Acoustic-emission inspection during water-pressure testing of pressure vessels

1976 ◽  
Vol 9 (5) ◽  
pp. 227-232 ◽  
Author(s):  
T. Watanabe ◽  
S. Hashirizaki ◽  
H. Arita
Keyword(s):  
Acoustic Emission ◽  
Water Pressure ◽  
Pressure Vessels ◽  
Pressure Testing ◽  
Water Pressure Testing

The Technique of Segmental Pigging Process for Long Distance Pipeline of Oil and Gas in China

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Tao Deng ◽  
Jun Zhou ◽  
Yu Zhang ◽  
Yuanyuan Chen ◽  
Gong Jing
Keyword(s):  
Complex Terrain ◽  
Oil And Gas ◽  
Water Pressure ◽  
Oil And Gas Industry ◽  
Long Distance ◽  
Gas Industry ◽  
Vapor Cavity ◽  
Pressure Testing ◽  
Pressure Pulses ◽  
Water Pressure Testing

Worldwide, the pipeline mileage has increased dramatically since 1948 when the industry began to keep mileage statistics for pipeline construction, especially in China. Before operating long distance oil and gas pipelines, the pressure testing for tightness and strength is of great importance for ensuring operating safety. Water is used as service fluid for the pressure testing due to its safety, and long distance pipeline is divided into a number of small sections according to complex terrain conditions. Segmental water pressure testing is now very frequently used in the oil and gas industry, ensuring safety and efficient construction of pipelines. However, some new problems may arise, in practice, for the pigging process, following water pressure testing. Based on the review of previous papers about pipes accidents, the causes can be classified into hydraulic and nonhydraulic aspects. With the method of characteristic (MOC) and basic theory of gas–liquid two-phase unsteady flow, a mathematical model is developed to simulate the hydraulic transients during the pigging process. The model has been applied to some segmental pipes in China to predict varying pressures under complex terrain conditions. Pressure pulses predicted at the end of pigging in the numerical results have also been found to occur in field trials. The analysis shows that pressure pulses may cause overpressure accidents due to vapor cavity collapse. The techniques in this paper can give reasonable instructions in long distance pipeline constructing, promoting the development of Chinese oil and gas industry.

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.

Pressure Testing Feedwater Heaters and Power Plant Auxiliary Heat Exchangers

2010 ◽  
Author(s):  
Stanley Yokell
Keyword(s):  
Heat Transfer ◽  
Power Plant ◽  
Heat Exchangers ◽  
Wire Drawing ◽  
Pressure Vessels ◽  
Shell Side ◽  
Auxiliary Equipment ◽  
National Board ◽  
Pressure Testing ◽  
Test Pressure

This paper discusses factory and field pressure testing of tubular heat transfer equipment such as closed feedwater heaters, steam surface condensers and power plant auxiliary heat exchangers built to Section VIII Division 1 of the ASME Boiler and Pressure Vessel Code (the ASME Code) and repaired or altered in accordance with the National Board Inspection Code (NBIC). It discusses the ASME Code’s and the NBIC’s requirements for hydrostatically testing unfired pressure vessels which includes tubular heat transfer equipment. It points out that using pressure gage indications of pressure loss to determine if there is a leak from the tube side to the shell side when the back face of the tubesheet is not visible does not reveal very small leaks or weeping. For the purposes of this paper, we define weeping, VRRLeak, as a leak of 20 drops per hour or approximately 1 cm3 [0.061 in3]. During typical half-hour hydrostatic test pressure holding periods, such weeping would amount to 10 drops of water on the tubesheet face or 0.5 cm3 [0.0305 in3]. Weeping through tube-to-tubesheet joints of high-pressure feedwater heaters can lead to wire drawing (wormholing), which can materially reduce the heater life. Leaks from the channel to the shell side of steam surface condensers and auxiliary condensers can introduce brackish water into the condensate. Depending upon the fluid flowing in the tubes, contaminants can enter the shell side of other auxiliary equipment when the channel pressure is higher than that of the shell. The paper concludes that Users must advise Designers and Manufacturers of the hazards of small leaks through the tube-to-tubesheet joints. It recommends that these three entities must agree on suitable leak tests.

Sign in / Sign up

Export Citation Format

Share Document