Non-destructive method


This guiding principle provides a guidance on the measures necessary to ensure the safe completion of non-destructive testing (NDT) procedures.

This document does not include technical specifications for NDT, as all inspectors must be properly trained for such procedures, beforehand.


Pressure vessels, storage tanks and other components (including pipework and valves) are designed to contain liquids, gases and solids. Leaks or the mechanical or structural failures of such equipment may result in a major accident on-site.

Non-Destructive Testing (NDT) is the application of measurement techniques to identify damage and irregularities in materials/equipment. NDT often provides the only method of obtaining information about the current condition of equipment.

If done well, NDT can provide useful information to assist in the management of quality and safety. If inappropriate NDT is applied or it is not applied correctly, then the results are likely to give a false impression of the integrity and safety of equipment. Six main types of NDT techniques will be explored, these include: radiography, ink/dye penetrant, magnetic particle inspection, ultrasonic testing, electro-magnetic testing (eddy currents) and visual inspections. The hazards included in carrying out these techniques will be elaborated on below.


  • NDT must be properly documented and authorized by a work permit where necessary (radiography).
  • NDT inspectors must be specifically trained to carryout NDT procedures.
  • NDT procedures should be properly isolated/cordon off to prevent exposure/injury to others.
  • Smoking is prohibited during NDT procedures. Designated smoking areas should be used.
  • Mandatory job specific PPE should be enforced during all NDT procedures.

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Non-destructive testing