Non-Destructive Testing: The Unsung Hero of Safety

Since the dawn of the Industrial Revolution, workplace safety has evolved by leaps and bounds, as industries and individuals raised the standards and expectations for safety. Along the way, the science of non-destructive testing (NDT) emerged, providing a critical tool to detect issues in the early stages. By helping to ensure the structural integrity of parts, components, systems, equipment and structures, NDT has helped prevent untold injuries and saved countless lives.

What Is Non-Destructive Testing?
NDT, also known as non-destructive examination (NDE), is a discipline that allows us to inspect components and materials inside and out — without damaging the item or affecting its ability to function. The goal of non-destructive inspection is to identify structural integrity issues (flaws, cracks, voids, leaks, fatigue, defects and corrosion) in the early stages, before they lead to accidents, injuries or fatalities. Without non-destructive tools, defects could go undetected and lead to dangerous conditions or failures.

In addition to visual inspection, the use of repeatable methods to detect flaws that could impact performance dates back centuries. Ancient Romans were known to use oils and fine powders to reveal surface cracks and defects in materials. Skilled blacksmiths often relied on the sound and resonance of metal to assess its strength.

A Breakthrough in Industrial Safety
By the late 1800s, the visual inspection — the original form of non-destructive examination — was fairly standard. By nature, however, this approach was limited to detection of visible surface defects.

In 1895, Wilhelm Conrad Roentgen took NDT to a new level when he discovered the mysterious x-ray. With the ability to pass through most solid matter, the x-ray offered an unprecedented view of internal condition without harming the person or object being tested. Just six months after Roentgen’s discovery, battlefield doctors were using X-rays to locate bullets in wounded soldiers.

NDT first found its footing in the industrial world in the early 1900s, as engineers began using radiography (X-ray) to reveal hidden defects in the internal structures of metal castings. Today, radiography remains one of the most popular methods of NDT in industry, and the field of non-destructive evaluation continues to evolve.

Along with radiography (X-ray or RT), the primary conventional non-destructive testing methods in use today are dye penetrant (PT), magnetic particle (MT), ultrasonic testing (UT) and visual testing (VT). Depending on the customer’s needs and inspection conditions, technicians may also employ advanced NDT, such as guided wave testing (GWT), phased array ultrasonic testing (PAUT), and time-of-flight diffraction (TOFD).

Why Non-Destructive Testing Matters Potentially dangerous threats to structural integrity often start small. If left undetected, even a miniscule defect in a critical component can lead to catastrophic failure.

Ever since Roentgen’s revolutionary discovery of the X-ray, testing methods have continued to evolve to allow for increasingly accurate detection of issues that impact structural integrity. Today’s NDT methods and safety standards could have made all the difference in tragic events like the 1967 collapse of the Silver Bridge between West Virginia and Ohio. Caused by a small crack in a suspension eyebar, the failure claimed 46 lives.

Mid-flight failures caused by fatigue cracking, such as the de Havilland Comet crashes in the 1950s and the Aloha Airlines Flight 243 accident in the 1980s, helped spur the development of modern aerospace NDT standards. These and other aerospace disasters underscored the need for specialized NDT programs to detect fatigue before visible signs appear.

These tragic lessons are not limited to bygone eras. The U.S. National Transportation Safety Board (NTSB) cited inadequate testing as a contributing factor in the 2023 Titan submersible disaster, which claimed five lives.

Safety & Other Benefits of NDT
As a non-destructive test method, NDT is a proven tool to support a strong safety culture. Some of the key benefits of NDT are highlighted below.

• Safety & Quality: Through accurate, early detection of structural integrity issues, NDT helps to keep issues from escalating dangerously.
• Cost Savings: Without the use of NDT, defects and flaws could worsen, leading to costly repairs or replacements, equipment failures, unplanned shutdowns or catastrophes.
• Compliance: The routine use of NDT helps to ensure that materials, components and equipment meet internal design specifications, as well as external standards and regulations. In light of its many benefits, it’s no surprise that NDT has become a go-to method in many industries — from transportation and amusement parks to medicine and manufacturing. For example, the aerospace industry inspects aircraft parts, components and structures to help ensure flight safety. The oil and gas industry uses NDT to monitor pipelines, storage tanks, and refineries for corrosion and cracking to prevent leaks and potential environmental disasters.

NDT for a Safer World
Prevention is at the heart of safety and the driving force behind non-destructive testing. Rather than waiting for something to go wrong before dealing with it, NDT offers companies the chance to stop serious safety issues in their tracks before major damage is done.

From buildings and bridges to medical implants and multivitamins, non-destructive testing is a non-negotiable for any organization committed to safety. As a cornerstone of prevention, NDT helps to protect people, property and the planet.

LEARN MORE ABOUT IIA’S NON-DESTRUCTIVE TESTING SERVICES

What's the Importance of Low TRIR?