RMC-12-24 Avoiding Costly Repairs Of Storage Tanks By Performing Hydrostatic Test Exemption And Floor Settlement Assessments

Description:

Advanced integrity assessments based on inspection results can demonstrate that tanks and their components are fit for continued service, allowing tank operators to often postpone repairs until the next shutdown, eliminate the need for repairs or be exempt from hydrostatic testing. Improvements in inspection and computing technologies, coupled with the emergence of fitness-for-service standards, have advanced tank integrity assessments. Advanced inspection technolo-gies including ultrasonic testing (UT) and laser scanning provide detailed mappings of corrosion, settlement, bulging and denting of tank shells and floors. Quest Integrity Group assesses fitness-for-service and determines remaining useful life of tanks using finite element analysis (FEA) si-mulations incorporating the measured condition of the tank. Simulations include crack stability and propagation, shell buckling and floor settlement. This article presents three examples to demonstrate the benefits of advanced structural integrity assessments: hydrostatic test exemption, tank floor settlement and local thinning.