WO2022009864A1 - Gasket control method, system, and program - Google Patents

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

Gasket management methods, systems and programs

The present disclosure relates to a gasket management technique used for, for example, fastening a piping system.

Traditionally, the tightening torque and bolt axial force value applied to the flange by bolts are used to tighten the gasket. Tightening torque and bolt axial force value are information on tightening bolts that tighten between flanges.

Regarding the tightening of this gasket, in order to grasp the tightening torque, a system using information on the tightening surface pressure corresponding to the type of gasket and internal fluid, a plurality of tightening forces, bolts, etc. is known (for example, Patent Document 1). ). Regarding the tightening of bolts, it is known that the strain generated in the bolts is converted into data and the tightened state of the bolts is visualized (for example, Patent Document 2). Further, a sheet type pressure sensor embedded inside the gasket is known to measure the force applied to a part of the gasket by fastening (for example, Patent Document 3).

Japanese Unexamined Patent Publication No. 2014-225219 Japanese Unexamined Patent Publication No. 2015-141345 Japanese Patent No. 46999935

By the way, the reason why the bolt tightening torque and axial force value are used for gasket tightening management is that the bolt is a means of tightening between flanges, and if the bolt strain is measured, the tightening force applied to the gasket from the bolt can be easily grasped. ,and so on.

However, as a result of scrutinizing the relationship between the bolt, the flange and the gasket, the tightening force of the bolt acts on the flange, and only indirectly acts on the gasket through the flange. That is, the flange receives a load due to the tightening of the bolt, and this load merely acts on the gasket through the flange. The torque value and the axial force value applied to the bolt are the loads acting on a part of the flange, and do not represent the surface pressure acting on the gasket.

Therefore, there are the following problems in gasket tightening management.

A) The torque value and axial force value obtained from the bolt are information about the bolt, and it cannot be said that the surface pressure received by the gasket is measured.

B) From the viewpoint of the surface pressure that the gasket receives from the flange, the torque value and axial force value of the bolt are only indirect information and are only a guideline for the surface pressure.

C) The torque value and axial force value of the bolt are affected by the tightening state of the bolt and flange, and this fluctuation tendency cannot be ignored.

When the surface pressure of the gasket is estimated from the torque value or axial force value measured with a torque wrench or bolt axial force meter, the surface pressure applied to the gasket (= estimated surface pressure) when affected by the tightening state of the bolt or flange. ) And the surface pressure (= actual surface pressure) actually received by the gasket,
Estimated surface pressure ≠ actual surface pressure. Even if the measurement accuracy of the torque value and the axial force value is improved, the estimated surface pressure and the actual surface pressure of the gasket do not match. It is not possible to grasp the surface pressure that the gasket receives.

Regarding such a problem, the inventor has found that the shape change of the gasket depends on the load received from between the flanges, and it is useful to observe the shape change in the tightening management of the gasket. Patent Documents 1 to 3 do not disclose or suggest such a problem. Further, such a problem cannot be solved by the configurations disclosed in Patent Documents 1 to 3.

Therefore, an object of the present disclosure is to observe a change in the shape of a gasket that receives a load between flanges based on the above problems and the above findings, and to use the observation result for management of gasket tightening.

In order to achieve the above object, according to one aspect of the gasket management method of the present disclosure, there is a step of applying a load to the gasket restrained between the flanges and a step of observing a shape change caused in the gasket due to the load. The tightening of the gasket is controlled based on the shape change.

In this management method, the shape change includes at least a change in the spacing direction between the flanges of the gasket, or a change in the spacing direction and the crossing direction, or both.

In order to achieve the above object, according to one aspect of the management system of the present disclosure, a measuring means for measuring a shape change of a gasket which is restrained between flanges and receives a load, and tightening between the flanges based on the shape change. It includes a management server that generates management information to be managed, and an information presentation unit that presents the management information.

In order to achieve the above object, according to one aspect of the program of the present disclosure, it is a program to be realized by a computer, in which a gasket is restrained between flanges and a load is received from between the flanges, and the load causes the gasket. The computer realizes a function of acquiring shape information representing the shape change caused in the above and a function of generating management information for managing the tightening of the gasket based on the shape change.

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

(1) The change in the shape of the gasket that occurs between the flanges represents the load that the gasket receives from between the flanges and the tightening state of the gasket, and the tightening of the gasket can be controlled by observing the change in the shape of the gasket.

(2) The change in the shape of the gasket between the flanges indicates the tightened state of the gasket between the flanges and the tightness between the flanges. If this shape change is directly observed from the gasket itself, the tightened state and the space between the flanges can be observed. The tightness can be easily evaluated.

(3) Compared to the conventional management by bolt torque value and axial force value, the gasket tightening management accuracy can be improved without depending on the skill of the worker.

And other objects, features and advantages of the present invention will be further clarified by reference to the accompanying drawings and each embodiment.

It is a figure which shows the flange fastening part which concerns on 1st Embodiment. It is a figure which shows the cut end face of the II-II line part of FIG. It is a figure which shows the gasket management system which concerns on 1st Embodiment. It is a figure which shows the gasket management database. It is a figure which shows the gasket management system which concerns on 3rd Embodiment. A is a diagram showing a gasket according to the first embodiment, and B is a diagram showing an example of a shape observing unit for the gasket. It is a figure which shows the shape change with respect to the load in the gasket which concerns on Example 1. FIG. A is a diagram showing a gasket according to the second embodiment, B is a perspective view showing an outer cut of the gasket, and C is a diagram showing a shape change appearing in the outer cut. It is a figure which shows the shape change with respect to the load in the outer cut which concerns on Example 2. FIG. A is a diagram showing the gasket according to the third embodiment, B is a perspective view for explaining the inner cut, and C is a diagram showing a shape change appearing in the inner cut. It is a figure which shows the shape change with respect to the load in the gasket which concerns on Example 3. FIG. It is a figure which shows an example of the shape observation of the gasket which concerns on Example 4. FIG. In the shape observation example according to the fourth embodiment, A is a diagram showing shape changes on the outer diameter side and the inner diameter side, and B is a diagram showing shape changes in the circumferential direction and the radial direction. A is a diagram showing the shape of the gasket according to the fifth embodiment, B is a diagram showing an example of a state before a load is applied, and C is a diagram showing an example of a state when a load of a predetermined value is applied. It is a figure which shows the shape observation example which concerns on Example 5.

[First Embodiment]
FIG. 1 shows a flange fastening portion 2 according to the 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, the Y-axis, and the Z-axis are shown at the center of the flange fastening portion 2 as an example.
The flange fastening portion 2 has a pipeline 4-1 and a pipeline 4-2 arranged in the Z-axis direction. A flange 6-1 is formed in the pipeline 4-1 as a means for fastening to the pipeline 4-2. A flange 6-2 is formed in the pipeline 4-2 as a means for fastening to the pipeline 4-1.

A gasket 8 is arranged between the flanges 6-1 and 6-2. The flanges 6-1 and 6-2 penetrate a plurality of bolts 10 at predetermined angular intervals (for example, 45 degrees) and are fastened to each bolt 10 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 in which PTFE (Polytetrafluoroethylene) and a filler are blended. The gasket 8 may be a gasket using a resin or rubber other than PTFE. Further, the gasket 8 may be made of a metal material, or may be a combination of a metal material and a ceramic, a heat-resistant fiber material, or another material. Further, the gasket 8 includes a spiral gasket 80 (FIG. 5), a flat plate gasket having a sheet such as PTFE or graphite attached to the surface, a groove formed on the gasket surface, or a flange portion on the outer edge portion. Includes can profile gaskets and the like.

The gasket 8 has a restraining portion 8-1 on the inner peripheral side and a non-constraining portion 8-2 on the outer peripheral side. The restraint portion 8-1 is sandwiched between the flanges 6-1 and 6-2 and restrained, and is a contact portion with the flanges 6-1 and 6-2, and is loaded from the flanges 6-1 and 6-2. This is the area that receives F. This load F is a tightening load by each bolt 10 and nut 12.

The non-constrained portion 8-2 is integrated with the restrained portion 8-1, and is not constrained by the flanges 6-1 and 6-2, and is a region on the peripheral edge side of the gasket 8. That is, the unconstrained portion 8-2 is not in contact with the flanges 6-1 and 6-2, is not constrained by the flanges 6-1 and 6-2, and receives the load F from the flanges 6-1 and 6-2. It is an area that is not received.

A plurality of shape observation units 14-1, 14-2, 14-3, and 14-4 are set in the non-restraint unit 8-2. Each shape observation unit 14-1, 14-2, 14-3, 14-4 is a region for observing a shape change appearing in the non-constrained portion 8-2 due to the load F received by the restrained portion 8-1. In this first embodiment, assuming an observation surface formed by the X-axis and the Y-axis, shape observation units 14-1, 14-2, 14-3, 14 of arbitrary width are set at angle positions set at 90-degree intervals. -4 is arranged.

<II-II line cut end face in Fig. 1>
FIG. 2 shows the cut end face of the line II-II portion of FIG. The restraint portion 8-1 is sandwiched and restrained between the gasket seats 16 of the flanges 6-1 and 6-2. On the other hand, the non-restraint portion 8-2 protrudes into the gap 18 between the flanges 6-1 and 6-2. The end portion of the gasket 8 is a free end in which when the restraining portion 8-1 receives the load F, strain with respect to this load appears as a shape change in the non-constraining portion 8-2, and constitutes a cantilever.

<Observation of shape change appearing in unconstrained part 8-2>
When the bolt 10 and the nut 12 are tightened to fasten the flanges 6-1 and 6-2, the restraining portion 8-1 of the gasket 8 receives the load F from between the flanges 6-1 and 6-2.

The gasket 8 that received this load F causes strain in the restraint portion 8-1, and this strain causes a shape change in the non-constrained portion 8-2. This shape change is the amount of change according to the load F.

This shape change changes depending on the magnitude of the load F and the direction of action. This shape change includes a change in the spacing direction (Z-axis direction) of the flanges 6-1 and 6-2 and a change in the crossing direction (X-axis direction, Y-axis direction) with respect to the spacing direction. The shape change of the gasket 8 of the first embodiment includes a change in the thickness direction, the radial direction, or the circumferential direction of the gasket 8.

<Gasket 8 management process>
The management process of the gasket 8 is an example of the management method of the present disclosure. This control step includes a generation step S1 of the restraint portion 8-1 and the non-constraint portion 8-2, a load F application step S2, a shape information acquisition step S3, and a shape information presentation step S4. S1 to S4 attached to each step are the order of each step, and the terms quoted are only used for convenience.

Generation step of generating the restrained portion 8-1 and the non-constrained portion 8-2 S1: When the gasket 8 is installed between the flanges 6-1 and 6-2, the portion of the gasket 8 in contact with the flanges 6-1 and 6-2 is formed. The portion of the gasket 8 that becomes the restraint portion 8-1 and does not contact the flanges 6-1 and 6-2 becomes the non-constraint portion 8-2. That is, the restrained portion 8-1 and the non-constrained portion 8-2 of the gasket 8 are generated by being installed between the flanges 6-1 and 6-2.

Load F application step S2: In the gasket 8, the load F is applied to the restraint portion 8-1 restrained by the flanges 6-1 and 6-2 by tightening the flanges 6-1 and 6-2. In response to this load F, the strain of the restraint portion 8-1 causes a shape change in the non-constrained portion 8-2.

Shape information acquisition process S3: The management server 24 (FIG. 3) acquires shape information including the shape change appearing in the non-constrained portion 8-2.

Presentation step of shape information and the like S4: The management server 24 generates presentation information including shape information and presents it by the information presentation unit 26 (FIG. 3).
The shape information acquired in the shape information acquisition step S3 may be subjected to Nth derivative (multi-step differentiation) to make the change points of the shape information stand out. If this processing result is reflected in the presentation information in the presentation step S4, the change point of the shape information can be clarified.

<Gasket management system 20>
FIG. 3 shows the gasket management system 20 according to the 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 those in FIG. 2 are designated by the same reference numerals.
The gasket management system 20 includes a strain sensor 22, a management server 24, and an information presentation unit 26.

The strain sensor 22 is an example of a measuring means for measuring a shape change from the shape observation unit 14 set in the unconstrained unit 8-2, and outputs a detection signal indicating the amount of change in the shape change generated in the shape observation unit 14. .. A laser displacement meter, a camera, or the like may be used for the strain sensor 22 as a device for detecting a shape change and converting it into an electric signal.

The laser displacement meter shines a laser beam on the shape observation unit 14, detects the shape change of the shape observation unit 14 with the reflected light, and observes the amount of change. The camera captures the shape observation unit 14, detects the shape change detected by the strain sensor 22 by the management server 24 by the number of pixels, and acquires the shape change information corresponding to the strain.

The management server 24 is composed of a computer having a communication function. The management server 24 includes a processor 28, a storage unit 30, an input / output (I / O) unit 32, and a communication unit 34. The processor 28 executes an OS (Operating System) and a management program in the storage unit 30, and performs information processing for gasket management. The storage unit 30 includes a storage medium for storing the OS and the management program. The gasket management database (DB) 36 (FIG. 4) is stored in the storage unit 30. The communication unit 34 controls the processor 28 to input and present information in cooperation with a management terminal (not shown). The management terminal is also used for acquiring shape information and writing and reading the gasket management DB 36.

Further, the information presenting unit 26, under the control of the management server 24, presents management information including load information and determination information related to the change information representing the shape change.

<Information processing of management server 24>
For information processing of the management server 24,
a) Processing for capturing the detection output of the strain sensor 22 b) Acquisition of shape information of the gasket 8 including the shape change of the unconstrained portion 8-2 c) Processing such as presentation of information by the information presenting unit 26 is included.

<Gasket management DB36>
FIG. 4 shows an example of the gasket management DB 36. The gasket management file 38 is stored in the gasket management DB 36.
In this gasket management file 38, as an example of gasket management information, a gasket information unit 40, a shape detection information unit 41, a time information unit 42, a load information unit 44, a strain sensor information unit 46, a detection information unit 48, and history information The unit 50 is set.

In addition to the identification information of the gasket 8, the gasket information unit 40 stores specification information for specifying the gasket 8.

The shape detection information unit 41 contains information on the shape observation units 14-1, 14-2, 14-3, and 14-4, for example, Example 1 (FIG. 6), Example 2 (FIG. 8), and Example 3 (. Shape observation unit information such as the form and arrangement position as shown in FIG. 10) is stored.

Time information such as the observation date and time is stored in the time information unit 42.

The load information unit 44 stores load information such as the load F applied between the flanges 6-1 and 6-2 by tightening the bolt 10 and the load conditions thereof.

The strain sensor information unit 46 stores the type of sensor that observes the shape change and the like.

The detection information unit 48 stores the detection values acquired by the strain sensor 22 from the shape observation units 14-1, 14-2, 14-3, and 14-4.

The history information unit 50 stores history information such as observation and information presentation such as shape change and load.

<Effect of the first embodiment>
According to this first embodiment, any of the following effects can be obtained.

(1) The shape change of the gasket 8 is caused by the load received by the gasket 8 from between the flanges 6-1 and 6-2, and represents the tightened state of the gasket 8. Therefore, by observing the shape change of the gasket 8 by the shape observing unit 14, the tightening state of the gasket 8 can be grasped and the tightening state can be managed.

(2) The shape change of the gasket 8 represents the sealing between the flanges 6-1 and 6-2 by the gasket 8 between the flanges 6-1 and 6-2, and this shape change is directly observed from the gasket itself. Then, the hermeticity between the flanges 6-1 and 6-2 can be easily evaluated.

(3) Compared to the conventional management based on the bolt torque value and axial force value, the tightening management accuracy of the gasket 8 can be improved without depending on the skill of the worker.

[Second Embodiment]
The management method of the gasket 8 according to the second embodiment further includes the estimation step S5 based on the inflection point information in the management method of the first embodiment.
In the estimation step S5 based on the inflection point information, the shape information includes the inflection point information of the shape change due to the specific load F, and the management server 24 can calculate the load F to be applied to the gasket 8 from the inflection point.

The inflection point represents, for example, a state in which the shape change in the circumferential direction of the gasket 8 changes significantly, and includes a minimum point. The minimum point is a point where the change direction of the shape change changes, and is, for example, a transition point from a compressed state to an extended (tensile) state or an extended (tension) state to a compressed state.

<Effect of the second embodiment>
According to the second embodiment, any of the following effects can be obtained.

(1) Inflection point information can be acquired as peculiar information of shape change from shape information.

(2) By associating this inflection point information with the load F to be added to the gasket 8, it is possible to optimize the load on the gasket 8 by confirming the inflection point information from the shape information.

(3) It is possible to facilitate load setting and load adjustment for the gasket 8.

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

This gasket management system 20 is arranged between the flanges 6-1 and 6-2, and the spiral gasket 80 is used as an observation target of the shape change due to the load F received from the flanges 6-1 and 6-2. Be done. As shown in FIG. 5, for example, the gasket 80 is a laminated body in which a plurality of members having different diameters are coaxially arranged, and includes an outer ring 801, a gasket main body 802, and an inner ring 803.

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 in a ring having a predetermined thickness or a shape close to the ring.

The gasket body 802 has a thin plate-shaped member made of, for example, a metal material, and a laminated body of a cushioning material (filler) such as graphite or fluororesin, which is spirally wound between the inner wall surface of the outer ring 801 and the outer wall surface of the inner ring 803. It is composed by winding around. The laminate constituting the gasket main body 802 is formed, for example, in a cross section having a “V” shape or a waveform close to it. In this laminated body, for example, the end faces are fixed to the outer ring 801 and the inner ring 803 by spot welding.

For example, in the flange fastening portion 2, the gasket 80 is restrained in which only the inner ring 803, a part or all of the inner ring 803 and the gasket body 802, and a part of the outer ring 801 come into contact with the gasket seat 16 (FIG. 2) to receive a load F. It may be part 8-1. That is, in the gasket 80, a part or all of the outer ring 801 becomes an unconstrained portion 8-2. In the gasket 80, the gasket main body 802 is deformed according to the load F from the flanges 6-1 and 6-2, and the outer ring 801 is distorted due to this deformation.

In this gasket management system 20, for example, a shape observation unit 14 is set in a part of the outer ring 801 which is an unconstrained portion 8-2, and a shape change such as a strain generated in the outer ring 801 is measured by a strain sensor 22. Then, the gasket management system 20 grasps the load F applied to the gasket 80 and the tightened state of the gasket by utilizing the amount of change in the shape change. As for the management process of the tightened state of the gasket 80, the same process as that of the above embodiment may be performed.

<Effect of the third embodiment>
According to the third embodiment, any of the following effects can be obtained.

(1) The same effects as those of the first embodiment and the second embodiment can be obtained.

(2) Even when the spiral gasket 80 is used, the tightened state can be grasped by measuring the shape change of the unconstrained portion 8-2 with the flanges 6-1 and 6-2.

<Example 1>
FIG. 6A shows the gasket 8 according to the first embodiment. In the first embodiment, the restrained portion 8-1 and the non-constrained portion 8-2 are set concentrically with the same width or substantially the same width. The restraining portion 8-1 is a coplanar surface on the gasket 8, and may be a region automatically determined as a contact portion between the flanges 6-1 and 6-2 described above and the gasket seat 16, and the non-constraining portion 8 may be formed. -2 may be a region separated from the gasket seat 16.

B in FIG. 6 shows a gasket 8 in which a plurality of 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 in the unconstrained unit 8-2 at an angular interval of 90 degrees at the center angle. θ indicates the angle range in which the shape observation units 14-1, 14-2, 14-3, and 14-4 are set. The arrangement positions of the shape observation units 14-1, 14-2, 14-3, and 14-4 may be set to positions that do not overlap with the arrangement positions of the bolts 10, but the arrangement position is not limited to this.

In FIG. 7, the gasket 8 according to the first embodiment has a load [kN] on the horizontal axis, a strain (shape change) on the vertical axis, and angles = 0 (deg), 45 (deg), 90 (deg) as parameters. The shape change appearing in is shown by the measured value measured by the strain sensor 22.

m1 is the deformation of the gasket 8 in the 0 (deg) direction (= circumferential direction of the gasket 8), m2 is the deformation of the gasket 8 in the 45 (deg) direction, and m3 is the deformation of the gasket 8 in the 90 (deg) direction (= thickness direction of the gasket 8). ) Is shown.

When the restraining portion 8-1 receives the load F from the flanges 6-1 and 6-2 in this way, the shape of the non-constraining portion 8-2 changes according to the load F.
An inflection occurs in this shape change, and the optimum load F can be specified 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 the completion of initial fastening.

<Example 2>
A in FIG. 8 shows the gasket 8 according to the second embodiment. In the second embodiment, similarly to the first embodiment, the restrained portion 8-1 and the non-constrained portion 8-2 are set to have the same width or substantially the same width and are concentrically set.

Outer cut 54 is formed in each shape observation unit 14-1, 14-2, 14-3, 14-4 in the non-restraint portion 8-2. The outer cut 54 is formed in the outermost edge portion of the non-restraint portion 8-2 of the gasket 8, and has a notch shape having a non-closed portion in a part thereof.

In the second embodiment, a plurality of outer cuts 54 are formed on the gasket 8, and each outer cut 54 is arranged on the non-restraint portion 8-2 at an angular interval of 90 degrees at a center angle.

As shown in B of FIG. 8, the outer cut 54 is, for example, a groove having a constant width W1 cut by a constant length L1 from the peripheral surface of the gasket 8 toward the center, and is an upper and lower surface of the gasket 8. It penetrates into. That is, the outer cut 54 has a vertical surface portion 56 and parallel surface portions 58 and 60 facing each other with a constant width W1 inside the gasket 8.

When a load F is applied from the flanges 6-1 and 6-2 to the restraint portion 8-1 of the gasket 8 provided with such an outer cut 54, as shown in FIG. 8C, the vertical surface portion 56 is applied according to the load F. Spreads as shown by the arrow a and is displaced toward the peripheral edge. Further, the parallel surface portions 58 and 60 are expanded in the peripheral direction as shown by arrows b and c. At this time, the edge surface of the gasket 8 extends outward as shown by the arrow d.

Such a shape change can be easily detected by the strain sensor 22. A sensor member such as metal or resin may be installed in the space portion of the outer cut 54, and the shape change of the outer cut 54 may be extracted from the sensor member.

FIG. 9 shows the relationship between the shape change and the load appearing in the gasket 8 according to the second embodiment, with the load [kN] on the horizontal axis and the opening width (shape change) [mm] of the outer cut 54 on the vertical axis. .. Similarly, Table 1 shows the relationship between the opening width W2 of the outer cut 54 and the load F.

When the restraint portion 8-1 receives the load F from the flanges 6-1 and 6-2 and the load F of the restraint portion 8-1 increases, the opening width W2 of the outer cut 54 indicating the shape change with respect to the load F increases. .. An inflection occurs in this shape change. Therefore, when the second embodiment is used, if the inflection point of the shape change appearing in the shape observation units 14-1, 14-2, 14-3, 14-4 is targeted, the relationship between the shape change and the load F is used. Can be identified.

<Example 3>
A in FIG. 10 shows the gasket 8 according to the third embodiment. In the third embodiment, similarly to the first and second embodiments, the restrained portion 8-1 and the non-constrained portion 8-2 are set concentrically with the same width or substantially the same width.

Inner cuts 62 are formed in the shape observation units 14-1, 14-2, 14-3, and 14-4 in the non-restraint portion 8-2. The inner cut 62 is a through-hole portion formed in the unrestrained portion 8-2 of the gasket 8.

Each inner cut 62 is arranged in the non-restraint portion 8-2 at an angular interval of 90 degrees at the center angle, but is not limited to this.

As shown in B of FIG. 10, the inner cut 62 is an arcuate groove portion concentric with the peripheral edge portion of the gasket 8 and having a constant width W, and penetrates the upper and lower surfaces of the gasket 8. That is, the inner cut 62 has vertical surface portions 64, 66, a constant length L2, and concentric arc portions 68, 70 facing each other with a width W3 inside the gasket 8.

When a load F is applied from the flanges 6-1 and 6-2 to the restraint portion 8-1 of the gasket 8 provided with such an inner cut 62, as shown in FIG. 10C, the arrow e, depending on the load F, As shown by f, the distance between the arc portions 68 and 70 is shortened, and the edge surface of the gasket 8 extends outward as shown by the arrow g. Such a shape change can be easily detected by the strain sensor 22.

Note that a sensor member such as metal or resin may be installed in the space portion of the inner cut 62, and the shape change of the inner cut 62 may be extracted from this sensor member.

FIG. 11 shows the relationship between the shape change and the load appearing on the gasket 8 according to the third embodiment, with the load [kN] on the horizontal axis and the strain (shape change) of the inner cut 62 on the vertical axis.

When the restraint portion 8-1 receives the load F from the flanges 6-1 and 6-2 and the load F with respect to the restraint portion 8-1 increases, the shape of the inner cut 62 representing the change in the load F changes. This shape change has a minimum point included in the inflection point, and in the third embodiment as well, the relationship between the shape change and the load F can be specified by targeting the minimum point. As described above, this minimum point is a point where the change direction of the shape change appearing in the unconstrained portion 8-2 of the gasket 8 changes, that is, the inner cut 62 is expanded (tensioned) or extended from the compressed state. This is the transition point from the (tensile) state to the compressed state.

Therefore, according to the third embodiment, in the relationship between the load F and the shape change, the minimum point appears remarkably due to the shape change in the circumferential direction, but the minimum point may be the inflection point. In addition, the change in shape in the circumferential direction may cause an inflection point in which the change in shape in the circumferential direction changes significantly, that is, not a minimum point.

<Detection of inflection points in shape information and tightening criteria>
As shown in Example 1, Example 2, and Example 3, inflection points can be generated in the shape information corresponding to a specific load F. As a result, when the flanges 6-1 and 6-2 are tightened, a specific load F can be estimated from the inflection point of the shape information, and can be used as a criterion for determining the completion of tightening.

<Comparison of Examples 1, 2 and 3>

Table 2 shows the shapes, shape changes, and inflection points of Example 1 (= outer cut 54 and inner cut 62: none), Example 2 (= outer cut 54), and Example 3 (= inner cut 62). Is shown.

In Example 1, the outer cut 54 and the inner cut 62 are not processed.
In Example 2, an outer cut 54 having a width W1 = 1 mm and a length L1 = 3 mm was formed.
In Example 3-1 the inner cut 62 was set to have a width W3 = 1 mm and a length L2 = 30 mm.
In Example 3-2, the width W3 = 2 mm and the length L2 = 30 mm were set.
In Example 3-3, the width W3 = 1 mm and the length L2 = 50 mm were set.

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

<Effects of Examples 1, 2 and 3>
As is clear from Examples 1, 2 and 3, in the outer cut 54, an appropriate load F can be estimated by measuring the opening width W2 of the cut shape from the side surface. When the outer cut 54 is used 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 is estimated by comparing the opening width W2 with the measured value. can. In this estimation, the opening width W2 of the outer cut 54 is stored in a database for each load F, and the load F can be easily and accurately calculated by comparing with the measured value of the shape change.

In the inner cut 62, a load F is applied to the flanges 6-1 and 6-2, and the inner wall surface of the through-hole-shaped inner cut 62 is closed (contacted), so that a remarkable change can be obtained.

In monitoring and measuring such shape changes, unlike torque management and bolt axial force measurement, the shape change of the non-restraint portion 8-2 (Example 1), the shape change of the outer cut 54 (Example 2), and the inner cut The shape change (Example 3) of 62 can be measured, and the change representing the load F can be obtained 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 8 without being affected by the bolt 10 and the flanges 6-1 and 6-2.

It was confirmed that the gasket 8 can also handle various diameters and thicknesses regarding the processed shapes of the outer cut 54 and the inner cut 62.

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

<Measurement of shape change Qa and Qb in the circumferential direction>
In FIG. 13, A has a load [kN] on the horizontal axis and a strain (shape change) in the circumferential direction on the vertical axis, and the shape change Qa appearing on the outer edge of the outer ring 801 and the shape change Qb appearing on the inner edge are measured by the strain sensor 22. The measured value is shown.

The strain on the inner edge side of the outer ring 801 is larger 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 change behavior of the gasket 80 or the gasket body 802 due to the load F.

<Measurement of shape change Qb in the circumferential direction and shape change R in the radial direction>
In FIG. 13, B has a load [kN] on the horizontal axis and a strain (shape change) on the vertical axis, and the strain sensor 22 measures the shape change Qb in the circumferential direction appearing on the inner edge of the outer ring 801 and the shape change R appearing in the radial direction. The measured value is shown.

From this measurement result, in the shape change Qb in the circumferential direction, the measured value increases in the positive direction as the gasket surface pressure increases, so it can be understood that a force in the tensile direction is acting. Further, in the shape change R in the radial direction, the measured value increases in the negative direction as the gasket surface pressure increases, so that it can be understood that the compressed state is obtained.

<Example 5>
FIG. 14A shows a configuration example of the gasket 80 according to the fifth embodiment. In the fifth embodiment, for example, at least the outer ring 801 constitutes the unconstrained portion 8-2. In the fifth embodiment, an inner cut 82 having a predetermined length is formed on a part of the outer ring 801 of the gasket 80 along the outer circumference. The inner cut 82 is a through-hole portion formed in the unrestrained portion 8-2 of the gasket 8. The inner cut 82 is formed at a position of 5 [mm], for example, as a predetermined distance t from the outer edge portion of the outer ring 801. In the fifth embodiment, for example, the shape observation unit 14 is provided at the outer edge portion along the formation position of the inner cut 82.

As shown in B of FIG. 14, for example, the outer ring 801 has a predetermined width of, for example, 0.1 [mm] before the load F from the flanges 6-1 and 6-2 is applied to the gasket body 802.
The inner cut 82a is open. Then, when the load F acts through the gasket main body 802, the outer ring 801 is formed into an inner cut 82b in which a part or all of the opening portion is deformed and closed, as shown in FIG. 14, for example, C. In the fifth embodiment, the gasket surface pressure due to the load F and the shape change Qc of the outer ring 801 in the state of the inner cut 82b are measured.

In FIG. 15, a load [kN] is applied on the horizontal axis and a strain (shape change) is applied on the vertical axis, and the shape change Qc in the circumferential direction appearing on the outer edge corresponding to the formation position of the inner cut 82b of the outer ring 801 is measured by the strain sensor 22. The measured value is shown.

In this measurement result, when the load on the gasket increases, for example, there is no significant change in strain from the start of loading to a predetermined value, and then when the load exceeds a predetermined value, a negative value is measured by the strain sensor. ing. This causes, for example, a shape change indicating that the outer edge portion of the outer ring 801 is compressed in the circumferential direction. Then, the strain in the circumferential direction increases in the positive direction after a minimum point appears when the load is around 220 kN, for example.

<Effects of Examples 4 and 5>
According to Examples 4 and 5, the following effects can be expected.

(1) By measuring the shape change of the outer ring 801 of the spirally 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.

(2) In the spiral-wound gasket 80, the state of strain differs depending on the measurement position of the outer ring 801 due to the shape characteristics of the gasket body 802 formed in a spiral shape, and the state of the gasket and the state of load. Can be grasped in detail.

(3) Since the gasket body 802 and the outer ring 801 are separate members of the spirally wound gasket 80, the load F from the flanges 6-1 and 6-2 is compared with the sheet gasket composed of a single member. On the other hand, although the tendency of strain formation generated in the unconstrained portion 8-2 is different, the load F applied from the flanges 6-1 and 6-2 can be estimated from the shape change of the gasket 80.

(4) The inner cut 82 formed in the spiral gasket 80 has a remarkable change in the strain generated in the outer ring 801 due to the opening being closed by the load F from the flanges 6-1 and 6-2.

(5) In the flange fastening portion 2 using the spirally wound gasket 80, the shape changes Qa, Qb, and R (Example 4) that occur in the outer ring 801 are different from the torque management and the measurement of the bolt axial force in the monitoring and measurement of the shape change. ) And the shape change of the inner cut 82 (Example 5), the change representing the load F can be obtained 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 and the flanges 6-1 and 6-2.

[Other embodiments]
(1) Regarding the outer cut 54, the vertical surface portion 56 and the parallel surface portions 58 and 60 are exemplified in the second embodiment, but these are examples. The outer cut 54 may have a shape that does not have the vertical surface portion 56, or may have a V-shaped shape in which the parallel surface portions 58 and 60 are non-parallel, for example.

(2) Regarding the inner cut 62, the concentric arc portions 68 and 70 are illustrated in the third embodiment, but these are examples. The inner cut 62 may have a shape in which the arcuate portions 68 and 70 do not have a constant width, or may be a parallel surface or a non-parallel surface instead of the arcuate shape.

(3) In the process of presenting shape information or the like in the management process of the gasket 8, the management server 24 may generate presentation information by processing the acquired shape information by multi-step differentiation or the like, and the information presentation unit may be used. A display unit that clearly indicates the change point may be presented in 26 (FIG. 3).

As described above, the most preferable embodiments of the present disclosure have been described. The present disclosure is not limited to the above description. Various modifications and modifications can be made by those skilled in the art based on the gist of the invention described in the claims or disclosed in the form for carrying out the invention. It goes without saying that such modifications and changes are included in the scope of the present disclosure.

According to the gasket management method, system and program of the present disclosure, it is possible to observe the change in the shape of the gasket due to the load received from the flange without measuring the axial force or torque value of the bolt that fastens between the flanges, and to observe the change in the shape of the gasket due to the load received from the flange. It is useful because the load on the gasket can be calculated from the shape information without being affected by the tightening state of the gasket, and it can be used for management information such as gasket replacement.

2 Flange fastening part 4-1, 4-2 Pipeline 6-1, 6-2 Flange 8,80 Gasket 8-1 Restraint part 8-2 Non-restraint part 10 Bolt 12 Nut 14, 14-1, 14-2, 14-3, 14-4 Shape observation unit 16 Gasket seat 18 Gap 20 Gasket management system 22 Strain sensor 24 Management server 26 Information presentation unit 28 Processor 30 Storage unit 32 Input / output (I / O) unit 34 Communication unit 36 Gasket management database (DB)
38 Gasket management file 40 Gasket information section 41 Shape detection information section 42 Time information section 44 Load information section 46 Strain sensor information section 48 Detection information section 50 History information section 54 Outer cut 56 Vertical surface section 58, 60 Parallel surface section 62, 82 Inner cut 64, 66 Vertical surface part 68, 70 Arc part 801 Outer ring 802 Gasket body 803 Inner ring

Claims (4)

1. The process of applying a load to the gasket restrained between the flanges,
   The process of observing the shape change caused by the gasket due to the load, and
   A management method comprising and controlling the tightening of the gasket based on the shape change.
2. The management method according to claim 1, wherein the shape change includes at least a change in the spacing direction between the flanges of the gasket, or a change in the spacing direction and the crossing direction, or both.
3. A measuring means that measures the shape change of the gasket that is restrained between the flanges and receives the load,
   A management server that generates management information that manages tightening between flanges based on the shape change, and
   The information presentation unit that presents the management information and
   A management system characterized by including.
4. It is a program to be realized by a computer.
   A function in which a gasket is restrained between flanges and a load is received from between the flanges, and shape information indicating a shape change caused in the gasket due to the load is acquired.
   A function to generate management information for managing the tightening of the gasket based on the shape change, and
   A program for realizing the above on the computer.
   
   

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