HDPE Retail Fuel Tanks

Introducing HDPE Retail Fuel Tanks. Fuel stations have been erected in South Africa for many years. It used to be infrastructure that only the oil majors owned and operated.

Oil majors write many rules and regulations into their design manuals to specify exactly what they want and ensure a standardized design for each station.

South Africa recently changed its regulations, and anybody or any brand can now open a filling station in South Africa if they get approval and a license from the DOE (Department of Energy).

This has led to several new brands opening retail fuel stations with less stringent design codes and regulations while still following international practices and ensuring safety at all times.

The new entrants in the retail fuel market have also started challenging certain practices that have been followed for many years. This has led to them exploring different equipment suppliers, material selections and layouts for retail fuel stations.

Driven by innovation and commitment to the industry, a lot of effort has gone into optimizing the retail fuel station market and providing better value to existing and new clients. One area of specific improvement is material selection for underground fuel tanks.

For many years, retail fuel tanks were single-wall carbon steel tanks installed below the ground surface with no cathodic protection. Although these tanks are cheap to build and install, we find many instances where they have rusted through, and the fuel that was supposed to be stored in them contaminated the soil around them.

Most of the old fuel stations in South Africa still have these tanks installed, but as stations get refurbished, the latest design tanks with a double wall get installed. These double-wall tanks are a lot better than the single wall tanks, they have an inside carbon steel wall and an outside layer of GRP (glass reinforced plastic). They also measure the pressure in the cavity and can indicate when one of the layers starts leaking. With the outside layer of GRP, cathodic protection is unnecessary, although it can still be installed as a backup system.

South Africa has several companies manufacturing these types of tanks, and most international retail tank manufacturers can manufacture and supply them. China manufactures most of these retail fuel tanks worldwide, and competition from imports is very stiff.

The fact that retail sector clients are cost-sensitive, combined with cheap imports from China and mature technology, creates a dog-eat-dog market where price plays a major role in the supply of these retail fuel tanks.

This has led to the EPCM team exploring new designs and working with one of the world’s best High-Density Polyethylene (HDPE) large-diameter pipe design and manufacturing companies from Germany. A new HDPE retail fuel tank was born, which will change how retail stations procure and install tanks in the future.

This fuel tank will have a capacity of 50m3 (50 000 l) and weigh only 1.4 tons. This is in comparison to the 40m3 (40000l) double-wall tank weighing more than 7 tons.

Installation techniques will change completely, as large cranes will no longer be needed to move the tanks into position. This will also improve site safety and reduce logistics costs.

The cost of materials will be considerably less than the steel fabrication of these tanks, which will be a big cost savings for the client.

Corrosion will also be a thing of the past, as the 2-layer tank will have an HDPE outside layer and a Pipelon/PE inside layer. The outer layer will prevent corrosion on the tank, and the inside layer will stop fuel diffusion and prevent static loading. A core tube will be integrated between the two layers to ensure the correct stiffness is obtained. The combined layers should be antistatic, fuel-resistant and corrosion-resistant.

The dome will be produced using the same process and having the same layers without the core tubes needed for stiffness. The dome ends will be welded to the tank shell with the electrofusion welding process.

The new retail fuel tanks have undergone two years of testing in Germany, and the results have been a big success. The tanks are now ready to enter the market and be certified in accordance with local codes and standards.

As part of the optimization process of retail fuel stations in Africa, EPCM will drive the design and supply of these tanks. The outcome of installing one of these HDPE fuel tanks at your depot would improve your CAPEX during construction, your OPEX during operations and environmental challenges and potential liabilities in the future.

The design life of one of these tanks would be 100 years, compared to the normal tanks, which usually have to be replaced every 20 years. This will also have a big impact when retail stations change hands, as the current norm is to replace tanks and pumps when stations are sold or refurbished. This means that oil companies can see their tanks as assets rather than an environmental liability when selling to another company.

The EPCM team also constructs many large API 650 storage tanks and is currently investigating the use of HDPE in different layers to construct these tanks. This will also be a market-disrupting technology, as the current method of constructing API 650 storage tanks is to weld steel plates together on-site. This leads to many logistical problems in Africa and quality problems when welding the steel plates together.

By switching to HDPE storage tanks to store fuel, most of the material and machines needed to construct these tanks could be loaded in a few containers and shipped to the site. HDPE also does not have a long lead time, and construction periods would be shortened considerably.

The challenge when constructing above-ground storage tanks is selecting the material that will give the tank its structural integrity. Many options exist, with the core tube being the most basic solution and a mesh-like layer being a bit more complex. This is currently in the development stages, and more refinement is needed to produce a final product.

The extrusion and potentially 3D printing solutions are currently evaluated to determine the best options for the HDPE fabrication on site. Site conditions will also play a big role and should be closely monitored to ensure they do not affect the quality of the application. Creating a controlled environment would also work similarly to a welding hut on a pipeline that controls humidity and temperature.

Although a lot of hard work still needs to be done to get these products to the market, it’s a giant leap for tank fabrication globally, and in the next few years, the way tanks are built and installed will completely change.