NDT is a short name used for ‘Non-Destructive Testing’ which is used for examination, inspection, and testing of welding section, material object and parts. here in this post introduction about NDT methods.
Introduction of NDT
The philosophy that often guides the fabrication of welded assemblies and structures is “to assure weld quality.” However, the term “weld quality” is relative. The application determines what is good or bad. Generally, any weld is of good quality if it meets appearance requirements and will continue indefinitely to do the job for which it is intended. The first step in assuring weld quality is to determine the degree required by the application. A standard should be established based on the service requirements.
“Whatever the standard of quality, all welds should be inspected.”
Standards designed to impart weld quality may differ from job to job, but the use of appropriate examination techniques can provide assurance that the applicable standards are being met. Whatever the standard of quality, all welds should be inspected, even if the inspection involves nothing more than the welder looking over his own work after each weld pass. A good-looking weld surface appearance is many times considered indicative of high weld quality. However, surface appearance alone does not assure good workmanship or internal quality.
Non-destructive examination (NDE) methods of inspection make it possible to verify compliance to the standards on an on-going basis by examining the surface and subsurface of the weld and surrounding base material. The growing use of computerization with some methods provides added image enhancement, and allows real-time or near real-time viewing, compare active inspections and archival capabilities. A review of each method will help in deciding which process or combination of processes to use for a specific job and in performing the examination most effectively.
NDT is a cost effective and reliable technique in a wide range of applications which aids in the delivery of quality products and cost effective plant maintenance. Selecting the appropriate technique for a particular application requires care and understanding since all NDT techniques have limitations that must be well understood to ensure the desired reliability of inspections. Managers, Supervisors, Engineers and Technicians often have a requirement for the use of Non-Destructive Testing (NDT) techniques to maintain their plant & equipment.