Introduction to non destructive testing (NDT): Non destructive testing (NDT) for welding is a term used for the examination of welded joints in a way that allows them to be examined without changing or destroying them. NDT plays an important role in everyday life and is necessary to assure safety and reliability. Examples are found in aircraft, motor vehicles, pipelines, bridges, trains, power stations; refineries and oil platforms which are all inspected using NDT. NDT …showed first 75 words of 3155 total…

…showed last 75 words of 3155 total…also X-rayed. A comparison of the negatives will indicate how closely the structure of the test pieces compares with that of the boiler itself and if this is very close, it can reasonably be supposed that the boiler weld would behave as the test pieces under test. The test pieces are then tested by the usual methods and finally tested to destruction. This affords an excellent indication as to the probable behavior of the boiler.