Liquid Penetrant Test (Leaving Cert Engineering): Flashcards

Non-destructive testing - finds flaws without damaging components

Cracks, voids, inclusions

Parts under extreme stress need integrity over many flight hours

Highlights surface cracks difficult to see with naked eye

Liquid penetrates surface cracks via capillary action

Clean material - remove oil, grease, dirt particles

Spray liquid dye over surface - penetrates into cracks

Wipe excess liquid away, leaving dye only in cracks

Apply developer spray - draws dye from cracks for contrast

Inspect flaws - decide to repair, replace, or leave component

UV sensitive penetrant glows under UV lamp in dark room

Better visibility of small defects