SGS provides hot hydrogen attack inspection for Shell in the Philippines
27/01/2012
Hot hydrogen attack (HHA) is a form of degradation caused by carbides reacting in steel, thereby forming methane (CH4). The probability of HHA damage in industrial plants is dependent on its partial hydrogen pressure and operating temperature. In the worst cases, HHA may lead to damage, which can have catastrophic results for people and the environment. Since even a minor failure could cause unacceptable downtime and a substantial loss of money, conducting regular hot hydrogen attack inspections is indispensable for detecting failures and discontinuities at the earliest stage possible.In order to assess the condition of the piping and heat exchanger in the refinery in Batangas, Philippines, Shell Petroleum Corporation looked for a reliable inspection, verification and testing company.
On 21 October 2011, SGS was awarded a contract, scheduled from 24-28 October 2011, to provide a comprehensive hot hydrogen attack (HHA) inspection due to its first-rate experience and competence in projects of this kind.
Throughout the hot hydrogen attack inspection, SGS’s team of highly-skilled experts inspected the piping and heat exchanger for the possible occurrence of hot hydrogen attack by applying advanced non-destructive testing (NDT) techniques.
Drawing on its extensive expertise, SGS used a combination of various inspection methods to ensure the highest probability of detection of HHA. In order to inspect the parent material of the piping and heat exchanger, SGS’s experts utilised manual backscatter and velocity ratio techniques.
Furthermore, SGS inspected the weld for cracks by means of manual ultrasonic testing (UT). In the case of any indication of HHA cracking, SGS carried out time-of-flight diffraction (TOFD) and manual pulse echo on welds for verification. TOFD inspections were conducted in combination with a high-frequency shear wave to improve the reliability of the weld inspection. With SGS’s assistance, hot hydrogen attack was detected and further analyses utilising time-of-flight diffraction were performed to the full satisfaction of the client.
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