Building an above ground storage tank is a big choice and investment for any company. So how do you navigate making the best choice in building an above ground steel storage tank (AST)? Like most products, quality of above ground tank fabrication boils down to sound design, quality material, and superior craftsmanship. So how does one measure these benchmarks for an AST? Look for the 3 hallmarks of reliable above ground tank fabrication: adherence to the API 650 Standard, Mill Certified Plate Steel, and Third-Party Weld Inspection.
Use of API 650 Standard
The international standard for above ground tank fabrication is API 650. This standard was developed and has been frequently revised by the American Petroleum Institute for above ground petroleum storage tanks. The need for a consistent standard arose out of combined war efforts for World War I and realizing that tanks and piping was not easily combined due to different designs and piping used by various companies.
The API 650 Standard is the culmination of expertise of the world’s best tank structural engineers as well as leading experts of using storage tanks, including tank owners. Based on the success and thoughtful revision of this standard from its original 1961 publication, the API 650 Standard is the gold standard in building any above ground steel storage tank where the product is stored at atmospheric pressure and is usually larger than 50,000 gallons.
What to remember about this Standard is that it sets the minimum requirements for the material, design, fabrication, erection, and inspection for vertical, cylindrical above ground tanks. When evaluating an above ground storage tank construction company, look at their adherence to the Standard. Cutting corners in use of the API 650 Standard decreases the strength of the tank design.
Based on this understanding of the API 650 Standard, you want to find a tank construction company that is well-versed in the Standard and adheres or goes above and beyond these minimum standards for tank design.
Mill Certified Plate Steel
Remember the adage that the proof is in the pudding? When it comes to above ground storage tanks, the proof is in the steel. The API 650 Standard sets the minimum requirements for the steel thickness and steel grade. Beyond these minimum requirements, the builder has the choice to use de-coiled steel or plate steel.
Plate Versus De-Coiled Steel
Using plate steel is a wiser choice to ensure the strength and accurate sizing of the steel for your tank. Plate steel is simply steel initially created in the plate sizes needed. De-coiled steel has been through the creation process and then rolled into large coils for storage. Once steel is needed, the steel is then de-coiled by heating and flattening the steel before it is cut. This reheating and bending of the steel can weaken the steel and just the general heating process can change the precise dimensions of the steel. Plate steel is preferred, because it is never reheated and is cut to the measurements needed for the project.
So how can you confirm that the steel in your above ground storage tank is truly plate steel? You must find a construction company that will give you the mill certifications for the steel. Make sure that there is a certification for all of the steel that is included in the tank and that the certification numbers match the numbers on the steel plates.
Third-Party Weld Inspection
The material of a product means nothing if the product is not well built. When it comes to ASTs, the welds are crucial to the strength and craftsmanship of tank. The best judge of a tank weld is an unbiased third party. The API 650 Standard recommends just that for inspection of tank welds once the tank is complete. However, the Standard does permit exceptions if the builder and buyer agree to have the builder inspect the tank. Don’t be an exception. Make sure to insist that a third party inspect the tank welds to ensure that they are strong and up to the code requirements.
Want to learn more about above ground tank fabrication? Please contact our professionals at Heartland Tank Companies, and we will gladly answer all of your questions for your specific tank needs.