Storage Tank Design & Selection

When it comes to upstream pumping, storage tanks usually have three defined uses: dry bulk tanks with hopper bottoms for storage of materials such as frac sand, liquid tanks for wastewater storage and processing and API 12B certified tanks for holding drilling fluids and unrefined oil.

The selection process for choosing a new storage tank can be challenging. All tanks may seem the same, but the material to be stored will determine the tank design needed. So, before approaching vendors, think about what is needed (and what isn’t) to get the best tank for the money.

Tank Construction

Two tank designs most commonly used in upstream pumping applications are field-welded tanks and factory-coated, bolted tanks. Field-welded tanks are shipped to the site in uncoated steel panels, which are welded together, inspected and then coated in the open air. Bolted steel panel tank designs receive their coating under monitored conditions at the factory, are tested during manufacturing and then shipped to the site and bolted with hardware and gaskets.

When it comes to speed of installation, the onsite process for field-welded tanks is longer, given the welding process, the required inspections and the on-site coating and coating testing processes. Field-welded tanks have specific labor requirements for installation, including certified welders as well as inspectors and painters. In contrast, bolted tank designs use a jack system to lift tanks and add rings at ground level. Because the panels are factory inspected and field ready, special labor is not required for installation. Therefore, bolted tanks have a shorter installation timeframe.

For many reasons, bolted tank designs that are coated at the factory are a more economical choice. They generally are used for storage volumes less than 6 million gallons. For storage of materials larger than this, tanks must be field erected and coated.