Everyday life is impacted by aboveground liquid storage tanks more than many realize. Fertilizer, water, oil, processing chemicals, and other liquids are stored in tanks before becoming part of the products and services the general population relies on every day.
While the basic purpose of a storage tank remains the same, vertical aboveground tanks are generally classified by one of two construction methods: shop-built or field-erected. The primary factor in choosing between the two is tank capacity, but the construction process, equipment, transportation requirements, and installation methods also differ.
Shop-Built Storage Tanks
The most obvious difference between shop-fabricated and field-erected tanks is size.
Shop-fabricated tanks are constructed at the tank manufacturer’s facility in a controlled environment. They are then transported to the installation site. Depending on the manufacturer, equipment, and transportation requirements, shop-built tanks can range from a few thousand gallons to approximately 30,000 to 50,000 gallons.
The practical size limit for a shop-fabricated tank is determined by the following factors:
- The manufacturer’s shop must have enough space and equipment to safely fabricate and handle the tank.
- The completed tank must be transportable from the shop to its final location.
Field-Erected Storage Tanks
When storage requirements exceed the practical limits of shop fabrication, a field-erected tank is typically the better solution.
Field-erected storage tanks can begin around 50,000 gallons and extend to several million gallons. Individual steel components are transported to the customer’s site and assembled there, allowing far larger tanks to be built. This process requires specialized equipment and a carefully coordinated construction process.
Bigger Tank, Bigger Equipment
Before the steel reaches the customer’s tank site, the material must be prepared for assembly. Heartland Tank, LLC uses a plasma CNC cutting system to ensure precision in cutting each piece of steel as well as efficient use of material. Bridge cranes are used to lift the large pieces of steel to and from the burn table.
On site, cranes are used to lift each steel sheet into place. The tank floor is built first and then steel sheets for the shell courses are positioned and welded to make the circular shape of the tank. Once all of the steel sheets are in place to create a shell ring, a double-sided girth welder can be used to weld the girth or round seams of the shell courses. After the shell courses are in place and the roof rafters are set, the crane places the roof plates.
Understanding the Difference
Understanding the differences between a shop-built and field-erected storage tank can help you determine which type of aboveground storage tank best fits your project. Transportation, available site space, construction equipment, installation requirements, and the intended use of the tank can all influence which approach is appropriate.
Learn More About Aboveground Storage Tanks
Heartland Tank, LLC and Heartland Tank Services, Inc. specialize in the construction, inspection, maintenance, and servicing of field-erected aboveground storage tanks.
Have questions about your storage tank project? Contact us at 800-774-3230 or use the contact form below.