Tank inspections are critical components of every operator’s Integrity Management Program. Inspection plans can be disrupted for many reasons, including political instability, socio-economic pressures, operational factors and extreme weather events. With limited resources at hand, operators need to prioritize and optimize their inspection activities to ensure reliable and safe operation of their assets.

We help to develop risk-based inspection (RBI) plans that will provide recommendations on the optimal inspection interval, location and technology as well as the correct interpretation of inspection results to balance expenditures between low-, medium- and high-risk items. Risk-based inspection (RBI) comprises the calculation of the probability and consequences of failure, for both tank bottoms and shells, obtaining the risk of failure as a function of time for each tank component. The assessment methodology is based on the guidance given in API Recommended Practices 580/581.

 

Risk Time Function

Figure 2: Inspection planning

Figure 1: Risk time function

Inspection Planning

Figure 2: Inspection planning

Figure 2: Inspection planning

Inspection Prioritization

Figure 3: Inspection prioritization based on risk analysis. Current risk and projected risk at next inspection date.

Figure 3: Inspection prioritization based on risk analysis. Current risk and projected risk at next inspection date.

 

The prioritization of tank inspections is established based on different risk criteria, such as the maximum acceptable risk and the risk-time-function for each tank component. In this way, a RBI target inspection date is defined.

Our experts in corrosion management, risk analysis and inspection technology support operators in optimizing their integrity management process and in determining appropriate, cost-effective risk control measures based on the following information:

  • Design and construction data
  • Inspection history
  • Economic factors, such as costs for clean-ups and production losses