NDT Testing is a wide range of evaluation technique employed in a number of industrial sectors to determine integrity of a material, components or product without destroying. The terms Nondestructive examination (NDE), Nondestructive inspection (NDI), Non Destructive Testing (NDT) and Nondestructive evaluation (NDE) usually are well known words used to explain this quality control technique. Since we do not have to permanently break the part being examined, it is extremely effective method which is used as important tool by quality assurance personnel to save both money and time in product reliability assessment. Typical NDT methods incorporate ultrasonic, magnetic-particle, magnetic flux leakage, leak testing, liquid penetrant, radiographic, visual and optical inspection, eddy currentestinut.NDT methods incorporate ultrasonic, magnetic-particle, magnetic flux leakage, leak testing, liquid penetrant, radiographic, visual and optical inspection, eddy current testing etc.

Nondestructive testing is needed extensively in all kinds of operations needing the use of machinery and piping technologies, cross country pipeline both of above and underground, off-shore platform, refineries, petrochemical, ship building, aviation, and nuclear plants. Determining product or service reliability in the process of any component is the objective of NDT, to guard life and property.

Metal Welding process is commonly used to join with each other metal surfaces, and welds are essentially the most common NDT test subjects. Cracking due to strain and fatigue, lack of fusion, lack of penetration, slag, porosity and undercuts are very common weld discontinuities are associated with the weldment .A number of echniques are widely-used to perform the inspection of welds. Liquid penetrant and Eddy current testing would be used to detect surface defects wherein magnetic Particle radiography, ultrasonic is going to be used to discover subsurface discontinuities or even hidden weld defects.