Fitness-for-service tank evaluations are performed utilizing appropriate assessment methodologies to ensure compliance with required standards, and for any significant repair or alteration to ensure that the tank continues to meet the necessary design requirements. These include:
- Leak-before-break (LBB) evaluation for preventive or mitigation measures (i.e., containment integrity)
- Hydrotest exemption for API653 tanks after reconstruction or repair (U.S.A.).
- Compliance to inspection requirements in AS/NZ 3788 (Australasia) for API620 storage tanks
- Guidance on optimizing maintenance and inspection required for continued service
API620 tanks are required to ensure containment integrity through a leak-before-break fracture mechanics assessment. The implementation of the LBB concept has several positive impacts such as (i) improving the monitoring of the plant and (ii) ensuring safe access for non-destructive testing (NDT) or regular maintenance.
API653 tanks, after repairs or alteration, can be exempted from costly hydrotesting requirements provided they meet the fitness-for-service evaluation criteria, in an assessment performed by a qualified engineer.
Quest Reliability has a multidisciplinary team of highly versatile and skilled engineers who will provide such comprehensive engineering tank assessments, including field inspections, and review of tank designs and operating history. High-level FFS evaluations are routinely performed using a combination of finite element stress modeling and established fracture mechanics concepts through Quest Reliability’s commercially available software – Signal FFS™ and FEAFlaw.
These tools also enable more advanced methodologies to be applied, such as evaluating the probability of making an LBB case through a statistical analysis of physical variables pertinent to the LBB concept or determining appropriate inspection intervals.
Signal FFS™ replaces and incorporates the features of two earlier generation Quest Reliability products – FractureGraphic and PetroFit – and adds many features and updates to current codes.
For further information about Above Ground Tanks, please contact us.