Practice for Acoustic Emission Examination of Welded Steel Sphere Pressure Vessels Using Thermal Pressurization

2011 ◽  
Author(s):  
Keyword(s):  
Acoustic Emission ◽  
Pressure Vessels ◽  
Welded Steel ◽  
Steel Sphere ◽  
Thermal Pressurization

Detection of Corrosion Damage on Pressure Equipment with Acoustic Emission

2006 ◽  
Vol 13-14 ◽  
pp. 127-132 ◽  
Author(s):  
Gerold Lackner ◽  
Peter Tscheliesnig
Keyword(s):  
Acoustic Emission ◽  
Test Procedure ◽  
Corrosion Damage ◽  
Practical Experience ◽  
Pressure Vessels ◽  
Destructive Testing ◽  
Widespread Application ◽  
Traditional Procedure ◽  
Emission Testing ◽  
Service Period

Acoustic emission testing (AT) is in Europe an already well established non-destructive testing (NDT) method. Qualification requirements as well as certification of testing personnel are laid down in European standard EN 473. A widespread application of AT deals with testing of unfired pressure vessels for re-qualification after a certain period of service (repetition test). The advantages of applying AT compared to the traditional procedure of hydrostatic test plus visual inside inspection are numerous. Just to name the most important: reduction of downtime, omitting of residual humidity and no risk of product contamination with water. It is a fact that AT provides much more useful information concerning the condition of the pressure vessel under test than a simple ‘passed’ or ‘not passed’ obtained usually by a hydrostatic test. This contribution gives two examples of practical experience, where severe corrosion defects have been detected by AT. The defects have been found in both cases on the vessel’s shell under the thermal insulation, where they have been hidden undetected for years. It can be assumed that even the vessel with the most severe damage (loss of more than 50% of the nominal wall thickness) would have passed the traditional repetition test procedure and that failure within the following service period would have occurred. In contrary to this scenario, AT enabled the vessel operator to perform appropriate repair in time.

INFORMATION AND KINETIC APPROACH TO THE EVALUATION OF STRESS STATE OF VESSELS OPERATING UNDER PRESSURE IN HYDROGEN ENVIRONMENTS

2021 ◽  
pp. 30-45
Author(s):  
V. V. Nosov ◽  
A. R. Yamilova
Keyword(s):  
Acoustic Emission ◽  
Pressure Vessels ◽  
Maximum Activity ◽  
The State ◽  
Material Structure ◽  
Diagnostic Efficiency ◽  
Active Volume ◽  
And Control ◽  
Non Destructive ◽  
Altitude Level

Separation of the influence of various factors on the strength of the material and control parameters is the basis for increasing the diagnostic efficiency. The article describes methods for assessing the state of pressure vessels, features of their damage under conditions of hydrogen absorption, presents data from acoustic emission and ultrasonic testing, compares them, sets out an approach to non-destructive assessment of the strength state of technical objects, based on a multilevel model of time dependences of acoustic emission parameters (AE), the kinetic concept of strength, micromechanics of fracture of discrete media, their relationship with the resource, parameters of fatigue curves and characteristics of the material structure, the problems of the influence of strength and metrological heterogeneity on the information content of control, the sequence of assessing the indicators of the strength state and resource of vessels, the model of strength and metrological heterogeneity of the AE are presented control, explaining the maximum activity of AE during tests in the first periods of operation, a methodology for assessing the strength state of pressure vessels is presented. Demonstration of the effectiveness of the technique is shown as an example of AE testing of an absorber for purifying hydrogen sulfide with a monoethanolamine solution by predicting the resource of its components and comparing the prediction results with the coordinate-altitude level of the adsorber belt, which correlates with the average internal hydrostatic stresses. Approbation of the approach has shown its versatility on the example of effective application for objects with defects of both fatigue and chemical origin under conditions of hydrogenation. Using the example of assessing the state of the most damaged lower belt, it is shown that an increase in the AE activity during hydrogenation of the material occurs mainly due to the growth of the acoustically active volume of the controlled zone, which is not unambiguously associated with the resource, and therefore the activity and energy intensity of the AE should not be considered sufficient a sign of the danger of a defect formed under the influence of hydrogen-containing media.

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