Nondestructive testing methods are periodically used by the industry as a means of ensuring the health of all the individual units comprising it. Thus, pipelines are regularly cleaned and tested for cracks. Turbines are similarly periodically checked for cracks and imperfections in either the blades or in the turbine itself. Units, due to being subjected to a combination of high temperature and stresses or high thermal stresses, also need to be checked using the appropriate tool in nondestructive testing. These tools and corresponding procedures include, are Eddy Current, Dye Penetrative agent, Radiography, Ultrasonic Testing and Magnetic Testing.
The Ultrasonic Testing applications include the measurement of thickness, the monitoring of corrosion as well as the build up of oxides, near drum boiler tools, and hydrogen induced cracking among others. The techniques used include the Acoustic Ranger, Advanced Flaw Sizing, EMAT or electromagnetic acoustic transmission, TOFD or time of flight diffraction and PA or Phased Array. In the TOFD method, a set of probes is used for the accurate estimation of cracks in welds. The probes are mounted on a buggy that travels along the weld being inspected. The data generated during travel is analyzed to reveal cracks.
Magnetic Testing methods are used for the examination of turbine blades, welds and pipelines. The Alternating Current Field Measurement (ACFM), Magnetic Flux Leakage (MFL) and the Portable Yoke are some of the methods in use. The ACFM can be used for metals, non-metals and their alloys and through coatings as well. The MFL is used for steel structures only.
The Ultrasonic Testing applications include the measurement of thickness, the monitoring of corrosion as well as the build up of oxides, near drum boiler tools, and hydrogen induced cracking among others. The techniques used include the Acoustic Ranger, Advanced Flaw Sizing, EMAT or electromagnetic acoustic transmission, TOFD or time of flight diffraction and PA or Phased Array. In the TOFD method, a set of probes is used for the accurate estimation of cracks in welds. The probes are mounted on a buggy that travels along the weld being inspected. The data generated during travel is analyzed to reveal cracks.
Magnetic Testing methods are used for the examination of turbine blades, welds and pipelines. The Alternating Current Field Measurement (ACFM), Magnetic Flux Leakage (MFL) and the Portable Yoke are some of the methods in use. The ACFM can be used for metals, non-metals and their alloys and through coatings as well. The MFL is used for steel structures only.
No comments:
Post a Comment