Non-Destructive Testing (NDT)
To ensure that the all the welds are to specification, we have a full NDT department on site.
Using the Fluorescent Penetration Inspection (FPI) process, we are able to detect much smaller flaws in welds or cold formed section materials than other dye penetrant inspections. This is because the penetrant emits a yellow glow which can easily be picked up by our skilled inspectors.
Due to this high sensitivity to small defects, FPI is an ideal procedure to ensure the weld quality of the exotic metals we use, such as inconel and titanium, which have very small, tight pores and smooth surfaces.
As FPI is a non-destructive inspection process, the inspected parts are not harmed or damaged during inspection.
The inspection process at GoodFabs is tailor made to ensure that high quality parts are delivered to our customers while still maintaining a quick turnaround.
A full NDT inspection consists of following steps:
1) Cleaning of the part
Before inspection can occur, the parts are thoroughly cleaned to remove any oil, dirt or contamination.
2) Application of the penetrant
The fluorescent penetrant is carefully applied to the part and allowed to seep into any possible defects or cracks. The time taken for the penetrant to seep into these defects is called the 'dwell' time and can depend on material and sizes of the inspected components.
3) Removal of excess penetrant and optional blow off
When the 'dwell' time has passed, the inspector carefully removes any excess penetrant from the outer surfaces using a lint-free cloth and a special cleaner. Or partial blow off to ensure the drying efficiency.
4) Oven drying
The items are placed in an oven for no longer than 5 minutes or until dry, this is carefully monitored by the inspector. At GoodFabs, this process is improved by slowly increasing the temperature during this time in a custom built oven.
5) Application of the developer
When the excess penetrant is removed, a contrasting developer can be applied to the surfaces. This developer can act as a non-fluorescent background to visualise any defects even better.
6) Inspection
The actual inspection happens in a dark room with ultraviolet radiation where the fluorescent lights up. Our qualified inspector then carefully inspects the parts and all its surfaces and records any indications he notices and marks these. The time of inspection is very important. If not enough time is allowed, the potential issues might not be visible enough; if too much time is allowed, there might be too much bleeding to make a good interpretation of the potential faults.
7) Final cleaning
After the NDT inspection process, the parts are fully cleaned to ensure no residue remains and the parts can safely be moved on to a next inspection process or packed for delivery to the customer.