How to Maintain Penetrant Testing System Performance

  •  

Learn how liquid penetrant testing products lose performance over time and what you can do to ensure penetrant test reliability

November 7, 2017  |  by Cheri Stockhausen, Product Applications Manager

Penetrant In an Dip Tank

 

Peak penetrant testing system performance is highly dependent on the integrity of the penetrant materials.

Although penetrants are carefully formulated to withstand the abuse and rigors of the industrial applications, any material is susceptible to contamination and degradation—and penetrant materials are no exception.

 

Causes of Liquid Penetrant Contamination

Some facilities apply penetrants on a one-time basis; others store penetrants in closed tanks or containers until used. However, most facilities use the immersion method, in which excess material is allowed to drain back after application to the part.

With the immersion method, tanks often are open to the environment, which increases the possibility of contamination. Used penetrants should be checked periodically for color or consistency changes to ensure acceptable performance for the inspection process.
 

Water

This is the most common contaminant and can result from careless rinsing, leakage from pipes or prewashed parts that are not fully dried. Water is not harmful until the water tolerance of the penetrant is met.

Dirt, soil and insoluble solids

Improper cleaning or allowing matter to fall into a tank can cause contamination.

Organic material

Oils, lubricants, paints, greases and organic solvents such as gasoline, cleaning solvents and degreasing fluid can cause contamination if not properly pre-cleaned. Although penetrants can absorb large amounts of oils and solvents, fluorescence will be decreased and washability will be affected.

Alkaline cleaners and acid

These are the most serious contaminants, alkaline cleaners and acid can destroy fluorescence upon contact. Also, some alkaline cleaners contain metasilicates, which can prevent penetrants from entering a crack.

 

Causes of Penetrant Degradation

Contamination isn't the only cause for penetrant performance to decrease over time, degradation can also play a role if you begin to see a decline in penetrant efficacy.
 

Heat

In some cases, heat can be used to speed up penetration. However, prolonged exposure to temperatures over 140°F (60°C) can reduce the fluorescence of penetrants. Temperatures over 250°F (121°C) will destroy fluorescence completely.

Evaporation

Penetrants stored in open tanks will undergo continuous evaporation, especially if they are stored in large tanks and exposed to warmer temperatures. Evaporation causes an increase in viscosity, which increases the dwell time, thus increasing labor time and inspection costs.

Faulty equipment

Un-calibrated or faulty equipment and accessories also can compromise penetrant systems. For example, drying oven thermostats or controls that are improperly set can lead to incorrect oven temperature readings. Also, water-pressure gauges can malfunction or output from black light bulbs can be reduced as bulbs age.

 

Effects of contamination and degradation will depend on the type and amount of contamination, but regular testing of penetrant materials is critical to finding problems and maintaining performance. Any changes in color, consistency or performance should be addressed immediately to ensure consistent, reliable inspection results.

 

Testing Options and Guidelines

Magnaflux recommends all users perform regular checks on in-use penetrants to comply with industry standards, ensure the conformance of penetrant materials and maintain the quality of penetrant system performance in aerospace inspections.

Regular testing also helps establish the point of performance loss and material failure.

Learn more about Magnaflux's PeneCert Test Service for Liquid Penetrant Testing

 

Penetrant system testing can be performed in-house or through an external service. ASTM E1417 has established standards for performance checks for in-use materials.

Read our blog on the different types of testing for liquid penetrants

 

Facilities which do not have the instrumentation or capacity required to perform testing on site can take advantage of Magnaflux PeneCert testing services for liquid penetrant, emulsifier and developers.

PeneCert uses state-of-the-art equipment to provide certification of compliance of in-use materials to various standards, testing is completed in just a few days and test results are emailed to the customer for immediate notification.

 

Contact Magnaflux customer service to learn more about PeneCert test services and annual subscription options

Want to stay up on the latest NDT insights and articles from Magnaflux? 

Subscribe to Magnaflux updates above to get fresh news delivered to your inbox once a week.

Please wait while we gather your results.

Related Blog Posts

Liquid Penetrant in Dip Tank

How to Maintain Penetrant Testing System Performance

Learn how liquid penetrant testing products lose performance over time and what to do to ensure penetrant test reliability.

Read More...

Magnaflux Penetrant Inspection

Understanding Type-, Batch- and In-Use-Testing for Liquid Penetrants [Case Study]

Learn the differences between type testing, batch testing and in-use testing for NDT liquid penetrants.

Read More...

Magnaflux Penetrant Inspection

Higher Sensitivity Penetrant Improves Inspection Quality [Case Study]

In this case study, we help an aerospace customer improve inspection quality and consistency with two Magnaflux penetrants

Read More...

Magnetic Particle Crack Comparison

How Brightness and Contrast Impact NDT Inspections

How perception and vision can have a significant impact on probability of detection in non-destructive testing inspections.

Read More...

Dye Penetrant Infographic

The Ultimate Guide to Visible Dye Penetrant Testing [Infographic]

Some handy tips for beginners who are new to visible dye penetrant testing or NDT pros who want an easy reference guide.

Read More...

Magnaflux Penetrant Testing

Exposing 10 Common Misunderstandings about Penetrant Testing

We reveal common misperceptions about liquid penetrant inspection we’ve seen in the field in recent years

Read More...

Magnaflux Water Washable Penetrant

Water Washable versus Post Emulsifiable Penetrant – Which is Right for You?

Learn the differences between water-removable and non-water-washable liquid penetrant to figure out which is right for you

Read More...

AMS 2644 Penetrant Sensitivity Levels

A Guide to AMS 2644 Penetrant Sensitivity Levels

Understand fluorescent liquid penetrant sensitivity levels and how to find the right one for your application

Read More...

Penetrant Testing Demo

How to Do Fluorescent Liquid Penetrant Testing [Video]

Watch a demonstration of the penetrant inspection method according to ASTM E1417, including basic steps for NDT with an AMS 2644 Type 1 penetrant.

Read More...

Leak-Detection-Penetrant-Testing

Leak Detection with Penetrant Testing Process

Read more about using penetrant testing products to inspect for leaks by using fluorescent or visible/colored penetrant to enhance visual detection of leaks.

Read More...

The following required items were not provided or are in the wrong format. Please provide the required responses and submit again:

Name:
  Please enter your name
  Please enter a valid email
Comment Title
Comment: 250 characters left
  Please enter a comment

Magnaflux

155 Harlem Avenue
Glenview, IL 60025, USA
Telephone: +1 847-657-5300
Fax: +1 847-657-5388
Contact Magnaflux Customer Service

Select Your Country North America Mexico Brazil China Europe Russia India New Zealand, Australia, Japan, Southeast Asia
© 2016 Magnaflux - all rights reserved.
top