If you operate in a high-risk industry, you know just how critical testing is to your ability to uphold safety standards. Non-intrusive inspections (NII) and non-destructive testing (NDT) are two types of tests that can help you ensure integrity and efficiency, but what are they, and what are their differences?
In this article, we’ll explore both NII and NDT and demonstrate how they can help you achieve equipment reliability without the downtime needed by other testing strategies.
What Is a Non-Intrusive Inspection?
NII is a testing process that uses external examination techniques to inspect and evaluate internal assets, whether that be a pressure vessel or pipeline. The assets are not entered or opened throughout, as they are with internal visual inspections (IVI). For this reason, NII reduces the risk associated with confined space entry (CSE) while limiting downtime.
Generally, NII follows a structured, four-step process:
- Step 1: The asset, operating conditions, testing needs, and risks are analysed. This stage determines whether the asset is suitable for NII.
- Step 2: The scope of the inspection is set. This will depend on the nature of the vessel.
- Step 3: The inspection is carried out using advanced technologies.
- Step 4: The results are examined. These show whether a degradation exists.
The benefits of NII include:
- Safety. There’s no need for personnel to enter equipment.
- Cost. CSE is avoided. So, too, is disassembly. NII, therefore, reduces inspection costs and operational downtime.
- Efficiency. Properly implemented NII lifts production revenue by limiting disruption to operations.
What Is Non-Destructive Testing?
NDT is another testing methodology that shares some similarities with NII. It’s used to evaluate materials, components, or systems for flaws or defects without causing damage.
However, unlike NII, which looks at an entire system externally, NDT typically looks for specific defects. For example, NDT might seek out welding discontinuities or material inconsistencies. In addition, NDT is a broader field that includes inspections performed during the manufacturing and maintenance phases.
The Major Differences Between Non-Destructive Testing and Non-Intrusive Inspections
While NDT inspection and non-intrusive inspection systems share common goals—evaluating the condition of equipment and materials—they serve distinct purposes and are suited to different applications. Let’s take a closer look.
Scope
NDT looks at specific materials or components. It is used throughout manufacturing, maintenance, and repair processes.
NII inspects entire systems. It’s best suited for in-service equipment assessments.
Technology
NDT techniques include things like ultrasonic testing, radiographic testing, and eddy current testing. These technologies uncover flaws like cracks and corrosion.
NII uses external imaging technologies, too, but applies the methods systematically to inspect the overall integrity of the equipment.
Accessibility
When conducting NDT, personnel may need to make direct contact with the material or structure.
In contrast, NII entirely avoids direct access to internal components.
Objective
NDT’s goal is to detect and analyse defects at a granular level.
NII maintains system integrity while reducing downtime and operational interruptions. Its structured process evaluates risk and identifies potential degradation.
Industries that Benefit from NDT and NII
Industries reliant on infrastructure and equipment maintenance can benefit from NDT and NII. This includes the following sectors:
- Oil and gas
- Mining
- Manufacturing
- Utilities
- Transportation
Choose Sonomatic for Quality Inspection Services
At Sonomatic, we design, develop, and perform NDT inspections. Our leading-edge approach combines data science with engineering best practices to give our clients access to a truly world-class inspection service.
When you choose Sonomatic, you get:
- Innovative NDT and NII techniques leveraging bespoke, purpose-built equipment that reduce downtime and boost production efficiency
- Total confidence in safety and compliance with industry standards
- A team of highly skilled integrity engineers who understand the unique challenges of your industry
Choose Sonomatic for a reliable, cost-effective inspection solution.
