(122a) Non-Intrusive Fitness for Service Evaluations of Critical Non-Metallic Aboveground Storage Tanks (ASTs): Ashland, Inc. Case Study

Periodic inspections and testing of chemical processing storage and manufacturing equipment play a critical role in supporting mechanical integrity and environmental health and safety principles. For the majority of such equipment, which are typically metallic, the inspection and testing strategies to assess and ensure asset integrity are often very straightforward and well understood and might include external and/or internal visual inspections, the application of conventional/advanced non-destructive technologies and/or more detailed computational engineering analysis. For non-metallic equipment, the inspection and testing strategies used for metallic equipment may or may not be appropriate to assess the condition of such assets; this could be further hindered if the equipment is in hazardous service where complete access to the equipment is limited for safety and environmental reasons.

This article describes the recent application of external visual inspections deployed together with off-the-shelf straight-beam ultrasonics technology to successfully assess the condition of a fiberglass reinforced plastic (FRP) aboveground storage tank (AST) in a toxic chemical service where access to the interior corrosion barrier was significantly limited. The testing methods and inspection methodologies will be described along with results and conclusions which confirmed the AST’s continued fitness for service. The cost savings in utilizing this inspection approach will also be reviewed along with inspection recommendations that were highlighted following the conclusion of this inspection.