Liquid Penetrant Testing

Detecting Flaws on Non-porous Surfaces

Liquid penetrant testingLiquid Penetrant Testing is also known as liquid penetrant inspection (LPI), dye penetrant testing, penetrant testing (PT). NDT Penetrant Testing is reliable for detecting surface-breaking flaws in materials with a non-porous surface such as metals, plastics, glass and ceramics.

The NDT PT method relies on a fluorescent or visible dye penetrant seeping into a flaw such as a lap, seam, fracture or crack. This forms a surface indication that can be evaluated under special lighting.

Penetrant Testing to Meet Your Requirements

Laboratory Testing Inc. is NADCAP and A2LA (ISO 17025) accredited for liquid penetrant inspection and provides a certified test report with each order. The Lab is located in the Philadelphia, PA (USA) area and also offers the following:

  • Fluorescent and Visible Dye Penetrant Testing
  • Orders are processed with the highest quality Magnaflux testing materials
  • Water-washable and post-emulsifiable fluorescent penetrants in sensitivity levels 2, 3 and 4 are available to meet your specification or application
  • Dye penetrant inspectionCertified NDT technicians:
    • ASNT SNT-TC-1A
    • NAS410
    • MIL-STD-2132
    • Pratt & Whitney PWA-NDTQ
  • Testing for products up to 25 ft. in length

Test Methods/Specifications

  • ASTM E1417
  • ASTM F601
  • MIL-STD-6866
  • MIL-STD-271
  • MIL-STD-2132

The Liquid Penetrant Testing Process

Before performing a liquid penetrant test, the surface of the test material must be thoroughly cleaned to remove any contaminants that could prevent the penetrant from entering flaws. Etching may be required if mechanical operations such as machining, sanding, or grit blasting have been performed on the item.

A fluorescent or red visible dye penetrant is applied to the cleaned test material, then it is left on the surface for a sufficient time to allow penetrant to seep into a defect. After this dwell time has elapsed, the excess penetrant is removed from the surface. Next, a thin layer of developer is applied to the item to assist in drawing penetrant trapped in flaws back to the surface where it will be visible as indications. The test item is viewed under special lighting so any indications can be evaluated according to the liquid penetrant testing specification or customer requirements. When performing fluorescent penetrant testing, indications must be viewed under darkened conditions with a high-intensity UV lamp.

LTI’s equipment includes three large liquid penetrant testing dip tanks, a 25 ft. dwell tank for pipe, tubing, bar, etc. and a large testing room with three high-intensity black lights.

Read a full description of the Penetrant Testing process.

LTI Capabilities

  • Dye Penetrants – Magnaflux brand
    • Visible dye
    • Fluorescent – water-washable and post-emulsifiable penetrants in sensitivity levels 2, 3 and 4
  • Products Tested – metals and other non-porous materials
  • Size Availability¬†– ability to test materials up to 25 feet long
  • Certified NDT Level 2 and Level 3 Inspectors – evaluate all test results

Request a Quote Contact Us

Tools & Resources

Accreditations Customer Portal Approvals Case Studies

» Watch Our VIDEOS to learn more!

Quality & Convenience

  • A2LA and NADCAP accreditations
  • ISO 17025 certification
  • Same day, next-day, 2nd-day Rush Services
  • Secure Portal to track orders and get certifications
  • Fast Certified Reports sent by email

Customer Testimonials

“Thank you for allowing me to visit your facility and witness a micrometer calibration first-hand, it helped me understand the concept so much better. It is clear that LTI is a wonderful group of people to work with and they operate in a true team environment. Your staff has gone over and above the call of duty to help Superior Tube. We truly appreciate your help.”

Deb Rosenberry,
Superior Tube Inc.


Get the LTI Newsletter

Sign Up Now

Connect with us!

LTI on Facebook LTI on Twitter LTI on LinkedIn LTI on YouTube LTI on Google+

We Accept:

VisaMasterCardAmerican Express