Non-Destructive Evaluation Mean?
Non-destructive evaluation (NDE) is a method of material testing that is non-invasive and doesn't affect the future usefulness of the material. NDE not only locates the defect, it also measures the size, shape and orientation of the damage and can be used to measure the materials physical properties. Ultrasonic, thermographic, radiographic, magnetic particle testing and optical methods are used for NDE.
Detected flaws can be rectified using trenchless rehabilitation methods such as mechanical spot repair, pipe bursting and thermoformed pipe.
Trenchlesspedia Explains Non-Destructive Evaluation
NDE can be used for a variety of purposes such as flaw detection and evaluation, leak detection, structure and microstructure characterization and measurement of stress and strain dynamic response. Pigs are used to carry the testing devices and flow along with the flow of liquid or gas that the pipe carries. The pigs are equipped with a small computer that collects, stores and transmits information as it passes along.
Most pigs use magnetic flux leakage (MFL) method while others use ultrasonic and other methods to perform the inspection. Sometimes remote visual inspection using cameras mounted on robotic crawlers are also used to carry out NDE.