The thickness of bottom plate can be determined while the tank is in service with advanced UT solution that is installed on the Robot. High density UT data is collected with 8-Channel UT transducers by standard procedure of immersion testing. Robot can be moved to any area of interest inside the tank and thickness data can be collected during each run. In API RP 575 Section 7.4.4 the number of measurements taken for a statistical sampling will depend on the size of the tank and the degree of soil-side corrosion found. Typically, 0.2% to10% of the bottom should be scanned randomly. The collection of thickness data is required to assess the remaining bottom thickness.

Our advanced robotics is capable to operate in clay type sludge up to 60 cm.The clay type sludge can be cleaned by the suction pump that is installed on the Robot body .After the path is cleaned by suction ,Bottom plate can be inspected clearly by high definition Robot camera and thickness can be determined at the same time on the cleaned surface of tank bottom.

The critical zone access is the challenge during robotic tank inspection. Critical zone is the area 3 inches inward from the shell to bottom joint of a tank. This area is tested by applying SRUT (Short range Ultrasonic Testing) from external side of the tank on annular plate.

High definition PTZ(Pan Tilt and Zoom) camera on the front face of Robot gives a crystal clear image for the bottom plate and bottom media. The camera can pan, tilt and zoom and any area of interest can be seen clearly. The display of image is obtained on the control unit LED that is placed outside the tank.

Vapor space camera is for the inspection of vapor space that is the region called between liquid surface and the tank roof. This HD camera is able to rotate along 360 degrees and gives a very clear picture of inside vapor space.

External and internal inspection of the tank is performed by certified API 653 Inspector that contains the details of all normal and abnormal findings on the external and internal condition as applicable e.g condition of roof,stairs,nozzles and fittings, connected piping, tank foundation, Shell plates and weld joints etc. As per API 653 Annex C external inspection is performed on the tank. Annex C contains sample checklists illustrating tank components and auxiliary items that should be considered for internal and external inspection of tanks. This information is provided as guidance to the owner/operator for developing an inspection assessment schedule for any specific tank installation. The checklist format facilitates the recording of inspection findings.

There may be voids, cracks, flaws and other geometric and structural discontinuities in the tank foundation that can be assessed and evaluated for integrity by MIRA LITE .MIRA LITE is the advanced UT solution for assessment of all these.

External roof UT inspection is performed by conventional UT method. Spot UT thickness is performed on the roof and results are evaluated by API 653 section 4.2 to assess the integrity of Roof.

There are different outlet and inlet lines connected to the storage tank that may have flaws not present/visible on the surface but on the subsurface that may not be ensured tested 100% quantitatively .This solution is achieved by 3DSL Laser crack detection in a very quick and precise manner.

Visual inspection of bottom plate by Robot HD camera is of very high-resolution giving crystal clear image. The videos can be recorded during all the time of inspection activity.

In convention offline tank inspection there is no predication about MRT (Minimum remaining thickness) values for the un-checked floor areas during UT testing. When typical range recommended by API 575 section 7.4.4, 0.2% to10% of the bottom is scanned randomly ,the unchecked 90 % floor area can be assessed for worst case possible scenario with a proactive approach using EVA(Extreme Value Analysis) having 99.99 % accuracy obtained for MRT results. Capabilities of EVA software include various methodologies such as Weibull, normal, lognormal, and Gumbel (lower and upper) distributions, and variations of these, as well as likelihood plotting, confidence plotting, design comparison, probabilistic analysis, outlier detection, optimum replacement, failure forecasting, test substantiation planning, accelerated testing, and mixture analysis.