NDT News

Exposing 10 Common Misunderstandings about Penetrant Testing

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

The liquid penetrant method of nondestructive testing has been used since the 1940’s. But even after being used by generations of NDT professionals, there are still some common areas of confusion or misunderstanding.

Here we set the record straight on 10 misperceptions we’ve seen in the field in recent years.

 

1. The highest sensitivity penetrant is the best penetrant for my application

The best penetrant for an application is the one that finds the right indications with the least amount of money and time. Sometimes this means not using the highest sensitivity penetrant.

While it is true that a higher sensitivity penetrant will produce indications for very small discontinuities, a higher sensitivity penetrant will probably not give you the best inspection results if you only need to find medium discontinuities since you will see far more indications than are relevant to the inspection.

To start selecting a penetrant, review any governing specifications and work procedures for required sensitivity levels.

Take into consideration the surface finish and configuration of the part.

A high sensitivity level fluorescent penetrant is appropriate for smooth, highly machined surfaces. However, a high sensitivity level fluorescent penetrant may leave excessive fluorescent background on a rough cast part, making inspection difficult. 

A lower sensitivity fluorescent penetrant is a better choice for rough surfaces.

 

2. A penetrant indication is a discontinuity

A penetrant indication is the visual results or response of the penetrant test which must be interpreted to determine its relevance.

Penetrant indications must be evaluated by a qualified inspector to determine if they are nonrelevant or relevant.

Nonrelevant indications may be present on parts because of inherent surface roughness or seams. Fingerprints or fibers may also cause nonrelevant indications.

Relevant indications are the result of a discontinuity, or interruption in the physical structure of an object, and are evaluated according to acceptance criteria. After evaluation, the part is accepted as is, reworked or discarded.

 

3. Water washable penetrants are water based

Some water washable penetrants are water based. However, this is not always the case. A penetrant can be water washable and not contain water.

Water-washable penetrants contain surfactants which allow the penetrant to be easily removed from the part surface with water rinsing, regardless of if they are water-based or oil-based.

 

4. Penetrants are only used on nonferrous metals

Penetrants can be used to inspect ferrous and nonferrous metals.

Penetrant inspection will find discontinuities open to the surface on ferrous and nonferrous metals.

Penetrant testing should not be done on porous surfaces, as the pores will act as discontinuities to trap penetrant and prevent accurate inspection.

 

5. Penetrant will be able to penetrate a discontinuity that contains water

Penetrant cannot seep into a discontinuity if it is already filled with water or other liquid.

Likewise, penetrant will not displace or penetrate through paint, particulate, oil or grease.

This is one of the reasons why an important prerequisite for a valid penetrant inspection is to start with properly cleaned and dried parts.

 

6. Tanks and an inspection booth are required for penetrant inspection

Penetrant inspection is easy to adapt to different environments and job sites.

Penetrant inspection systems with stationary tanks and booths are commonly seen in production environments. However, both fluorescent and visible dye penetrants are available in aerosol cans and kits for convenience and portability.

 

Check out our Penetrant Process Guide for a visual reference outlining each step in the various penetrant inspection methods and to learn 5 tips for penetrant testing

 

7. Penetrant is all that is needed to perform a penetrant inspection

At a minimum, penetrant and developer are required to perform a water washable penetrant inspection.

Additional products such as cleaner/removers and emulsifiers are required for solvent removable and post emulsifiable penetrant inspections.

 

8. Special lighting is required for penetrant inspection

Fluorescent penetrants do require inspection in a darkened area with specification compliant UV lighting. The UV lights may be mounted or hand-held for flexibility and portability.

Visible dye penetrants only require adequate white light, typically 100 foot candles minimum, for inspection.

 

9. Penetrant inspection should be the final check in a manufacturing process

Penetrant inspection is useful immediately after any manufacturing process which is known to cause discontinuities. This allows parts to be reworked or discarded earlier in the manufacturing process, which saves time and cost.

Penetrant inspection may sometimes be performed more than once during the manufacture of a part.

The placement of each penetrant inspection process should be optimized to locate manufacturing-induced discontinuities and reduce the amount of scrap or rework done later in the manufacturing process.

 

10. Penetrant inspection can take place at any point in the manufacturing process

As discussed, it is important to perform penetrant inspection after manufacturing operations likely to cause discontinuities open to the surface in parts.

However, care must be taken to perform penetrant inspection prior to mechanical operations that will smear the metal surface. Machining operations such as shot blasting, peening or grinding may close surface discontinuities, which can prevent subsequent penetrant inspections from finding these discontinuities.

Penetrant inspection should take place before machining operations like shot blasting, peening or grinding unless chemical etching can be used between these operations and the penetrant testing to reliably expose the discontinuities.

 

What other common misunderstandings or mistakes have you seen? 
Share your knowledge in the comments section below.

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How to Improve Fluorescent NDT Process Control with LED UV Lighting [Case Study]

In this article, we show how an aerospace OEM manufacturer increased NDT inspection reliability and efficiency with wide-beam, overhead LED UV-A lamps

Mercury-vapor lamps are the biggest culprits when it comes to inconsistent UV lighting. Whether you’re using a hand-held 100W lamp, a larger 400W HID fixture or even low-pressure fluorescent tube lighting, the intensity and coverage of the lamp can change dramatically throughout the day.

Not only do mercury-vapor lamps take time to warm up to full intensity, but any variation in the line voltage directly translates to a change in intensity. Power fluctuations can change from day to day, or even from shift to shift depending on what equipment is running in the plant.

Even with regular maintenance, the intensity of a particular lamp will fade over time as the bulb is used. An inspection booth with both stationary fixtures and hand-held lamps will have different coverage depending on the age of the individual bulbs and when they were last replaced.

The move from mercury-vapor lamps to LED UV lights helps to eliminate these kinds of variations, but swapping out existing lamps with LEDs can bring its own challenges.

Magnaflux is working with our customers to better understand the issues that end-users face. Below, we explain the challenges one aerospace OEM manufacturer faced, and how Magnaflux helped address their challenges.

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Another Happy Graduate of AINDT!

Hey guys,

I just finished my first week and thought I'd share what it has been like. Of course, I'm just assisting on these for now, but once I get my certs, I'll be out there on my own doing this stuff.

Day 1: MT on welds for a piece to be used by a private space exploration company.

Day2: UT lamination scans on large steel plates used for construction of a new ferry.

Day 3: PT on welds for ferry construction; UT shear wave on pipe welds

Day 4: UT thickness gauging the hull of a small freighter

Day 5: UT thickness gauging safety pins on the top of a grain elevator (about 100 feet up, harnessed and dangling off the roof); MT on a repair weld for the boom of a cement truck

Never know what the day will hold for me, and I really like that. No RT, which is unfortunate. We've mostly got maritime customers, but it seems like there is quite a bit of railroad, construction, paper mill, and manufacturing customers, too.

It's a good gig. I'll let you know when another position opens up.

Thanks again for everything,

Morris
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9 Transparently Amazing Facts About X-Rays

9 Transparently Amazing Facts About X-RaysIn 1895, Wilhelm Roentgen, a professor of Physics in Worzburg, Bavaria, was the first to find a way to peer inside the body without surgery. On the evening of November 8, he was experimenting with the conduction of electricity through low-pressure gases using an induction coil and a partially-evacuated glass tube when he accidentally discovered a mysterious ray capable of lighting up a fluorescent screen a few meters away.

On the evening of November 8, he was experimenting with the conduction of electricity through low-pressure gases using an induction coil and a partially-evacuated glass tube when he accidentally discovered a mysterious ray capable of lighting up a fluorescent screen a few meters away.

When he passed his hand between the ray and the screen, he glimpsed a shadow of his own bones. Further experimentation showed that the screen could be replaced by a photographic plate—and the x-ray was born. Roentgen would later earn the first Nobel Prize in physics for his discovery.

http://mentalfloss.com/article/70900/9-transparently-amazing-facts-about-x-rays

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Understanding Hydrogen Induced Cold Cracking in Welds

Karsten Madsen | Apr 26, 2017

https://www.linkedin.com/pulse/understanding-hydrogen-induced-cold-cracking-welds-karsten-madsen

"Like others, I probably contributed to some weld cracking earlier in my career through ignorance about the effects of hydrogen on some metals. Problem #1 … working as a young Welder, there was usually a stash of 7018 electrodes somewhere handy saving a trip to the holding oven. Problem #2 … I'm showing my age in saying that at that time, microwave ovens had not yet showed up in cafeterias to warm up meals. No problems though as electrode ovens did a good job of heating up leftover mac 'n cheese or a can of baked beans for a warm dinner.

Adding to our ignorance, the welding rods used in both of these circumstances seemed none the worse for the wear making welds that appeared to be acceptable. So the loosely applied rules about keeping the electrodes only in dry holding ovens and used within 4 hours did not seem to justify compliance. Moisture absorbed by SMAW electrode flux coating is only one source of hydrogen entering a weld deposit. It can also exist in FCAW wires, SAW flux or come from high ambient humidity or lubricants used in other manufacturing processes. Moisture of course is hydrogen and oxygen while oils and greases are usually hydrocarbons.

My intent here is to explain in understandable terms why it is so important to control weld exposure to hydrogen for those higher strength steels that are susceptible to hydrogen induced cold cracking (HICC). I’m not a Metallurgist and I may be taking some liberties in the following explanation, but to me at least hearing the effects of HICC first hand and my analogies to explain this phenomenon seem to make sense."

Click here to read more about the strategy.

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5 Most Popular Inspection Techniques for the Oil and Gas Industry

By Lawrence Agbezuge
April 17, 2017

"The oil and gas industry operates according to stringent standards that primarily strive to keep equipment running efficiently while maintaining workplace safety. Conforming to such standards is challenging because oil and gas operations involve drilling (both on land and offshore), reservoir engineering, well servicing, production services, refining and transportation of petroleum products, and many other operations.
Not only is it challenging to conform to industry standards, but it is expensive to maintain a safe workplace and to protect workers from harm. It is necessary to equip workers with protective apparel; to continually train them on practicing safety procedures; and to keep them up to date on practicing improved equipment inspection techniques.

What is NDT?

Many NDT (Non Destructive Testing) methods are utilized in the oil and gas industry. The best NDT methods address issues regarding safety, equipment reliability, and environmental protection and government regulations."

Click Here to find out the greatest benefits of NDT

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Why AINDT?

American Institute of Nondestructive TestingThe American Institute of Nondestructive Testing not only offers training for exciting, high-demand careers with competitive salaries—we offer blended learning, which the U.S. Department of Education has found to be the most effective method of learning. AINDT's blended learning program combines flexible, affordable instruction as well as hands-on training to complete your course. Best of all, our online courses offer the ultimate flexibility. You can study, watch video lectures, and even complete quizzes on your iPad, iPhone, and Android devices! Instructors are able to teach active learning courses over the internet, and students can work at home on other assignments at their own pace, which helps stimulate self-directed learning. Instructors are free to offer more individualized assistance to those who need it, rather than being in a large lecture hall. AINDT's blended learning is designed to ensure success. Are YOU ready for an exciting new direction? Call AINDT for details today. Instructors are on hand waiting to speak with you! (855) 313-0325.

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How Nondestructive Testing Helps Keep Railways on Track

By Olympus NDT Applications Team - January 31, 2017

"One of the oldest methods of modern transportation, the history of rail dates back nearly 500 years. With an expansive and aging infrastructure, railroads require constant support to maintain their integrity and operate safely.

Many types of nondestructive testing (NDT) techniques have been used to help ensure the quality of both the rail and the many components that make up a rail car. These methods range from the so-called “car knocker,” which uses acoustic resonance to detect cracked wheels, to the “oil and whiting” test used for fatigue crack detection in steam locomotive pins and axles. Currently, ultrasonic testing (UT) is the preferred method of NDT in the railroad industry.

Ultrasonic testing uses high frequency, directional sound waves to measure material thickness, find hidden flaws, or analyze material properties. UT requires the use of a transducer that transmits and/or receives the ultrasound signals being passed into the metal and a flaw detector to process the results. While UT is used in a range of applications, it is especially important for rail testing."

If you are interested in exploring a career in Nondestructive Testing, talk to an NDT Instructor today 855-313-0325!

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NDT Certification

NDT CertificationAINDT offers your complete training and certification to get you started on a rewarding, high-paying career in nondestructive testing. NDT is a constantly-evolving field in high demand in all manner of industries, from transportation to utility and power. If you are looking for an NDT training school that offers all the training you need to get into a rewarding career in nondestructive testing, look no further than AINDT! Our blended learning program offers you the convenience of online NDT training from wherever you may live, followed by hands-on NDT training at our Baxter, MN facility. The combination of our online NDT curriculum, followed by 18 days of hands-on training using the most up-to-date NDT equipment will give you the skills needed to enter into a rewarding career in nondestructive testing. Our NDT training program includes all required study material and books for your online training, which takes approximately 6 months. Our training program will prepare you for NDT certification by an NDT employer. The online portion of your NDT training can be started at any time, and hands-on training is available 6 times per year (every other month starting in January) and will be scheduled at the student's discretion. With job placement assistance and an amazing new career waiting for you, call AINDT today for more information: (855) 313-0325. Instructors are waiting to speak with you!

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Save The Dates

Save The DatesOur current enrollment is starting for our UT Shearwave Weld Examination courses this year. Earn your certification and earn more opportunities for lucrative employment in the future! AINDT is offering this 5-day, intensive, hands-on course at our Baxter, Minnesota location on the following dates in 2017:

  • March 27th - March 31st
  • May 22nd - May 26th
  • July 31st - Aug. 4th
  • Oct. 2nd - Oct. 6th

If these dates don’t work out for you, we are offering custom dates to groups of four or more from your company. Contact us for details or to arrange your custom dates: (855) 313-0325. We look forward to speaking with you!

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ASNT Level III Basic Exam

ASNT Level III Basic ExamAt AINDT, our success is your success. We want you to have the best possible opportunities in this exciting field, so we prepare you with the most effective methods. Our ASNT Level III Basic Exam prep course is tailored to best prepare you for exam success. This online program covers the three main components of the ASNT Level III Basic Exam:

  • SNT-TC-1A/CP-189 comparisons and analysis to understand various programs which establish the criteria for NDT personal certification as well as their differences
  • Materials and processes for NDT technology, and
  • 11 various methods contained in Recommended Practice TC-1A

Call (855) 313-0325 today for more information on the ASNT Level III Basic Exam prep course and getting started with your new career in NDT.

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New Corporate Training

New Corporate TrainingAINDT is excited to announce our newest corporate training program for UT Level I and II Training: UT Shearwave Weld Examination. This 5-day course is held on our campus and features an intensive, hands-on 40-hour course. This course is designed for Ultrasonic Level I and II technicians wanting to gain in-depth knowledge of shearwave calibration, scanning, interpretation and evaluation techniques. UT Shearwave Weld Examination will cover AWS D1.1, AWS D1.5, ASME V, API 1104 requirements. Your new certification awaits. Call (855) 313-0325 today for more information. Instructors are waiting to speak with you!

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NDT training services market is expected to grow at the highest rate during the forecast period

Source:
http://www.prnewswire.com/news-releases/ndt-services-market-by-testing-technique-type-vertical--geography---global-forecast-to-2022-300370291.html

NEWS PROVIDED BY
ReportBuyer
Nov 29, 2016, 23:38 ET

"NDT training services market is expected to grow at the highest rate during the forecast period"

"The demand for NDT services would increase in the near future owing to the aging infrastructure and the increasing rate of new infrastructure development. Moreover, owing to the shift to advanced NDT techniques, such as phased array ultrasonic testing (PAUT) from traditional NDT techniques; there would be a need for skilled technicians. As a result, the NDT training services market is expected to grow because of the shortage for trained technicians for conducting NDT inspections in the NDT market.
"Oil & gas sector is expected to hold the largest share during the forecast period"

The demand for NDT technologies in the oil & gas sector is largely driven by government regulations for improving the safety of people and environment by avoiding oil spillage due to leaks, bursting of pipes, or any other accidents. As majority of the piping infrastructure and refineries are timeworn, it is imperative to conduct regular NDT inspections to ensure the integrity of these assets. The fall in oil prices since the end of 2014 are not expected to significantly impact the demand for NDT inspection on existing infrastructure. Thus, the oil & gas sector is expected to remain the largest market for NDT during the forecast period."

Click Here to read the rest of the article.

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The Rewards Are Endless

The Rewards Are EndlessAINDT offers online certification courses and vocational training in an exciting, expanding industry. What's more, you want more than a new job, you want a career. AINDT not only offers job placement assistance to those who complete our technical vocational training, you will become certified in an industry that is expanding every year. That's what we call job security. Non-destructive testing offers a crucial service to just about every industry you can think of. Enroll today and get started on an exciting new career in non-destructive testing. Call 855-313-0325. Instructors are waiting to speak with you and answer your questions.

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NDT Careers

NDT CareersAINDT offers top-notch training in a variety of rewarding fields. NDT is more than a job—it's a career. What's more, the demand for NDT is increasing every year, and will never become obsolete. How's that for job security? NDT examinations are crucial to ensure safety and reliability for companies, personnel, products, and the public in general. NDT testing is used for just about everything you can imagine including pipelines, bridges, motor vehicles, buildings, aircraft, watercraft, power stations, oil platforms, and refineries, to name a few. Graduating from AINDT qualifies you to begin a career in a wide variety of fields including: aerospace, aviation, auto and boat racing, construction, manufacturing, oil and gas development, amusement parks, railroad, and alternative energies. With so many different fields in need of NDT graduates, you can't go wrong with AINDT. Call 855-313-0325 today. An exciting new career awaits!

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