Dye penetrant inspection works on various materials

Dye penetrant

Non-destructive testing is vital for an array of reasons. For example it can detect flaws that could affect the strength and performance of different materials, welds, and products. At Format NDT Ltd we have a lot of experience in this area. We can provide different tests to cater for a variety of needs. One of the most dynamic options we offer is dye penetrant inspection.

What is it?

DPI, also known as liquid penetration inspection (LPI), is a method of finding flaws that break the surface. This could be a crack in a metal sheet, a seam in a weld, or pores or laps. The testing is non-destructive and won’t cause any harm to the specimen.

How does it work?

The idea with this form of NDT is that the dye or liquid will seep in if there are any discontinuities in the surface. As a result, it can provide a really good idea of the location of a flaw. With fluorescent dye or liquid the test can show even fine flaws when the specimen goes under a UV light.

Before it is possible to test a specimen, it is important to clean it. This will remove anything from the surface that could affect the results, including things like dirt and grease. Then it is a simple case of adding the dye or liquid. Generally inspectors do this by spraying or brushing it on.

Next, the penetrant is given time to soak in. Afterwards the specimen is cleaned of excess penetrant. Finally, a developer will draw any dye or liquid out that was trapped in flaws. This should show up as a visible indication on the surface. If necessary, the tester can use UV light to detect the lines.

Why is dye penetrant a good method?

The biggest advantage of this method of NDT is it is suitable for all kinds of materials. For example you can use it effectively on both ferrous and non-ferrous metals. You can also use it on ceramics and plastics that are non-porous.

DPI is a cost effective method of testing and is also incredibly convenient. You can use it in almost any setting and don’t need electricity or water. In addition, there are a lot of different dyes and liquids to use, giving people more options in terms of the sensitivity.

Talk to us about testing

If you need to arrange non-destructive testing, you can rely on us to help. We have experience with dye penetrant inspection and various other methods. Our team are also experts with the very best qualifications.

You can contact us if you would like to book DPI or any other type of testing. We can conduct tests on-site or in-house.