Petroleum Storage Tanks – Overfill Prevention and Containment

Facilities with aboveground and underground storage tanks for petroleum products must make spill prevention a priority. A single faulty overfill prevention valve can cause massive losses, environmental hazards, and risk to people and property. Furthermore, businesses may have to pay hefty penalties imposed by regulating agencies in case of an overflow, and this can further damage reputation and trustworthiness.

Using an outdated fault management system to prevent overflows is simply not enough. Incidents like the Buncefield fuel depot that took place in the UK in 2005, and the CAPECO facility that took place in Puerto Rico in 2009, show that we need safe and reliable measures and additional layers of protection.

Future-ready features are essential to petroleum tank overfill prevention and to avoid the buildup of flammable vapor, which can catch fire and contaminate the environment. The massive explosions in both cases mentioned above damaged a great deal of property, polluted water, and caused billions of dollars in liabilities.

How to Achieve Overfill Prevention?

Most petroleum product storage facilities are equipped with one or more of the following safety mechanisms to avoid overfill accidents.

• Category 1: Overfill Prevention Systems
  • These systems require manual gauging of liquid levels in the tank and require human personnel surveillance throughout the filling operation to close the valves when required. Level instrument readings (if any) are local without an alarm, and no monitoring data is transmitted to a central control room for further study.
• Category 2: Overfill Prevention Systems
  • This mechanism of overfill prevention depends on Automated Tank Gauging (ATG) and transmits gauge data to a central control room. In case of an overfill, alarms automatically go off. However, manual intervention is required to switch off the safety valves to either stop or divert the flow of the filling operation.
• Category 3: Overfill Prevention Systems
  • This is a combination of ATG and Overfill Prevention System (OPS) alarm equipment. The level-sensor for alarm activation is either a point level device or a continuous level device. A local or remote hand switch triggered by electrical, pneumatic, or another operator on the valve achieves the termination or diversion of the filling operation.

Automated Overfill Prevention Systems

These systems are usually installed in fully automated and unattended facilities, and they are an additional measure to the Automated Tank Gauging and the independent OPS alarm systems.

A risk analysis is performed to assess the Safety Integrity Level (SIL) to ensure that the tank is adequately protected from the consequences of overflow. Automated Overfill Prevention Systems (AOPS) help monitor fuel levels in the tanks and automatically regulate the inflow based on the measurements sent via sensors installed in the tank.

They shut down the flow of oil through emergency check valves. Sound and flashing beacon alarms are set to go off to alert the monitoring team in case of overfills. Similar systems can be installed in both aboveground storage tanks and underground tanks.

Why Automated Overfill Prevention Systems Are Important

Industry best practices for storage tanks now combine current API 2350 prescriptive standards with IEC 61511 functional safety standards. These add to other pressures tank farms commonly face – the need to reduce maintenance costs, maximize productivity, and to fill knowledge gaps to empower the workforce.

OPS for petroleum storage tanks today need to go beyond ensuring safety – they must eventually help reduce commissioning time and costs and help you cut down on maintenance expenses.  Here are some benefits Automated Overfill Prevention Systems (AOPS) offer.

•   Detailed, automated warning messages to make improved savings and safety for your entire depot possible.
•   Safe time with unattended multiple fillings executed simultaneously – this is not possible in simple systems.          
•   A completely automatic and documented proof test of the entire system increases transparency – and can be done without dismounting devices.
•   An automatic OPS system enables reduced reaction times to shutdown, making increased tank capacity possible.

Spill Mitigation and Containment

Besides fail-safes, any business needs to prepare for worst-case scenarios. Failure in the system, no matter how improbable, can lead to unforgiving, uncontrolled spillage.

Your response plan will need to factor in quick containment measures and seasoned partners in fire damage and spill mitigation. Portable fluid storage tanks like frac tanks can be used with portable containment berms as part of your emergency response to minimize loss of fuel and damage.

Frac tanks of up to 21,000 gallons are specifically designed to hold hazardous fluids and are already used in the maintenance of petrochemical plants. They can act as temporary storage tanks that contain the spilled fuel, while the main storage tank and the OPS can be checked for faults.

If you are looking for experienced flow containment, vapor recovery, and spill mitigation partners who are effective and responsive, you need not look further.

How Can Ironclad Environmental Solutions Help?

In case of emergencies and spills, Ironclad Environmental Solutions provide a range of solutions for safe and reliable on-site storage of petroleum products using OSHA-compliant frac tanks.

•   Our 21,000-gallon closed-top frac tanks are ideal for storing flammable petroleum products. They come with an external manifold for easier access, quick-draining, and inline tank sets. These frac tanks have a steel interior, multiple 4″ valved fill/ drain ports, 8″ vent with 1 lb. pressure, and a V-shaped bottom for quick drain out and cleaning.
•   The 8,400-gallon closed-top mini tanks are useful in tight spaces and are compatible with roll-off trucks. Our frac tanks come with audible alarms, strobes, and digital and mechanical gauges to monitor stored liquid levels. They have a bare steel interior, 3″ fill line, multiple 4″ valved/ drain ports, and 4″ vents with 1 lb. pressure/ 4 oz. vacuum pressure release valve.

We also offer portable spill containment berms in custom sizes for all sorts of projects. Head over to our oil & gas solutions page to find the right answers to your storage and containment needs.

Contact our expert support team and rapid response teams that are available 24/7/365. We ensure a seamless onsite experience when every second is important. Our industry-leading and purchase-ready frac tanks are fit to fulfill your project needs any time of the year. Contact us for more information or request a quote for frac tanks for emergency spill containment.