In Flanders it is mandatory to have storage tanks for hazardous liquids inspected by a certified environmental expert. According to VLAREM (Flemish regulations on environmental permits), this must be performed at least every 20 years. The interval for the next inspection is determined by the environmental expert depending on his experience and the findings during the last inspection.
Sea-Tank, an international company with tank farms in Antwerp and Ghent, is taking matters a stage further than VLAREM requires. In fact, they have opted to apply the methodology of RBI (Risk-Based Inspection) according to API 580-581 for their tank farms.
RBI: From data collection and corrosion study to inspection planning
Since the first release of API 580 in 2002, this methodology has been gaining ground in the chemical and petrochemical industries, but its application in tank farms in Belgium is still limited. The result of an RBI methodology is an inspection schedule where inspection times are determined based on risk: the product of probability of failure (POF) and consequence of failure (COF). Data collection and corrosion study form the essential basis that precedes RBI planning.
The corrosion study consists of a theoretical and an applied approach:
Theoretical corrosion study
Different integrity loops are defined as well as the theoretically possible failure mechanisms per integrity loop/material combination.
Applied corrosion study & Cor-life
The results of the corrosion study are further fine-tuned through team sessions. An estimate of the rate of progression of the mechanisms is also made for trending mechanisms. Subsequently, the results of this study are entered into an RBI software. METALogic uses its own developed RBI software: Cor-Life. The software generates inspection plans for the client on the basis of the information entered. With each inspection, new results are added to the system. The software can thus be regarded as a management system that learns dynamically.
The benefits of RBI according to Sea-Tank
Sea-Tank already chose to cooperate with METALogic in 2013 and has by now already gone through the entire process for a number of its tank farms. According to Sea-Tank, the benefits of this RBI approach are:
- increased knowledge related to possible degradation mechanisms tank farm;
- improved control of integrity;
- reduced risk of leaks or spills;
- better estimation of cost/timing for repairs.
Sea-Tank intends to apply the RBI methodology for other group sites in Belgium as well. After the implementation, the "evergreening" follows: the knowledge of the process and the plant evolves with time, as more inspection results are known or as installations/processes are adapted or improved. In that case, the model should be re-evaluated and a new inspection or action plan should be developed.
Applying the RBI method to your tank farm will therefore certainly prove fruitful. This prevents possible negative consequences for people and the environment, and saves you the associated costs, which can mount up considerably.
Our experts are ready to assist you throughout the RBI process. Do not hesitate to contact us if you have any questions or are interested.
Besides RBI, METALogic also offers other checks in the context of VLAREM, which you can find here.
