Fluorescent penetrant inspection (FPI)

Accurate inspection without damage

With penetrant crack inspection (FPI), we reveal surface defects such as porosity, cracks, and micro-cracks in your material without causing any damage. We use special penetrant liquids for this purpose. 

During penetrant crack inspection, the penetrant liquid is drawn into any porosity and cracks by capillary action. This makes even the smallest defects visible. This type of inspection was originally developed for the aerospace industry and is now the preferred method for detecting surface defects in metals and non-porous materials. 

We apply this technique with a strong focus on precision, specifically for aluminum products within, among others, the aerospace industry. By using fluorescent penetrant liquids—the most sensitive variant of this technique—you are assured of maximum quality. With both our immersion and electrostatic installations, we can thoroughly inspect small products (up to 850 × 350 × 300 mm) as well as larger components (up to 4000 × 3000 × 500 mm) for surface defects. 

How does penetrant crack inspection work? 

• Preparation: We degrease and pickle the products and, if necessary, mask critical fits and threaded holes. 

• Application of penetrant liquid by means of an immersion or electrostatic process. The liquid penetrates deeply into any cracks via capillary action. 

• Removal of excess penetrant liquid. 

• Drying. 

• Application of developer: This absorbs the penetrant liquid from any defects, making them clearly visible. 

• Inspection and reporting: We carry out a detailed evaluation of any indications, including full reporting. 

• Cleaning: Finally, we thoroughly clean the products. 

Penetrant crack inspection is essential for aerospace applications and industrial products where safety and reliability are paramount. 

This process is certified by NADCAP and various OEMs. 

Curious about the possibilities of penetrant crack inspection for your project? We would be happy to advise you. 

Please contact our Sales department: sales@surfacetreatment.nl