Gasket management method, system, and program

Abstract

Tightening of a gasket (8) held between flanges (6-1, 6-2) is controlled on the basis of a step in which a load due to tightening is applied, a step in which a change in the shape of the gasket generated by the load is observed, and the change in shape. The change in shape includes a change in the gasket in at least the direction of the interval between the flanges, or a change in a direction orthogonal to the interval direction, or both of said changes. Thus, if a change in the shape of the gasket receiving the load is observed, tightening of the gasket can be controlled.

Description

[Technical field]

[0001] The present disclosure relates to a management technique for gaskets used, for example, in fastening piping systems. [Background technology]

[0002] The tightening torque and bolt axial force applied to the flanges by the bolts are traditionally used for tightening gaskets. The tightening torque and bolt axial force are information on the tightening of the bolts that fasten the flanges.

[0003] Regarding the tightening of this gasket, a system is known that uses tightening surface pressure corresponding to the type of gasket and internal fluid, multiple tightening forces, bolt-related information, etc., to grasp the tightening torque (for example, Patent Document 1). Regarding the tightening of a bolt, it is known to convert the strain generated in the bolt into data and visualize the tightening state of the bolt (for example, Patent Document 2). Also known is a system that uses a sheet-type pressure sensor embedded inside the gasket to measure the force applied to a part of the gasket by tightening (for example, Patent Document 3). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-225219 A [Patent Document 2] JP 2015-141345 A [Patent Document 3] Patent No. 4699935 Summary of the Invention [Problem to be solved by the invention]

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

[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 acts on the gasket via the flange. In other words, the flange receives the load caused by the tightening of the bolts, and this load only acts on the gasket via the flange. The torque value and axial force value applied to the bolts are loads acting on a 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 the gasket:

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

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

[0010] c) The bolt torque and axial force values ​​are affected by the tightening condition 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, if it is affected by the tightening condition of the bolts or flanges, 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 as follows: Estimated surface pressure ≠ actual surface pressure Even if the measurement accuracy of the torque and axial force values ​​is improved, the estimated contact pressure and the actual contact pressure of the gasket do not match. It is not possible to grasp the contact pressure that the gasket receives.

[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 the change in shape is useful for managing the fastening of the gasket. Patent Documents 1 to 3 do not disclose or suggest this problem. Furthermore, the configurations disclosed in Patent Documents 1 to 3 cannot solve this problem.

[0013] Therefore, based on the above problems and findings, an object of the present disclosure is to observe the change in 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. [Means for solving the problem]

[0014] In order to achieve the above object, according to one aspect of the gasket management method of the present disclosure, and a non-constrained portion adjacent to the constrained portion. applying a load to the gasket; and compressing the gasket by the load. A shape observation section is set at a plurality of positions in the non-restraint section. and observing a shape change occurring in the In the step of observing the shape change, a strain sensor that detects an amount of change in the shape change is used to obtain shape information including the shape change in the circumferential direction of the gasket in the shape observation unit; The shape information The tightening of the gasket is controlled based on the above.

[0015] In this control method, the shape change is determined by measuring either or both of a change in the spacing direction between the flanges of the gasket and a change in the spacing direction and a direction intersecting the spacing direction. moreover Contains The inflection point of the shape information obtained by performing N-th order differentiation is used as a criterion for determining whether or not the fastening of the gasket is completed.

[0016] In order to achieve the above object, according to one aspect of the management system of the present disclosure, a gasket that is restrained between flanges and subjected to a load is provided. Observation of the shape of the non-restrained area The system includes a measuring means for measuring a change in shape, a management server for generating management information for managing the fastening between the flanges based on the change in shape, and an information presentation unit for presenting the management information. The measuring means is a strain sensor that detects the amount of change in the shape change, and acquires shape information including the shape change in the circumferential direction of the gasket in the shape observation unit, and the management server manages the tightening between the flanges based on the shape information.

[0017] In order to achieve the above object, according to one aspect of the program of the present disclosure, there is provided a program for executing a program by a computer, the program comprising: a gasket that is constrained between flanges; RestraintsA load is applied between the flanges, and the load The gasket is then subjected to a circumferential observation at a plurality of shape observation sections set at the periphery of the non-restrained portion adjacent to the restrained portion. Shape information that represents shape changes Using a strain sensor to detect the amount of change in the shape The function to be obtained and the shape information The computer realizes a function of generating management information for managing the fastening of the gasket based on the above-mentioned. Effect of the Invention

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

[0019] (1) The change in gasket shape that occurs between the flanges indicates the load the gasket receives between the flanges and the tightening condition of the gasket. By observing the change in gasket shape, it is possible to control the tightening of the gasket.

[0020] (2) The change in the shape of the gasket between the flanges represents the tightening condition of the gasket between the flanges and the airtightness between the flanges. By directly observing this change in shape from the gasket itself, the tightening condition and the airtightness between the flanges can be easily evaluated.

[0021] (3) Compared to the conventional method of management based on the torque value or axial force value of the bolts, the accuracy of gasket tightening management can be improved without relying on the skill of the worker.

[0022] Other objects, features and advantages of the present invention will become more apparent with reference to the accompanying drawings and each embodiment. [Brief description of the drawings]

[0023] [Figure 1] FIG. 2 is a diagram showing a flange fastening portion according to the first embodiment. [Diagram 2] 2 is a diagram showing a cross-sectional view of the section taken along line II-II in FIG. 1. [Diagram 3] FIG. 1 is a diagram showing a gasket management system according to a first embodiment. [Figure 4]FIG. 13 is a diagram showing a gasket management database. [Diagram 5] FIG. 13 is a diagram showing a gasket management system according to a third embodiment. [Figure 6] FIG. 1A is a diagram showing a gasket according to Example 1, and FIG. 1B is a diagram showing an example of a shape observation unit for the gasket. [Figure 7] FIG. 4 is a diagram showing a shape change with respect to a load in the gasket according to Example 1. [Figure 8] FIG. 10A is a view showing a gasket according to Example 2, FIG. 10B is a perspective view showing an outer cut of the gasket, and FIG. 10C is a view showing a change in shape that appears in the outer cut. [Figure 9] FIG. 11 is a diagram showing a change in shape with respect to a load in an outer cut according to Example 2. [Figure 10] FIG. 10A is a view showing a gasket according to Example 3, FIG. 10B is a perspective view for explaining an inner cut, and FIG. 10C is a view showing a shape change appearing in the inner cut. [Figure 11] FIG. 11 is a diagram showing a shape change with respect to a load in a gasket according to Example 3. [Figure 12] FIG. 13 is a diagram showing an example of observation of the shape of a gasket according to Example 4. [Figure 13] FIG. 13 is a shape observation example according to Example 4, in which FIG. 13A shows changes in shape on the outer diameter side and the inner diameter side, and FIG. 13B shows changes in shape in the circumferential direction and the radial direction. [Figure 14] FIG. 10A is a diagram showing the shape of a gasket according to Example 5, FIG. 10B is a diagram showing an example of the state before a load is applied, and FIG. 10C is a diagram showing an example of the state when a load of a predetermined value is applied. [Figure 15] FIG. 13 is a diagram showing an example of shape observation according to the fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] First Embodiment Fig. 1 shows a flange fastening portion 2 according to a first embodiment. The configuration shown in Fig. 1 is an example, and the present disclosure is not limited to such a configuration. In Fig. 1, the X-axis, Y-axis, and Z-axis are shown at the center of the flange fastening portion 2 as an example. Pipes 4-1 and 4-2 are arranged in the Z-axis direction in this flange fastening portion 2. A flange 6-1 is formed in the pipe 4-1 as a fastening means for connecting to the pipe 4-2. A flange 6-2 is formed in the pipe 4-2 as a fastening means for connecting to the pipe 4-1.

[0025] A gasket 8 is disposed between the flanges 6-1 and 6-2. A plurality of bolts 10 are inserted between the flanges 6-1 and 6-2 at predetermined angular intervals (for example, 45 degrees), and each bolt 10 is fastened with a nut 12. The gasket 8 is a sealing member between the flanges 6-1 and 6-2, and is, for example, a sheet gasket made of a mixture of PTFE (Polytetrafluoroethylene) and a filler. The gasket 8 may be made of a resin or rubber other than PTFE. The gasket 8 may be made of a metal material, or may be made of a combination of a metal material and ceramic, a heat-resistant fiber material, or other material. The gasket 8 may be a spiral gasket 80 (FIG. 5), a flat gasket with a sheet of PTFE or graphite attached to the surface, a cam profile gasket with a groove formed on the surface of the gasket or a flange on the outer edge, etc.

[0026] In this gasket 8, a restrained portion 8-1 is set on the inner circumferential side, and a non-restrained portion 8-2 is set on the outer circumferential side. The restrained portion 8-1 is sandwiched between and restrained by the flanges 6-1, 6-2, is a contact portion with the flanges 6-1, 6-2, and is an area that receives a load F from the flanges 6-1, 6-2. This load F is a tightening load by each of the bolts 10 and nuts 12.

[0027] The non-restrained portion 8-2 is integral with the restrained portion 8-1, is not restrained by the flanges 6-1 and 6-2, and is an area on the peripheral side of the gasket 8. In other words, the non-restrained portion 8-2 is not in contact with the flanges 6-1 and 6-2, is not restrained by the flanges 6-1 and 6-2, and is an area that does not receive the load F from the flanges 6-1 and 6-2.

[0028] A plurality of shape observation units 14-1, 14-2, 14-3, and 14-4 are set in the non-constrained portion 8-2. Each of the shape observation units 14-1, 14-2, 14-3, and 14-4 is an area for observing a shape change appearing in the non-constrained portion 8-2 due to the load F received by the constrained portion 8-1. In this first embodiment, an observation plane formed by the X-axis and the Y-axis is assumed, and the shape observation units 14-1, 14-2, 14-3, and 14-4 of arbitrary widths are arranged at angular positions set at 90 degree intervals.

[0029] <Cutting surface of line II-II in Fig. 1> Fig. 2 shows a cut end surface taken along line II-II in Fig. 1. The restrained portion 8-1 is sandwiched and restrained between the gasket seats 16 of the flanges 6-1 and 6-2. In contrast, the non-restrained portion 8-2 protrudes into the gap 18 between the flanges 6-1 and 6-2. The end of the gasket 8 is a free end where, when the restrained portion 8-1 receives a load F, strain due to this load appears as a change in shape in the non-restrained portion 8-2, forming a cantilever beam.

[0030] <Observation of shape changes occurring in the unconstrained portion 8-2> When the bolts 10 and nuts 12 are tightened to fasten the flanges 6-1 and 6-2 together, the restraining portion 8-1 of the gasket 8 receives a load F from between the flanges 6-1 and 6-2.

[0031] When the gasket 8 receives the load F, a strain is generated in the restrained portion 8-1, and this strain causes a shape change in the non-restrained portion 8-2. The amount of this shape change corresponds to the load F.

[0032] This shape change varies depending on the magnitude and direction of the load F. This shape change includes changes in the spacing direction (Z-axis direction) between the flanges 6-1, 6-2 and in directions intersecting this spacing direction (X-axis direction, Y-axis direction). The shape change of the gasket 8 in the first embodiment includes changes in the thickness direction, radial direction, or circumferential direction of the gasket 8.

[0033] <Gasket 8 Management Process> The management process of the gasket 8 is an example of a management method of the present disclosure. This management process includes a process S1 of generating the constrained portion 8-1 and the non-constrained portion 8-2, 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. S1 to S4 attached to each process indicate the order of each process, and the cited terms are used merely for convenience.

[0034] Step S1 of generating constrained portion 8-1 and non-constrained portion 8-2: When the gasket 8 is placed between the flanges 6-1 and 6-2, the portion of the gasket 8 that contacts the flanges 6-1 and 6-2 becomes the constrained portion 8-1, and the portion of the gasket 8 that does not contact the flanges 6-1 and 6-2 becomes the non-constrained portion 8-2. In other words, the constrained portion 8-1 and non-constrained portion 8-2 of the gasket 8 are generated by being placed between the flanges 6-1 and 6-2.

[0035] Load F application step S2: A load F is applied to the restrained portion 8-1 of the gasket 8, which is restrained by the flanges 6-1 and 6-2, by fastening the flanges 6-1 and 6-2. In response to the load F, the restrained portion 8-1 is distorted, causing a shape change in the non-restrained portion 8-2.

[0036] Shape information acquisition step S3: The management server 24 (FIG. 3) acquires shape information including the shape change appearing in the unconstrained portion 8-2.

[0037] Presentation step S4 of shape information, etc.: The management server 24 generates presentation information including the shape information, and presents it by the information presentation unit 26 (FIG. 3). Note that the shape information acquired in the shape information acquisition step S3 may be subjected to N-th order differentiation (multiple-stage differentiation) to highlight the change points of the shape information. If the result of this processing is reflected in the presented information in the presentation step S4, the change points of the shape information can be clarified.

[0038] <Gasket Management System 20> Fig. 3 shows a gasket management system 20 according to a first embodiment. This gasket management system 20 is a system for executing the above-mentioned management process by information processing. The configuration shown in Fig. 3 is an example, and the present disclosure is not limited to such a configuration. In Fig. 3, the same parts as in Fig. 2 are given the same reference numerals. The gasket management system 20 includes a strain sensor 22, a management server 24, and an information presentation unit .

[0039] The strain sensor 22 is an example of a measuring means for measuring a shape change from the shape observation section 14 set in the non-constrained section 8-2, and outputs a detection signal that indicates the amount of shape change that has occurred in the shape observation section 14. This strain sensor 22 may be a laser displacement meter, a camera, or the like, which is a device that detects the shape change and converts it into an electrical signal.

[0040] The laser displacement meter shines a laser light on the shape observation unit 14, detects the shape change of the shape observation unit 14 by the reflected light, and observes the amount of change. The camera captures an image of the shape observation unit 14, and the management server 24 detects the shape change detected by the strain sensor 22 in terms of the number of pixels, and obtains shape change information corresponding to the strain.

[0041] The management server 24 is composed of a computer with a communication function. This management server 24 has a processor 28, a memory unit 30, an input / output (I / O) unit 32, and a communication unit 34. The processor 28 executes the OS (Operating System) and management programs in the memory unit 30, and performs information processing for gasket management. The memory unit 30 includes a storage medium for storing the OS and management programs. A gasket management database (DB) 36 (FIG. 4) is stored in this memory unit 30. Under the control of the processor 28, the communication unit 34 inputs and presents information in cooperation with a management terminal (not shown). The management terminal is also used for obtaining shape information and writing and reading to and from the gasket management DB 36.

[0042] Further, under the control of the management server 24, the information presenting unit 26 presents management information including the load information and the judgment information associated with the change information representing the shape change.

[0043] <Information processing by management server 24> The information processing of the management server 24 includes the following: a) Acquisition process of the detection output of the strain sensor 22 b) Acquisition of shape information of the gasket 8 including changes in shape of the non-constrained portion 8-2 c) Presentation of information by the information presentation unit 26 This includes processes such as:

[0044] <Gasket Management DB36> 4 shows an example of the gasket management DB 36. The gasket management DB 36 stores a gasket management file 38. In this gasket management file 38, a gasket information section 40, a shape detection information section 41, a time information section 42, a load information section 44, a strain sensor information section 46, a detection information section 48, and a history information section 50 are set as examples of gasket management information.

[0045] In the gasket information section 40, in addition to the identification information of the gasket 8, specification information for identifying the gasket 8 is stored.

[0046] The shape detection information section 41 stores information about the shape observation sections 14-1, 14-2, 14-3, and 14-4, such as shape observation section information such as the form and arrangement position of Example 1 (FIG. 6), Example 2 (FIG. 8), and Example 3 (FIG. 10).

[0047] The time information section 42 stores time information such as the observation date and time.

[0048] The load information section 44 stores load information such as the load F applied between the flanges 6-1, 6-2 by fastening the bolts 10 and the load conditions.

[0049] The strain sensor information section 46 stores the type of sensor that observes the shape change, etc.

[0050] The detection information section 48 stores detection values ​​acquired by the strain sensor 22 from the shape observation sections 14-1, 14-2, 14-3, and 14-4.

[0051] The history information section 50 stores history information such as observation of shape changes and loads, and information presentation.

[0052] <Advantages of the First Embodiment> According to the first embodiment, any one of the following effects can be obtained.

[0053] (1) The change in shape of the gasket 8 occurs due to the load that the gasket 8 receives between the flanges 6-1 and 6-2, and represents the fastening state of the gasket 8. Therefore, by observing the change in shape of the gasket 8 using the shape observation unit 14 of the gasket 8, the fastening state of the gasket 8 can be grasped and the fastening state can be managed.

[0054] (2) The change in shape of the gasket 8 represents the sealing performance between the flanges 6-1 and 6-2 provided by the gasket 8 between the flanges 6-1 and 6-2. By directly observing this change in shape from the gasket itself, the sealing performance between the flanges 6-1 and 6-2 can be easily evaluated.

[0055] (3) Compared with the conventional method of controlling the tightening of the gasket 8 by using the torque value or axial force value of the bolt, the tightening control accuracy of the gasket 8 can be improved without depending on the skill of the worker.

[0056] Second Embodiment The method for managing a gasket 8 according to the second embodiment further includes an estimation step S5 using inflection point information in addition to the management method according to the first embodiment. In the estimation step S5 using the inflection point information, the shape information includes inflection point information of a shape change caused by a specific load F, and the management server 24 can calculate the load F to be applied to the gasket 8 from the inflection point.

[0057] An inflection point represents a state where the shape of the gasket 8 changes significantly, for example, in the circumferential direction, and includes a minimum point. A minimum point is a point where the direction of the shape change changes, for example, a transition point from a compressed state to an elongated (tensile) state, or from an elongated (tensile) state to a compressed state.

[0058] <Advantages of the second embodiment> According to the second embodiment, any one of the following effects can be obtained.

[0059] (1) Inflection point information can be obtained from shape information as specific information of shape change.

[0060] (2) By associating this inflection point information with the load F to be applied to the gasket 8 and confirming the inflection point information from the shape information, the load on the gasket 8 can be optimized.

[0061] (3) The load on the gasket 8 can be easily set and adjusted.

[0062] Third embodiment FIG. 5 shows a gasket management system 20 according to a third embodiment. The configuration shown in FIG. 5 is just an example, and the technology of the present disclosure is not limited to such a configuration.

[0063] This gasket management system 20 is disposed between the flanges 6-1 and 6-2, and uses a spiral-wound gasket 80 as an object for observing changes in shape due to a load F received from the flanges 6-1 and 6-2. This gasket 80 is a laminate in which a plurality of members with different diameters are coaxially disposed, as shown in Fig. 5, for example, and includes an outer ring 801, a gasket body 802, and an inner ring 803.

[0064] The outer ring 801 and the inner ring 803 are made of a metal material such as stainless steel, carbon steel, or titanium, and are formed into a ring of a predetermined thickness or a shape close to that.

[0065] Gasket body 802 is formed by spirally winding a laminate of a thin plate member formed of, for example, a metal material and a buffer material (filler) such as graphite or fluororesin between the inner wall surface of outer ring 801 and the outer wall surface of inner ring 803. The laminate constituting gasket body 802 has a cross section formed, for example, in a "V" shape or a waveform close to it. The end faces of this laminate are fixed to outer ring 801 and inner ring 803 by spot welding, for example.

[0066] In gasket 80, for example, at flange fastening portion 2, only inner ring 803 or inner ring 803 and part or all of gasket body 802, and part of outer ring 801 may be in contact with gasket seat 16 (FIG. 2) to form constrained portion 8-1 that receives load F. That is, in gasket 80, part or all of outer ring 801 becomes non-constrained portion 8-2. In gasket 80, gasket body 802 deforms in response to load F from flanges 6-1 and 6-2, and this deformation causes strain in outer ring 801.

[0067] In this gasket management system 20, for example, a shape observation unit 14 is set in a part of an outer ring 801, which is the non-constrained portion 8-2, and a shape change such as a strain occurring in the outer ring 801 is detected by a strain sensor 22. ToThe gasket management system 20 uses the amount of change in shape to grasp the load F applied to the gasket 80 and the fastening state of the gasket. The management process of the fastening state of the gasket 80 may be the same as that of the above embodiment.

[0068] <Advantages of the Third Embodiment> According to the third embodiment, any one of the following effects can be obtained.

[0069] (1) The same effects as those of the first and second embodiments can be obtained.

[0070] (2) Even when a spiral-wound gasket 80 is used, the tightening state can be grasped by measuring the change in shape of the non-constrained portion 8-2 between the flanges 6-1, 6-2. EXAMPLES

[0071] <Example 1> 6A shows a gasket 8 according to Example 1. In this Example 1, a restraining portion 8-1 and a non-restraining portion 8-2 are set concentrically with the same or almost the same width. The restraining portion 8-1 is on the same plane on the gasket 8, and may be a region that is automatically determined as a contact portion with the gasket seat 16 of the flanges 6-1 and 6-2 described above, and the non-restraining portion 8-2 may be a region outside the gasket seat 16.

[0072] FIG. 6B shows a gasket 8 on which multiple shape observation units 14-1, 14-2, 14-3, and 14-4 are arranged. The shape observation units 14-1, 14-2, 14-3, and 14-4 are arranged at angular intervals of 90 degrees on the non-constraint unit 8-2. θ indicates the angular range in which the shape observation units 14-1, 14-2, 14-3, and 14-4 are set. The positions of the shape observation units 14-1, 14-2, 14-3, and 14-4 may be set so as not to overlap with the positions of the bolts 10, but are not limited thereto.

[0073] FIG. 7 shows the load (kN) on the horizontal axis and strain (shape change) on the vertical axis, with angles of 0 (deg), 45 (deg), and 90 (deg) as parameters, and shows the shape change occurring in the gasket 8 of Example 1 as measured by the strain sensor 22.

[0074] m1 indicates the deformation of the gasket 8 in the 0 degree direction (= the circumferential direction of the gasket 8), m2 indicates the deformation of the gasket 8 in the 45 degree direction, and m3 indicates the deformation in the 90 degree direction (= the thickness direction of the gasket 8).

[0075] When the restrained portion 8-1 receives a load F from the flanges 6-1 and 6-2 in this manner, a shape change corresponding to the load F occurs in the non-restrained portion 8-2. 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 8 and the inflection point of the shape change, and can be used as information for determining whether the initial fastening is complete.

[0076] <Example 2> 8A shows a gasket 8 according to Example 2. In Example 2, similar to Example 1, a restraining portion 8-1 and a non-restraining portion 8-2 are set concentrically with the same width or substantially the same width.

[0077] In the non-constraint portion 8-2, an outer cut 54 is formed in each of the shape observation portions 14-1, 14-2, 14-3, and 14-4. The outer cut 54 is formed in the outermost edge portion of the non-constraint portion 8-2 of the gasket 8, and has a notch shape having an unclosed portion in part.

[0078] In the second embodiment, a plurality of outer cuts 54 are formed in the gasket 8, and the outer cuts 54 are arranged at angular intervals of 90 degrees at the central angle in the non-constrained portion 8-2.

[0079] 8B, the outer cut 54 is a groove of a constant width W1 cut from the peripheral surface of the gasket 8 toward the center by a constant length L1, and penetrates through the top and bottom surfaces of the gasket 8. In other words, the outer cut 54 has, on the inside of the gasket 8, a vertical surface portion 56, and opposing parallel surface portions 58, 60 of the constant width W1.

[0080] When a load F is applied from the flanges 6-1, 6-2 to the restraint portion 8-1 of the gasket 8 having such an outer cut 54, the vertical surface portion 56 expands as indicated by the arrow a and is displaced in the circumferential direction in response to the load F, as shown in Fig. 8C. Also, the parallel surface portions 58, 60 expand in the circumferential direction as indicated by the arrows b, c. At this time, the edge surface of the gasket 8 extends outward as indicated by the arrow d.

[0081] Such a change in shape can be easily detected by the strain sensor 22. Note that a sensor member made of metal, resin, or the like may be placed in the space of the outer cut 54, and the change in shape of the outer cut 54 may be detected from this sensor member.

[0082] 9, with the horizontal axis representing load [kN] and the vertical axis representing the opening width (shape change) [mm] of the outer cut 54, shows the relationship between the load and the shape change that appears in the gasket 8 of Example 2. Similarly, Table 1 shows the relationship between the opening width W2 of the outer cut 54 and the load F.

[0083] [Table 1]

[0084] When the restraint portion 8-1 receives a load F from the flanges 6-1 and 6-2 and the load F on the restraint portion 8-1 increases, the opening width W2 of the outer cut 54, which indicates the shape change in response to the load F, increases. An inflection point occurs in this shape change. Therefore, when using the second embodiment, the relationship between the shape change and the load F can be identified by targeting the inflection points of the shape change appearing in the shape observation portions 14-1, 14-2, 14-3, and 14-4.

[0085] <Example 3> 10A shows a gasket 8 according to Example 3. In Example 3, similar to Examples 1 and 2, a restraining portion 8-1 and a non-restraining portion 8-2 are set concentrically with the same width or substantially the same width.

[0086] In the non-constraint portion 8-2, an inner cut 62 is formed in each of the shape observation portions 14-1, 14-2, 14-3, and 14-4. The inner cut 62 is a through hole portion formed in the non-constraint portion 8-2 of the gasket 8.

[0087] The inner cuts 62 are arranged at angular intervals of 90 degrees in the non-constrained portion 8-2, but are not limited to this.

[0088] As shown in FIG. 10B, the inner cut 62 is concentric with the periphery of the gasket 8 and has a constant width W 3 It is an arc-shaped groove that penetrates the top and bottom surfaces of the gasket 8. That is, the inner cut 62 has vertical surface portions 64, 66 on the inside of the gasket 8, and concentric arc portions 68, 70 that face each other and have a certain length L2 and width W3.

[0089] When a load F is applied from the flanges 6-1, 6-2 to the restraint portion 8-1 of the gasket 8 having such an inner cut 62, the distance between the arc portions 68, 70 decreases as shown by the arrows e, f in response to the load F, and the edge surface of the gasket 8 extends outward as shown by the arrow g, as shown in C of Fig. 10. Such a change in shape can be easily detected by the strain sensor 22.

[0090] It is also possible to place a sensor member made of metal, resin or the like in the space of the inner cut 62 and detect the change in shape of the inner cut 62 from this sensor member.

[0091] FIG. 11 shows the relationship between the load and the deformation of the gasket 8 according to Example 3, with the horizontal axis representing the load [kN] and the vertical axis representing the strain (deformation) of the inner cut 62.

[0092] When the restraint portion 8-1 receives a load F from the flanges 6-1 and 6-2 and the load F on the restraint portion 8-1 increases, the shape of the inner cut 62, which represents the change in the load F, changes. This shape change has a minimum point included in the inflection point, and in this Example 3 as well, it is possible to specify the relationship between the shape change and the load F by targeting such a minimum point. As described above, this minimum point is a point where the direction of the shape change appearing in the non-restraint portion 8-2 of the gasket 8 changes, that is, a transition point where the inner cut 62 transitions from a compressed state to an elongated (tensile) state, or from an elongated (tensile) state to a compressed state.

[0093] Therefore, according to Example 3, in the relationship between the load F and the shape change, a minimum point appears conspicuously due to the shape change in the circumferential direction, but there are also cases where the minimum point is equal to the inflection point. Also, there are also cases where the shape change in the circumferential direction produces not a minimum point, but an inflection point where the shape change in the circumferential direction changes significantly.

[0094] <Detection of inflection points of shape information and tightening criteria> As shown in the first, second and third embodiments, an inflection point can be generated in the shape information corresponding to a specific load F. This makes it possible to estimate the specific load F from the inflection point of the shape information when tightening the flanges 6-1 and 6-2, and to use this as a criterion for determining whether tightening is complete.

[0095] <Comparison of Examples 1, 2, and 3>

[0096] [Table 2]

[0097] Table 2 shows the shapes, changes in the shapes, and inflection points for Example 1 (=no outer cut 54 and inner cut 62), Example 2 (=outer cut 54), and Example 3 (=inner cut 62).

[0098] In Example 1, the outer cut 54 and the inner cut 62 are not processed. In Example 2, the outer cut 54 was formed with a width W1 of 1 mm and a length L1 of 3 mm. In Example 3-1, the inner cut 62 was set to have a width W3 of 1 mm and a length L2 of 30 mm. In Example 3-2, the width W3 was set to 2 mm and the length L2 was set to 30 mm. In Example 3-3, the width W3 was set to 1 mm and the length L2 was set to 50 mm.

[0099] In Example 1, an inflection point load of 140 kN was obtained from the change in shape in the circumferential direction, and a minimum point load was not obtained. In Example 2, an inflection point load of 125 kN was obtained from the change in shape in the circumferential direction, and a minimum point load was not obtained. In Example 3-1, an inflection point load of 135 kN was obtained from the shape change in the circumferential direction, and a minimum point load of 135 kN was obtained. In Example 3-2, an inflection point load of 115 kN was obtained from the shape change in the circumferential direction, and a minimum point load of 115 kN was obtained. In Example 3-3, an inflection point load of 120 kN was obtained from the shape change in the circumferential direction, and a minimum point load of 120 kN was obtained.

[0100] <Effects of Examples 1, 2, and 3> As is clear from Examples 1, 2 and 3, with the outer cut 54, the appropriate load F can be estimated by measuring the opening width W2 of the cut shape from the side. When using the outer cut 54 for shape detection, the opening width W2 of the outer cut 54 is measured in advance for each load F applied to the gasket 8, and the load F can be estimated by comparing the opening width W2 with the actual measured value. This estimation can be performed by creating a database of the opening width W2 of the outer cut 54 for each load F, and easily and accurately calculating the load F by comparing it with the actual measured value of the shape change.

[0101] In the inner cut 62, a load F is applied to the flanges 6-1 and 6-2, and the inner wall surfaces of the through-hole-shaped inner cut 62 close (come into contact), resulting in a noticeable change.

[0102] Unlike torque management or bolt axial force measurement, such monitoring and measurement of shape changes measures the shape changes of the non-constrained portion 8-2 (Example 1), the outer cut 54 (Example 2), and the inner cut 62 (Example 3), and can obtain changes representing the load F from the gasket 8. Therefore, the load F applied to the flanges 6-1, 6-2 can be estimated from the shape change of the gasket 8 without being affected by the bolt 10 or the flanges 6-1, 6-2.

[0103] It was confirmed that the processed shapes of the outer cut 54 and the inner cut 62 can accommodate the gasket 8 in various diameters and thicknesses.

[0104] <Example 4> 12 shows a configuration example of a gasket 80 according to Example 4. In this Example 4, for example, at least an outer ring 801 of a spiral-wound gasket 80 constitutes a non-constrained portion 8-2. In this Example 4, shape changes Qa and Qb on the outer edge side and inner edge side of the outer ring 801 of the gasket 80 that expand and contract in the circumferential direction, and shape change R that expands and contracts in the radial direction of the gasket 80 are measured.

[0105] <Measurement of circumferential shape changes Qa and Qb> FIG. 13A shows the load (kN) on the horizontal axis and the circumferential strain (shape change) on the vertical axis, and shows the measurement values ​​of the shape change Qa appearing on the outer edge of the outer ring 801 and the shape change Qb appearing on the inner edge, measured by the strain sensor 22.

[0106] The strain on the inner edge side of the outer ring 801 is greater than the strain on the outer edge side. That is, since the shape of the outer ring 801 changes significantly on the inner edge side, it is easy to detect the behavior of the gasket 80 or the gasket main body 802 due to the load F.

[0107] <Measurement of circumferential shape change Qb and radial shape change R> FIG. 13B shows the load (kN) on the horizontal axis and strain (shape change) on the vertical axis, and shows the measurement values ​​of the circumferential shape change Qb and the radial shape change R that appear on the inner edge of the outer ring 801, measured by the strain sensor 22.

[0108] From these measurement results, it can be seen that for the circumferential shape change Qb, the measured value increases in the positive direction as the gasket contact pressure increases, indicating that a tensile force is acting, and for the radial shape change R, the measured value increases in the negative direction as the gasket contact pressure increases, indicating that the gasket is in a compressed state.

[0109] <Example 5> FIG. 14A shows an example of the configuration of a gasket 80 according to a fifth embodiment. In this fifth embodiment, for example, at least an outer ring 801 constitutes the non-constraining portion 8-2. In this fifth embodiment, an inner cut 82 of a predetermined length is formed along the outer periphery of a part of the outer ring 801 of the gasket 80. This inner cut 82 is a through hole formed in the non-constraining portion 8-2 of the gasket 8. This inner cut 82 is formed at a position, for example, a predetermined distance t of 5 mm from the outer edge of the outer ring 801. In this fifth embodiment, for example, the inner cut A shape observation section 14 is provided on the outer edge portion along the position where the groove 82 is formed.

[0110] As shown in FIG. 14B, before a load F from the flanges 6-1 and 6-2 is applied to the gasket body 802, the outer ring 801 has a predetermined width of, for example, 0.1 mm. 14C, the gasket surface pressure and the shape change Qc of the outer ring 801 in the state of the inner cut 82b are measured.

[0111] Figure 15 shows the load (kN) on the horizontal axis and strain (shape change) on the vertical axis, and shows the measurement values ​​of the circumferential shape change Qc that appears on the outer edge corresponding to the formation position of the inner cut 82b of the outer ring 801, measured by the strain sensor 22.

[0112] In the measurement results, when the load on the gasket increases, for example, there is no significant change in strain from the start of loading until a certain value, and then when the load exceeds the certain value, a negative value is measured by the strain sensor. This indicates that a shape change has occurred, for example, indicating that the outer edge of the outer ring 801 has been compressed in the circumferential direction. Then, after a minimum point appears when the load is, for example, around 220 kN, the circumferential strain value increases in the positive direction.

[0113] <Effects of Examples 4 and 5> According to the fourth and fifth embodiments, the following effects can be expected.

[0114] (1) By measuring the change in shape of the outer ring 801 of the spiral-wound gasket 80 sandwiched between the flanges 6-1 and 6-2, the surface pressure of the gasket 80 due to the load F can be grasped.

[0115] (2) In the spiral-wound gasket 80, due to the geometric characteristics of the gasket body 802, which is formed in a wound shape, there are differences in the state of strain depending on the measurement position of the outer ring 801, making it possible to grasp the state of the gasket and the load state in detail.

[0116] (3) In the spiral wound gasket 80, the gasket body 802 and the outer ring 801 are separate members. Therefore, compared to a sheet gasket constructed from a single member, the tendency for strain to be generated in the non-restrained portion 8-2 in response to the load F from the flanges 6-1, 6-2 is different. However, the load F applied from the flanges 6-1, 6-2 can be estimated from the change in shape of the gasket 80.

[0117] (4) When the opening of the inner cut 82 formed in the spiral-wound gasket 80 is closed by the load F from the flanges 6-1 and 6-2, a significant change occurs in the strain generated in the outer ring 801.

[0118] (5) In the flange fastening portion 2 using the spiral gasket 80, unlike torque management or bolt axial force measurement, monitoring and measurement of shape change can be performed by measuring the shape changes Qa, Qb, R (Example 4) that occur in the outer ring 801 and the shape change of the inner cut 82 (Example 5), thereby obtaining a change representing the load F from the gasket 8. Therefore, the load F applied to the flanges 6-1 and 6-2 can be estimated from the shape change of the gasket 80 without being affected by the bolt 10 or the flanges 6-1 and 6-2.

[0119] Other Embodiments (1) In the second embodiment, the outer cut 54 has the vertical surface 56 and the parallel surface portions 58, 60, but these are merely examples. The outer cut 54 may have a shape that does not have the vertical surface portion 56, or the parallel surface portions 58, 60 may be non-parallel, for example, a V-shape.

[0120] (2) Although the concentric arc portions 68, 70 of the inner cut 62 are illustrated in the third embodiment, these are merely examples. The inner cut 62 may have a shape in which the arc portions 68, 70 do not have a constant width, and may have parallel or non-parallel surfaces instead of the arc shape.

[0121] (3) In the process of managing the gasket 8, in the process of presenting shape information (S4), the management server 24 may generate presentation information by processing the acquired shape information such as multi-stage differentiation, and a display unit showing the change points may be presented on the information presentation unit 26 (FIG. 3).

[0122] As described 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 described in the claims or disclosed in the description for carrying out the invention. It goes without saying that such modifications and changes are included in the scope of the present disclosure. [Industrial Applicability]

[0123] The gasket management method, system, and program disclosed herein are useful in that it is possible to observe changes in the shape of the gasket due to the load received from the flanges without measuring the axial force or torque value of the bolts that fasten the flanges, and to calculate the load on the gasket from the shape information without being affected by the tightening state of the bolts or flanges, and this can be used for management information such as gasket replacement. [Explanation of symbols]

[0124] 2 Flange fastening 4-1, 4-2 pipeline 6-1, 6-2 flange 8, 80 Gasket 8-1 Restraint part 8-2 Unrestrained part 10 Volts 12 Nut 14, 14-1, 14-2, 14-3, 14-4 Shape observation section 16 Gasket seat 18 Gap 20 Gasket Management System 22 Strain Sensor 24 Management Server 26 Information Presentation Department 28 processors 30 Storage section 32 Input / Output (I / O) Section 34 Communications Department 36 Gasket Management Database (DB) 38 Gasket Management File 40 Gasket Information Department 41 Shape detection information section 42 Time Information Department 44 Load Information Section 46 Strain sensor information section 48 Detection Information Section 50 History Information Section 54 Outer Cut 56 Vertical section 58, 60 Parallel surface part 62, 82 Inner cut 64, 66 Vertical surface section 68, 70 Arc section 801 Outer ring 802 Gasket body 803 Inner Circle

Claims

1. applying a load to a gasket having a restrained portion that is restrained between flanges and a non-restrained portion adjacent to the restrained portion; observing a shape change caused by the load at shape observation sections set at a plurality of positions of the non-constrained portion of the gasket; Including, In the step of observing the shape change, a strain sensor that detects an amount of change in the shape change is used to obtain shape information including the shape change in the circumferential direction of the gasket in the shape observation unit; A management method comprising the steps of: managing fastening of the gasket based on the shape information.

2. The shape change further includes either or both of a change in a spacing direction between at least the flanges of the gasket, or a change in a direction intersecting the spacing direction, 2. The management method according to claim 1, wherein an inflection point of said shape information obtained by performing N-th order differentiation is used as a criterion for determining whether or not fastening of said gasket is complete.

3. a measuring means for measuring a shape change occurring in shape observation sections set at a plurality of positions in a non-restrained portion of the gasket that is restrained between the flanges and receives a load; a management server that generates management information for managing the fastening between the flanges based on the shape change; an information presenting unit that presents the management information; Including, the measuring means is a strain sensor that detects an amount of change in the shape change, and acquires shape information including the shape change in the circumferential direction of the gasket in the shape observation unit; The management system is characterized in that the management server manages the fastening between the flanges based on the shape information.

4. A program for implementing the program on a computer, a function of receiving a load from between the flanges on a restraining portion where the gasket is restrained between the flanges, and acquiring shape information representing a change in the circumferential shape of the gasket due to the load at shape observation portions set at multiple locations on the periphery of a non-restraining portion adjacent to the restraining portion, using a strain sensor that detects the amount of change in the shape; a function of generating management information for managing fastening of the gasket based on the shape information; A program for realizing the above on the computer.

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