When do we Inspect the Welding?

What is the ideal time to inspect a welding? Inspection is most crucial in any welding procedure, having an idea of when to inspect, what to lookout for and the criteria that is acceptable for a particular code or specification. These are just a few things that we have to keep in mind at the time of inspecting a weld and has to be done prior to, in the course of and at the end of a welding process. There are some things that have to be checked before welding commences. For instance, we have to ensure that we have prepared the metal which has to be weld properly and following all the drawings.

In case there is a specification for the welding process, we have to see that the configuration of the joint and the material prep is in compliance with that of the document. It is important to check the material and see that it both clean and free from any grease, oil, paint or rust or other surface impurities and other residue which can affect the quality of the weld.

Special attention should also be taken to use the prescribed welding rod as specified in the welding procedure. See and ensure that the base material coincides with both, the bill of materials and the requirements on the drawings. We should not start welding unless factors like correct shielding gas and any other welding variables which influence the quality are perfect – wait till everything is approved and making sure that the welder is well qualified. We have to remember certain other important factors while the welding process in going on too!

These would include checking and making sure that there are no discontinues in the weld ensuring that proper cleaning is done in between the individual passes. Check and ensure that the right inter-pass temperatures don’t exceed and make sure that there are no cracks present. At times, additional inspections may be required over and above the regular visual inspections while in the process of creating a weld. For instance, in some cases a dye penetrant inspection or a magnetic particle inspection may be necessary after the initial root pass of certain joint configurations.

Once we have finished with the welding we should do a last, final inspection of the weld to ensure that it matches or even exceeds all of the requirements given I the drawing and the specifications of the welding procedure. Ensure that both, the weld and the base materials are well bonded. Make certain that the porosity doesn’t go beyond the accepted criteria. All kinds of size requirements must be checked only with the proper tool or gauge and if any post weld heat treatment is done, the weld should again be checked. In case any kind of non-destructive testing is required, they should also be done only in accordance to specifications.

For instance, in case the drawing demands RT at the tail of the welding symbol, it means an x-ray or a radiographic testing of the weld has to be performed. If a tail of the weld has a PT symbol, then it requires a permanent test and an MT symbol at the tail of the weld calls for a magnetic particle testing. In case the drawing cites the need of a CWI, then the part has to be inspected by an inspector who is certified following all the code requirements.

Welding inspections are very important at all three stages of a weld – before, during and after! It is all the more important for the welder to realize the requirements for an inspection, since on raising his hood and removing his goggles, he will have the first opportunity of inspecting the weld so naturally, they must be our primary line of defense when it comes to addressing issues on quality control.

Check out on YouTube channel (www.youtube.com/longevitywelding) or the Longevity website (www.longevity-inc.com) for more information and details regarding the equipments for the various cutting and welding procedures. Longevity has all the right machines for your exact requirement and application. So just go through and choose what best suits your materials, products and requirements.