Non Destructive Testing – NDT Inspection Methods at Work
Non Destructive Testing (NDT) or Non Destructive Inspection as it is best known is often a variety of techniques that enable the testing of materials without needing to damage or restrict the material in anyway. In practice NDT allows various industries to check the condition of apparatus including boilers, tubes, pipes, heat exchangers etc. without degrading it of course, if necessary, without taking systems offline or upsetting finely calibrated equipment.
NDT is used throughout a number of industries including chemical, petroleum, power, bulk storage & offshore, amongst additional. Typically NDT services are utilized within a written scheme of examination, spec gauges (calspec.com.au) which ensures regular tests are carried out on equipment as a way to maintain safety and stop failures. In practice the level of NDT carried out in different industries varies widely, and it is not unusual for testing to simply be done each time a failure occurs.
Recently employment involved being called over to inspect tube leaks occurring from the client’s main condenser, the tubes were not as a result of be replaced for 2 years, and had forced the system offline on multiple occasions. The leaks can’t be isolated to 1 area, so a complete inspection was ordered as a way to assess the situation and plug the leaks.
The situation was remedied and also the condenser remained online without incident before the next scheduled shutdown. Situations like these could be avoided, and whether this became the situation above or not, regular inspections can keep units online preventing loss in revenue from reduced capacity, in addition to make sure the safety of everyone operating in your neighborhood.
Inspection of plants usually involves a number of different methods to fully assess flaws. Ultrasonic can often be used to sure up tests performed via other strategies to example. This helps not waste time and money by using cheaper, quicker ways to have an thought of where the flaws are, before investigating them more thoroughly.
Some of the very common techniques used include;
LFET – Low Frequency Electromagnetic Technique, originally developed to inspect tanks floors, scanners have been developed for most applications.
RFET – Remote Field Electromagnetic Technique, designed to quickly and accurately inspect ferrous tubing from inside.
ECT – Eddy Current Technique, developed to test nonferrous metals, though expanded to also include ferrous metals via mag wave technology.
BFET – Balanced Field Electromagnetic Technique, used instead of eddy current and is also considerably quicker than other methods such as dye penetrant and magnetic particle, this might be used virtually anywhere cracking is a concern.
Ultrasonic Inspection – Often useful for thickness measurements, as well as to sure up readings via other methods.