Inspectioneering Journal

Robotics for Internal In-Service Inspection of Aboveground Storage Tanks

By George C. Williamson, P.E., VP of Integrity, Risk Management & Litigation Support at Integrity & Emission Reduction Partners, LLC, and Steven Trevino, Vice President at Quasset, Inc. This article appears in the May/June 2021 issue of Inspectioneering Journal.


The conventional approach for tank floor inspection involves taking equipment out of service and performing a Confined Space Entry (CSE). CSE includes de-inventorying, fluid transfer, cleaning, hazardous waste disposal, and many other activities, some which may be hazardous. This approach can take months to complete for large tanks. Asset owners may incur high costs and potential revenue losses from unavailable tanks in critical production service. 

Robotic inspection tools and application procedures are available for implementation in and around potentially explosive atmospheres. Often tanks need not be de-inventoried or cleaned for in-service inspection using robotic tools. This type of robot can be inserted through a deployment assembly attached to a manway on the tank roof (Figure 1). Most robots are remotely controlled and connected by an electrical umbilical cord back to a control module (Figure 2). The robot is lowered into the tank and propelled along the tank bottom.

The types of hazardous fluid tanks that are inspected with in-service robots now include crude oil, jet fuel, kerosene, diesel, lube oil, gasoline, other hydrocarbon distillates, and chemicals. The technology provides a method that in some cases can meet tank floor coverage requirements in API 653 [1].

Figure 1. Deployment assembly on tank roof. Image courtesy of Diakont Advanced Technologies, Inc.
Figure 1. Deployment assembly on tank roof. Image courtesy of Diakont Advanced Technologies, Inc.

This content is available to registered users and subscribers

Register today to unlock this article for free.

Create your free account and get access to:

  • Unlock one premium article of your choosing per month
  • Exclusive online content, videos, and downloads
  • Insightful and actionable webinars
Interested in unlimited access? VIEW OUR SUBSCRIPTION OPTIONS

Current subscribers and registered users can log in now.

Comments and Discussion

There are no comments yet.

Add a Comment

Please log in or register to participate in comments and discussions.

Inspectioneering Journal

Explore over 20 years of articles written by our team of subject matter experts.

Company Directory

Find relevant products, services, and technologies.

Training Solutions

Improve your skills in key mechanical integrity subjects.

Case Studies

Learn from the experience of others in the industry.


Inspectioneering's index of mechanical integrity topics – built by you.

Industry News

Stay up-to-date with the latest inspection and asset integrity management news.


Read short articles and insights authored by industry experts.

Expert Interviews

Inspectioneering's archive of interviews with industry subject matter experts.

Event Calendar

Find upcoming conferences, training sessions, online events, and more.


Downloadable eBooks, Asset Intelligence Reports, checklists, white papers, and more.

Videos & Webinars

Watch educational and informative videos directly related to your profession.


Commonly used asset integrity management and inspection acronyms.