In the bolted steel tank industry, two coating options are common; factory powder coating and glass-fused-to-steel coating. Each of the coatings has its own unique properties and characteristics when applied to bolted tanks and steel tanks for water storage.

Bolted tanks with a glass-fused-to-steel coating are attractive to potential buyers as the coating is non-porous and very rigid. The glass is applied directly to the steel then heated to 1500˚F to melt the glass and bond the glass to the steel. In theory, the glass coating isolates the steel from the liquids stored in the bolted tank. Unfortunately, the real world can be very different from theory. Ironically, the same properties which make the glass coating attractive for use with water storage tanks also make the coating vulnerable to cracking. The rigidity of the coating does not allow the glass to flex with the steel tank panels which expand and contract with temperature changes. This difference in expansion rates can lead to the coating cracking under stress. In addition, the extreme rigidity of the glass coating can help to resist very minor impacts but can lead to cracking if impacted with any significant force. When the coating on a glass-lined bolted tank cracks, the steel underneath is exposed and corrosion will likely occur. After the corrosion starts to spread, it can result in undercutting and the overall failure of the coating. As the glass coating is applied to the steel at the factory and melted at a very high temperature, it is not possible to fully repair a bolted tank with a glass-fused-to-steel coating. The only “fix” possible is to cover the cracked area with mastic. The proper way to ensure the panel does not experience corrosion and coating failure is to replace the entire damaged panel as glass-lining cannot be fixed or repaired in the field. The vulnerability of a glass-lined tank to impact makes it critical to protect the storage tank panels during shipping and installation as well as after the ground storage tank is installed. A dropped tool or thrown rock can result in an expensive repair and require the storage tank to be taken out of service to replace an entire panel.

Read More “We Don’t Crack Under Pressure!”

With winter weather coming, it is important to prepare your steel water storage tanks. Winter weather and colder temperatures will impact your steel storage tanks, no matter how severe the weather is.

Below are several techniques which can keep your potable water tanks in top operating condition:
 
• Inspect interior and exterior of tank for evidence of corrosion on metal surfaces
• Check screens on roof vents and overflow piping are intact
• Examine tank for potential areas of contamination such as roof hatches and other shell penetration
• Ensure all access hatches have working locks to prevent unauthorized entry
• Visually inspect tank interior for excessive levels of sediment
• Inspect tank for safety equipment such as anti-fall systems, roof tie offs and roof railing to ensure components are compliant with current codes.
• Perform coating assessment to evaluate remaining lifespan
• Review foundation integrity, remove organic debris and determine if potential seismic upgrades are required
• Install active tank mixing system to prevent ice buildup and maintain water quality
• Develop tank plan service/maintenance schedule
 

Read More “10 Tips on Tank Preparation for the Winter Season”

Some bolted steel tank companies’ warranty lasts only as long as you can see the taillights on their trucks as they leave the job site.  We take great pride in the quality of our bolted tanks and the skill of our tank installation teams. Superior Tank Co., Inc. backs all of its bolted tanks with one of the best warranties in the ground storage tank industry.

Over the last 30 years, Superior Tank has earned an outstanding reputation for customer service and our warranty coverage.  We are known for doing business the right way and taking care of our customers. We send out our people to resolve any issues with your steel tank. Our warranty does not require you to uninstall the part, ship the part back then wait for us to decide what to do next. Nor will we ever prorate the value of the part and send you a check and expect that will resolve the problem.

We understand the high cost of having your storage tank out of service or the extensive amount of damage a defective oil or water storage tank can cause. We design, manufacture and install all of our ground storage tanks NOT to have problems in the first place! Our API SPEC Q1/ISO 9001:2008 certification is evident of our commitment to quality.

Read More “No “Tail-Light Warranty” here!”

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!

In recent years, glass lined bolted steel tanks have become more frequent despite the higher initial cost. The arguments for a glass lined tank are simple: glass coating is non-porous and very rigid. Therefore, the theory is that liquids cannot reach the steel and cause corrosion, which could destroy the tank.

Unfortunately, there are a few details which impact performance of glass lined bolted steel tanks in real life. First, great care must be taken when shipping, unloading and installing steel staves to not crack the glass overlay as cracks will allow water and liquids to penetrate the enamel coating. A particular area of susceptibility is the edge of steel staves as the hard and brittle glass coating is vulnerable to impact. Even minor damage to the edge can result in a catastrophic failure of the enamel coating system. Once the glass lining has been compromised, the steel will begin to corrode under the glass coating, resulting in the coating delaminating. As the glass lining of the tank is fused to the steel at very high temperatures at the factory, this process cannot be replicated in the field. The only way to attempt to correct damage is by covering the area with mastic putty. Not only is this unattractive, but the putty mastic can peel off over time, re-exposing the damage underneath.

Read More “Glass Lined Bolted Tanks: I Can See Clearly Now…”