Test device for determining the effect of insulation section on the galvanic corrosion inhibition of dissimilar metal pipelines

Abstract

The present invention discloses a test device for measuring the effect of an insulating section on the galvanic corrosion inhibition of dissimilar metal pipelines. The device comprises: an anode tube segment, an insulating tube segment, a cathode tube segment, a control tube segment, a plurality of first insulating flanges, a second insulating flange, and a third insulating flange. One end of the insulating tube segment is connected to one end of the anode tube segment. One end of the cathode tube segment is connected to the other end of the insulating tube segment. One end of the control tube segment is connected to the other end of the cathode tube segment. The plurality of first insulating flanges are respectively arranged between the anode tube segment, the insulating tube segment, the cathode tube segment, and the control tube segment. The second insulating flange is arranged at the other end of the anode tube segment. And the third insulating flange is arranged at the other end of the control tube segment. Thus, the present invention can accurately measure the influence range of galvanic corrosion and the maximum local galvanic corrosion coefficient under different insulating tube segment lengths.

Description

Technical Field

[0001] The invention relates to the technical field of environmental testing, in particular to a testing device for measuring the galvanic corrosion inhibition effect of an insulating section on a dissimilar metal pipeline. Background Art

[0002] Ship piping systems often involve metal pipes and appendages made of different materials. Although these are separated by insulating gaskets, these dissimilar metal components can easily become electrically connected through pipe supports, branch pipes, and the ship's hull, causing galvanic corrosion between the dissimilar metal piping systems. Insulating sections between dissimilar metal piping systems to increase the solution resistance between the cathode and anode is an effective measure to reduce galvanic corrosion. However, determining the appropriate insulation section length is often difficult and lacks a basis. The insulation section length that effectively inhibits galvanic corrosion in dissimilar metal piping systems must be determined using galvanic corrosion testing equipment.

[0003] Existing pipeline galvanic corrosion test devices, such as the patent "CN202310046623.1, a pipe segment seawater pipeline corrosion test device", have a simple structure and can study the galvanic corrosion distribution of pipe segments with different media and different materials as a whole, as well as the axial and circumferential directions of the pipeline. However, they cannot study the effect of the solution resistance between the cathode segment and the anode segment on galvanic corrosion, and cannot evaluate the effect of the solution resistance on the galvanic corrosion between the cathode segment and the anode segment, which limits the research on the inhibitory effect of setting an insulating segment on the galvanic corrosion of dissimilar metal pipe systems.

[0004] In summary, existing pipeline galvanic corrosion testing devices can study the distribution of galvanic corrosion from the perspectives of overall and local conditions, as well as from the perspectives of medium and material. However, for marine dissimilar metal pipeline galvanic systems, the impact of solution resistance on galvanic corrosion is still not considered. This makes it impossible to study the scope and distribution of galvanic corrosion when an insulating section exists between the anode and cathode sections. Therefore, a galvanic corrosion testing device that can account for the influence of solution resistance between the anode and cathode is needed to address this issue.

[0005] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the Invention

[0006] The purpose of the present invention is to provide a test device for measuring the galvanic corrosion inhibition effect of an insulating section on dissimilar metal pipelines, which can accurately measure the influence range of galvanic corrosion and the maximum local galvanic corrosion coefficient under different insulating pipe section lengths.

[0007] To achieve the above objectives, the present invention provides a test device for measuring the effectiveness of an insulating segment in inhibiting galvanic corrosion of dissimilar metal pipes, comprising: an anode pipe segment, an insulating pipe segment, a cathode pipe segment, a control pipe segment, a plurality of first insulating flanges, a second insulating flange, and a third insulating flange. One end of the insulating pipe segment is connected to one end of the anode pipe segment. One end of the cathode pipe segment is connected to the other end of the insulating pipe segment. One end of the control pipe segment is connected to the other end of the cathode pipe segment. The plurality of first insulating flanges are respectively disposed between the anode pipe segment, the insulating pipe segment, the cathode pipe segment, and the control pipe segment. The second insulating flange is disposed on the other end of the anode pipe segment. And the third insulating flange is disposed on the other end of the control pipe segment.

[0008] In one embodiment of the present invention, the anode tube segment is composed of a plurality of first anode annular electrodes and a plurality of first insulating spacers arranged alternately, and the cathode tube segment is composed of a plurality of first cathode annular electrodes and a plurality of second insulating spacers arranged alternately.

[0009] In one embodiment of the present invention, the insulating pipe section is made of nylon, polypropylene plastic or other materials with insulating inner walls.

[0010] In one embodiment of the present invention, the insulating tube segment is composed of a plurality of insulating short tubes that cooperate with each other, adjacent insulating short tubes are sealed by sealing rubber rings, and adjacent insulating short tubes can slide relative to each other, thereby changing the length of the insulating tube segment.

[0011] In one embodiment of the present invention, a first opening is formed on the top of each of the first anode annular electrodes, and a second opening is formed on the top of each of the first cathode annular electrodes.

[0012] In one embodiment of the present invention, the test apparatus for determining the galvanic corrosion inhibition effect of an insulating section on dissimilar metal pipelines further includes: a plurality of first reference electrodes and a plurality of second reference electrodes. The plurality of first reference electrodes are respectively mounted in the first openings on the tops of the plurality of first anode annular electrodes. The plurality of second reference electrodes are respectively mounted in the second openings on the tops of the plurality of first cathode annular electrodes.

[0013] In one embodiment of the present invention, the control tube segment is composed of a second anode annular electrode, a second cathode annular electrode, and an inert metal ring, and the second anode annular electrode, the second cathode annular electrode, and the inert metal ring are not electrically connected to the plurality of first anode annular electrodes and the plurality of first cathode annular electrodes; wherein the second anode annular electrode, the second cathode annular electrode, and the inert metal ring are insulated and separated. A third opening is provided on the top of the second anode annular electrode, and a third reference electrode is installed in the third opening. A fourth opening is provided on the top of the second cathode annular electrode, and a fourth reference electrode is installed in the fourth opening.

[0014] In one embodiment of the present invention, the test device for determining the galvanic corrosion inhibition effect of the insulating section on dissimilar metal pipes further includes: a first conductor, a plurality of second conductors, a plurality of third conductors, a fourth conductor, and a fifth conductor. One end of the plurality of second conductors is electrically connected to the plurality of first anode ring electrodes, and the other end of the plurality of second conductors is electrically connected to the first conductor. One end of the plurality of third conductors is electrically connected to the plurality of first cathode ring electrodes, and the other end of the plurality of third conductors is electrically connected to the first conductor. One end of the fourth conductor is electrically connected to the second anode ring electrode, and the other end of the fourth conductor is electrically connected to the inert metal ring. And one end of the fifth conductor is electrically connected to the second cathode ring electrode, and the other end of the fifth conductor is electrically connected to the fourth conductor.

[0015] In one embodiment of the present invention, the test apparatus for determining the galvanic corrosion inhibition effect of an insulating section on dissimilar metal pipelines further includes: a plurality of first zero-resistance ammeters, a plurality of second zero-resistance ammeters, a third zero-resistance ammeter, and a fourth zero-resistance ammeter. The plurality of first zero-resistance ammeters are respectively disposed on the plurality of second conductors. The plurality of second zero-resistance ammeters are respectively disposed on the plurality of third conductors. The third zero-resistance ammeter is disposed on the fourth conductor. And the fourth zero-resistance ammeter is disposed on the fifth conductor.

[0016] In one embodiment of the present invention, the test device for determining the effect of an insulating segment on the galvanic corrosion inhibition of dissimilar metal pipes further includes: a controller and an electronic weighing mechanism. The controller is electrically connected to the multiple first zero-resistance ammeters, the multiple second zero-resistance ammeters, the third zero-resistance ammeter, and the fourth zero-resistance ammeter, respectively. The electronic weighing mechanism is electrically connected to the controller, and the electronic weighing mechanism is used to measure the weight of the anode pipe segment and the control pipe segment before and after the experiment. The controller is also electrically connected to the multiple first reference electrodes, the multiple second reference electrodes, the third reference electrode, and the fourth reference electrode, respectively.

[0017] Compared with the prior art, the test device for determining the galvanic corrosion inhibition effect of an insulating section on dissimilar metal pipelines according to the present invention can measure the corresponding galvanic corrosion distribution when an insulating pipe section exists in the middle of the dissimilar metal pipeline, and quickly determine the influence range of different insulating pipe section lengths on galvanic corrosion through the retractable insulating pipe section, so as to solve the shortcomings of the existing pipeline galvanic corrosion test device that cannot simulate the galvanic corrosion working conditions of marine pipelines with insulating pipe sections and cannot quickly study the influence of insulating section length on galvanic corrosion. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 2 is a schematic cross-sectional view of a test apparatus for determining the effect of an insulating segment on galvanic corrosion inhibition of dissimilar metal pipelines according to one embodiment of the present invention;

[0019] Figure 2 2 is a schematic cross-sectional structural diagram of an insulating pipe section of a test device for measuring the effect of an insulating section on galvanic corrosion inhibition of dissimilar metal pipes according to one embodiment of the present invention;

[0020] Figure 3 2 is a schematic structural diagram of a control pipe section of a test device for determining the effect of an insulating section on galvanic corrosion inhibition of dissimilar metal pipes according to an embodiment of the present invention;

[0021] Figure 4 2 is another structural schematic diagram of a control pipe section of a test apparatus for determining the galvanic corrosion inhibition effect of an insulating section on dissimilar metal pipelines according to one embodiment of the present invention.

[0022] Description of main reference numerals:

[0023] 1- anode tube segment, 2- insulating tube segment, 3- cathode tube segment, 4- control tube segment, 5- first insulating flange, 6- second insulating flange, 7- third insulating flange, 8- first anode ring electrode, 9- first insulating gasket, 10- first cathode ring electrode, 11- second insulating gasket, 12- insulating short tube, 13- sealing rubber ring, 14- first reference electrode, 15- second reference electrode, 16- second anode ring electrode, 17- first wire, 18- second wire, 19- third wire, 20- first zero-resistance ammeter, 21- second zero-resistance ammeter, 22- second cathode ring electrode, 23- inert metal ring, 24- fourth wire, 25- fifth wire, 26- third zero-resistance ammeter, 27- fourth zero-resistance ammeter, 28- third reference electrode, 29- fourth reference electrode. DETAILED DESCRIPTION

[0024] The following is a further detailed description of the embodiments of the present invention in conjunction with the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the embodiments of the present invention and are not intended to limit the embodiments of the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions of the embodiments of the present invention, rather than all structures.

[0025] To facilitate understanding, the main implementation concepts of the embodiments of the present invention are first briefly described.

[0026] In the marine industry, with the continuous advancement and increasing complexity of ship technology, the design of ship piping systems has become increasingly complex. These piping systems must not only meet the functional requirements of fluid transmission but also possess high corrosion resistance to ensure long-term stable operation in harsh marine environments. However, ship piping systems often use a variety of metal pipes and appendages made of different materials, such as stainless steel, copper alloys, and aluminum alloys. These dissimilar metals are highly susceptible to galvanic corrosion in electrolyte environments (such as seawater).

[0027] Galvanic corrosion not only causes pipe wall thickness to decrease, or even perforation and leakage, seriously threatening the safe operation of ships, but also increases maintenance costs and shortens the service life of equipment. To alleviate this problem, engineers typically install insulation sections between dissimilar metal pipes to reduce the rate of galvanic corrosion by increasing the solution resistance between the cathode and anode. However, selecting the length of the insulation section is not easy, as insulation sections that are too long or too short may not achieve the optimal anti-corrosion effect. An insulation section that is too short may not effectively isolate the galvanic effect, while an insulation section that is too long may increase installation difficulty and cost.

[0028] Although some pipeline galvanic corrosion testing devices have been developed to study galvanic corrosion behavior, most of these devices focus on corrosion distribution across entire pipe sections or under specific conditions. Research into the relationship between insulation section length and galvanic corrosion suppression effectiveness remains insufficient. These existing devices are particularly inadequate when simulating the complex operating conditions found in actual ship piping systems. For example, they may not accurately simulate the effects of actual environmental factors such as seawater flow, temperature fluctuations, and pressure changes on galvanic corrosion, nor can they directly evaluate the galvanic corrosion suppression effectiveness under different insulation section lengths.

[0029] Furthermore, with the continuous advancement of marine technology, the application of new materials and insulation materials is becoming increasingly widespread. These new materials may offer significant advantages in corrosion resistance and mechanical properties, but they also present new research challenges. Determining the optimal insulation length for these new material combinations to minimize galvanic corrosion has become a pressing issue.

[0030] Having identified the aforementioned deficiencies in the prior art, the inventors have developed a test device for measuring the effectiveness of insulation sections in inhibiting galvanic corrosion in dissimilar metal pipes. This device accurately simulates the actual operating conditions of dissimilar metal pipes in ship piping systems and systematically studies the effects of varying insulation section lengths on galvanic corrosion. This is of great significance for improving the corrosion resistance of ship piping systems and reducing maintenance costs. The test device of this invention is designed precisely to address this need, aiming to fill a gap in the prior art in this area and provide strong support for the corrosion protection design of ship piping systems.

[0031] Figure 1 2 is a schematic cross-sectional view of a test apparatus for determining the effect of an insulating segment on galvanic corrosion inhibition of dissimilar metal pipelines according to one embodiment of the present invention; Figure 2 2 is a schematic cross-sectional structural diagram of an insulating pipe segment 2 of a test apparatus for determining the galvanic corrosion inhibition effect of an insulating segment on dissimilar metal pipes according to an embodiment of the present invention; Figure 3 2 is a schematic structural diagram of a control pipe section of a test device for determining the effect of an insulating section on galvanic corrosion inhibition of dissimilar metal pipes according to an embodiment of the present invention; Figure 4 2 is another structural schematic diagram of a control pipe section of a test apparatus for determining the galvanic corrosion inhibition effect of an insulating section on dissimilar metal pipelines according to one embodiment of the present invention.

[0032] like Figures 1 to 4As shown, a test device for measuring the galvanic corrosion inhibition effect of an insulating segment on dissimilar metal pipelines according to a preferred embodiment of the present invention includes: an anode tube segment 1, an insulating tube segment 2, a cathode tube segment 3, a control tube segment 4, multiple first insulating flanges 5, a second insulating flange 6, and a third insulating flange 7. One end of the insulating tube segment 2 is connected to one end of the anode tube segment 1. One end of the cathode tube segment 3 is connected to the other end of the insulating tube segment 2. One end of the control tube segment 4 is connected to the other end of the cathode tube segment 3. The multiple first insulating flanges 5 are respectively arranged between the anode tube segment 1, the insulating tube segment 2, the cathode tube segment 3, and the control tube segment 4. The second insulating flange 6 is arranged on the other end of the anode tube segment 1. And the third insulating flange 7 is arranged on the other end of the control tube segment 4.

[0033] Specifically, the test device of the present invention for determining the inhibitory effect of an insulating segment on galvanic corrosion of dissimilar metal pipelines is mainly composed of an anode pipe segment 1, an insulating pipe segment 2, a cathode pipe segment 3, a control pipe segment 4 and multiple insulating flanges. The retractable design of the insulating pipe segment 4 allows its length to be adjusted to study the influence of different insulation lengths on galvanic corrosion. The pipe segments are connected by insulating flanges to ensure electrical insulation, and are equipped with high-precision measuring equipment to monitor the galvanic corrosion situation in real time, thereby accurately simulating and evaluating the inhibitory effect of the insulating segment on galvanic corrosion of dissimilar metal pipelines.

[0034] In this embodiment, the anode tube segment 1 is composed of a plurality of first anode annular electrodes 8 and a plurality of first insulating spacers 9 arranged alternately, and the cathode tube segment 3 is composed of a plurality of first cathode annular electrodes 10 and a plurality of second insulating spacers 11 arranged alternately.

[0035] Specifically, the anode tube segment 1 and the cathode tube segment 3 both adopt a modular design, wherein the anode tube segment 1 is composed of a plurality of first anode ring electrodes 8 and first insulating gaskets 9 arranged tightly and alternately to ensure effective transmission and isolation of the anode current; the cathode tube segment 3 is similarly composed of a plurality of first cathode ring electrodes 10 and second insulating gaskets 11 arranged alternately to support the cathode current path while achieving electrical insulation. Such a structural design not only ensures that the current path during the galvanic corrosion test is clear and controllable, but also facilitates adjustment of the number and spacing of electrodes according to experimental requirements.

[0036] In this embodiment, the insulating tube section 2 is made of nylon, polypropylene plastic or other materials with insulating inner walls.

[0037] Specifically, the insulating pipe section 2 is made of carefully selected high-performance insulating materials, such as nylon or polypropylene plastic. These materials not only have excellent electrical insulation properties, can effectively block the direct flow of current between the anode and cathode pipe sections, and reduce the occurrence of galvanic corrosion, but also have excellent corrosion resistance, mechanical strength and processing performance, ensuring long-term stable operation under complex environmental conditions, and providing reliable protection for the accurate measurement of the galvanic corrosion inhibition effect.

[0038] In this embodiment, the insulating tube segment 2 is composed of a plurality of insulating short tubes 12 that cooperate with each other. Adjacent insulating short tubes 12 are sealed by sealing rubber rings 13, and adjacent insulating short tubes 12 can slide relative to each other, thereby changing the length of the insulating tube segment 2.

[0039] Specifically, the insulating tube segment 2 is cleverly designed, consisting of multiple meticulously crafted insulating short tubes 12, tightly connected by highly elastic sealing rubber rings 13. This ensures a good seal even when the length is adjusted, preventing electrolyte infiltration. A unique sliding mechanism allows adjacent insulating short tubes 12 to move relative to each other while maintaining a seal, making it easy to adjust the overall length of the insulating tube segment 2. This design not only allows experimenters to flexibly adjust the insulation distance according to specific testing requirements, but also ensures the stability and reliability of the device under various testing conditions.

[0040] In a specific embodiment, both ends of each insulating short tube 12 are designed with specific sliding grooves or guide structures, which allow adjacent insulating short tubes 12 to slide relative to each other within a certain range. The outer diameter of the insulating short tube 12 is slightly smaller than the inner diameter of the adjacent short tube to leave sufficient sliding space. Highly elastic sealing rubber rings are installed at the connection between the insulating short tubes 12. These rubber rings can fit tightly against the outer wall of the insulating short tube when compressed to form an effective sealing barrier. The material of the sealing rubber ring must have good corrosion resistance and aging resistance to ensure the sealing effect under long-term use. The experimenter can push the insulating short tube 12 to slide manually or mechanically as needed. During the sliding process, it should be ensured that the insulating short tube 12 remains horizontal or moves at a predetermined angle to avoid sealing failure or degradation of insulation performance due to angle deviation. After the required length of the insulating tube section 2 is reached, the adjacent insulating short tubes can be fixed together by a locking device (such as a bolt, a buckle, etc.) to prevent sliding during the experiment. In other words, the sliding mechanism of the insulating short tube 12 of the insulating tube section 2, through its ingenious structural design and sealing measures, enables flexible adjustment of the insulating tube section length, providing strong support for the precise measurement of the galvanic corrosion inhibition effect. At the same time, this mechanism also ensures safety and reliability during the experiment.

[0041] In this embodiment, a first opening is formed on the top of each of the first anode annular electrodes 8 , and a second opening is formed on the top of each of the first cathode annular electrodes 10 .

[0042] Specifically, the top of each first anode annular electrode 8 and first cathode annular electrode 10 is carefully designed, with a first opening and a second opening, respectively. These openings not only facilitate the installation of monitoring equipment such as reference electrodes to obtain real-time potential information on the electrode surface and analyze the galvanic corrosion process, but also optimize the flow field distribution on the electrode surface, helping to improve the accuracy and reliability of the test. At the same time, precise control of the opening position and size is also a key factor in ensuring the consistency and repeatability of experimental data.

[0043] In this embodiment, the test device for determining the galvanic corrosion inhibition effect of the insulating section on dissimilar metal pipelines further includes: a plurality of first reference electrodes 14 and a plurality of second reference electrodes 15. The plurality of first reference electrodes 14 are respectively installed in the first openings at the tops of the plurality of first anode annular electrodes 8. And the plurality of second reference electrodes 15 are respectively installed in the second openings at the tops of the plurality of first cathode annular electrodes 10. The first reference electrodes 14 and the second reference electrodes 15 are both used to measure voltage. Voltage parameters are also important parameters for studying corrosion, that is, voltage parameters can serve as auxiliary data.

[0044] Specifically, in the test device for measuring the galvanic corrosion inhibition effect of the insulating section on dissimilar metal pipelines, in order to more comprehensively monitor and analyze the corrosion process, a plurality of first reference electrodes 14 and second reference electrodes 15 are specially configured. These reference electrodes, as key tools for voltage measurement, are precisely installed in the openings at the top of the first anode ring electrode 8 and the first cathode ring electrode 10. Specifically, a first reference electrode 14 is embedded in the first opening at the top of each first anode ring electrode 8 for real-time monitoring of the potential changes on the surface of the anode electrode. Similarly, a corresponding second reference electrode 15 is also installed in the second opening at the top of each first cathode ring electrode 10 to obtain the potential data on the surface of the cathode electrode. Such a layout ensures that the potentials of all key positions in the corrosion system can be effectively captured, providing valuable first-hand data for the study of corrosion mechanisms. The main function of the reference electrode is to measure the potential difference of the working electrode (here, the anode and cathode ring electrodes) relative to the reference electrode by comparison with the standard potential, that is, the potential of the working electrode. In galvanic corrosion research, changes in potential reflect the activity and direction of chemical reactions on the electrode surface and are a key indicator for assessing corrosion rate and extent. It is noteworthy that voltage parameters have independent significance in corrosion research, complementing current parameters to reveal the essence of the corrosion process. Voltage data not only serves as auxiliary information to help interpret current measurement results but also provides deeper information about corrosion driving forces and reaction directions. Therefore, in experiments to determine the inhibitory effect of insulating sections on galvanic corrosion of dissimilar metal pipelines, the reference electrode and the voltage parameters it measures play an irreplaceable and important role.

[0045] In this embodiment, the control pipe section 4 is composed of a second anode ring electrode 16, a second cathode ring electrode 22 and an inert metal ring 23, and the second anode ring electrode 16, the second cathode ring electrode 22 and the inert metal ring 23 are not electrically connected to the multiple first anode ring electrodes 18 and the multiple first cathode ring electrodes 10; wherein, the second anode ring electrode 16, the second cathode ring electrode 22 and the inert metal ring 23 are insulated and separated.

[0046] Specifically, the design of the control pipe section 4 plays a crucial role. The control pipe section 4 is carefully composed of the second anode ring electrode 16, the second cathode ring electrode 22 and the inert metal ring 23. These components together constitute an independent corrosion test unit. Specifically, the second anode ring electrode 16 and the second cathode ring electrode 22 respectively simulate the anode and cathode in the actual working environment, but in this control pipe section, they are not electrically connected to the main test section (i.e., the pipe section containing the first anode ring electrode 18 and the first cathode ring electrode 10). This design ensures that the corrosion process in the control pipe section is carried out without interference from the external galvanic effect, thereby accurately reflecting the corrosion characteristics of the material itself. At the same time, the introduction of the inert metal ring 23 further enhances the scientific and practical nature of the control pipe section. Since inert metals have high chemical stability and are not prone to corrosion, they are mainly used here as a reference. By monitoring the state changes of the inert metal ring 23 during the test process, the stability and reliability of the test environment can be further verified. Among them, strict insulation measures are taken between the second anode ring electrode 16, the second cathode ring electrode 22 and the inert metal ring 23 to ensure that no electrical connection is formed between them. This insulating and isolating design not only prevents unnecessary galvanic corrosion reactions from occurring inside the control pipe section, but also provides a reliable benchmark for accurately evaluating the inhibitory effect of the insulating section on galvanic corrosion. In summary, the control pipe section 4, through its unique structure and design principle, plays an irreplaceable role in the test of determining the inhibitory effect of the insulating section on the galvanic corrosion of dissimilar metal pipes. It not only provides valuable data on the corrosion characteristics of the material itself, but also serves as a reference standard for evaluating the inhibitory effect of the insulating section, ensuring the accuracy and reliability of the test results. Among them, the second anode ring electrode 16, the second cathode ring electrode 22 and the inert metal ring 23 are insulated and isolated, for example, by installing an insulating sleeve or insulating gasket between the electrodes. These materials are usually made of materials with excellent electrical insulation properties, such as polytetrafluoroethylene (PTFE), ceramics or certain high-performance plastics. These insulating materials can effectively block the current path between the electrodes.

[0047] In this embodiment, the test apparatus for determining the galvanic corrosion inhibition effect of an insulating section on dissimilar metal pipelines further includes: a first conductor 17, multiple second conductors 18, a third conductor 19, a fourth conductor 24, and a fifth conductor 25. One end of each of the multiple second conductors 18 is electrically connected to each of the multiple first anode annular electrodes 8, and the other end of each of the multiple second conductors 18 is electrically connected to each of the first conductors 17. One end of each of the multiple third conductors 19 is electrically connected to each of the multiple first cathode annular electrodes 10, and the other end of each of the multiple third conductors 19 is electrically connected to each of the first conductors 17. One end of each of the fourth conductors 24 is electrically connected to the second anode annular electrode 16, and the other end of each of the fourth conductors 24 is electrically connected to the inert metal ring 23. Furthermore, one end of each of the fifth conductors 25 is electrically connected to the second cathode annular electrode 22, and the other end of each of the fifth conductors 25 is electrically connected to the fourth conductor 24.

[0048] Specifically, in the test device for measuring the effect of insulation sections on the galvanic corrosion inhibition of dissimilar metal pipes, the layout and connection of the wires are key to ensuring a clear current path and accurate data transmission. The following is a detailed description of the specific connection method and function of each wire:

[0049] The function of the first conductor 17 is to serve as the main bus conductor to collect and transmit current signals from multiple anode or cathode ring electrodes. Connection method: The first conductor 17 is not directly connected to any ring electrode, but is indirectly connected to the anode and cathode ring electrodes through multiple branch conductors (the second conductor 18 and the third conductor 19). This design facilitates the centralized processing of current signals from multiple electrodes and reduces circuit complexity. The number of second conductors 18 is multiple, and the specific number depends on the number of anode ring electrodes. Its function is to transmit the current signal generated by each first anode ring electrode 8 to the first conductor 17, and its connection method is: one end of each second conductor 18 is electrically connected to the corresponding first anode ring electrode 8, and the other end converges to the first conductor 17 to form a parallel circuit structure. This connection method ensures that the current of all anode electrodes can be effectively collected and transmitted. There are multiple third wires 19, corresponding to the number of anode ring electrodes. Their function is similar to that of the second wire 18, but they are used to connect to the first cathode ring electrode 10 and transmit the cathode current signal to the first wire 17. One end of each third wire 19 is electrically connected to the corresponding first cathode ring electrode 10, and the other end is also converged to the first wire 17 to form a parallel circuit. This design ensures that the cathode current and the anode current remain independent and clearly distinguishable during the transmission process. The fourth wire 24 is specifically used to connect the second anode ring electrode 16 and the inert metal ring 23 in the control pipe section. One end of the fourth wire 24 is electrically connected to the second anode ring electrode 16, and the other end is connected to the inert metal ring 23. This connection method allows a closed loop to be formed in the control pipe section for monitoring parameters such as the self-corrosion rate. The fifth wire 25 connects the second cathode ring electrode 22 and the fourth wire 24 (indirectly connected to the inert metal ring 23) in the control pipe section to form a complete control test circuit, and one end of the fifth wire 25 is electrically connected to the second cathode ring electrode 22, and the other end is connected to the fourth wire 24. This design allows the cathode and anode in the control pipe section to be electrically connected through the inert metal ring, simulating some circuit characteristics in the actual working environment, but not being affected by external galvanic effects. In other words, the careful layout and connection of these wires ensure that the test device can accurately measure and transmit current signals from different ring electrodes, providing reliable data support for evaluating the inhibitory effect of the insulating section on galvanic corrosion of dissimilar metal pipes. At the same time, the wire connection in the control pipe section also simulates some circuit characteristics in the actual working environment, enhancing the practicality and reference value of the test results.

[0050] In this embodiment, the test apparatus for measuring the galvanic corrosion inhibition effect of an insulating section on dissimilar metal pipelines further includes: a plurality of first zero-resistance ammeters 20, a plurality of second zero-resistance ammeters 21, a third zero-resistance ammeter 26, and a fourth zero-resistance ammeter 27. The plurality of first zero-resistance ammeters 20 are respectively disposed on the plurality of second conductors 18. The plurality of second zero-resistance ammeters 21 are respectively disposed on the plurality of third conductors 19. The third zero-resistance ammeter 26 is disposed on the fourth conductor 24. And the fourth zero-resistance ammeter 27 is disposed on the fifth conductor 25.

[0051] Specifically, the introduction of zero-resistance ammeters (e.g., high-precision ammeters) is crucial for accurately measuring current changes in circuits. The following is a detailed description of these ammeters: Zero-resistance ammeters (high-precision ammeters) are primarily used to monitor the current flowing through conductors. They provide highly accurate current readings, which are crucial for analyzing current changes during galvanic corrosion. Because galvanic corrosion involves tiny current flows, ammeters with high sensitivity and low internal resistance are required to ensure measurement accuracy. Multiple first zero-resistance ammeters 20 are connected in series to multiple second conductors 18, each connected to a first anode annular electrode 8. The current flowing from each first anode annular electrode 8 is monitored and recorded. This current data is used to analyze current changes during anodic corrosion and evaluate the effectiveness of the insulation segment in suppressing anodic corrosion. Multiple second zero-resistance ammeters 21 are connected in series to multiple third conductors 19, each connected to a first cathode annular electrode 10. The current flowing to each first cathode annular electrode 10 is monitored and recorded. Combined with the anode current data, this data allows for a comprehensive analysis of current distribution and changes during galvanic corrosion. A third zero-resistance ammeter 26 is connected in series to a fourth conductor 24, which connects the second anode ring electrode 16 and the inert metal ring 23 in the control pipe section. This ammeter monitors the self-corrosion current in the control pipe section. Since the control pipe section is used to simulate corrosion without the galvanic effect, the data from this ammeter will serve as a benchmark for evaluating the effectiveness of galvanic corrosion inhibition. A fourth zero-resistance ammeter 27 is connected in series to a fifth conductor 25, which connects the second cathode ring electrode 22 and the fourth conductor 24 (indirectly connected to the inert metal ring 23) in the control pipe section. This ammeter monitors the current in the closed loop formed between the cathode and anode in the control pipe section through the inert metal ring. This helps verify the correctness and stability of the circuit connection in the control pipe section. The current data recorded by the high-precision ammeter can be used to analyze the current changes during the galvanic corrosion process in real time, thereby evaluating the effectiveness of the insulation section in inhibiting galvanic corrosion of dissimilar metal pipes. This data will be combined with the voltage data measured by the reference electrode and the weight loss data measured by the electronic weighing mechanism to form a comprehensive corrosion assessment report, providing a scientific basis for engineering practice. In summary, zero-resistance ammeters play a vital role in the test setup. They ensure the accuracy and reliability of current measurement and provide a solid foundation for the evaluation of galvanic corrosion inhibition effects.

[0052] In this embodiment, the test apparatus for determining the galvanic corrosion inhibition effect of an insulating segment on dissimilar metal pipes further includes a controller and an electronic weighing mechanism. The controller is electrically connected to the plurality of first zero-resistance ammeters 20, the plurality of second zero-resistance ammeters 21, the third zero-resistance ammeter 26, and the fourth zero-resistance ammeter 27. The electronic weighing mechanism is electrically connected to the controller and is used to measure the weight of the anode pipe segment 1 and the control pipe segment 4 before and after the experiment.

[0053] Specifically, in the test device for measuring the galvanic corrosion inhibition effect of an insulating segment on dissimilar metal pipelines, the controller and electronic weighing mechanism are core components for data processing and result analysis. As the hub of the entire test device, the controller is responsible for coordinating and managing the operating status of each component to ensure the smooth progress of the test process. It collects and processes test data in real time through electrical connections with multiple high-precision ammeters (although called "zero-resistance ammeters," they are actually high-precision ammeters) and the electronic weighing mechanism. The controller is electrically connected to a plurality of first zero-resistance ammeters 20, a plurality of second zero-resistance ammeters 21, a third zero-resistance ammeter 26, and a fourth zero-resistance ammeter 27. This connection allows the controller to read the current values ​​measured by each ammeter in real time, providing raw data for subsequent data processing and analysis. Communication Protocol: The controller and the ammeters can use standard communication protocols (such as RS-232, RS-485, CAN bus, etc.) for data transmission to ensure data accuracy and reliability. The controller's built-in data processing module can perform preliminary processing on the received current data, such as filtering, denoising, and calibration, to improve data accuracy and reliability. The controller can also further analyze the current data based on a preset algorithm to extract characteristic parameters related to the galvanic corrosion inhibition effect. An electronic weighing mechanism is used to accurately measure the weight change of the anode tube segment 1 and the control tube segment 4 before and after the experiment. Since galvanic corrosion causes the weight of metal pipes to decrease, measuring the weight difference before and after the experiment can visually assess the extent of corrosion and the inhibitory effect of the insulation segment. The electronic weighing mechanism is electrically connected to the controller, transmitting measurement data via wired or wireless means. This connection allows the controller to obtain the weighing results in real time and combine them with the current measurement data for comprehensive analysis. To ensure the accuracy of the measurement results, the electronic weighing mechanism features high precision and stability, for example, achieving accuracy to the milligram or even microgram level, and can maintain consistent measurement results over a long period of time. In addition, to eliminate the influence of environmental factors (such as temperature, humidity, and vibration) on the measurement results, the electronic weighing mechanism also includes corresponding environmental compensation functions. Before the test begins, the electronic weighing mechanism is used to measure the initial weight of the anode tube segment 1 and the control tube segment 4 and record the data. The galvanic corrosion test is then carried out according to the test plan, during which the controller collects current data in real time. After the test, the weights of anode pipe segment 1 and control pipe segment 4 were measured again using an electronic weighing mechanism and compared with their initial weights. By comparing the weight changes before and after the experiment and combining them with the current data, the effectiveness of the insulation segment in inhibiting galvanic corrosion of dissimilar metal pipes can be fully evaluated.

[0054] In a specific embodiment, the test device of the present invention for determining the galvanic corrosion inhibition effect of an insulating segment on dissimilar metal pipes is composed of an anode pipe segment 1, a cathode pipe segment 3, an insulating pipe segment 2, a control pipe segment 4, and insulating flanges (a first insulating flange 5, a second insulating flange 6, and a third insulating flange 7). The anode pipe segment 1 is composed of a first insulating gasket 9 and an anode ring electrode arranged in an alternating arrangement; the cathode pipe segment 3 is composed of a second insulating gasket 11 and a first cathode ring electrode 10 arranged in an alternating arrangement, and the insulating pipe segment 2 is made of nylon, polypropylene plastic, or other materials with inner wall insulation. The control pipe segment 4 has insulating flanges at both ends and a second anode ring electrode 16 in the middle. The anode ring electrode and the first cathode ring electrode 10 are respectively cut from two types of metal pipes in sections, wherein the electrode made of the metal pipe with a lower galvanic sequence is the anode ring electrode, and the electrode made of the metal pipe with a higher galvanic sequence is the first cathode ring electrode 10. The anode ring electrode and the first cathode ring electrode 10 can be adjusted according to the test requirements.

[0055] The insulating tube segment 2 is placed between the anode tube segment 1 and the cathode tube segment 3, while the control tube segment 4 is placed to the left of the anode tube segment 1 or to the right of the cathode tube segment 3. Insulating flanges are installed on both sides of the entire tube segment for docking and fastening with the pipeline system. The insulating tube segment 2 is composed of multiple interlocking insulating short tubes 12. Adjacent insulating short tubes 12 are sealed by sealing rubber rings 13. Adjacent insulating short tubes 12 can slide relative to each other, allowing the entire insulating tube segment 2 to contract in the longitudinal direction. The solution resistance between the anode tube segment 1 and the cathode tube segment 3 is adjusted to study the effect of solution resistance on galvanic corrosion. Specifically, the galvanic corrosion system has a maximum acceptable value, such as 1.2. This means that when the cathode and anode are electrically connected, the corrosion of the anode is accelerated by 0.2 compared to when they are not electrically connected. Based on this critical value, this requirement can be achieved by adjusting the length of the insulating tube segment 2. Generally, the longer the insulation length, the weaker the accelerating effect of the cathode segment on the anode segment. The critical value (galvanic corrosion coefficient) here refers to the galvanic corrosion coefficient corresponding to the first anode ring electrode.

[0056] All the first anode annular electrodes 8 and the first cathode annular electrodes 10 are electrically connected through wires (first wire 17 and second wire 18) (to simulate coupled dissimilar metal pipes), and the branch wire (second wire 18) corresponding to each annular electrode is connected to a zero-resistance ammeter for measuring the distribution of the galvanic current.

[0057] The second anode ring electrode 16 of the control pipe section 4 is not electrically connected to any other electrode and its function is to measure the self-corrosion rate, that is, it is not coupled to any other metal.

[0058] When the pipeline (i.e., the anode segment 1, the insulating segment 2, the cathode segment 3, and the control segment 4) is filled with a corrosive electrolyte, the anode segment 1 will experience accelerated galvanic corrosion due to coupling with the cathode segment 3. However, the control segment 4, which only experiences self-corrosion, can be used to measure galvanic corrosion. After a period of corrosion, pickling, and drying, the weight of the first anode ring electrode 8 and the second anode ring electrode 16 of the anode segment 1 and the control segment 4 will change before and after the test. The weight change is the metal weight loss caused by corrosion (measured by an electronic weighing mechanism). The number of anode ring electrodes and first cathode ring electrodes 10 can be adjusted to study the effect of different anode and cathode area ratios on galvanic corrosion. Specifically, due to structural characteristics and the size of the reference electrode, the length of the anode and cathode ring electrodes often has a minimum settable value. The ring electrodes are usually set shorter at the anode and cathode interface because the current jump is greater in these areas. The ring electrodes can be set longer closer to the second or third insulating flange because the current change tends to be more gradual the further out they are. By adjusting the total length of all anode ring electrodes and the total length of all cathode ring electrodes, the positive and negative area ratio can be adjusted.

[0059] If the weight loss of the first anode ring electrode 8 distributed in sequence along the axial direction is m1, m2, m3...m i , the average weight loss of the second anode ring electrode 16 of the control pipe section 4 is m0, then the distribution of the galvanic corrosion coefficient of the anode section can be calculated as (m1-m0) / m0, (m2-m0) / m0, (m3-m0) / m0…(m i -m0) / m0, the effect of different lengths of insulation segments on the galvanic corrosion distance can be accurately determined by the change of the galvanic corrosion coefficient.

[0060] In practical application, the specific process of the test device of the present invention is as follows:

[0061] The entire apparatus is integrated into a seawater pipeline test bench via the second and third insulating flanges. Before the test begins, the weights of the control pipe section, cathode ring, and anode ring are measured, and then the test apparatus is assembled. During the test, all zero-resistance ammeters incorporated into the test circuit operate continuously, and the corresponding test results are recorded in a multi-channel electrochemical workstation. The specific test frequency is continuously adjustable through the multi-channel electrochemical workstation. After the test, the test apparatus is dismantled, and the weights of the control pipe section, cathode ring, and anode ring are measured to calculate the weight loss of each measured object. Based on the weight loss of the anode ring and the control group, the galvanic corrosion acceleration factor (i.e., the galvanic corrosion coefficient) is calculated. During the test, the values ​​measured by the zero-resistance ammeters represent the instantaneous current flowing out of or into the anode or cathode ring. Based on this data, the current distribution along the pipe length of the anode and cathode pipe sections at each sampling point is generated, dynamically understanding the impact range of galvanic corrosion at a specific insulation length.

[0062] The weight loss data in the test is the most accurate corrosion data. However, during the long-term corrosion test, the weight loss data can only be used to stop the test and conduct the test, which not only affects the continuity of the test but also increases the difficulty of the test. Therefore, the weight loss data in the test is only used as a reference value.

[0063] The data measured by the zero-resistance ammeter provides dynamic corrosion data throughout the entire corrosion process, allowing for analysis of the overall corrosion progression. Furthermore, by integrating each instantaneous corrosion data over time, the final corrosion status over the entire test period can be determined. This means that the final corrosion data calculated above should equal the weight loss data. While the test medium of this invention is primarily seawater, this is not limited to seawater and can be applied to other media.

[0064] In summary, the test device for determining the galvanic corrosion inhibition effect of an insulating section on dissimilar metal pipelines of the present invention has the following beneficial effects:

[0065] 1. The test device of the present invention can accurately simulate the actual operating conditions of dissimilar metal pipes in ship piping systems, especially the complex environment with insulating sections, thereby ensuring the accuracy and reliability of the experimental results. This is of great significance for understanding and solving the problem of galvanic corrosion in ship piping systems.

[0066] 2. Through the design of retractable insulation tube segments, the device can quickly adjust the length of the insulation segment, thereby systematically studying the effect of different insulation segment lengths on galvanic corrosion inhibition. This helps engineers determine the optimal insulation segment length in actual applications to achieve the best anti-corrosion effect.

[0067] 3. The device can measure the distribution of galvanic corrosion when an insulating section exists between dissimilar metal pipes, including corrosion conditions at the anode section, cathode section, and near the insulating section. This comprehensive assessment helps to gain a deeper understanding of the mechanisms and characteristics of galvanic corrosion, providing a scientific basis for anti-corrosion design.

[0068] 4. Compared with traditional test methods, this device uses high-precision measuring equipment such as electronic weighing mechanism and zero-resistance ammeter, which can record experimental data in real time and accurately. At the same time, the design of retractable insulating pipe section greatly shortens the experimental cycle and improves experimental efficiency.

[0069] 5. The design of the device takes into account the effects of different experimental conditions such as media, temperature, and pressure on galvanic corrosion, making the experimental results more extensive and applicable. In addition, by adjusting the number and material of the anode ring electrode and the first cathode ring electrode, the effects of different anode and cathode area ratios and material combinations on galvanic corrosion can also be studied;

[0070] 6. By accurately simulating and rapidly evaluating the effectiveness of insulation sections in suppressing galvanic corrosion, this device helps ship manufacturers optimize anti-corrosion plans during the design phase, reducing equipment damage and replacement costs caused by galvanic corrosion. It also provides a scientific basis for ship maintenance, reducing long-term maintenance costs.

[0071] In summary, the test device for determining the inhibitory effect of an insulating section on galvanic corrosion of dissimilar metal pipelines of the present invention has obvious beneficial effects in simulating actual working conditions, studying the influence of the insulating section length on galvanic corrosion, evaluating the distribution of galvanic corrosion, improving experimental efficiency and accuracy, supporting a variety of experimental conditions, and reducing R&D costs and maintenance expenses.

[0072] The foregoing descriptions of specific exemplary embodiments of the present invention are for purposes of illustration and description. These descriptions are not intended to limit the invention to the precise forms disclosed, and it is apparent that many variations and modifications are possible in light of the foregoing teachings. The exemplary embodiments have been selected and described for the purpose of explaining the specific principles of the invention and their practical application, thereby enabling those skilled in the art to realize and utilize a variety of exemplary embodiments of the invention and various options and modifications. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A test device for determining the effect of an insulating section on the galvanic corrosion inhibition of dissimilar metal pipelines, characterized in that: include: Anode tube segment; an insulating pipe segment, one end of which is connected to one end of the anode pipe segment; a cathode tube segment, one end of the cathode tube segment being connected to the other end of the insulating tube segment; a control tube segment, one end of which is connected to the other end of the cathode tube segment; a plurality of first insulating flanges, respectively disposed between the anode tube segment, the insulating tube segment, the cathode tube segment and the control tube segment; A second insulating flange is provided on the other end of the anode tube segment; and a third insulating flange, disposed on the other end of the control pipe section; The anode tube segment is composed of a plurality of first anode annular electrodes and a plurality of first insulating gaskets arranged alternately, and the cathode tube segment is composed of a plurality of first cathode annular electrodes and a plurality of second insulating gaskets arranged alternately; The insulating tube segment is composed of a plurality of mutually cooperating insulating short tubes, and adjacent insulating short tubes are sealed by sealing rubber rings, and adjacent insulating short tubes can slide relative to each other, thereby being able to change the length of the insulating tube segment; Wherein, a first opening is formed on the top of each of the first anode annular electrodes, and a second opening is formed on the top of each of the first cathode annular electrodes; The test device for determining the effect of the insulating section on the galvanic corrosion inhibition of dissimilar metal pipelines further includes: a plurality of first reference electrodes, respectively installed in the first openings on top of the plurality of first anode ring electrodes; a plurality of second reference electrodes, respectively installed in the second openings on the tops of the plurality of first cathode annular electrodes; The control pipe section is composed of a second anode annular electrode, a second cathode annular electrode, and an inert metal ring, and the second anode annular electrode, the second cathode annular electrode, and the inert metal ring are not electrically connected to the plurality of first anode annular electrodes and the plurality of first cathode annular electrodes; The second anode annular electrode, the second cathode annular electrode and the inert metal ring are insulated and separated from each other.

2. The test device for measuring the effect of an insulating section on the galvanic corrosion inhibition of dissimilar metal pipes according to claim 1, characterized in that: The insulating pipe section is made of nylon, polypropylene plastic or other materials with insulating inner walls.

3. The test device for measuring the effect of an insulating section on the galvanic corrosion inhibition of dissimilar metal pipes according to claim 1, characterized in that: Also includes: First conductor; a plurality of second wires, one end of each of the plurality of second wires being electrically connected to the plurality of first anode ring electrodes, and the other end of each of the plurality of second wires being electrically connected to the first wires; a plurality of third wires, one end of each of the plurality of third wires being electrically connected to the plurality of first cathode annular electrodes, and the other end of each of the plurality of third wires being electrically connected to the first wires; as well as a fourth wire, one end of the fourth wire being electrically connected to the second anode ring electrode, and the other end of the fourth wire being electrically connected to the inert metal ring; A fifth wire, one end of which is electrically connected to the second cathode annular electrode, and the other end of which is electrically connected to the fourth wire.

4. The test device for measuring the effect of an insulating section on the galvanic corrosion inhibition of dissimilar metal pipes according to claim 3, characterized in that: Also includes: a plurality of first zero-resistance ammeters, respectively disposed on the plurality of second conducting wires; a plurality of second zero-resistance ammeters, respectively disposed on the plurality of third conducting wires; a third zero-resistance ammeter, disposed on the fourth conducting wire; as well as The fourth zero-resistance ammeter is arranged on the fifth conducting wire.

5. The test device for measuring the effect of an insulating section on the galvanic corrosion inhibition of dissimilar metal pipes according to claim 4, characterized in that: Also includes: a controller electrically connected to the plurality of first zero-resistance ammeters, the plurality of second zero-resistance ammeters, the third zero-resistance ammeter, and the fourth zero-resistance ammeter, respectively; as well as An electronic weighing mechanism is electrically connected to the controller and is used to measure the weights of the anode tube segment and the control tube segment before and after the experiment.

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