Bolted Storage Tanks - Design & Engineering

What products can be stored in bolted tanks?

Any liquid with specific gravity of 0.85 and higher can be stored in abolted tank. Special applications such as aggressive and corrosive liquids can also be stored in a bolted tank but for applications such as these, it should be reviewed on a case by case basis.

The most common products stored in bolted tanks are: potable water, fire water, waste water, industrial waste, leachate, petroleum fluids, process water, mining fluids/slurries, tailing fluids, food & beverage, frac water as well as dry bulk storage.
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Are there concerns with bolted tanks leaking?

No. When constructing a bolted tank, the joints are sealed either with gaskets or sealants. As long as this is done right, and the correct gasket or sealant is chosen for the application, leaking will not occur. Hydrostatic testing upon erection also ensures a leak proof system prior to commissioning.
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Do you meet Fire Water and/or Potable Water storage requirements?

Yes. Our tanks can be designed to fully comply with NFPA 22 requirements for Fire Water Storage applications. Our coatings and sealants/gaskets are also NSF-61 approved for Potable Water storage.
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What pressure and temperature can bolted tanks be designed to?

Internal Pressures up to 6 kPa and External Pressures up to 0.5 kPa.

For temperatures, our tanks can be operated up to +95°C continuously with excursions up to 110°C. For Cold temperatures, our tanks have been installed in areas with temperatures as low as -50°C.
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Can Cathodic Protection systems be added to bolted tanks?

In general, corrosion is not an issue with bolted tanks given the high performance of the shop-applied coatings. All components are coated on all sides during manufacturing including the underside of the steel floor, so there is no bare metal on the tank. If desired by the owner, sacrificial anodes may be incorporated in the tank upon request.
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How do you prevent liquid from freezing at cold temperatures?

Typical mitigations against freezing include insulating the tank, agitating or circulating the tank contents and the installation of tank heaters. However, there are many possible solutions based upon the product being stored and how the tank is planned to be operated.
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Can you engineer and construct the tank foundation?

Yes, we routinely design, and install the foundations for our tanks. If preferred, we can do the design for the foundation and the General Contractors have the option of doing the installation work themselves.
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What are your limitations for building in cold weather and harsh climate conditions?

Our tanks offer factory-manufactured sheets that are assembled on-site which results in minimal limitations due to weather or environment conditions. We have experience building during harsh climates for projects located in northern BC, Alberta, Saskatchewan and Manitoba during the winter months.

When using Flat Panel Tanks with joint sealants, it is important to note that the sealant will not be cured in sub-zero temperatures; generally after erection of the tank in cold temperatures, the tank is hydrotested in the coming spring months; If time is of essence, heating and hoarding has been used to speed up the curing process and commissioning.
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Can you build in confined areas and inside buildings/structures?

When tanks are to be added to an existing confined area such as underground mining facility, basement area or existing buildings with equipment in place, our tanks are the best solution. Panels are handled individually and can be maneuvered through tight areas; for our flat panel tanks, by utilizing our jacking system and installing the tanks from the ground up, there is no need for heavy lifting equipment and as a result, minimal laydown area around the perimeter of the tank is required.

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How do the nozzles and other attachments connect to Bolted Tanks?

All attachments to bolted tanks are through a bolt up connection. Nozzles are welded and built as a separate entity in the shop and are bolted to the tank shell through a nozzle backing plate. These plates are sealed in the same manner as all of the other joints on the tank.

Other attachments such as ladders, pipe supports etc. are connected to the tank shell with a clip bolted and sealed through the tank walls.

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Would a welded floor be safer in terms of leak concerns?

No. Both floor types (bolted and welded) are tested to the same industry accepted standards (API or AWWA) and both will generally be equipped with the same leak detection system. Where the two floor styles differ is in how a leak (if detected) is repaired.

A bolted tank floor leak can be fixed by simply adding extra sealant or re-tightening the bolt(s). A repair to a welded floor is much more complicated, it involves hot work and welding and their corresponding NDE testing, followed by a re-coating of the affected area.

One of the unique benefits of a bolted tank is that the steel receives its final coating at the factory. This means that both sides of the floor sheets are coated to the same high standard, limiting the corrosion potential from inside and outside the tank. This feature eliminates the need for additional corrosion allowance and cathodic protection, which would be generally required on a welded floor where the underside is uncoated.

To learn about fixing a bolted floor leak, see “How do you repair a Leak?”.
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