Abstract: A three dimensional object under test is measured to obtain shape data representing a shape of the three dimensional object. The object under test is measured using, for example, an ultrasonic probe LED to obtain defect test data. A processing mechanism forms a three-dimensional graphic image of a defect zone from the defect test data and a three-dimensional graphic image of the object under test from the shape data. A display mechanism is provided for displaying the three-dimensional graphic image of the defect zone superimposed over the three-dimensional graphic image of the object under test.

Abstract: A radiographic test is conducted on a welded portion of a pipe or the like to form a radiographic image, which is introduced into a computer. Volumetric defects and planar defects in the radiographic image are emphasized and extracted by separate methods to obtain a volumetric candidate defect image and a planar candidate defect image. The candidate defect images are then combined to form a single image in which defects can be easily identified. Features of defects in the images are measured, and a set of interference rules is applied to the measured features. Each inference rule gives a degree of certainty that a defect is of a certain type. The degrees of certainty determined by a plurality of the rules are collated to obtain a total degree of certainty, and the type of a defect is inferred from the total degree of certainty.

Abstract: A corrosion-resistant pipe coupling made of carbon steel has on its inner surface an intermediate annular projection directed radially inward. At least an innermost part of the annular projection is formed of corrosion-resistant material such as stainless steel. The annular projection may be covered by a corrosion-resistant annular member which is secured by friction welding, electron beam welding, an adhesive or mechanical engagement. The annular member prevents corrosion of the coupling by corrosive fluids flowing in pipes.

Abstract: A corrosion-resistant pipe coupling made of carbon steel has on its inner surface an intermediate annular projection directed radially inward. At least an innermost part of the annular projection is formed or corrosion-resistant material such as stainless steel. The annular projection is covered by a corrosion-resistant annular member or which is secured by friction welding, electron beam welding, an adhesive or mechanical engagement. The annular member prevents corrosion of the coupling by corrosive fluids flowing in pipes.