Spotlight on Welding Inspection in Construction
Perhaps the simplest test of all when it comes to welding inspection in Hong Kong is a visual examination. This can be carried out prior to construction, during construction or as an evaluation following the completion of work. The strength and integrity of welds are important to determine, and while there are destructive tests where a section of welded material is broken off, there are also a range of non-destructive tests (NDT) available.
One NDT utilises x-rays or Gamma-rays to produce an image of materials both with an exterior and an interior view. This can be used as a comparison aid to identity defects. While this is an accurate test, multiple comparisons over time may be required to truly work out the extent of an issue.
Soundwaves can also test welding quality, with these signals detecting where flaws are present through disturbances in the frequency. This method also notes where a disturbance is and can be used to ascertain the extent of the problem.
Welding requires highly skilled expertise and inevitably, by the very nature of the amount of welding that is required in even the most standard builds, issues and defects can arise. It is preferable to deal with these as easily and efficiently as possible to avoid extensive repairs that can be not only costly but highly inconvenient and time-consuming.
A tried-and-tested method for welding inspection is a so-called liquid penetrant test. Powder is applied over a liquid on the surface to be examined. This powder absorbs any excess liquid and what is left is a clear indication of where there is any discontinuity in the surface and where breaks are.
Magnetic particle testing is also used to test steel, and can not only highlight where surface defects are present but also sub-surface ones. A distortion is created in the magnetic field where a problem is present on magnetised materials. In turn, this creates a pattern that shows up any irregularities.
Welding tests ensure that welding practices are in line with professional levels and attain a high standard. These tests can be useful for welders too, so that they are able to carry out their work more proficiently. Weld cracking and lack of weld fusion and fatigue issues often need to be addressed, while each industry and project has its own individual demands.