Liquid Penetrant Inspection (PT)

Liquid Penetrant Inspection (LPI), also known as Dye Penetrant Inspection (DPI), is an effective method for detecting fine surface cracks and defects in non-porous materials. This technique works by applying a visible or fluorescent dye to the surface of a component. The dye seeps into any cracks or voids, revealing their size, shape, and location.

LPI is widely used to inspect both ferrous and non-ferrous materials, including:

• dummy Metals and ceramics
• dummy Plastics and glass

1. Application: A visible or fluorescent dye is applied to the clean, dry surface of the part.


2. Penetration & Removal: The dye is drawn into any cracks through capillary action, and after a set period, the excess dye is removed.


3. Development & Inspection: A developing agent is applied, pulling the dye from defects, making them clearly visible for inspection.

LPI is a fast, affordable, and effective method for identifying surface defects like:

• dummyCracks, seams, laps, laminations, and lack of fusion in castings and forgings.
• dummyStress cracks in aircraft structures.
• dummyIntegrity testing of welds in fabricated structures.

Our experienced technicians carefully assess surface conditions, material type, and defect characteristics to customize the inspection process for maximum accuracy.

• dummy Cost-Effective – Simple and ideal for high-volume inspections
• dummy No Specialized Equipment Needed (except for fluorescent inspections)
• dummy Highly Sensitive – Detects very fine surface flaws
• dummy Versatile – Works on almost any non-porous material
• dummyQuick & Efficient – Ideal for high-volume inspections
• dummyLarge Area Coverage – Can examine large surfaces in one process

• dummySurface preparation (degreasing) is required before inspection
• dummySome penetrants are difficult to remove, leading to false readings
• dummySurface imperfections may cause spurious indications
• Fluorescent penetrant inspections require special UV lighting

• dummyProper handling of penetrant chemicals is essential
• dummyUV light exposure should be minimized to prevent health risks

With our extensive experience in high-volume inspections and on-site testing, we ensure accurate, efficient, and reliable results for all manufacturing and structural applications.

Contact us today to discuss your inspection needs!

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