EPMICS | BLOG
The Art of the Roll
A Deep Dive into Vertical Steel Tanks (VST)
A Deep Dive into Vertical Steel Tanks (VST)
In the world of industrial storage, there are two ways to build a tank: the slow way, and the smart way. At EPMICS-Engineering, we generally prefer the latter. While the traditional “plate-by-plate” assembly method has its charms (if you enjoy watching paint dry or logistical nightmares), the Roll-up (Coiling) Method has revolutionized how we think about bulk liquid storage.
Whether you are storing crude oil in the Fujairah port or desalinated water in Dubai, understanding the structural elegance of a roll-up tank is essential.
Whether you are storing crude oil in the Fujairah port or desalinated water in Dubai, understanding the structural elegance of a roll-up tank is essential.
1) Applications: Where do they live?
Vertical Steel Tanks (VSTs) of the roll-up type aren’t just for show; they are the workhorses of the energy and utility sectors.
We typically deploy these for:
Vertical Steel Tanks (VSTs) of the roll-up type aren’t just for show; they are the workhorses of the energy and utility sectors.
We typically deploy these for:
- Petroleum & Refineries: For the storage of crude oil, diesel, and bitumen.
- Water Treatment: Essential for desalinated water reserves and industrial wastewater.
- Cooling stations: For accumulating the chilled water to reduce peak load on chillers.
- Chemical Industry: Safe containment for non-aggressive and slightly aggressive liquids.
- Agriculture: Bulk storage for liquid fertilizers and grain.
2) The Competitive Edge: Why Roll-up?
The EPMICS Perspective: By shifting the heavy lifting – specifically the welding of the tank wall – from the dusty field to a controlled factory environment, we reduce the “human error” factor significantly. It turns out that robots in a factory weld better than a tired human in 45°C heat. Who knew?
Feature | Roll-up Method | Plate-by-Plate Method |
Welding Quality | 80–90% performed in-shop (automatic). | 100% performed on-site (manual). |
Speed | Up to 3–4 times faster. | Weather-dependent and slow. |
Logistics | Compact rolls; easier to transport. | Dozens of loose plates; high loss risk. |
Labor Cost | Minimal site crew required. | Large army of welders needed. |
The EPMICS Perspective: By shifting the heavy lifting – specifically the welding of the tank wall – from the dusty field to a controlled factory environment, we reduce the “human error” factor significantly. It turns out that robots in a factory weld better than a tired human in 45°C heat. Who knew?
3) The Sequence of Execution: Eight Steps From Coil to Castle
At EPMICS-Engineering, we manage the transition from a flat sheet of steel to a towering reservoir through a choreographed sequence of events.
Step 1: Survey
To design it accurately, we have to understand in what particular conditions your future tank will be operated, for what purpose, what is around. Is it a “greenfield” or “brownfield”? What are the soil properties? Are there any existing underground pipelines or communications? Geological and geodetic data are supposed to be obtained to be accounted in design. You can provide us with all this data if it’s available or we can arrange the turn-key survey from our side.
At EPMICS-Engineering, we manage the transition from a flat sheet of steel to a towering reservoir through a choreographed sequence of events.
Step 1: Survey
To design it accurately, we have to understand in what particular conditions your future tank will be operated, for what purpose, what is around. Is it a “greenfield” or “brownfield”? What are the soil properties? Are there any existing underground pipelines or communications? Geological and geodetic data are supposed to be obtained to be accounted in design. You can provide us with all this data if it’s available or we can arrange the turn-key survey from our side.
Step 2: Design
We’ll design the tank specially for you… It can be more or less standard design or deeply customized in all aspects: capacity, size, internals, protective coating, heat insulation, accessories… The foundation design is based on soil investigation report, the nozzle schedule is customized for connections to the system. By the way, if needed we could design and equip the whole system around the tank, but well, it’s another story…
We’ll design the tank specially for you… It can be more or less standard design or deeply customized in all aspects: capacity, size, internals, protective coating, heat insulation, accessories… The foundation design is based on soil investigation report, the nozzle schedule is customized for connections to the system. By the way, if needed we could design and equip the whole system around the tank, but well, it’s another story…
Step 3: Fabrication and Delivery
The key part of the tank is ready-made rolls which will be converted into the tank. Up to 85…90% of welding will be performed in factory environment, mostly by automated machinery, with full cycle non-destructive control of welding. The rolls will be made with specialized equipment, accounting geometry of the tank’s walls, bottom and top. Depending on application the internals will be supplied along with rolled tank as well as all other accessories, like stairs, service platforms, inner pipes, fittings, etc. When required, the heat insolation and specific inner coating, external cladding and paint will be supplied with the rolls.
The key part of the tank is ready-made rolls which will be converted into the tank. Up to 85…90% of welding will be performed in factory environment, mostly by automated machinery, with full cycle non-destructive control of welding. The rolls will be made with specialized equipment, accounting geometry of the tank’s walls, bottom and top. Depending on application the internals will be supplied along with rolled tank as well as all other accessories, like stairs, service platforms, inner pipes, fittings, etc. When required, the heat insolation and specific inner coating, external cladding and paint will be supplied with the rolls.
Step 4: Foundation Preparation
Before the steel arrives, we ensure the ground is ready. This involves a slab on top of piles field or a concrete ring wall with sand-and-bitumen cushion - what the geology says. To make your reinforcement easy to install, corrosion resistant and durable in concrete the basalt FRP rebars could be the best choice.
Pro tip: Gravity is unforgiving. If the foundation isn’t level, your tank won’t be either. But do not worry, we will check upfront.
Before the steel arrives, we ensure the ground is ready. This involves a slab on top of piles field or a concrete ring wall with sand-and-bitumen cushion - what the geology says. To make your reinforcement easy to install, corrosion resistant and durable in concrete the basalt FRP rebars could be the best choice.
Pro tip: Gravity is unforgiving. If the foundation isn’t level, your tank won’t be either. But do not worry, we will check upfront.
Step 5: Installation
All work at site is to be done in accordance with detailed and customized method statement which we deliver upfront. Usually, the installation sequence is:
All work at site is to be done in accordance with detailed and customized method statement which we deliver upfront. Usually, the installation sequence is:
Bottom Plate Assembly
The bottom plates are shipped in rolls or segments. They are laid out, joined by lap welding, and tested for vacuum tightness. Prefabricated. Ready for prompt installation… Once done the wall’s supports are welded to make site ready for unrolling of the walls…
The “Unrolling” (The Magic Part)
The tank shell, which has been pre-welded and rolled into a tight coil at the factory, is stood upright using a specialized jig and a crane.
We then begin the unrolling process along the perimeter of the bottom plate: tractor pulls the coil to unroll it. With just two final welding joins… Bottom and the final vertical seams are closed. These are particularly two of the few critical welds done on-site, and we treat them with the reverence they deserve (and plenty of X-ray testing). You could see your tank positioned in just a couple of days!
The bottom plates are shipped in rolls or segments. They are laid out, joined by lap welding, and tested for vacuum tightness. Prefabricated. Ready for prompt installation… Once done the wall’s supports are welded to make site ready for unrolling of the walls…
The “Unrolling” (The Magic Part)
The tank shell, which has been pre-welded and rolled into a tight coil at the factory, is stood upright using a specialized jig and a crane.
We then begin the unrolling process along the perimeter of the bottom plate: tractor pulls the coil to unroll it. With just two final welding joins… Bottom and the final vertical seams are closed. These are particularly two of the few critical welds done on-site, and we treat them with the reverence they deserve (and plenty of X-ray testing). You could see your tank positioned in just a couple of days!
Stiffening and Roof Installation
As the wall unrolls, we install the top edge stiffness ring and the roof structures (conical or dome). This prevents the tank from turning into a giant, expensive soda can if the wind picks up. For relatively small tank it’s usually conical structure which transforms to roof from prefabricated roll just by upping it, or frame-type structure for larger diameters, or roof assembled from prefabricated segments.
Other welding: accessories and nozzles
Ready-made metal structures for ladders, maintenance platforms, lightning rods, etc. are installed on the tank and welded to pre-installed integrated reinforcements. Then fittings are welded into the tank... Done!
As the wall unrolls, we install the top edge stiffness ring and the roof structures (conical or dome). This prevents the tank from turning into a giant, expensive soda can if the wind picks up. For relatively small tank it’s usually conical structure which transforms to roof from prefabricated roll just by upping it, or frame-type structure for larger diameters, or roof assembled from prefabricated segments.
Other welding: accessories and nozzles
Ready-made metal structures for ladders, maintenance platforms, lightning rods, etc. are installed on the tank and welded to pre-installed integrated reinforcements. Then fittings are welded into the tank... Done!
Step 6: Hydrostatic Testing
Ready-made metal structures for ladders, maintenance platforms, lightning rods, etc. are installed on the tank and welded to pre-installed integrated reinforcements. Then fittings are welded into the tank... Done!
Ready-made metal structures for ladders, maintenance platforms, lightning rods, etc. are installed on the tank and welded to pre-installed integrated reinforcements. Then fittings are welded into the tank... Done!
Step 7: Internals
Well, if you need a large tank for some reason, then most likely you will have something to store in it... Oil, diesel, bitumen? Or just a reserve of water for firefighting? Or is it intended for hot/cold water separation in cooling systems? For every application it can be equipped with specific internal devices and protected with suitable internal coating.
Well, if you need a large tank for some reason, then most likely you will have something to store in it... Oil, diesel, bitumen? Or just a reserve of water for firefighting? Or is it intended for hot/cold water separation in cooling systems? For every application it can be equipped with specific internal devices and protected with suitable internal coating.
Step 8: External
If heat insulation is required, then it's time to get it done. It could be spraying of the polyurethane foam, or basalt wool, or just painting with nano-ceramic spheres coating... Remember, we have discussed it in detail at design. Let's proceed accordingly. Cladding… All that remains is to attach a stencil with your logo.
If heat insulation is required, then it's time to get it done. It could be spraying of the polyurethane foam, or basalt wool, or just painting with nano-ceramic spheres coating... Remember, we have discussed it in detail at design. Let's proceed accordingly. Cladding… All that remains is to attach a stencil with your logo.
4) Navigating the UAE Landscape with EPMICS-Engineering
Operating in the UAE requires more than just engineering – it requires an understanding of local regulations, or ADNOC/DEWA standards, and the unique challenges of the Middle Eastern climate.
Operating in the UAE requires more than just engineering – it requires an understanding of local regulations, or ADNOC/DEWA standards, and the unique challenges of the Middle Eastern climate.
EPMICS-Engineering offers a true end-to-end partnership:
- Design & Documentation: We produce full and detailed engineering packages (API 650/620) that pass local authority inspections with flying colors.
- Procurement & Supply: We source high-grade steel and handle the complex logistics of delivering “rolls” to your site.
- On-site Execution: Our specialist teams handle the mounting, welding, and testing, ensuring your project doesn’t become a permanent construction site.