New at PipingDesign.com: 31 December 2000

A reader inquiry reminded me that there was very little at the site concerning testing.

Happy new year, all.

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Pipeline Radiography
Inspection Equipment Ltd.

<<Most pipeline radiography is performed using crawlers which produce a
panoramic X-ray beam. To take maximum economic and quality benefit from crawler technology, Inspection Equipment Ltd. developed specific accessories in collaboration with customers and film manufacturers. These products have now been used to radiograph literally hundreds of thousand of kilometres of gas and oil pipelines.>>

On-Line Radiographic Wallthickness-Measurement of Insulated Piping in the Chemical and Petrochemical Industry
NDT.net

<<Wall-thickness measurement of insulated piping is a typical
NDT-application in the chemical and petrochemical industry. For ultrasonic wall-thickness measurements the insulation has to be removed, and - additionally - the accuracy is restricted by the pipeīs temperature. Under these circumstances radiographic methods should be preferred. Radiographic wall-thickness measurements had been carried out since the 50īs, but there is only very little literature about this special radiographic technique. A major disadvantage of this radiographic method is, that the results are obtained off-line after film processing. There is a great industrial need for making radiographic wall-thickness measurements really on-line, which requires the availability of a filmless -ray imager. This paper deals with first results obtained with a new flat and lightweighted Radiation Image Detector (RID).>>

Inspection Techniques for Detecting Corrosion Under Insulation American Society for Nondestructive Testing, Inc.

<<Corrosion under insulation is difficult to find because of the
insulation cover that masks the problem until it is too late. It is expensive to remove the insulation, particularly if asbestos is involved. There are a number of methods used today to inspect for corrosion under insulation. The main ones are profile radiography, ultrasonic spot readings, and insulation removal. The other method now available is real time X-ray. Real time X-ray has proven to be a safe, fast, and effective method of inspecting pipe in plant operations.>>

Ultrasonic Crack Depth Measurement of Surface Bracking Cracks in Piping NDT.net

<<The article introduces results of a program for validation of
different ultrasonic test techniques for crack depth determination of surface breaking cracks. Two techniques, the TOFD technique and the angle beam testing with corner effect, both using time of flight measurement of the diffracted signal from the crack tip, are employed. Since it is not certain that all crack edges generate diffracted waves, the optimized ultrasonic pulse echo technique should be used. Applying TOFD as an additional analytic method for verification of Impulse Echo Technique or Radiography results seems to be more applicable. The first intensive programs focusing on detection of cracks in austenitic piping of nuclear power plants began in 1992. Defects studied include cracks in the weld section; lying circumferentially and more or less perpendicular to the inner surface. Analysis showed stress corrosion cracking to be the cause. Nonuniformities in the performance of weld geometry, such as misalignment and weld root penetration, make clear ultrasonic or radiography testing difficult. Ultrasonic diffraction technique was also employed as a test method. In the USA this method was first applied for crack detection and sizing (depth, length) in austenitic pipe welds. The tested welds were investigated destructively and the ultrasonic results were compared with those obtained via metalography. The inspection method and its parameters were validated.>> Received on Sun Dec 31 12:26:00 2000