The storage tank floor annular ring is a critical component of tank design, serving as the juncture where the shell and floor plates meet. These segmented plates extend under the tank shell wall, both outside and inside by a required distance, forming a ring around the tank floor periphery. Due to the position at the outermost perimeter and hence exposure to the elements and inherent corrosion, combined with the structural stress at the junction of the tank shell, the annular ring plating which is generally butt or lap-welded to the tank bottom sketch plates, is of a greater thickness than the remaining sketch plates. 

Traditionally, the inspection of the annular ring requires the tank to be drained to facilitate internal inspection. Whilst robotic inspection systems such as “RUVI OilDiver” offer on-line inspection, the thoroughness of inspection coverage due to peripheral region inaccessibility incurs inherent limitations. 

Our innovative approach used in conjunction with and to complement our RUVI OilDiver robotic on-line inspection (or used standalone) is PAars, an automated scanner attached to the tank shell wall. The system utilizes the integration of ultrasonic phased array and 0-degree, driven around the outer surface region of the annular ring. The system boasts the ability to detect plate defects at up to 1m distance from the probe contact position, and to accurately characterize up to 40cm. 

This inspection not only answers inspection requirements of this critical zone, but in conjunction with our RUVI OilDiver compliments the overall inspection thoroughness, whilst alleviating the need for tank drainage and manual entry associated with traditional methods. 

For a more comprehensive understanding of our technologies, and how we can help streamline your annular ring inspections process and to explore the benefits of this advanced approach, please feel free to reach out for further details.