Acoustic Emission Testing and Structural Evaluation of Seamless, Steel Tubes in Compressed Gas Service

1986 ◽  
Vol 108 (2) ◽  
pp. 234-240 ◽  
Author(s):  
P. R. Blackburn ◽  
M. D. Rana
Keyword(s):  
Acoustic Emission ◽  
Test Method ◽  
Department Of Transportation ◽  
Structural Evaluation ◽  
Emission Testing ◽  
Industrial Gases ◽  
Acoustic Emission Testing ◽  
Acoustic Emission Test ◽  
Seamless Steel Tubes ◽  
Seamless Steel

Tube trailers are used in the distribution of industrial gases. The tubes, which are seamless steel, measure 22-in. diameter, about 1/2-in. wall, and 34 ft long. The U. S. Department of Transportation mandates periodic re-tests of tubes every 5 yr. Acoustic emission re-tests have been substituted for hydrostatic re-tests. This paper presents an analysis of flaws using fracture mechanics methods and establishes a maximum allowable flaw depth. It describes the acoustic emission test method and presents some typical results. Also, some discussion of the hydrostatic re-test is included.

On the Reproducibility of Transducer Coupling for Acoustic Emission Testing

2006 ◽  
Vol 13-14 ◽  
pp. 117-124 ◽  
Author(s):  
James J. Hensman ◽  
C.V. Cristodaro ◽  
Gareth Pierce ◽  
Keith Worden
Keyword(s):  
Acoustic Emission ◽  
Test Results ◽  
Coupling Condition ◽  
Waveform Data ◽  
Three Point Bending ◽  
Emission Testing ◽  
Acoustic Emission Testing ◽  
Acoustic Emission Test ◽  
Point Bend ◽  
Ultrasonic Propagation

An acoustic emission test was simulated using a three point bend specimen and an artificial AE source. Waveform data was recorded as the sample was cyclically loaded in three point bending, and the cross correlation coefficient of the waveforms was used to measure the repeatability of the test. Results were twofold: the stress state of a specimen affects the ultrasonic propagation therein; and the coupling condition of a transducer may not remain constant during a test.

More than a Quarterly Century of Acoustic Emission Testing (AT) at TÜV Austria

2006 ◽  
Vol 13-14 ◽  
pp. 365-376
Author(s):  
Peter Tscheliesnig
Keyword(s):  
Acoustic Emission ◽  
Data Acquisition ◽  
Rapid Development ◽  
Test Method ◽  
Electronic Data ◽  
Emission Testing ◽  
Acoustic Emission Testing

The TÜV Austria (formerly TÜV Vienna) has been testing different structures, mainly pressure equipment, since 1977 with Acoustic Emission. I will not enumerate all the different tests, which are more than 20.000 till today, but I will point out, how the test method has changed on some typical tests over the years. I will also remind you on the different possibilities, which have been offered by the rapid development of the electronic data acquisition and treatment, especially during the last 10 – 15 years.

Periodic Inspection of Compressed Gas Cylinders and Tubes—Flaw Detection Using Acoustic Emission Testing

1988 ◽  
Vol 110 (2) ◽  
pp. 161-167 ◽  
Author(s):  
H. Barthe´le´my
Keyword(s):  
Acoustic Emission ◽  
Flaw Detection ◽  
Internal Corrosion ◽  
Periodic Inspection ◽  
Emission Testing ◽  
Industrial Gases ◽  
Test Pressure ◽  
Acoustic Emission Testing ◽  
Periodic Inspections ◽  
Gas Cylinders

Hydrostatic re-tests are performed on gas cylinders and trailer tubes which are used to supply industrial gases. In this paper we review how to apply acoustic emission tests during periodic inspections to detect flaws, i.e., internal corrosion and cracks, which could occur on these containers during service. It appears that internal corrosion can be very easily detected at low pressure. However, to be sure of detecting cracks, it is best to perform AE tests during pressurization up to the test pressure. AE testing carried out during hydro-testing improves the reliability of the inspection, presents a greater accuracy in flaw detection than the water jacket test, and allows safe extension of the interval between re-tests.

Acoustic Emission Testing of a Process Reactor

2005 ◽  
Author(s):  
Simon Yuen ◽  
David Wang ◽  
Paul Benedictus
Keyword(s):  
Acoustic Emission ◽  
Slag Inclusion ◽  
Thick Wall ◽  
Operating Pressure ◽  
Weld Overlay ◽  
Emission Testing ◽  
Acoustic Emission Testing ◽  
Acoustic Emission Test ◽  
Ae Signals

An Acoustic Emission Test (AET) was performed on a hydrocarbon processing reactor to inspect for environmental cracking in 2000. The thick-wall reactor was built in 1965, fabricated from 2.25Cr-1Mo steel with Type 347 stainless steel weld overlay. Past internal inspections of the reactor using liquid penetrant had revealed cracking at internal ring supports. Such inspections were exhaustive and time consuming. The AET was performed to achieve 100% inspection coverage of the reactor and to identify suspect areas for further evaluation. The test included over-pressurization of the reactor to 10% above its operating pressure before the shutdown and the actual cooling of the reactor from 745°F to 300°F. Upon completion of the acoustic emission (AE) monitoring, significant indications were identified, most noticeably at the reactor dump nozzle and the bottom head to shell weld. Both of these were in areas that had not been inspected previously. Follow-up inspections, including external ultrasonic and internal liquid penetrant test, were performed to investigate all the areas of significant AE activities. The results showed internal cracks isolated to the weld overlay at the catalyst dump nozzle and a 12” long weld slag inclusion in the bottom head to shell weld. A methodology was developed also to evaluation criticality of AE signals during different stages of AE test.

Sign in / Sign up

Export Citation Format

Share Document