Skip to main content

What is Non Destructive Testing in Welding (NDT)?

Non Destructive testing is also called NDT Test, Non-Destructive Inspection, Non-Destructive Test, Non-Destructive Evaluation, Non-Destructive Weld Testing, NDT Inspection, etc.,

  • NDE – (non-destructive examination or evaluation)
  • NDI – (non-destructive inspection)
  • NDT – (non destructive testing)

Non-destructive inspection is a kind of group consisting of a variety of non-destructive examination or evaluation methods, these are the methods by which surface and internal defects of a material, components, etc. are detected.

What is non destructive testingThere are many types of NDT inspection techniques in which examination or evaluation of materials is done without damaging the property, structure of materials, components, etc.

Why use Non Destructive testing methods?

Due to cracks, defects, etc. in any material, parts, machine, welding joint, etc., there is a possibility of an accident in the future, therefore cracks, defects, etc. are detected and removed in advance by NDT methods So that further accidents can be avoided and the ongoing works are not hindered,
NDT is used in power plants, turbines, piping, welding, casting, forging, structures, construction, etc., NDT methods are used because of saving money and resources, efficiency and quick valuation of assets, safety, as they are not harmless to people, accuracy, etc.

Nondestructive testing codes and standards creator

These are the most common organizations in the world to create non-destructive inspection codes and standards for the use of NDT methods,

  • API – (American Petroleum Institute),
  • ASME – (American Society for Mechanical Engineers),
  • ASTM – “(American Society for Testing and Materials)”,
  • ASNT – “(American Society For Nondestructive Testing)”,
  • CSA Group – (Canadian Standards Association),
  • COFREND – (French Committee for Nondestructive Testing Studies),
  • CGSB – “(Canadian General Standards Board)”, etc.

Any welding engineer, production, QA/QC, engineer, inspector, and technician working in welding or fabrication, etc company should know about non destructive testing.

Materials, Component Inspection Methods

These two techniques are mainly used to test or evaluate any material, components, etc., including destructive testing methods and non-destructive testing methods,
Destructive Testing Methods and Non-Destructive Test Methods Both of these methods include other types of methods, which are determined according to the material, components, company’s production, customers, codes and standards, etc.
Click and Read our Destructive Testing article.

NDT Testing Methods

The following methods are mostly used in the testing of non-destructive inspections –

Other commonly used non-destructive inspection methods

  • Eddy Current (ET)
  • Acoustic Emission (AE)
  • Leak Testing (LT) etc.,

Materials, components can be reused after performing non-destructive testing methods on any materials, components, etc. This method does not damage the property of the components,

What is non-destructive testing?

NDT inspection in which an NDT technician examines or evaluates materials, components, etc., with training, knowledge, experience in any NDT methods, After carrying out non-destructive testing methods on any material, components, etc., that material, components can be reused,
In this, NDT technicians, NDT inspectors, and NDT certified persons follow the non-destructive testing standard, specification, code, norms, etc. at the time of NDT inspection,
In NDE non destructive examination, NDT technicians and NDT inspectors have levels according to different methods, including level 1, level 2, and level 3, all NDT levels differ according to the level of work.

Types of NDE methods

NDT is a group of many types of techniques, in which you will see many types of NDT methods in a single technology, It also comes with advanced NDT methods, in which you will get to see different NDT methods,
There are many methods in this kind of non-destructive inspection, but there are main 5 methods of NDT which are used in all companies, you will find these NDT testing methods given below in all companies in which-
Visual inspection (VI)
It is an NDT method in which NDT technicians and NDT inspectors can detect visible defects on the surface of any material and object with their open eyes and with the help of any visual inspection equipment.
Liquid penetrant testing
It is a non-destructive test method in which organic colored penetrant liquid is used, due to which it is called liquid penetrant test,
In this, open to surface defects and discontinuities of any material and object are detected, it works on the capillary action of NDT inspection liquid penetrant.
Magnetic particle inspection (MPI)
This is also a non destructive testing method in which magnetic iron particles and magnetic field are used, In these two types of iron particles are used, dry or wet, for the magnetic field a magnetic field is created by using some magnetic techniques,
Magnetic particle inspection is performed to detect subsurface defects and imbalances of a material. know more about magnetic particle inspection
Ultrasonic testing (UT)
It is a non-destructive evaluation method in which high-frequency sound waves are sent from an ultrasonic machine by a piezoelectric transducer into a mechanical wave across materials, components, etc., and received back from a mechanical wave into an electrical wave. by ultrasonic machine,
In ultrasonic testing, if there is a defect and discontinuity in the middle of wave travel, the position and discontinuity of that defect are determined by the travel time interval of that wave,
In this method, any material, thickness of components, internal imbalance location, size, etc. is detected.
Radiography testing (RT)
It is a highly efficient non-destructive evaluation method, in which X-rays method are performed like human X-rays, but it is an industrial radiography test X-ray method, in which high gamma or X-radiation rays are used in any material, components,
Radiography testing is a non-destructive weld test method that visually shows the internal incompatibility of any materials, components, etc. on X-ray film,
this method requires highly experienced NDT radiographers and NDT technicians having knowledge of radiography cameras, instruments and radiation sources of the camera, etc.
This article has been written for some basic information related to non destructive testing, you can subscribe us to read other article updates related to our non destructive inspection.