Development of Smart Membrane for Leak Detection in Pipeline

• Author / Creator

  Nguyen, Trung V

• Pipelines are the most important liquid and gas transportation methods in various industries. They help to reduce the cost and to minimize the environmental impacts. However, the public maintains high resistance to pipeline’s developments because they are exposed to the consequents of pipeline’s leakages. Thus, pipeline operators must aim at zero leakage in their systems for publics’ safety and also for gaining public support. However, leaks are inevitable due to various reasons, and pipeline operators can only reduce leak consequences by early detections. As a result, many leak detection systems (LDSs) have been developed. According to the study of Afzal, most of those systems suffered from both technical and economical problems when applied to complex pipeline systems. These LDSs systems are optimized to detect different leaks and also to minimize the costly false alarms; thus, they overlook small leaks, i.e. pinhole leaks. This thesis introduces a new LDS that will solve both technical and economic problems. The system includes a flexible membrane with a sensor printed on its surface. This membrane will be wrapped around the 36” pipe to capture the release products. Also, its sensor will detect the membrane’s strain created by these products and send the signal to pipeline operators. For the system to be sensitive and cost effective, the membrane had to be optimized to achieve the longest lengths with the predefined thicknesses. Since this technology will be incorporated into to the protective wraps, the optimization procedure will use the material properties and the popular thicknesses of the protective wraps. To achieve the optimum design, the sensors’ geometry was optimized first. Then, they were printed on a flexible membrane using a low-cost printer, conductive ink, and resistive ink. The sensors were designed as a half Wheatstone bridge because this setup gave the highest signal outputs under different loading conditions. The sensors were studied using the four points bending test, and the gauge factors were determined to be 4 and 7.85 for the conductive ink and resistive ink, respectively. Based on this information, a prototype of the membrane was manufactured. This prototype was subjected to the dimple test to evaluate its workability and to compare with the FEA model. Also, the full FEA model of the membrane with the sensor was created. This model was used to optimize the length and thickness of the membrane. The optimum design was achieved when the printed sensor can generate a signal with a signal-to-noise ratio (S/N) of 30 dB under deformation. The simulation indicated that the elastomer membrane with the length of 8.5 ft and thickness of 0.03” can detect pinhole leak on the 36” pipe in 0.8 seconds.

• Subjects / Keywords

  • Pipeline
  • Strain Gauge
  • Leak Detection

• Graduation date

  Spring 2016

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3X34N775

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.