Two to Tango: Combining Robotic Inspections with Manual Ultrasound

When It Comes To Plant Inspections, One Size Does NOT Fit All

Equipment employed at a coal-fired power generation plant is different from what’s used in an oil refinery, an ammonia/fertilizer plant, or even a specialty chemicals plant. Sure, there are pressure relief devices and some form of fired heaters in all. But the similarity ends with the way different assets are deployed to do very industry-specific jobs.

The experience of an inspection team in your specific industry should be a prime consideration in selecting a third-party partner.

At the same time, while internal inspectors have greater knowledge of the plant and its equipment, they may not be experienced in the operation of inspection robots.

For a power generation company, there seem to be two choices:

  • Invest in robotic inspection equipment. But, if you buy a robot you have to have someone (multiple someones) trained to operate it, maintain it, and repair it when necessary.
  • Engage a third-party inspection firm with knowledge of robotics and hope they have industry experience, as well.

Or, you could consider Gecko Robotics as a resource that can deliver Rapid Ultrasonic Gridding (RUG) of your assets, conducted by certified NDT inspectors, and that provide rich, actionable data on the health of your equipment.

That was the choice made by one power generation company, last year.

After an unplanned outage revealed a previously undetected issue, the company implemented a strategy of complete, robust inspections during planned downtime, to assure that in the future the plant would stay reliably online, producing electricity for thousands of business and residential customers. Like any other coal-fired power plant, this company was focused on reducing outage events, while maintaining the historic dollars per kWh and reliability advantages over intermittent renewable energy alternatives.

But even within a specific industry, using industry-specific knowledge and methodology, one size does not fit all.

Manual Takes Time - Robots Can't Go Everywhere

Handheld Inspection

The company recognized that a complete inspection of the plant assets was essential. For this inspection, the variety of assets required extensive power plant knowledge. Those assets included boilers, tanks, drums, and economizers.

Since manual inspections are notoriously slow, the scope of the inspections are often limited to fit within an outage window. The idea of using Gecko’s robotic solution, known to be 10X faster, was attractive to cover more square footage in the given time. However, executing inspections of the entire fleet of assets was a challenge.

That was what attracted the company to Gecko’s robotic solution. RUG is 10X faster than manual inspection. However, some of the assets and asset sections were not accessible to robotic methods.

The solution involved an innovative approach by the Gecko robotics inspection Team.

One of the most important features of every Gecko Robotics Inspection Team (GRIT) is that our inspectors have, at minimum, NDT Level II certification. This provides an added layer of inspection knowledge, as opposed to robot operators who do not have training or experience in a specific industry, or in manual inspection methodology.

Our inspectors began with an inspection of the integrity of the boiler tubes located on waterwalls and man-ways of each of the units. Gecko provided a robotic ultrasonic and visual inspection of boiler front, rear, and side waterwalls as well as roof tubes. Because of the flat orientation of the waterwalls, the inspection was accomplished using Gecko’s TOKA 3 robots.

Advanced Technology Combines with Old-School Inspection

However, boiler tubes in the man-ways did not have sufficient clearance for the Gecko robot to operate. So, two Gecko inspectors conducted manual UT and visual inspection of man-way tubes, as well as Convection Cages, Economizers, Super-heaters, and Re-heaters.

Overall, the Gecko team included 6 inspectors with 2 robots working 12-hour shifts, to complete the scope of work within 5 shifts per boiler. Using the TOKA 3 robotic platforms allowed for capturing 2 angles of data per tube quickly and efficiently; compared to the complexity and lack of coverage when inspecting manually.

How Long Does All This Data Mining Take? It's Wicked Fast!

Gecko delivered 50% of the inspection data to the power company in 24 hours after the completion of the inspection. The second 50% was delivered 24 hours later. Both data from the robotic inspection as well as the manual inspection were able to be displayed into a single source of truth for the client, living in the Gecko PortalTM

Deliverables included:

  • Tube condition analysis (UT thickness data map every 1’ elevation)
  • Robotic visual inspection video/still frame
  • Manual UT/VT report
  • Post inspection debrief

The inspections revealed tube-level corrosion issues that plant maintenance staff could quickly address within the time frame of the planned outage.

How Success is Measured

Boiler Robotic Inspection

The speed of Gecko’s robotic and manual inspection of the assets, combined with rapid data delivery, ensured that all boiler tube issues could be repaired during the one planned outage.

Over the past year, the units that had caused unplanned outages on a fairly regular basis have remained online and reliable.

As a result, the client has engaged Gecko with ongoing inspection initiatives, to continue to help plant personnel identify and address asset integrity issues while minimizing outages.

Gecko Robotics Inspection Team (GRIT) has the ability to mobilize quickly, run robotic inspection platforms, all while being experts in ultrasonic testing methods in the traditional sense. Pairing the expertise of GRIT with innovation allows maintenance professionals to have confidence in their repair and maintenance programs and future plans.

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