Inspection + Testing
And What Makes Cathodic Protection So Awesome?
Cathodic protection is a key technology for protecting against corrosion because it can be easy to apply and can be monitored 24/7. It’s as near to a set-it-and-see-it method for keeping buried, immersed or steel in concrete metal structures safe from corrosion as we can get. Plus, it’s cost-effective and works on many metals, as well as steel. It even works for atmospherically exposed steel when embedded in concrete.
What causes corrosion in the first place?
Corrosion is caused by a metal being in contact with a corrosive environment. Factors like the metallurgical condition of the metal, connection to dissimilar metals or varying levels of oxygen exposure can speed up the corrosion process.
You see, metal wants to go back to its natural state (ore) through a process known as corrosion. This is the metal “rusting” away. It’s an electro-chemical process that involves the flow of electrical currents, with an anodic reaction involving the oxidation of the metal to its ions.
So, how does cathodic protection actually work?
The idea behind cathodic protection is to turn the entire surface of the metal into a “cathode”, thus stopping the corrosion process.
An external “anode” is connected to the vulnerable metal with the result that the metal structure should not corrode. There are two main types of cathodic protection . . .
Read more @ Institute of Corrosion
#inspection #corrosion #cathodicprotection #cathodic
Inspection + Testing
The hidden dangers of corrosion under insulation (CUI) span the oil and gas industry from upstream operations to midstream infrastructure and downstream applications, including the production of LNG. CUI is a severe form of localized corrosion that occurs when water, inorganic salts, and other contaminants become trapped beneath insulation covering pipes, valves, tanks, and other assets, leading to the formation of corrosion cells that are hidden from view and can spread unnoticed.
In oil and gas operations, elevated process temperatures may accelerate corrosion rates, leading to pitting and metal loss that may cause leaks and potentially catastrophic failures, with the potential to harm personnel and, in extreme cases, cause the loss of life.
Yet, in LNG operations, cold/cryogenic temperatures can also contribute to increased CUI risks. A perfect recipe for corrosion – moisture, oxygen, and chlorides – exists in both temperature scenarios, but moisture from condensation can be especially prevalent under insulation in cryogenic LNG operations due to the extreme temperature differentials with ambient air. Studies show that moisture causes 85% of insulation system failures in LNG operations. At the same time, some LNG applications also operate at high heat, compounding CUI threats across entire facilities.
Read full article @ LNG Industry
#corrosionunderinsulation #lng #corrosion #cui
Inspection + Testing
Drones are increasingly being used in Nondestructive Testing (NDT) because they offer a lot of benefits, especially for inspecting large or hard-to-reach structures and confined spaces.
- Access to Difficult Areas: Imagine trying to inspect a tall bridge or a big wind turbine. It’s not only hard but can also be dangerous for people to climb up there. Drones can easily fly to these high or awkward spots and carry cameras and sensors to take a close look.
- Safety: Since drones can go to places that might be risky for humans, they make the inspection process much safer. For example, inspecting the outside of a tall building or a large dam can be dangerous work. By using a drone, you can keep the inspection team safe on the ground.
- Speed and Efficiency: Drones can cover large areas quickly, much faster than humans on foot or using ladders and scaffolding. This means inspections can be done more frequently and thoroughly, which is great for keeping structures in good shape.
- Advanced Technology: Drones can be equipped with different types of technology, like infrared cameras, ultrasonic sensors, or laser scanners. These tools help detect problems like cracks, corrosion, or other damage without touching the structure.
Groups / Resources for Inspection Drone Services:
Axess Group
Flyability
PLP Inspection Services
Commercial Drone Alliance
Inspection + Testing
Probability of detection (POD) evaluation is a commonly used method of quantifying the reliability of an inspection. Inspections in practice have multiple factors which affect the detectability of flaws (e.g. human factors, uncertainty in the geometry of the part under test, or sensor/instrument noise). A POD study seeks to quantify the effect of these factors by answering the question:
What is the largest flaw that could be missed when this inspection is implemented in production?
POD provides an answer to this question by assessing the probability of detecting a flaw as a function of some defining characteristic (typically flaw length or depth).
Along with estimating false call rate, POD has been successfully implemented in multiple industries as the primary method of reliability quantification for NDI inspections. This article is intended to introduce key aspects of POD that will help in understanding the scope and limitations of a POD study.
Read the full article @ NDE Engineering: The Probability of Detection
#NDE #Engineering
