High-capacity storage tanks are vital to many businesses and organizations, including manufacturing facilities, food processors, municipal water distribution systems, wastewater treatment facilities, power plants, the oil and gas industry, and fire protection systems. They are often used to store potable water for municipal water systems, chemicals for manufacturing, fire suppressants, food products, drilling fluids, dry goods or fuel, and to perform well they must be water-tight, easy to maintain and repairable.
Traditionally, large storage tanks have been either made from steel, which is welded together and finished onsite, or concrete, which is poured in place at the facility. Both types of tanks perform well, but have some serious disadvantages. Field-welded steel tanks can be difficult to finish properly at the site, leading to an increased probability of corrosion, and the welds must be thoroughly inspected after completion to ensure that the tank will not leak. Concrete tanks are exceedingly heavy, take large amounts of time to cure, and need constant resealing to prevent leaks.
A third option is bolted tanks, which use laser or die-cut steel panels that are bolted into place onsite. Bolted tanks offer the strength of steel, are quick to install and easy to maintain or repair.
Compared to concrete or field-welded steel tanks, bolted tanks from Gulf Coast Tank & Construction offer several distinct advantages.
#1 Quick Assembly
Steel tanks must be welded and inspected onsite and concrete tanks must be poured in place. Both require days of installation time, including plenty of labor and the associated costs, and if there happens to be inclement weather, the installation process can be delayed or postponed. Because bolted tanks are manufactured offsite and arrive in ready-to-assemble sections, installation is quick and easy, and it can be done in just about any weather.
Unlike field-welded or concrete tanks that must be sealed and coated onsite, bolted tanks come in pre-finished sections. Each section is manufactured at an environmentally-controlled manufacturing facility, where the metal is formed and welded, then the surface coating is applied before there is any chance of corrosion taking place. The bare metal is coated with a silica and zirconium liquid seal that inhibits corrosion and encourages adhesion of the final surface coating, which is an epoxy powder coating that is electrostatically applied and heat-cured to ensure a durable, corrosion-free finish. Because the metalwork and finishing work are done at a manufacturing facility, there is less pollution and waste involved in the finishing process.
Welded steel and concrete tanks are finished onsite, which often involves sprayed-on sealants that have environmental consequences if applied incorrectly, and the process can easily be delayed by bad weather, such as rain or wind, which can inhibit the curing of the sealant or lead to over-spray. In some municipalities, restrictions may be placed on how or when the sealants can be applied, leading to delays or high compliance costs. With no onsite finishing required, bolted tanks are much more convenient and environmentally friendly.
#3 Installation Flexibility
Bolted steel tanks allow installation flexibility that surpasses steel or concrete tanks. They are available in sizes ranging from 2500 gallons to over 2 million gallons, and they can be customized to fit the allocated installation space. For narrow areas, the tank can be built taller, and in wider ares, the width can be increased. Bolted tanks can be built over a grade band foundation, a concrete ring wall or a full concrete slab, depending on the project requirements and local regulations.
Should the need for more capacity arise in the future, bolted tanks can also be easily expanded with a minimum investment of materials and labor, unlike concrete or welded steel tanks, which would require considerable amounts of time, materials, and labor to either expand an existing tank or build a secondary tank. Because bolted tanks are built with modular panels, it simply requires more panels and the time and effort required to reconfigure and expand the existing tank.
#4 Easy Maintenance and Repair
Concrete and steel tanks need regular maintenance, including frequent resealing to prevent leaks or corrosion. They are also difficult to repair, requiring extensive labor and special tools to pour new concrete or to cut, weld and refinish a steel tank, which can lead to high material and labor costs.
Bolted tanks require minimal maintenance and last longer than welded steel or concrete tanks, and should a gasket ever leak, a panel corrode or an accessory such as a valve or door need to be repaired, the damaged part can easily be unbolted and repaired or replaced.
#5 Compliance with Industry Standards
Bolted tanks designed to store drinking water comply with the AWWA D103-09 & AWWA D103-97 standards, as well as the FDA and EPA requirements and NSF Standard 61 for potable water usage. Bolted tanks for other uses comply with AWWA D103 standards, using steel sheets that meet ASTM A1011 Grade 33 requirements and steel plates that meet ASTM A36 requirements. Fasteners are galvanized steel with neoprene-coated washers that meet API 12B and Appendix A standards. Bolted tanks also comply with NFPA, API and FM Global standards.
#6 Lower Shipping Costs
Because bolted tanks are shipped disassembled, they are more compact to transport than the large sections of a welded tank, reducing shipping costs. Compared to the materials required for a concrete tank, shipping costs are much lower for bolted tanks as well, because they are relatively light compared to concrete.
Bolted tanks are a cost-effective, durable and low-maintenance alternative to both welded steel and concrete tanks, and they can be used for just about any purpose, from storing water for town or village, to storing sand for a concrete factory. With so many advantages, they are an attractive alternative for any business or industry.