Description:TECHNICAL FIELD
[0001] The present disclosure relates generally to field of pipeline inspection and non-destructive testing (NDT). More specifically, it pertains to a tethered intelligent pigging system for the real-time inspection of small-diameter pipelines, coiled tubes, and U-bend coils.

BACKGROUND
[0002] Pipeline and tubular structure inspection is a critical aspect of maintenance and reliability assessment in industries such as oil and gas, petrochemical refineries, power plants, and industrial heating systems. Traditionally, pipeline integrity is assessed using intelligent pigging, a technique where an inspection device (pig) moves through the pipeline, collecting data on corrosion, material loss, and defects. However, conventional intelligent pigging systems are largely designed for straight, large-diameter pipelines and face significant limitations when applied to small-diameter coiled tubes and U-bend coils, which are commonly found in economizers, heaters, and boilers.
[0003] Existing inspection methods for small-diameter, U-bend pipelines primarily rely on visual inspection and localized ultrasonic testing (UT), which only allow for partial defect detection. These methods fail to provide a comprehensive assessment of the internal surface, especially in hard-to-reach areas like tight U-bends and long coiled tubes. Additionally, conventional free-floating smart pigs require high pipeline pressure for movement, making them unsuitable for low-pressure environments or complex geometries where pressure fluctuations can cause them to stall or miss critical defects.
[0004] There is, therefore, a need to overcome the above-mentioned drawbacks, shortcomings and limitations associated with existing solutions, by providing a tethered intelligent pigging system that can navigate small-diameter tubes, multiple one-dimensional radius U-bends, and extended coil lengths while providing real-time, full-coverage inspection..

OBJECTS OF THE PRESENT DISCLOSURE
[0005] A general object of the present disclosure is to provide a tethered pigging system capable of inspecting small-diameter pipelines and U-bend coils.
[0006] An object of the present disclosure is to enable real-time defect detection and data analysis through an integrated ultrasonic, electromagnetic, and a high-definition camera-based inspection.
[0007] An object of the present disclosure is to facilitate controlled movement and navigation of the inspection probe, allowing efficient maneuverability through bends and long coiled sections.

SUMMARY
[0008] Aspects of the present disclosure relate to technical field of pipeline inspection and non-destructive testing (NDT). More specifically, it pertains to a tethered intelligent pigging system for the real-time inspection of small-diameter pipelines, coiled tubes, and U-bend coils.
[0009] According to an aspect, the present disclosure relates to a tethered pigging system for inspecting U-bend coils and small-diameter pipelines. The system comprises a launching device configured to introduce and retrieve a probe assembly into a pipeline or coiled tube for inspection. The probe assembly is operably connected to the launching device, the launching device having ultrasonic sensors, electromagnetic sensors, and an high-definition camera to detect structural defects, corrosion, and material loss. In addition, the system comprises a tethered cable operatively connected to the probe assembly to facilitate real-time control, retrieval, and data transmission. The system comprises a fluid propulsion unit having a water tank, water pump, and inlet/outlet hoses, where the water pump directs water from the water tank through the inlet hose into the launching device, the probe assembly is propelled by the water flow and guided through the pipeline or coiled tube and water exits the pipeline through an outlet hose, returning to the water tank, forming a closed-loop fluid circulation arrangement. Further, the system comprises a data acquisition unit configured to collect, process, and transmit real-time inspection data to an external monitoring unit for defect detection and structural assessment.
[0010] The fluid propulsion unit may be guided through the pipeline or coiled tube by a parachute or propeller mechanism.
[0011] The probe assembly may be configured to inspect pipelines and coiled tubes with diameters ranging from 25 mm to 300 mm and lengths up to 500 meters, covering a total of 1000 meters when accessed from both ends.
[0012] The tethered cable may facilitate bidirectional movement of the probe assembly.
[0013] The high-definition camera may capture real-time visual data, the ultrasonic sensors may detect structural defects, corrosion and material loss and electromagnetic sensors may detect micro-structural damages in metal. The micro-structural damages in metal may be due to creep carburization and cracks.
[0014] The fluid propulsion unit may operate within a pressure range of 1.0 to 10 bar for smooth movement of the probe assembly.
[0015] The data acquisition unit may provide real-time defect classification, location mapping, and predictive maintenance insights.
[0016] Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

BRIEF DESCRIPTION OF DRAWINGS
[0017] The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.
[0018] FIG. 1 illustrates an exemplary schematic diagram of the proposed tethered pigging system for inspecting U-bend coils and small-diameter pipelines, in accordance with an embodiment of the present disclosure.
DETAILED DESCRIPTION
[0019] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such details as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims..
[0020] Embodiments explained herein relate to a tethered intelligent pigging system for real-time inspection of small-diameter pipelines, coiled tubes, and U-bend coils.
[0021] Referring to FIG. 1, a tethered pigging system for inspecting U-bend coils and small-diameter pipelines is disclosed. The system can detect defects, corrosion, and material loss in U-bend coils 1011 and small-diameter pipelines. The system can utilize a probe assembly 1002 that is propelled through the pipeline 1010 using a fluid propulsion unit, allowing for real-time monitoring and data collection. A tethered cable 1004 can facilitate precise control, bidirectional movement, and immediate data transmission, ensuring comprehensive pipeline assessment. The system can be integrated with ultrasonic sensors 4, electromagnetic sensors 3, and an high-definition camera 1 to enable the detection of structural abnormalities in pipelines.
[0022] In an embodiment, the system can include a launching device 1001 serving as an entry and retrieval point for the probe assembly 1002. The launching device 1001 can be configured to ensure smooth insertion and extraction of the probe assembly 1002 into and out of the pipeline or coiled tube 1010. The launching device 1001 can be strategically configured to accommodate the fluid propulsion unit, which can use pressurized water to push the probe assembly 1002 forward. Additionally, the launching device 1001 can act as an interface for the tethered cable 1004, essential for controlling the movement of the probe and transmitting real-time inspection data. The launching device 1001 can be a rigid chamber with an inlet and an outlet hose to control fluid flow.
[0023] In an embodiment, the probe assembly 1002 of the system can be equipped with multiple sensors and an high-definition (HD) camera 1 to assess pipeline conditions. As the probe assembly 1002 moves through the pipeline or coiled tube 1010, the probe assembly 1002 can scan the inner walls, capturing detailed information about potential structural defects, corrosion, and material degradation. The probe assembly 1002 can be connected to the tethered cable 1004 for real-time control, power supply, and data transmission. The sensors can be ultrasonic sensors 4 to utilize high-frequency sound waves to measure material thickness and identify corrosion or cracks. Ultrasonic waves can reflect off surfaces, providing accurate data on wall thinning and defects. The sensors can be electromagnetic sensors 3 to detect metal loss, pitting, and surface cracks using electromagnetic induction. They can be particularly effective for assessing ferrous pipelines where corrosion and erosion are common. The HD camera 1 can capture visual data from inside the pipeline or coiled tube 1010, offering a clear view of obstructions, deposits, or mechanical deformations. This visual assessment can be crucial for confirming sensor-detected anomalies. The probe assembly 1002 can be dimensioned to fit within pipelines with diameters ranging from 25 mm to 300 mm and can travel distances of up to 500 meters in a single pass. When accessed from both ends, it can cover a total length of 1000 meters, ensuring comprehensive inspection.
[0024] In an embodiment, the tethered cable 1004 can be a flexible, reinforced cable that allows bidirectional movement of the probe assembly 1002. The tethered cable 1004 can also serve as a safety mechanism in case of an unexpected obstruction, allowing the probe assembly 1002 to be manually retracted if needed. Furthermore, the cable can ensure seamless data transfer from the probe assembly’s 1002 sensors to an external monitoring unit, allowing for immediate analysis of pipeline 1010 conditions.
[0025] In an embodiment, the fluid propulsion unit can provide necessary force to drive the probe assembly 1002 through the pipeline or coiled tube 1010 by utilizing water pressure. The fluid propulsion unit can include a water tank 1006 for storing and circulating water used for propulsion, a water pump 1007 to control the water flow rate and pressure to push the probe assembly 1002 forward, an inlet hose 1005 to water from the pump to the launching device 1001 and an outlet hose 1008 to extract water from the pipeline, returning it to the tank to form a closed-loop system. Additionally, a parachute or propeller may be included in the fluid propulsion unit to regulate movement and prevent erratic motion in the pipeline or coiled tube 1010, allowing for better navigation in complex geometries, such as U-bends 1011 and coiled tubes. The fluid propulsion unit can operate within a pressure range of 1.0 to 10 bar, ensuring smooth and controlled motion of the probe inside the pipeline or coiled tube 1010. Further, an outlet hose 1012 can form part of the fluid propulsion unit. This can work alongside 1005 (inlet hose) and 1008 (outlet hose) to facilitate the movement of water through the system. The water pump 1007 can direct water from the water tank 1006 through the inlet hose 1005 to propel the probe assembly 1002 through the pipeline or coiled tube 1010. The water can then exit through the outlet hose 1012, returning to the water tank 1006 to complete the closed-loop fluid circulation arrangement.
[0026] In an embodiment, the system can include a data acquisition unit to process and analyze the real-time inspection data collected by the probe assembly’s sensors. This unit can be responsible for detecting, classifying, and mapping defects within the pipeline or coiled tube 1010. The collected data can be transmitted to an external monitoring unit, where the data can be further analyzed for predictive maintenance and structural integrity assessment. The data acquisition unit can automatically identify and classify structural issues such as corrosion, cracks, and deformations in the pipeline. The data acquisition unit can include an electronic circuit, a processor, and a communication interface that collect signals from the ultrasonic sensors 4, electromagnetic sensors 3, and HD camera 1. The electronic circuit can receive raw signals from the ultrasonic and electromagnetic sensors 3. The circuit can filter, amplify, and convert these signals into a usable format for processing. The processor can include a microcontroller (MCU) or Field-Programmable Gate Array (FPGA), is integrated into the system to execute real-time data processing algorithms. The processor can control sensor operation, data acquisition timing, and signal interpretation. The communication interface can be a wired or wireless interface, such as Ethernet, USB, Wi-Fi, or Bluetooth, to transmit collected data to an external monitoring station for analysis. The data acquisition unit can process and transmit this data to an external monitoring unit.
[0027] The data acquisition unit can use algorithms for real-time defect detection, classification, location mapping, and predictive maintenance insights, and can help analyze the acquired data and generate reports for maintenance planning. To refine raw data from ultrasonic and electromagnetic sensors 3, signal processing algorithms can be utilized. Techniques such as Fast Fourier Transform (FFT) convert time-domain signals into the frequency domain, making it easier to detect defects while reducing noise. Similarly, Wavelet Transform is particularly effective in analyzing transient signals, such as sudden material loss or crack formation. Additionally, Kalman Filtering can be used for minimizing noise interference, thereby improving the accuracy of defect detection and location tracking. Once the data is processed, defect detection algorithms can help in identifying structural irregularities such as cracks, corrosion, and material degradation. Edge detection techniques (e.g., Sobel and Canny) can allow for precise identification of defect boundaries in visual data captured by the HD camera 1. Meanwhile, thresholding methods like Otsu’s algorithm aid in segmenting defective areas in ultrasonic and electromagnetic scan images. For more advanced analysis, Convolutional Neural Networks (CNNs) can be employed to automatically detect and categorize defects from both visual and sensor data with high accuracy.
[0028] In another embodiment, the system can include a flow control valve 1009, which can regulate the rate of water or fluid flow, ensuring optimal propulsion of the probe assembly 1002 through the pipeline or coiled tube 1010. In another embodiment, 1009 can act as a pressure regulator to help maintain a stable pressure level within the system, preventing potential damage to components due to excessive force. Alternatively, 1009 can also act as a check valve, ensuring unidirectional flow, preventing backflow and maintaining the efficiency of the closed-loop fluid propulsion mechanism.
[0029] In another embodiment, the external monitoring unit can oversee the entire pipeline inspection process by receiving, analyzing, and visualizing real-time data from the data acquisition unit. The external monitoring unit can act as an interface between the inspection system and human operators. The monitoring unit can collect real-time data transmitted from the probe assembly 1002 through the tethered cable 1004 and process it for visualization and analysis. The monitoring unit can provide detailed insights into pipeline integrity by displaying sensor readings, defect locations, and classified anomalies. Additionally, the monitoring unit can facilitate remote control of the probe assembly 1002, allowing operators to adjust movement and inspection parameters as needed. The external monitoring unit can be composed of both hardware and software elements that facilitate real-time data visualization and informed decision-making. At its core, a high-performance computing system or industrial workstation can process large volumes of inspection data received from the probe assembly 1002. A user interface (UI) software can present this data through an intuitive dashboard, allowing operators to monitor pipeline conditions, sensor readings, and detected defects. To ensure data retention and future analysis, the monitoring unit can incorporate cloud-based or local storage, enabling efficient archiving and maintenance planning. A communication interface, equipped with both wired and wireless connectivity can be used to ensure seamless data transmission between the probe assembly 1002 and the monitoring unit.
[0030] The probe assembly 1002 can be introduced into the pipeline or coiled tube 1010 through the launching device 1001. The water pump 1007 can be activated, pushing pressurized water into the pipeline via the inlet hose 1005, propelling the probe forward. As the probe moves, the ultrasonic sensors 4, electromagnetic sensors 3, and HD camera 1 scan the inner walls of the pipeline or coiled tube 1010, detecting any defects or abnormalities. The HD camera 1 can capture real-time visual data, the ultrasonic sensors 3 can detect structural defects, corrosion and material loss and electromagnetic sensors 4 can detect micro-structural damages in metal. The micro-structural damages in metal can be due to creep carburization and cracks. The tethered cable 1004 transmits real-time inspection data to the data acquisition unit, where it is analyzed. If needed, the probe assembly 1002 can be moved backward using the tethered cable 1004, allowing for detailed rescanning of critical areas. After the inspection is complete, the probe assembly 1002 can be withdrawn through the launching device 1001, and the collected data can be reviewed for maintenance planning. The data acquisition unit generates a comprehensive report, highlighting defect locations and suggested repairs.
[0031] Thus, the present disclosure provides a system for inspecting U-bend coils and small-diameter pipelines, ensuring structural integrity and early defect detection. By utilizing a combination of ultrasonic sensors, electromagnetic sensors, and an HD camera, the system provides comprehensive real-time data for accurate analysis. The integration of a fluid propulsion mechanism and a tethered cable enables precise movement and bidirectional operation, enhancing inspection capabilities. With its ability to navigate complex pipeline geometries and deliver predictive maintenance insights, this system significantly improves pipeline monitoring, reduces downtime, and enhances operational safety.
[0032] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

ADVANTAGES OF THE PRESENT DISCLOSURE
[0033] The present disclosure provides a system that integrates ultrasonic sensors, electromagnetic sensors, and an HD camera, enabling precise detection of structural defects, corrosion, and material loss within small-diameter pipelines and U-bend coils.
[0034] The present disclosure provides a system that utilizes a tethered cable to facilitate continuous data transmission to an external monitoring unit, allowing real-time analysis, defect classification, and predictive maintenance insights for timely decision-making.
[0035] The present disclosure provides a system that closed-loop fluid circulation arrangement that ensures smooth and controlled movement of probe assembly, reducing energy consumption.
[0036] The present disclosure provides a system that utilize a probe assembly with tethered configuration, allowing it to move in both directions, enabling detailed rescanning of critical areas, improving inspection accuracy, and ensuring complete pipeline coverage.
, Claims:1. A tethered pigging system for inspecting U-bend coils 1011 and small-diameter pipelines, comprising:
a launching device (1001) configured to introduce and retrieve a probe assembly (1002) into a pipeline or coiled tube (1010) for inspection;
the probe assembly (1002) operably connected to the launching device (1001), the launching device (1001) comprising ultrasonic sensors (4), electromagnetic sensors (3), and a high-definition (HD) camera (1) to detect structural defects, corrosion, and material loss;
a tethered cable (1004) operatively connected to the probe assembly (1002) to facilitate real-time control, retrieval, and data transmission;
a fluid propulsion unit having a water tank (1006), water pump (1007), and inlet/outlet hoses (1005, 1008, 1012), wherein the water pump (1007) directs water from the water tank (1006) through the inlet hose (1005) into the launching device (1001), the probe assembly (1002) is propelled by the water flow and guided through the pipeline or coiled tube (1010) and water exits the pipeline through an outlet hose (1008), returning to the water tank (1006), forming a closed-loop fluid circulation arrangement; and
a data acquisition unit configured to collect, process, and transmit real-time inspection data to an external monitoring unit for defect detection and structural assessment.

2. The system as claimed in claim 1, wherein the fluid propulsion unit is guided through the pipeline or coiled tube (1010) by a parachute or propeller mechanism (2).

3. The system as claimed in claim 1, wherein the probe assembly (1002) is configured to inspect pipelines and coiled tubes with diameters ranging from 25 mm to 300 mm and lengths up to 500 meters, covering a total of 1000 meters when accessed from both ends.

4. The system as claimed in claim 1, wherein the tethered cable (1004) facilitates bidirectional movement of the probe assembly (1002).

5. The system as claimed in claim 1, wherein the HD camera (1) captures real-time visual data, the ultrasonic sensors (4) detect structural defects, corrosion and material loss and electromagnetic sensors (3) detect micro-structural damages in metal.

6. The system as claimed in claim 1, wherein the fluid propulsion unit operates within a pressure range of 1.0 to 10 bar for smooth movement of the probe assembly (1002).

7. The system as claimed in claim 1, wherein the data acquisition unit provides real-time defect classification, location mapping, and predictive maintenance insights.