Degradation Trending of Boiler Evaporator Tubes Without Scaffolding

2010 ◽  
Author(s):  
Coen Boxma ◽  
Jan Willem Noteboom ◽  
Joop Kraijesteijn
Keyword(s):  
Wall Thickness ◽  
Life Time ◽  
Non Destructive Testing ◽  
Preventive Action ◽  
Destructive Testing ◽  
Covered Wall ◽  
Overlay Welding ◽  
Waste Incinerators ◽  
Eu Project ◽  
Non Destructive

Inspection of wall thickness of the evaporator walls is usually performed from the inside of the boiler with standard ultrasonic (UT) spot testing. The costs for this type of inspection is largely determined by the cost for scaffolding and grinding and by safety measures which sometimes even include radiation control. The necessity for grinding also slightly impacts the accuracy of the readings. A new non-destructive testing application has been developed which provides the possibility to do this inspection from the outside of a boiler and thus eliminating the need for scaffolding. Windows of interest of about 10 to 120 ft2 are selected and provisions in the boiler insulation are made. The tubes in the selected areas are tested through UT scanning. The minimum wall thickness of each tube in that window is graphically presented in a report and repeat measurements enable the plant owner to compare these values in time. Trends in wall thickness reduction provide a basis for boiler life time prediction and to take preventive action. As a tool for preinspection to assess required maintenance measures (such as overlay welding or tube replacement), this test application has already shown to be very valuable. Recent applications include wall thickness assessment of refractory covered wall tubes, testing of boiler wall tubing with internal wall thickness loss at the fire sided tube face and wall thickness assessment of Inconel clad tubes at waste incinerators (EU project: NextGen Biowaste). This paper will discuss the method of non-destructive testing of wall thickness of the evaporator walls from the outside and will present examples where this method is applied.

Variation of the Modulus of Elasticity and Anisotropic Factor over the Thickness of the Bamboo Wall

2017 ◽  
Vol 737 ◽  
pp. 522-527
Author(s):  
M.A. Smits ◽  
V.D. Pizzol ◽  
P.V. Krüger ◽  
M.A.P. Rezende ◽  
R.C. Alves ◽  
...  
Keyword(s):  
Wall Thickness ◽  
Modulus Of Elasticity ◽  
Density Variation ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Anisotropic Factor ◽  
Anova Table ◽  
Inner Region ◽  
Non Destructive ◽  
Shell Region

The objective of this study is to experimentally determine the physical and elastic properties of bamboo and set the anisotropic factor along the wall thickness of the bamboo. The physical properties were determined following the requirements of the Brazilian standard. The elastic modulus was determined by non-destructive testing using the impulse excitation method. The density in the shell region is 40% larger than the inner portion. The density variation in the wall thickness of the bamboo is not linear, having a more pronounced nonlinearity in the shell region. The results of the ANOVA table indicate that shrinkage factors in bamboo wall thickness can be considered statistically the same, i.e., they do not vary with the wall thickness of the bamboo. The anisotropic factor in the intermediate and inner region can be considered statistically equal, 1.8. As for the factor measured in the region close to the bark, 2.03, it cannot be considered equal to the other regions. There is a variation of the modulus of elasticity, between the interior and the bamboo bark, of 279%.

Determination of actual wall thicknesses of equipment and pipelines exposed to flow-accelerated corrosion on the example of conical reducers

2020 ◽  
Vol 12 (4) ◽  
pp. 274-280 ◽  
Author(s):  
D. A. Kuzmin ◽  
A. Yu. Kuz’michevskiy
Keyword(s):  
Wall Thickness ◽  
Initial Time ◽  
Control Procedure ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Accelerated Corrosion ◽  
Equipment And Pipelines ◽  
Flow Accelerated Corrosion ◽  
Non Destructive

Flow-accelerated corrosion is a common type of damage to heat engineering equipment and pipelines. This process is subject to almost all elements of the condensate-feed and steam pipelines of turbine sets of nuclear and thermal power plants. Other types of metal thinning, in most cases, occur in conjunction with this process. In accordance with the requirements of the Federal Norms and Rules in Nuclear Energy, it is necessary to conduct regular non-destructive testing of thermal mechanical equipment using the method of ultrasonic thickness measurement to measure the thickness of walls, followed by assessment of compliance of the product quality and determination of the predictive value for the next in-service inspection. To estimate the rate of thinning and predict the value of thinning, it is necessary to know the values of actual wall thicknesses of pipeline systems at the initial time, which is usually not known. The actual wall thickness at the initial time is usually assumed to be equal to the nominal value without taking into account possible deviations, which is not always a reasonable solution in terms of assessing the rate of flow-accelerated corrosion. Functions are obtained that describe the profile of thinning with high accuracy. The coefficients included in the equation have a physical meaning: the actual wall thickness, the value of thinning and the area of local corrosion on the inner surface of the reducer. The developed approach is based on approximation of results of non-destructive testing, which allows to distinguish between areas exposed and not exposed to the mechanism of flow-accelerated corrosion in conical reducers. This makes possible to determine the thickness of the wall of a conical reducer of pipeline at the time of its being put in operation and to assess the rate of thinning based on a single control procedure, which reduces the possible rejection of metal and increases the accuracy of predictive calculations. This approach increases the safety and reliability of operation of conical reducers.

Non destructive testing techniques for risk based inspection

2012 ◽  
Vol 2 (2) ◽  
pp. 161-171
Author(s):  
Filip Van den Abeele ◽  
Patrick Goes
Keyword(s):  
Oil And Gas ◽  
Life Time ◽  
Crack Size ◽  
Offshore Structures ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Damage Models ◽  
Gas Drilling ◽  
Industry Standard ◽  
Non Destructive

Ensuring the safety of offshore structures is of vital importance for the reliability of oil and gas drilling rigs.Risk based inspection (RBI) is becoming an industry standard for management of equipment integrity. Theobjective of risk based inspection is to determine the likelihood of equipment failure (probability) and theconsequences of such an event. Combining the probability of an event with its possible consequencesallows determining the risk of an operation. Risk based inspection enables to optimize the frequency ofinspection, by moving from periodic inspection (based on arbitrary calendar dates) to an informedinspection program (based on equipment condition).One of the most important tools to determine the condition of the equipment, and to calculate its reliability,is the use of non destructive testing (NDT) techniques to detect cracks, flaws and defects. The probability ofdetection and the probability of sizing depend on the type of NDT method used. Combining NDTinformation on crack size and depth with fracture mechanics based damage models, allows predicting theremaining life time of a component.In this paper, the philosophy of risk based inspection is introduced and recent advances in non destructivetesting (in particular ultrasonic and electromagnetic techniques) are reviewed. Then, the use of fracturemechanics based damage models is demonstrated to predict fatigue failure for offshore structures.

Non destructive testing of works of art by terahertz analysis

2013 ◽  
Vol 64 (2) ◽  
pp. 21001 ◽  
Author(s):  
Jean-Luc Bodnar ◽  
Jean-Jacques Metayer ◽  
Kamel Mouhoubi ◽  
Vincent Detalle
Keyword(s):  
Non Destructive Testing ◽  
Destructive Testing ◽  
Works Of Art ◽  
Non Destructive

Modeling of a sensitive element on a planar mushroom-shaped metamaterial for non-destructive testing and searching for inhomogeneities in technological media

2020 ◽  
pp. 54-59
Author(s):  
A. A. Yelizarov ◽  
A. A. Skuridin ◽  
E. A. Zakirova
Keyword(s):  
Sensitive Element ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Resonant Frequency Shift ◽  
Maltese Cross ◽  
Informative Parameters ◽  
Non Destructive ◽  
Cross Type ◽  
Electrodynamic Structure ◽  
Electrophysical Parameters

A computer model and the results of a numerical experiment for a sensitive element on a planar mushroom-shaped metamaterial with cells of the “Maltese cross” type are presented. The proposed electrodynamic structure is shown to be applicable for nondestructive testing of geometric and electrophysical parameters of technological media, as well as searching for inhomogeneities in them. Resonant frequency shift and change of the attenuation coefficient value of the structure serve as informative parameters.

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