NDT Flashcards
What are the five most common methods of NDT?
Visual inspection, dye penetrant, magnetic particle, ultrasonic, radiography
What are the two methods of testing materials and assemblies?
Destructive testing and non destructive testing
What is the only method that does not require any training?
Visual inspection
What are advantages of liquid penetrant testing?
Very portable, and easy to do, does not require ferromagnetic materials, inexpensive
What are limitations of liquid penetrant ?
It can only detect imperfections that are open to the surface. Extremely rough or porous surfaces, are likely to produce false results.
How far around a test area should be cleaned for a liquid penetrant test?
At least 1 inch beyond the area being tested
What is dwell time?
The waiting time for the dye to penetrate crevices open to the surface
How does the dye penetrate the flaws?
Through capillary action
What two inspection methods use a UV light for inspection?
Dye penetrant, and magnetic particle
What is used when only a small area is to be tested?
Solvent removable penetrant a
What is direction of magnetic flow?
South to north
How deep subsurface cracks can mag particle detect?
Not greater than 1/4” deep
How must magnet be oriented to detect a flaw?
The magnetic field must be oriented at 90° to the direction of the defect
How can the inside of the vessel be NDT tested
Dye penetrant can be sprayed on the inside and developer on the outside
What are the two general types of sources used in industrial radiography
GammaRay and x-ray
