Non-destructive testing (NDT) is a technique used in asset inspection to test and analyse a structure or asset to detect and evaluate flaws without causing damage to the asset. The results from these tests can then be used to inform engineering analysis and asset management decisions. There are a range of different NDT testing methods designed to ensure the structure can continue to perform cost effectively, reliably, and safely – without damaging the structure.
At Revo Group, we perform NDT on a range of different resources including poles, pipes, etc. We use NDT methods to test defects. A defect is any variation to the original design of the item, whether that be from damage, deterioration, corrosion or fatigue. We use the results of these tests to identify and/or implement the following:
- Safety issues.
- Quality Assurance (QA).
- Accident prevention.
- Product integrity.
- Calculating and categorising risk.
- Condition monitoring.
- Testing to best practises and standards.
Why is Non-Destructive Testing Used?
The goal of non-destructive testing is to gather condition information about an asset to inform any of the above while not adversely affecting the future usefulness and effectiveness of the item being tested.
All assets are at risk of aging, damage and failing. Man-made materials tend to want to return to their natural form (e.g. steel to iron oxide), and natural materials tend to stay the same unless acted upon by an external agent (e.g. decay or termites).
All assets have a projected life when first designed. NDT is used to help assess the item for any unexpected defects because of fabrication, installation, in-service environmental impacts like corrosion or decay, or other factors. Implementing regular tests can provide the data needed to safeguard the asset, environment, personnel, and the public from higher risks of failure. NDT is widely used to regularly inspect and maintain structures in a wide range of industries including oil rigs, pipes, power grids, bridges, railway lines, aircraft and more.
NDT is also a QA tool used to:
- Determine acceptance of an asset to a given standard/requirement.
- Give information for the repair of a component to a set criterion.
- Help prevent accidents.
- Increase the reliability of a product.
What are the Advantages of NDT?
As the component remains undamaged or destroyed and can (in many cases) continue in-service throughout the non-destructive testing process, there are a range of advantages over destructive testing methods.
Efficient and Accurate Results
NDT provides efficient and accurate results when appropriate devices are used properly. Non-destructive testing is often faster than a destructive alternative, saving time in stopping production, dismantling, and then testing.
The most obvious advantage is that in many cases no dismantling or operation halting is required to conduct the test. For some, this advantage is only worth a matter of convenience but for many organisations continuing production while testing, or with short pauses in operation rather than long shut-downs can save millions of dollars.
NDT also provides cost efficiencies in other areas. Regular NDT can alert asset owners to breakdowns, malfunctions or failures that would cost more to repair instead of preventative maintenance that would be identified in an assessment.
A reduction in wasted materials can also be a significant benefit, ensuring that the asset is repaired/replaced only when required. If a non-destructive method is used to test assets first, there is less chance of breaking a still-usable asset.
Efficient Identification of Areas of Concern
Some NDT testing methods can identify areas of concern without impacting or disturbing the item being tested. Even the ability to narrow down the area of potential concern can be a considerable benefit, and is the focus of some technologies (including the Innerspec MRUT and LRUT equipment and the PortaSCAN devices). Such techniques provide significant time and cost savings through ensuring time and money is focussed on critical areas of an asset, or critical assets in general, that show some level of degradation.
As technology continues to get better, testing becomes a greater requirement and as more innovators expand on each other’s work, NDT equipment continues to improve and perform to a higher level. This means faster testing, more efficient data gathering, simple and more in-depth reporting and the visualisation of the problem. NDT techniques are already the cornerstone of most effective inspection techniques across a range of industries and are continuing to improve as the global asset base ages and deteriorates.
What are the Disadvantages of NDT?
Training Often Required
Depending on the NDT method and equipment required, having certified/trained technicians may be a requirement of your state or country. However, training can normally be completed on the job with the new equipment with the right supplier. For smaller asset bases, experienced contractors can be called upon to complete the work, removing the need to train and maintain in-house technicians that may not use the tools frequently enough to maintain competency/efficiency.
Non-destructive testing equipment requires tools that most businesses do not have lying around. New equipment always comes with a cost. Making the investment in NDT tools, whether upfront or rental, is money that could be used elsewhere. However, when taking into consideration the cost of any required destructive testing, reduction in failure costs (including incidental costs), and a reduction in wastage or replacement of serviceable parts, the up-front costs of NDT normally become easily supported in a business case.
Is NDT more expensive than DT?
The main factor that influences this question is the cost of the asset and replacing it vs. the cost of the NDT equipment, training and technicians. It is also impacted by the frequency of replacing the asset in comparison to testing. Every case differs, and as stated above, a cost-benefit analysis must be carried out for each application of DT and NDT.
Industries that benefit from NDT
Many different industries have been employing extensive NDT practises as an integral part of their asset management regime for many decades. The first common use of modern NDT was in British rail yards. Workers would soak steel items in dirty used oil, wipe clean and cover them in chalk dust. Any cracks would hold the black oil and the chalk dust would blot it out of the tight crack and show it with a visible contrast against the chalk. This was the first use of what we now call dye penetrant testing.
The aircraft industry has largely championed modern NDT innovation, developing advanced ultrasonic, eddy current and X-ray methods since wings started cracking at the roots and failing on Canberra Bombers in the 1950s.
Modern oil and gas, mining and railway industries use NDT extensively everyday, further driving technology and innovation to impressive levels with Phased Arrau Ultrasonics, EMAT Ultrasonics and Phased Eddy Current testing, not to mention the robots and drones that drive these instruments into hostile and hard to reach environments with amazing precision.
Can you benefit from Non-Destructive Testing?
Many businesses in a wide range of industries can benefit greatly from NDT services. A simple non-destructive test can locate potential problems earlier, reducing the risk of accidents and lost revenue.
When choosing what NDT tools to use or what company to outsource your testing to, make sure you choose an expert team that puts your company and needs first. Contact us to learn more about our cost-effective and expert solutions, and how we can help you today.