Welcome to segment 2 of 4 looking at the benefits and constraints of using aerial robotic systems for contact-based UT measurements. In this segment, we will examine how and when this new aerial robotic measurement technology should be used, and its benefits and constraints. In the next segment, “it’s all about data”, we look at data, gathering it, reporting it, storing it for future use, and more. In segment 4 we will review how these systems can be used in your organization, the value creation they can unlock and what may be in store for the future of this exciting technology.

Introduction

Robotic inspection equipment for the coatings industry is forecast to grow exponentially in 2021 and beyond, as asset owners and service providers realize their economic value creation, increased data collection, and safety contributions. Robotic equipment such as the Apellix Opus X4 UT system, when properly selected and utilized, positively impact safety, time, analytics, access, and cost. Companies looking to keep personnel out of danger at height or potentially hazardous situations should adopt these systems.  However, as with many things, choosing the right system for the job is essential for optimal results.

Opus X4 UT Measurements at Height

     Taking manual corrosion measurements at height via a lift, scaffolding, ladders or other solutions can be both dangerous due to the possibility of falls, and time-consuming due to set up. The Opus X4 UT aerial robotic system, on the other hand, allows inspection at height while the operator is safely on the ground while collecting UT measurements, video and images, and other data for both live and post job analysis. The Opus X4 UT system can fly to a designated point on an asset under full computer control and make contact with a surface for inspection obtaining wall thickness (UT/UTT) measurements. Manual inspection would involve a person moving from one elevated access point to another which is a risky and time-consuming process. Crawling robotic systems can move from point to point, but they tend to be less agile and slower than the Opus X4 system. Thus, for applications such as above-ground storage tanks, flare and chimney stacks, and other assets requiring measurements in difficult to access areas, the aerial robotic system may be the best tool to use.

UT Measurement Constraints

     Measurements from the Apellix Opus X4 UT system are compliant with SSPC, ASTM, API, and other industry standards. While these systems can be highly effective when properly used, they do have limitations and cases in which they are the incorrect choice of tool. One example would be if a coating is chalking, in poor condition, or covered with rust, and the engineer would need to brush or wipe the surface prior to placing a probe tip in contact with it to get a valid reading. As the Apellix aerial robotic systems do not perform surface preparation (at present), it is unlikely to be unable to get a valid measurement in such a situation.

Image 1 – An example of an Unmanned Aerial System with a robotic arm and a contact-based measurement device being flown near a ship [1].

Of historical note, the ship in this image the Artic Discoverer used a famous and cutting edge technology ROV, the NEMO [2], in 1988 to locate and retrieve one of the largest shipwreck treasure discoveries in history - over 21 tons of gold from the shipwreck of Central America [3].

     The Opus X4 UT aerial robotic system can take several hundred measurements at different physical contact locations/Corrosion Monitoring Locations (CMLs) per hour, for coated substrates in relatively good condition. For example, part of an API inspection on an aboveground storage tank could be completed in hours. However, just as with surface conditions, environmental conditions can impact the ability of the system to get valid UT readings and measurements. The Opus X4 UT system is designed to operate in winds up to 12 knots (14 mph) but even then, the number of readings per hour decreases as wind conditions increase. Similarly, the surface and coating condition impact measurement speed as the “dwell time” at locations needs to increase as the condition of the surface decreases to allow the UT device additional time at a certain area to obtain accurate readings.

Image 2 – An example of Coating with an approximate age of 40 years with extensive scale containing large air pockets/bubbles that prevents echo to echo ultrasonic signals, even with copious quantities of couplant [4].

Image 3 – An example of a coated and uncoated ferrous steel substrate with an approximate age of 2 years (2 years from construction with weather exposure in Florida in the southeast USA). UT readings can be taken from both the coated and uncoated surfaces of this structure [5].

When it is the proper tool for the job, the Opus X4 UT system is a force multiplier for the safety, operational effectiveness, and efficacy of assets. This is because the system gathers data that can be turned into actionable tasks for knowledge-based information-driven decision making.

     The Opus X4 UT system is a new technology currently used on a relatively simple and mostly vertical external surface such as above-ground storage tanks, chimneys, or stacks. It is not currently designed for internal use and cannot fly too close to obstacles such as pipes, built-in ladders or stairs, etc. Further, it is not designed to take readings close to the ground, or on horizontal surfaces (currently). If a corrosion engineer can safely reach a location, for example, the first 6 feet of the external skin/shell of an above-ground storage vessel, you would want them to take the UT reading not the aerial robotic system.

UT Measurement Constraints

Using the Opus X4 UT industrial robotic inspection system has a multitude of benefits but also drawbacks and limitations. While robotic inspection systems portend a more automated future, one must ensure the benefits outweigh the drawbacks. As with any tool, selecting the correct tool from a toolbox is important and care should be taken to ensure you choose the appropriate one.

Image 4 – An example of the Opus X4 UT system collecting a reading on a live, in-service flare stack at an operating oil and gas facility [6].

     The Apellix X4 UT system is able to obtain UT measurements on hot metal in excess of 200 degrees F (93 C) when the UT gauge is properly selected and calibrated using a high-temperature compatible couplant. It is able to fly close to or come in contact with structures without requiring a skilled pilot. The precision flight is automated via onboard computers allowing for up to 50 micro-adjustments to the flight per second, something a human pilot is incapable of.

Benefits and Drawbacks of Robotic Inspections

     One recent report detailed five areas where industrial robotic inspections create value helping to create compelling reasons to invest in and scale them rapidly. The areas are; safety, time, analytics, access, and cost [7].

     The Apellix Opus X4 UT system can safely go to many places people can’t or don’t want to go.  It can help reduce the time it takes to conduct industrial inspections by completing them more quickly than a person. The Opus X4 UT system helps align human work hours to optimize the use of human resources and reduce the number of changeovers and repositioning required to conduct such inspections. It also enables data collection on a scale and scope heretofore unimaginable, feeding the hungry Nondestructive Examination (NDE) 4.0 paradigm for analytics and other computational and informational purposes.

     The Opus X4 UT system also affords access to difficult to inspect areas. Assets are not always box-shaped simple structures and may have nonlinear geometry. One of the great things about aerial robotics is that they can adapt. They can easily conform to non-linear surfaces while other techniques (robotic or other) may have a long adaptation curve. Reducing cost is essential as industrial inspections can be very expensive. Most inspectors are not replaced by inspection robots, instead, the robots are a tool that eliminates the dirty, dull, and dangerous tasks of collecting the inspection data and allows them to spend more time on the higher value components of operations and maintenance. Cost savings do not come from labor, instead, they are driven by mitigating the cost of the safety equipment required for inspections with workers.

     A rule of thumb in the industry for elevated inspections is an average of 60% of the costs are placing the workers at height. In 2020 it costs $1,000 to $1,500 per week to rent a standard 30 feet capacity lift (aka mobile elevated work platform), plus delivery and pick-up fee, taxes, and insurance. Larger models such as those that extend 100 feet or more are significantly more expensive [8]. Robotic inspection systems such as the Opus X4 UT can also be easier to use and more frequently, enhancing preventative and predictive maintenance activities and reducing the costs associated with performing repairs on equipment. Finally, one area of huge economic value creation by using the Opus X4 UT system is to eliminate the need for an asset to be taken out of service or allowing an asset to be returned to service quickly. For example, shutting down multiple portions of an oil and gas refinery that feed excess gas into a flare stack to take it out of service for inspection can cost millions of dollars a day in lost revenue [9]. Using an aerial robotic system such as the one shown in the images below allows for the asset to be inspected and measurement data gathered while keeping the asset in service.

Image 5 – An example of an Aerial Inspection Robotic system for Ultrasonic Thickness (UT/UTT) Measurements on an ~200-degree Fahrenheit in-service operational chimney at a refinery (~93 Celsius) [10].

Drawbacks of Industrial Robotic UT Measurements and Inspections

The Apellix Opus X4 UT system is not always the ideal solution. In many situations, the existing inspection regime and methods are done relatively inexpensively and safely. They provide the requisite data and information for good operations and knowledge of the current and projected future state of the asset. Robots can require a relatively high upfront investment [11], although on a per inspection cost basis the robotic inspections may cost less. The acquirement of robotic inspection systems requires an upfront investment, even if it is the financial commitment to lease rather than purchase.

     Additionally, robots do not respond well to many unexpected situations. Robots are not as versatile as people and while they may exceed at certain specific tasks, especially repeated programmatical tasks, they might not be able to adapt in unexpected or unanticipated situations or if something unexpected occurs.

Since they are not human inspectors, robotic inspection systems may not pick up on or discover rare issues that an experienced human inspector might. Due to this limitation, companies supplement robotic-powered inspections and examinations with ones completed by people.

As we know, selecting the right tool for the right job is essential. When properly selected and utilized, robotic inspection systems can assist with creating safer workplaces, provide better data to manage assets, and unlock cost savings. While industrial robotic inspection systems can be highly effective when properly used, they do have limitations and, in some cases, they are the incorrect tool.

Drawbacks of Industrial Robotic UT Measurements and Inspections

While industrial UT inspections are necessary and critical, they can be expensive and dangerous. The Apellix Opus X4 aerial robotic Inspection systems and automation help organizations improve safety and reduce costs by performing UT measurement safer, better, and faster than completing the same tasks with people. With its unique ability to gather data, the Opus X4 UT system can allow your organization to capitalize and extrapolate data and information gathered thus providing users with a scenario wherein 2 + 2 equals more than four.

In the next segment (segment 3) we discuss the data gathered by the Opus X4 UT system, both contact-based UT measurement, visual and other data. In segment 4 we look at how the Opus X4 UT system might be used in your organization and what the future may be for this exciting technology.

[1] Image Copyright 2017

[2] Man Overboard: The Robots That Found the Ship of Gold, Then and Now. Columbus Monthly By Michelle Sullivan, Oct 28, 2014, https://www.columbusmonthly.com/article/20141028/lifestyle/310289314

[3] History of the Arctic Discoverer Treasure Ship http://www.wncrocks.com/ARCTIC%20DISCOVERER%20HISTORY.html

[4] Image Copyright 2020 Apellix

[5] ibid

[6] ibid

[7] 5 Reasons To Consider Robots for Industrial Inspections, John Santagate 10/30/18 | Industrial Robotics, Factory Automation | Service Robots - Robotics Tomorrow https://www.roboticstomorrow.com/article/2018/10/5-reasons-to-consider-robots-for-industrial-inspections/12729/

[8] How much does it cost to rent a cherry picker https://costfigures.com/cherry-picker-rental-cost/

[9] Flares. Part ii. Capital and Annual Costs. Diana K. Stone , Susan K. Lynch , Richard F. Pandullo , Leslie B. Evans & William M. Vatavuk (1992) Flares. Part II. Capital and Annual Costs, Journal of the Air & Waste Management Association, 42:4, 488-493, DOI: 10.1080/10473289.1992.10467008 https://www.tandfonline.com/doi/abs/10.1080/10473289.1992.10467008

[10] Image Copyright 2017 Apellix

[11] Guide to Inspection Robots Used in Industrial Sectors https://gesrepair.com/guide-inspection-robots-used-industrial-sectors/

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