Dye Penetrant Inspection (DPI)

DPI---Dye Penetrant InspectWe offer Dye Penetrant Testing on site or in one of our laboratories using either fluorescent or colour contrast applications as a one off test or batches of machined parts. This type of testing is commonly used on welds, machined parts, castings and forgings.

Also known as Dye Penetrant Inspection (DPI), Liquid Penetrant Inspection (LPI) or Fluorescent Penetrant Inspection (FPI); it is a method that is used to reveal surface breaking flaws by bleed-out of a coloured or fluorescent dye from the flaw.

The technique is based on the ability of a liquid to be drawn into a “clean” surface breaking flaw by capillary action. After a period of penetration time, excess surface penetrant is removed and a developer applied. This ‘draws’ the penetrant from the flaw to reveal its presence. Colour contrast (or “visible”) penetrants require good white light, while fluorescent penetrants need to be used in darkened conditions with an ultraviolet light (also known as black light).

Penetrant inspection can be used on almost any non-porous material. It is essential that the material is carefully cleaned first; otherwise the penetrant will not be able to enter the defect. If surface penetrant is not fully removed, misleading indications will result.

With our capacity, capabilities and our collection and delivery service, we can assure you of a quality service with a fast turn around to assist you in achieving your production commitments.