American Petroleum Institute Tanks

At Southeastern Construction, we design custom fabricated above ground, welded steel storage tanks that meet the exacting standards of the American Petroleum Institute (API).

API establishes standards for the design and fabrication of welded steel storage tanks for storing oil and other liquids. The API standard is applicable for stationary atmospheric and low pressure petroleum storage tanks used in all sectors of the petroleum and petrochemical industry. We serve customers in the oil and gas industry and beyond for their custom, over dimensional, API certified storage tanks in carbon steel and stainless steel.

Decades of Experience

Southeastern Construction has decades of experience in designing, fabricating, assembling, and inspecting API 620 and API 650 storage tanks. We are proud to be an API Accredited 12 acre, 65,000 square foot manufacturing facility in West Central Florida. We have the professional designers, welders, and fabricators needed to build your custom welded API storage tanks.

Examples of API tanks that can be fabricated:


  • Water treatments
  • Distillation tanks
  • Flocculation tanks
  • Separator tanks
  • Petroleum storage tanks
  • Chemical storage tanks
  • Storage tanks
  • Water storage tanks
  • Sulfuric acid storage tanks
  • Condensate tanks
  • Condensate storage tanks
  • Bulk tanks
  • Caustic tanks
  • Caustic storage tanks
  • Sludge tanks
  • Diesel tanks
  • Underflow tanks
  • Amine storage tanks
  • Oily water tanks
  • Water holding tanks
  • Sulfuric acid tanks

API 620 Tanks

The design of API 620 tanks has a single, vertical, centered axis of revolution and is used for materials with higher internal pressures such as liquified natural gas and cryogenic tanks. The API 620 requires a flat or elevated bottom in order to properly store the steel tank.

API 650 Tanks

The design of API 650 tanks allows them to store gas, oil, chemicals, water, and biofuel for common steel tanks in the oil industry. API 650 tanks need even support for the whole bottom and stored in non refrigerated facilities that have a maximum design temperature of 200 degrees Fahrenheit.

API Tanks are designed, fabricated, and delivered to your facility worldwide.

  • Meets API 620, API 650 standards
  • API storage tanks fabricated from carbon steel or stainless steel
  • Oversized, super load, custom heavy storage tanks
  • Lined internally for special applications
  • Can be used across many industrial markets

API Tank Industries Served

We serve the exacting needs of facility operators, EPC contractors, general contractors, and OEMs in oil and gas and multiple other industries.

Oil & Gas

Chemical Treatment

Food & Beverage Processing

Mining & Minerals


Power Generator

Water & Wastewater Treatment

Pulp & Paper

Waste Treatment



Structural Facilities AISC Certified

Standard for Steel Building Structures with the Sophisticated Paint Endorsement P2

Plate/Vessel Facility ASME Accredited

S and U Stamp Fabrications

AWS Certified Welding Fabricator

National Fire Protection Association Member

Fireline V Certified

Field Services Division National Board Accredited

R Stamp for Repairs, Alterations, and Rerating of Pressure Retaining Items

UL Certified

Supply Chain Certification

ISNetworld Contractor

Contact Us for an API Tank Quote