Valve maintenance assistance device and method

Abstract

The valve maintenance assisting device and method of the present invention improve the work efficiency of valve maintenance. The valve maintenance assisting device of the present invention comprises: a fully open data extraction unit (5) which searches for data of an opening instruction value indicating full opening among the opening instruction values ​​assigned to the bellows valve, extracts the actual opening value of the bellows valve assigned the opening instruction value, and the actual opening value of the time period corresponding to the opening instruction value indicating full opening as diagnostic data; a fully open incomplete determination unit (6) which determines whether the bellows valve assigned the opening instruction value indicating full opening has a fully open incomplete state that has not become fully open based on the diagnostic data; and a determination result prompting unit (8) which prompts the ID of the bellows valve determined to have been in the fully open incomplete state as the ID of the valve in which the bellows is damaged.

Description

Technical Field

[0001] The present invention relates to a technology for assisting maintenance work, and more particularly to a valve maintenance assisting device and method for assisting maintenance work of a bellows valve, wherein the bellows valve has a corrugated bellows arranged in a manner surrounding the outer periphery of a valve shaft coupled to a valve core. Background Art

[0002] Conventionally, valves used in petrochemical equipment, etc. (e.g. Fig.10 Control valves) require special attention to safety and therefore require regular maintenance. Fig.10 The valve 100 shown includes a valve body 101, a positioner 102, and an operator 103. The operator 103 moves a valve shaft (valve stem) 104 up and down according to the air pressure Po supplied from the positioner 102 to adjust the valve opening (the gap between the valve element 105 and the seat ring 106), that is, to adjust the flow of the fluid.

[0003] The positioner 102 detects the lift position of the valve shaft 104 , i.e., the actual valve opening, based on the rotation angle position of the feedback rod 107 connected to the valve shaft 104 , and supplies the air pressure Po corresponding to the difference between the detected actual opening and the set opening to the operator 103 .

[0004] In the valve 100, in order to prevent external leakage of the fluid, a corrugated bellows (bellows seal) 108 is provided on the outer periphery of the valve shaft 104 connected to the valve core 105. The bellows 108 is made of a corrosion-resistant metal material and is provided in a lower flange 109 connected to the valve body 101 so as to surround the outer periphery of the valve shaft 104.

[0005] In the lower flange 109, the bellows 108 is supported between a bellows ring 111 and a bellows flange 112. The bellows ring 111 is embedded in the valve shaft 104, and the bellows flange 112 is sandwiched between the lower flange 109 and the upper flange 110. In the upper flange 110, in order to further prevent external leakage of the fluid, a gland packing 113 is provided between the outer peripheral surface of the valve shaft 104 and the inner peripheral surface of the upper flange 110. In addition, the lower part of the upper flange 110 becomes an upper cover relative to the lower flange 109.

[0006] The valve 100 having such a corrugated bellows 108 is called a bellows valve. In a factory or the like where these valves are installed, a plurality of valves need to be efficiently maintained, and a method of detecting damage of a bellows valve has been proposed to improve the efficiency of the maintenance work (see Patent Document 1).

[0007] The valve maintenance support device disclosed in Patent Document 1 presents information on the maximum friction force of the bellows valve to an operator as a diagnostic index, thereby estimating whether the bellows valve is suspected of being damaged.

[0008] However, even if the bellows 108 is damaged, the friction force detection result may not be affected by the damage. The leakage of fluid from the bellows 108 is a serious event, but in the technology disclosed in Reference 1, there is a possibility that the damage of the bellows 108 cannot be detected.

[0009] Many valves are used in petrochemical plants, etc. For example, Fig.11 In the example, valves 100-A and 1000-M are arranged in flow path 114-1, and valve 100-C is arranged in flow path 114-3. 115-A, 115-C, and 115-M are flow rate measuring devices, 116 is a tank, and 117 is a pressure transmitter. In this way, in equipment using multiple valves, etc., further improvement in the efficiency of maintenance work is required.

[0010] Prior art literature

[0011] Patent Literature

[0012] Patent Document 1: Japanese Patent Application Publication No. 2019-087003 Summary of the invention

[0013] Problem that the invention aims to solve

[0014] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a valve maintenance support device and method capable of improving the work efficiency of the maintenance of a bellows valve.

[0015] Technical means of solving problems

[0016] The valve maintenance auxiliary device of the present invention is characterized in that it comprises: an opening instruction value storage unit, which is configured to store data of an opening instruction value assigned to a bellows valve in correspondence with the ID of the bellows valve as the data transmission source; an opening measurement value storage unit, which is configured to store data of an actual opening value of the bellows valve in correspondence with the ID of the bellows valve as the data transmission source; and a fully open data extraction unit, which is configured to search for data of an opening instruction value indicating a fully open opening among the opening instruction values ​​stored in the opening instruction value storage unit. , extracting the actual opening value of the bellows valve assigned the opening instruction value, and the actual opening value of the time period corresponding to the opening instruction value indicating full opening as diagnostic data; a full-opening part-determination unit, which is configured to determine whether the bellows valve assigned the opening instruction value indicating full opening has occurred an incomplete fully-opening state that has not become fully open based on the diagnostic data; and a determination result prompting unit, which is configured to prompt the ID of the bellows valve determined to have occurred an incomplete fully-opening state as the ID of the valve with bellows damage.

[0017] In addition, in 1 configuration example of the valve maintenance auxiliary device of the present invention, it is characterized in that it is also provided with a bellows damage determination unit, which is configured to determine that the bellows valve has a bellows damage when the fully-open state occurs multiple times in the same bellows valve and the degree of insufficient opening in each of the multiple fully-open states increases monotonically, and the judgment result prompting unit prompts the ID of the bellows valve determined by the bellows damage determination unit as having a bellows damage, instead of prompting the ID of the bellows valve determined by the fully-open incomplete determination unit as having an incomplete fully-open state.

[0018] In addition, a configuration example of the valve maintenance support device of the present invention is characterized in that, when the degree of insufficient opening of the same bellows valve increases monotonically with a substantially constant slope, the bellows damage determination unit determines that the bellows valve has a bellows damage.

[0019] In addition, the valve maintenance assistance method of the present invention is characterized in that it includes a first step of storing data of an opening instruction value assigned to a bellows valve in correspondence with the ID of the bellows valve as the data transmission source; a second step of storing data of an actual opening value of the bellows valve in correspondence with the ID of the bellows valve as the data transmission source; a third step of searching for data of an opening instruction value indicating full opening among the opening instruction values ​​stored in the first step, extracting the actual opening value of the bellows valve assigned the opening instruction value, and the actual opening value of the time period corresponding to the opening instruction value indicating full opening as diagnostic data; a fourth step of determining, based on the diagnostic data, whether a bellows valve assigned an opening instruction value indicating full opening has entered an incompletely opened state that has not yet become fully opened; and a fifth step of prompting the ID of the bellows valve determined to have entered an incompletely opened state as the ID of a valve in which a bellows damage has occurred.

[0020] In addition, in one configuration example of the valve maintenance assistance method of the present invention, it is characterized in that it also includes a step 6, in which, when the same bellows valve is in a fully open state for multiple times and the degree of insufficient opening in each of the multiple fully open states increases monotonically, it is determined that the bellows valve has a bellows damage, and the step 5 also includes the following step: prompting the ID of the bellows valve determined to have a bellows damage in the step 6, instead of prompting the ID of the bellows valve determined to have a fully open state in the step 4.

[0021] In addition, in a configuration example 1 of the valve maintenance assistance method of the present invention, it is characterized in that the sixth step includes the following step: when the degree of insufficient opening of the same bellows valve increases monotonically with a substantially constant slope, it is determined that the bellows of the bellows valve is damaged.

[0022] Effects of the Invention

[0023] According to the present invention, by monitoring the full opening abnormality of the bellows valve, leakage of fluid from the bellows can be detected, and the operation supervisor can be assisted in selecting a bellows valve as a maintenance candidate. As a result, in the present invention, the maintenance efficiency of the bellows valve can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a block diagram showing the structure of the valve maintenance support device according to the first embodiment of the present invention.

[0025] Figure 2 This is a flowchart for explaining the operation of the valve maintenance support device according to the first embodiment of the present invention.

[0026] Figure 3 This is a flowchart illustrating the operation of the valve maintenance support device according to the first embodiment of the present invention.

[0027] Figure 4 This is a diagram showing an example of the opening operation of the bellows valve.

[0028] Figure 5 This is a diagram showing an example in which the degree of insufficient opening increases monotonically with a substantially constant slope.

[0029] Figure 6 This is a diagram showing an example in which the degree of insufficient opening does not increase monotonically.

[0030] Figure 7 This is a graph showing an example in which the degree of insufficient opening increases but the slope is not substantially constant.

[0031] Figure 8 It is a diagram showing the structure of a factory and its equipment management system according to the second embodiment of the present invention.

[0032] Fig. 9 This is a block diagram showing an example of the configuration of a computer that realizes the valve maintenance support device according to the first and second embodiments of the present invention.

[0033] Fig.10 This is a diagram showing an example of a control valve.

[0034] Fig.11 This is a diagram showing an example of a plurality of valves used in a tank in a factory. DETAILED DESCRIPTION

[0035] [Principle of the invention]

[0036] The inventors have found that even if the damage of the bellows valve is such that the effect of the damage is unlikely to be detected in the friction force detection, there is a case where the damage becomes a major event of fluid leakage, and there is a possibility that the fluid leaks from the bellows ( Fig.10108) leakage. In the case of bellows damage, the fluid flowing in the valve intrudes from the outside of the bellows to the inside of the bellows. Further, in the bellows, the valve shaft ( Fig.10 The expansion and contraction of the bellows shape of the bellows that moves up and down sometimes acts as a propulsion force for the fluid, and the fluid intrudes into the upper cover ( Fig.10 Since the upper cover is not originally conceived to be in contact with the fluid, the leakage of the fluid from the bellows can be detected by monitoring the full opening abnormality of the valve caused by the intrusion of the fluid.

[0037] In addition, when the fluid enters the upper cover, the fluid once it enters will not disappear. Therefore, when the degree to which the valve cannot be fully opened increases monotonically at a certain speed to a certain extent, the possibility of fluid leakage is particularly high. In other words, if the phenomenon that the full opening abnormality disappears suddenly and naturally after the full opening abnormality of the valve occurs, it is considered that the cause is the temporary adhesion of scale (such as carbonaceous substances contained in the fluid flowing through the valve) at a place far away from the bellows.

[0038] [First embodiment]

[0039] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Figure 1 This is a block diagram showing the configuration of a valve maintenance support device according to a first embodiment of the present invention. In the following embodiments, for the sake of simplicity of description, examples such as valve IDs (identification information) are assumed to be simpler than those used in actual factories.

[0040] The valve maintenance auxiliary device comprises: a valve ID storage unit 1, which pre-stores the IDs of a plurality of bellows valves that may become candidates for maintenance; an opening acquisition unit 2, which acquires the opening instruction value assigned to the bellows valve and the actual opening value of the bellows valve; an opening instruction value storage unit 3, which stores the data of the opening instruction value in correspondence with the ID of the bellows valve as the data transmission source; an opening measurement value storage unit 4, which stores the data of the actual opening value in correspondence with the ID of the bellows valve as the data transmission source; and a fully open data extraction unit 5, which searches for data of the opening instruction value indicating full opening among the opening instruction values ​​stored in the opening instruction value storage unit 3, and extracts the data of the opening instruction value assigned to the fully open valve. The actual opening value of the bellows valve assigned the opening instruction value, and the actual opening value of the time period corresponding to the opening instruction value indicating full opening are used as diagnostic data; a fully open or partially open judgment unit 6, which judges whether the bellows valve assigned the opening instruction value indicating full opening has occurred an incomplete fully open state that has not become fully open based on the diagnostic data; a bellows damage judgment unit 7, which judges that the bellows valve has a bellows damage when the fully open state occurs multiple times in the same bellows valve and the degree of insufficient opening of each of the multiple fully open states increases monotonically; and a judgment result prompting unit 8, which prompts (displays) the ID of the bellows valve judged to be a bellows damage.

[0041] Figure 2 , Figure 3 1 is a flowchart for explaining the operation of the valve maintenance support device of this embodiment. In this embodiment, for example, there are 26 valves in the equipment, and unique IDs such as "A", "B", "C", ..., "M", ..., "X", "Y", and "Z" are pre-assigned to each of these 26 valves. In particular, valves with valve IDs "A", "C", and "M" are bellows valves equipped with bellows, and the IDs "A", "C", and "M" are pre-stored in the valve ID storage unit 1.

[0042] Positioner used by each bellows valve ( Fig.10 102) supplies the air pressure corresponding to the difference between the opening command value SP (valve stem position command value) assigned by the host device and the actual opening value PV (valve stem position measurement value) of the bellows valve to the operator ( Fig.10 103).

[0043] For the bellows valves whose valve IDs are registered in the valve ID storage unit 1, the opening acquisition unit 2 acquires data of the opening command value SP and the actual opening value PV from the positioner of each bellows valve ( Figure 2 Step S100).

[0044] The opening acquisition unit 2 stores the data of the opening command value SP, the ID of the bellows valve as the source of the data, and the information of the time of receiving the data in the opening command value storage unit 3 in association with each other. Figure 2Step S101). In addition, the opening acquisition unit 2 stores the data of the actual opening value PV, the ID of the bellows valve as the data transmission source, and the information of the time of receiving the data in the opening measurement value storage unit 4 in correspondence ( Figure 2 Step S102).

[0045] The ID of the bellows valve can be obtained by the opening acquisition unit 2 by adding the valve ID to the opening command value SP and the actual opening value PV sent by the positioner of the bellows valve. The time information can be added by the positioner of the bellows valve or by the opening acquisition unit 2.

[0046] By repeating the processing of steps S100 to S102 in this manner, time series data of the opening command value SP and the actual opening value PV are accumulated in the opening command value storage unit 3 and the opening measurement value storage unit 4 .

[0047] Next, the fully opened data extraction unit 5 searches for data (i) of the opening command value SP indicating the fully opened position among the opening command values ​​SP stored in the opening command value storage unit 3. Figure 3 Step S103). Then, the full-open data extraction unit 5 extracts the actual opening value PV of the bellows valve (bellows valve with the same ID) to which the opening command value SP indicating full opening is assigned from the actual opening value PV stored in the opening measurement value storage unit 4, and the actual opening value PV of the time period corresponding to the opening command value SP indicating full opening is extracted as the diagnostic data ( Figure 3 Step S104).

[0048] The actual opening value PV of the time period corresponding to the opening command value SP indicating full opening refers to the actual opening value PV from the same moment as the opening command value SP indicating full opening to the moment after the prescribed time Top has passed. The bellows valve has a response delay relative to the opening command value SP. Therefore, for example, a time longer than the time required for the opening of a normal bellows valve from 0% to 100% can be set as the prescribed time Top. If it is a normal bellows valve, it will be in a fully open state within the prescribed time Top from the moment the opening command value SP indicating full opening is given.

[0049] The partially fully opened determination unit 6 determines whether the bellows valve to which the opening command value SP indicating the fully opened valve is assigned has entered a partially fully opened state (i.e., not fully opened) based on the diagnostic data extracted for the opening command value SP indicating the fully opened valve. Figure 3 Step S105).

[0050] Figure 4 (A) Figure 4 (B) is an example of the opening action of the bellows valve. Figure 4In the example (A), the actual opening value PV of the bellows valve to which the opening command value SP indicating full opening is given becomes 100% within the predetermined time Top. In this case, the partially fully opened determination unit 6 determines that the bellows valve is not in the partially fully opened state.

[0051] On the other hand, Figure 4 In the example (B), the actual opening value PV of the bellows valve does not reach 100% within the predetermined time Top. In this case, the partially fully opened determination unit 6 determines that the bellows valve is in a partially fully opened state.

[0052] In the case where it is determined that the bellows valve is partially opened, and the bellows valve is partially opened multiple times (in the case of Figure 3 (Yes in step S106), the bellows damage determination unit 7 determines whether the degree of insufficient opening Dif in each of the plurality of partially fully opened states increases monotonically.

[0053] like Figure 4 As shown in (B), the insufficient opening degree Dif refers to the difference between the maximum value of the opening command value SP indicating full opening (100%) and the actual opening value PV corresponding thereto. The value from the opening command value SP indicating full opening to a value other than full opening is counted as one opening action, and the state in which the bellows valve does not become fully open in this one opening action is counted as one incomplete fully open state. The insufficient opening degree Dif can be obtained in each determination process of the incomplete fully open determination unit 6.

[0054] When the degree of insufficient opening Dif of the same bellows valve in the multiple fully opened incomplete states increases monotonically (Yes in step S107), the bellows damage determination unit 7 determines that the bellows valve has a bellows damage ( Figure 3 Step S108) At this time, when the degree of insufficient opening Dif of the same bellows valve increases monotonically with a substantially constant slope, the bellows damage determination unit 7 determines that the bellows is damaged, excluding the case where the slope is not substantially constant.

[0055] For example, Figure 5 Indicates that the degree of insufficient opening Dif increases monotonically at a substantially constant slope. Figure 6 It indicates that it is not a monotonically increasing situation. Figure 7 This indicates that the degree of insufficient opening Dif increases but the slope is not approximately constant.

[0056] The method for determining whether the degree of insufficient opening Dif increases monotonically with a substantially constant slope can be appropriately set. For example, when the bellows damage determination unit 7 linearly approximates the change in the degree of insufficient opening Dif by the least squares method, if the determination coefficient R 2 (0≦R 2If it is 1 or less and not less than a specified value TH (TH is a real number where 0 < TH ≤ 1), it is determined that the degree of opening insufficiency Dif increases monotonically with a substantially constant slope. This method is an example, and of course, other determination methods can also be used. The reason why the degree of opening insufficiency Dif increases monotonically with a substantially constant slope is the phenomenon that the fluid gradually penetrates into the upper cover along with the viscous resistance of the fluid. However, in a case such as Figure 7 it is preferably captured as an abnormality different from the bellows breakage (such as the adhesion of scale that does not peel off).

[0057] In addition, in the present embodiment, when the fully open incomplete state occurs multiple times in the same bellows valve, it is determined whether the degree of opening insufficiency Dif increases monotonically. However, the above-mentioned multiple times can be, for example, n times (n is an integer of 3 or more) or more.

[0058] The determination result presentation unit 8 presents to the operation supervisor the valve ID of the bellows valve determined to have a bellows breakage among the bellows valves for which the valve ID is registered in the valve ID storage unit 1 ( Figure 3 step S109).

[0059] However, the determination result presentation unit 8 may also present (display) one of the information "there is a breakage" and "there is no breakage" for all the bellows valves for which the valve ID is registered in the valve ID storage unit 1. In this case, the operation supervisor (operator) can also confirm the valve ID for the bellows valve for which the determination result of bellows breakage is that there is no breakage.

[0060] In this way, the processes of steps S100 to S109 are performed regularly. In addition, in the Figure 3 flowchart, it is determined that a bellows breakage has occurred in the bellows valve in which the degree of opening insufficiency Dif increases monotonically with a substantially constant slope. However, the processing of the bellows breakage determination unit 7 (steps S106 to S108) may also be omitted. In this case, the determination result presentation unit 8 only needs to present (display) the valve ID of the bellows valve determined to be in the fully open incomplete state by the fully open incomplete determination unit 6 as the ID of the valve with a bellows breakage. Figure 3 In the present embodiment, by monitoring the fully open abnormality of the bellows valve, it is possible to detect the leakage of the fluid from the bellows, and it is possible to assist the operation supervisor in the operation of selecting the bellows valve as a maintenance candidate.

[0061] In the present embodiment, by monitoring the fully open abnormality of the bellows valve, it is possible to detect the leakage of the fluid from the bellows, and it is possible to assist the operation supervisor in the operation of selecting the bellows valve as a maintenance candidate.

[0062] [Second Embodiment]

[0063] Next, a second embodiment of the present invention will be described. This embodiment describes an installation example of the first embodiment. Figure 8 is a diagram showing the configuration of a factory and its equipment management system, and the same reference numerals are given to the same configurations as Fig.11 those.

[0064] In the equipment management system of a petroleum and chemical plant, a management device 10 for controlling and managing each device of the plant is provided. The valve ID storage unit 1, the opening acquisition unit 2, the opening command value storage unit 3, and the opening measurement value storage unit 4 described in the first embodiment are preferably installed in the management device 10 because they need to process a huge amount of information inherent to the plant.

[0065] On the other hand, the fully open data extraction unit 5, the fully open incomplete determination unit 6, the bellows damage determination unit 7, and the determination result prompting unit 8 provide necessary processing only when determining whether valve maintenance is required in principle. In addition, the maintenance implementer (the person in charge of the operation of the maintenance entrusted enterprise) is generally entrusted by the factory owner enterprise to implement the factory maintenance. Therefore, assuming that multiple unspecified devices are the object, it is preferred to install the fully open data extraction unit 5, the fully open incomplete determination unit 6, the bellows damage determination unit 7, and the determination result prompting unit 8 in the portable computer 11 carried by the person in charge of the operation (operator) of the maintenance entrusted enterprise.

[0066] When the maintenance work is performed, the plant management device 10 and the computer 11 are temporarily connected using a communication function such as Ethernet (registered trademark).

[0067] When the operator starts the application software on the computer 11, the CPU (Central Processing Unit) of the computer 11 executes processing according to the program stored in the memory, realizing the functions of the full-open data extraction unit 5, the full-open incomplete judgment unit 6, the bellows damage judgment unit 7 and the judgment result prompt unit 8.

[0068] The determination result display unit 8 reads the valve ID from the valve ID storage unit 1 on the management device 10, and reads the determination result of the bellows damage determination unit 7 (or the incomplete opening determination unit 6), and displays the ID of the bellows valve determined to be damaged on the display of the computer 11 ( Figure 3 Step S109).

[0069] The operator confirms the bellows valve for which special attention should be paid to the inspection of the bellows based on the displayed valve ID. After confirming the displayed matters, the operator disconnects the computer 11 and the management device 10.

[0070] In this way, the valve maintenance support device described in the first embodiment can be applied to an actual factory.

[0071] The valve maintenance support device described in the first and second embodiments is realized by a computer including a CPU, a storage device, and an interface, and a program for controlling these hardware resources. Fig. 9The configuration example of the computer is shown. The computer includes a CPU 300, a storage device 301, and an interface device (I / F) 302. For example, a valve, a management device, a display, etc. are connected to the I / F 302. In such a computer, a program for realizing the valve maintenance support method of the present invention is stored in the storage device 301. The CPU 300 executes the processing described in the first embodiment and the second embodiment according to the program stored in the storage device 301.

[0072] In addition, as shown in the second embodiment, when the valve maintenance support device is installed separately from the management device 10 and the computer 11, it is possible to use Fig. 9 Such a configuration realizes these devices.

[0073] [Industrial Applicability]

[0074] The present invention can be applied to the technology of auxiliary valve maintenance work.

[0075] Explanation of symbols

[0076] 1...valve ID storage unit, 2...opening acquisition unit, 3...opening instruction value storage unit, 4...opening measurement value storage unit, 5...full-open data extraction unit, 6...full-open incomplete judgment unit, 7...bellows damage judgment unit, 8...judgment result prompt unit, 10...management device, 11...computer.

Claims

1. A valve maintenance auxiliary device, characterized in that: have: an opening command value storage unit configured to store data of an opening command value to be given to the bellows valve in association with an ID of the bellows valve as a transmission source of the data; an opening measurement value storage unit configured to store data of an actual opening value of the bellows valve in association with an ID of the bellows valve as a transmission source of the data; a fully open data extraction unit configured to search for data of an opening command value indicating a fully open position among the opening command values ​​stored in the opening command value storage unit, and extract, as diagnostic data, an actual opening value of the bellows valve to which the opening command value is assigned, and an actual opening value in a time period corresponding to the opening command value indicating a fully open position; a partially fully opened determination unit configured to determine, based on the diagnostic data, whether the bellows valve to which the opening command value indicating full opening is assigned has entered a partially fully opened state in which the bellows valve has not become fully opened; a bellows damage determination unit configured to determine that the bellows of the bellows valve is damaged when the same bellows valve is in a state of partially fully opened multiple times and the degree of insufficient opening in each of the multiple partially fully opened states increases monotonically at a substantially constant slope; and The determination result presenting unit is configured to present, as the ID of the valve in which the bellows damage has occurred, the ID of the bellows valve determined by the bellows damage determining unit to have undergone the bellows damage.

2. A valve maintenance auxiliary method, characterized in that: Include: The first step is to store data of an opening command value assigned to the bellows valve in correspondence with the ID of the bellows valve as a transmission source of the data; Step 2, storing the data of the actual opening value of the bellows valve in correspondence with the ID of the bellows valve as the source of the data transmission; The third step is to search for data of the opening instruction value indicating full opening among the opening instruction values ​​stored in the first step, and extract the actual opening value of the bellows valve assigned with the opening instruction value, and the actual opening value of the time period corresponding to the opening instruction value indicating full opening as diagnostic data; A fourth step is to determine, based on the diagnostic data, whether the bellows valve to which the opening command value indicating full opening is assigned has entered a partially fully opened state. Step 5: if the same bellows valve is in a state of partially fully opened multiple times, and the degree of insufficient opening in each of the multiple partially fully opened states increases monotonically at a substantially constant slope, it is determined that the bellows of the bellows valve is damaged; as well as In step 6, the ID of the bellows valve determined to have suffered a bellows damage in step 5 is presented as the ID of the valve in which the bellows damage has occurred.

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