AE08.pdf

The variety of factors influencing the presence and

This preview shows page 31 - 34 out of 41 pages.

The variety of factors influencing the presence and location of cracklike discontinuities adds complexity to the test. The shear amount of acoustic emission data to be analyzed poses 294 Acoustic Emission Testing F IGURE 33. Example of data plots that show noise from the coking operations.
Image of page 31

Subscribe to view the full document.

another challenge, which can be managed with proper postprocessing filtering techniques. Predetermined evaluation criteria, especially for the first pass, facilitate evaluation. Results Acoustic emission testing of coke drums has provided a reliable way to detect and locate active cracklike discontinuities. These tests provide the owner with valuable data to optimize tests of these units and to maintain and operate them. Results from acoustic emission monitoring of coke drums are useful in determining present structural integrity of the component. When carried out just before a planned shutdown, acoustic emission can direct maintenance and test personnel to critical areas of the drum. Directing attention this way shortens the maintenance window allocated to the shutdown. Fabrication Testing Acoustic emission testing has been used to test coke drums during their initial design code acceptance hydrostatic pressurization (Fig. 34). These tests were carried out to detect and locate code acceptable discontinuities that could initiate fatigue cracks in service. Acoustic emission testing of new drums falls under the normal practice for testing new pressure equipment as embodied in documents such as those issued by ASME International. 18-20 Testing of new coke drums during their code acceptance hydrostatic testing has the benefit of detecting and locating fabrication discontinuities. Although small discontinuities may be acceptable by the design code, their removal should enhance the fatigue life of the vessel by controlling crack nucleation. Detection of such otherwise minor discontinuities will usually require adjustment to the evaluation criteria. 295 Acoustic Emission Testing of Pressure Vessels, Pipes and Tanks F IGURE 34. Fabrication of a coke drum.
Image of page 32
Introduction Testing of tank floors is not difficult or costly. Taking a tank out of service, cleaning and preparation for entry, however, is often both time consuming and costly. Deciding which tanks to test and when is, therefore, a critical element in managing a terminal or tank farm. Avoiding failure (leakage) is very important but equally an operator must avoid unnecessary downtime or expenditure to remain competitive. With corrosion rates varying from 0 to 1 mm (0.04 in.) per year depending on the type of service and local conditions, the condition of a particular tank floor is often unpredictable. This makes a nonintrusive acoustic emission test a useful and economical part of a tank testing program.
Image of page 33

Subscribe to view the full document.

Image of page 34
  • Fall '19
  • Nondestructive testing, Hydrostatic test, Acoustic Emission

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern