Bolted Tanks: “Designed to” vs. “Certified”

Bolted Tanks: “Designed to” vs. “Certified”

bolted tank

Most bolted tank companies use the term “designed to” when referring to industry and quality standards. At Superior Tank Co., Inc. we can positively confirm all of our bolted steel tanks meet or exceed the expected design and quality objectives.


Superior Tank has undergone the very rigorous API SPEC Q1 and ISO 9001:2008 certification process which reviews the various elements of bolted steel tank manufacturing including tank order, engineering, production, delivery, installation and service. During the certification, countless processes were audited to ensure policies and procedures were in place to guarantee our steel tanks comply with set standards, meet or exceed customer expectations and are delivered within the prescribed timeframe. For example, the external ISO audit team reviewed our procedure to exactly transfer all bolted steel tank specifications from the approved Sales Order to our Engineering Department for design.  Our Engineering Department maintains an extensive electronic central library of steel tanks and steel tank components which have been verified to industry standards and exact specifications. Starting with solid and consistent design elements ensures our bolted steel tanks will meet engineering performance standards.  Raw materials such as steel used for staves is verified to meet specific quality standards. For example, surface quality, edge quality, silicone content, squaredness and flatness are checked and materials not meeting standards are rejected. Inferior and low quality materials are never used. Another element of the certification process is making sure our ground storage tanks are manufactured to precise tolerances using the latest CNC and robotic welding machinery. Quality inspectors are located at key stages to ensure finished parts meet various established specifications. Any non-conforming parts are discovered during manufacturing stage and are rejected. At the completion of the production cycle, the various steel tank components are final inspected by a designated quality control auditor and the complete inventory of parts is compared to original production checklist for accuracy.


In addition to being certified under the API SPEC Q1 and ISO 9001:2008 process, critical aspects of our tanks have been tested by an independent laboratory. Our factory powder coating has been stress tested for various characteristics including resistance to abrasion, significant impact, salt spray, high humidity, temperature and corrosive chemicals. In separate testing, our Silica -Zirconium (SiZr) underseal was verified to prove its ability to prevent corrosion and coating undercutting if the powder coating is damaged by a thrown rock or dropped tool. In all areas of testing, our powder coated bolted steel tanks meet or exceed performance standards for durability.


We understand we could save money by eliminating our strict quality standards but we have witnessed competitor’s tanks fail due to inferior materials and processes and we are unwilling to compromise quality.


When purchasing your next bolted steel tank, look for companies which have been API SPEC Q1 / ISO 9001:2008 certified to ensure you are actually receiving what you ordered. At Superior Tank, we can confidently state that all of our bolted steel tanks meet or exceed design and performance expectations. We do not simply try to “design to”; we succeed!