).

[0083] In this way, when the restrained portion 2-1 receives the load F from the flanges 16-1 and 16-2, the non-restrained portion 2-2 undergoes a change in shape in accordance with the load F. In the example, the same measurement results as those shown in FIG. 9 were also obtained.

[0084] This shape change has an inflection point, and the optimum load F can be identified from the relationship between the load F applied to the gasket 2 and the inflection point of the shape change, and can be used as information for determining whether initial fastening has been completed.

[0085] 10 shows the relationship between the load and the shape change that occurs in the gasket 2 according to the example, with the horizontal axis representing the load [kN] and the vertical axis representing the opening width [mm] of the outer cut 4. Similarly, Table 2 shows the relationship between the load and the opening width W2 of the outer cut 4.

[0086]

[0087] When the restraint portion 2-1 receives a load F from the flanges 16-1 and 16-2 and this load increases, the opening width of the outer cut 4 increases in response to the load. This shape change has a significant inflection point that differs from that of the comparative example. Therefore, with the gasket 2 according to the example, by targeting the inflection point of the shape change that appears in each outer cut 4 or any one of the outer cuts 4, it is possible to identify the relationship between the shape change and the load.

[0088] Therefore, in the gasket 2 according to the embodiment, an inflection point can be generated in the shape information corresponding to a specific load. As a result, when tightening the flanges 16-1 and 16-2, the specific load can be estimated from the inflection point in the shape information, and this can be used as a criterion for determining whether tightening is complete.

[0089] <Detection of Inflection Points in Shape Information and Tightening Criteria> In the gasket 2 according to the embodiment, an inflection point can be generated in the shape information corresponding to a specific load. As a result, when tightening the flanges 16-1 and 16-2, a specific load can be estimated from the inflection point in the shape information, and this can be used as a criterion for determining whether tightening is complete.

[0090] <Effects of the Example> Shape changes occurring in the gasket 2 can be observed by the opening width W2 of the outer cut 4. In other words, the opening width W2 of the outer cut 4 is measured in advance for each load on the gasket 2, and the load can be easily estimated by comparing the opening width W2 with the actual measured value. This estimation is performed by creating a database of the opening width W2 of the outer cut 4 for each load, and comparing it with the actual measured value of the shape change to easily and accurately estimate the load.

[0091] Unlike torque management and bolt axial force measurement, such monitoring and measurement of shape changes measure the shape changes that appear in the outer cut 4 of the non-restrained portion 2-2 and can obtain shape information that represents the load from the gasket 2. Therefore, the load can be estimated from the shape changes of the gasket 2 due to the load F applied to the flanges 16-1 and 16-2 without being affected by the bolts 18 or the flanges 16-1 and 16-2.

[0092] It was confirmed that the processed shape of the outer cut 4 can accommodate various diameters and thicknesses of the gasket 2.

[0093] <Supplementary Notes> Supplementary notes are disclosed below regarding the above-described embodiments and examples.

[0094] (Appendix 1) A gasket to be installed between flanges of a flange fastening portion, the gasket comprising: a restrained portion that is restrained between the flanges and receives a load; a non-restrained portion that is not restrained between the flanges; and a notched portion provided in the non-restrained portion, wherein the notched portion undergoes a change when subjected to the load.

[0095] (Appendix 2) A management system for managing a flange fastening portion having a gasket between flanges, the management system comprising: a restraining portion that is restrained between the flanges and receives a load, a non-restraining portion that is not restrained between the flanges, and a gasket that has a notch portion provided in the non-restraining portion, and that causes a change in the notch portion when subjected to the load; a measuring instrument that measures the change in the notch portion with or without contact with the gasket; a management server that acquires measurement information from the measuring instrument and generates management information including the fastening force between the flanges; and an information presentation unit that presents the management information in association with the gasket or the flange fastening portion.

[0096] (Appendix 3) A recording medium having recorded thereon a program for being implemented by a computer, the program having the following functions: a function of acquiring shape information including a change that occurs in a notch in a non-restrained portion of a gasket due to the load that is applied between the flanges while the gasket is restrained between the flanges; a function of generating management information including a tightening force between the flanges based on the shape information; and a function of presenting the management information.

[0097] [Other Embodiments] (1) In the above embodiment and example, the initial fastening of the flange fastening portion 12 was exemplified by observing the shape change that occurred in the gasket 2 when a load was applied between the flanges, but this is not limited to the initial fastening of the flange fastening.

[0098] (2) The embodiment illustrates the vertical surface portion 6 and the opposing surface portions 8-1 and 8-2 for the outer cut 4. This is just one example, and the outer cut 4 may have a shape without the vertical surface portion 6, or the opposing surface portions 8-1 and 8-2 may be non-parallel, such as a V-shape, a polygonal shape, or a rectangular shape.

[0099] (3) The above-described embodiment, comparative example, and example describe the load F applied to the gasket 2 sandwiched between the flanges 16-1 and 16-2 and the change in shape of the gasket 2. The load F applied to the gasket 2 is equivalent to the surface pressure that the gasket 2 receives from the flanges 16-1 and 16-2, and there is no qualitative difference between the two. In other words, the surface pressure of the gasket 2 can be estimated from the relationship between the load F applied to the gasket 2 and the change in shape that appears in the outer cut 4.

[0100] (4) In the process of managing the gasket 2, in the process of presenting shape information (S4), the management server 30 may generate presentation information by processing the acquired shape information such as multi-stage differentiation, or may present a display unit on the information presentation unit 32 (FIG. 6) that clearly indicates change points.

[0101] As explained above, the most preferred embodiment of the present disclosure has been described. The present disclosure is not limited to the above description. Various modifications and changes are possible for those skilled in the art based on the gist of the invention as set forth in the claims or disclosed in the description for carrying out the invention. It goes without saying that such modifications and changes are included within the scope of the present disclosure.

[0102] The gasket, its management method, system, and program disclosed herein make it possible to easily observe the change in shape of the outer cut that deforms when subjected to a load F from the flange, estimate the load and surface pressure without being affected by the tightening state of the bolts or flange, and manage the tightening state of the gasket.

[0103] 2 Gasket 2-1 Restraint portion 2-2 Non-restraint portion 4, 4-1, 4-2, 4-3, 4-4 Outer cut 6 Vertical surface portion 8-1, 8-2 Opposing surface portion 12 Flange fastening portion 14-1, 14-2 Pipe line 16-1, 16-2 Flange 18 Bolt 20 Nut 22 Gasket seat 24 Gap 26 Gasket management system 28, 28-1, 28-2, 28-3, 28-4 Strain sensor 30 Management server 32 Information presentation unit 34 Processor 36 Memory unit 38 Input / output (I / O) unit 40 Communication unit 42 Gasket management database (DB) 44 Gasket management file 46 Gasket information unit 47 Outer cut information unit 48 Time information unit 50 Load information unit 52 Strain sensor information section 54 Detection information section 56 Judgment information section 58 History information section 60-1, 60-2, 60-3, 60-4 Shape observation section

Claims

1. A gasket, comprising an outer cut provided in an unconstrained portion adjacent to a constrained portion constrained between flanges, wherein the shape of the outer cut changes due to a load received by the constrained portion.

2. A management method, comprising the steps of: installing a gasket having an outer cut whose shape changes under a load between flanges; applying a load to the gasket constrained between the flanges; measuring the shape of the outer cut that has changed under the load; and managing the tightening of the gasket based on the shape.

3. A management system, comprising: measuring means for measuring the shape of an outer cut provided in a gasket; a management server for generating management information for managing the tightening between flanges based on the shape; and an information presentation unit for presenting the management information.

4. A program for being realized by a computer, the program causing the computer to realize functions of: acquiring shape information of an outer cut provided in a gasket constrained between flanges and receiving a load; generating management information for managing the tightening of the gasket based on the shape information; and presenting the management information.

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