SIL Certified Overfill Prevention Systems
2016-02-09
There are many tank farms around the world. From a business point of view, you would think those tank farm operators would be interested in something other than overfilling a tank. How is that good for business? Yet, many tank farms still have inferior tank-level management systems and procedures. They are not in a position to manage overfilling properly and in a safe manner.
In the last couple of years, we have seen a few terrible tank farm accidents:
- In 1999, a tank farm explosion in Laem Chabang, Thailand
- In 2005, there was the Hertfordshire Oil Storage Terminal explosion in Buncefield, UK
- In 2009, the Sitapura Oil Terminal exploded in Jaipur, India
- In the same year of 2009, there was the Cataño Oil Depot explosion in Bayamón, Puerto Rico
In all four cases, the tanks were poorly equipped, poorly maintained and had poor safeguards - if they had safeguards in the first place. The tanks all had instrumentation installed, but that does not help much if it is not maintained correctly and when there are no additional safeguards in case of equipment failures. In the case of Buncefield, for example, the level switch had failed and was already out of service for one month. In Bayamón, the level measurement device had failed, and it took months to repair them. See the video at the bottom.
These companies needed to do proper risk assessments. Had they done this, they would not only have realised that an explosion is bad for business but also injures and kills people, destroys the environment and ruins their reputation in the market.
Because of the history of tank farm accidents, the industry and legislation in these countries are not sitting still. If companies do not learn from each other and keep having the same problems, then standards are created that support industry in implementing safety solutions. Nowadays, the IEC 61511 and API 2350 standards apply in the tank farm business. In countries like the UK and India, these standards and the methods they advocate, like HAZOP and LOPA, have become mandatory.
Also, legislation needs to have a 'wait and see' attitude. Legislation might move slowly, but legislation steps in when the industry cannot fix its problems. And once it is there, it is not removed very quickly. In India and the UK, the accidents have caused legislation to take action, and tank farms are now obliged to follow safety standards and implement state-of-the-art safety solutions.
Overfill Preventions Systems
An Overfill Prevention System is one of the most effective safety solutions against overfilling of a tank. There are two types of systems:
- Manual Overfill Prevention Systems (MOPS)
- Automatic Overfill Prevention Systems (AOPS)
The first system depends on an operator closing the valve after an alarm is generated due to overfilling. This solution requires a well-designed alarm system, correct procedures, and training for the operator when the alarm goes off. The second system takes care of overfilling by automatically stopping the flow into the tank when a certain level is reached. This system needs to be well-designed.
The MOPS and AOPS must be designed according to IEC 61511 and API 2350 according to where the tank farm is located. Building an Overfill Prevention System that works is not so difficult. But making it in a way that complies with the standard, and you can prove that, turns out to be a big challenge for most companies. This is where our certification services can help you. Whether you are an End User, an EPC, or a System Integrator, independent certification proves that you did your work in compliance with the standards.
Install Certified Overfill Prevention Systems
Risknowlogy certifies Overfill Prevention Systems according to IEC 61511 and API 2350. We approve not only the design but also the manufacturing process and the site installation. A certificate can be issued for each design if a manufacturer makes multiple designs. The end-user can select the desired design and ask the manufacturer to build it. To ensure the Overfill Prevention System is manufactured according to the certified design, we certify the manufacturing process, including FAT and iFAT. Some end users hire installation companies to install the Overfill Prevention System. To make sure that the certified manufactured solution is installed correctly in the field and also works, Risknowlogy offers Site Certificate. In practice, this means we verify that the installed Overfill Prevention System is the one that was manufactured, including SAT.
Risknowlogy Certified Overfill Prevention System exists at 20+ tank farms in 4 countries.