Crude Oil Storage Roofs: Floating and Geodesic Dome

Crude oil storage roofs control evaporation and keep vapor and rain out of large hydrocarbon tanks, and the two proven options are the external floating roof and the aluminum geodesic dome roof. Built for API 650 welded shells of 100-150,000 m3, Shijiazhuang Zhengzhong Technology Co., Ltd. (Center Enamel) supplies clear-span aluminum geodesic dome roofs in 6061-T6 aluminum with a 30-50 year design life.

What a Crude Oil Storage Roof Is

A crude oil storage roof is the top closure of an API 650 welded tank that limits vapor loss and weather entry. The external floating roof rides on the product with a 6-40 mm shell and a pontoon deck, while the aluminum geodesic dome roof is a clear-span 6061-T6 structure up to 75 m that caps any tank. Both target a 30-50 year life with low maintenance.

• Shell: API 650, 100-150,000 m3.
• EFR: pontoon on product.
• Dome: clear span 75 m.
• Life: 30-50 years.

How the Roof Controls Vapor

The external floating roof cuts the vapor space to near zero by sitting on the oil, using a rim seal and a drain to manage the 6-40 mm shell movement. The aluminum geodesic dome roof seals the tank with EPDM or PVC and a 6-12 kg/m2 self-weight that adds almost no load to the 30-50 year shell. Both keep the hydrocarbon at -20 to 60 C under the design pressure.

• Seal: rim seal or EPDM.
• Weight: 6-12 kg/m2 dome.
• Temp: -20 to 60 C.
• Span: up to 75 m.

Key Roof Types and Components

The family covers the external floating roof, the internal floating roof, and the aluminum geodesic dome roof, each with its own deck, seal, and access. Core parts are the 6061-T6 aluminum panels, the EPDM or PVC seal, the manway, and the catwalk. A documented EN 1090 and API 650 calculation is the feature that qualifies the roof for hydrocarbon duty.

• Panels: 6061-T6 aluminum.
• Seal: EPDM or PVC.
• Code: EN 1090 / API 650.
• Access: manway plus catwalk.

Applications of Oil Storage Roofs

They serve crude terminals, refineries, and fuel depots where evaporation loss and fire risk must be controlled on 100-150,000 m3 tanks. The aluminum geodesic dome roof is also used on water and clean-product tanks where a clear span up to 75 m removes internal posts. The light 6-12 kg/m2 weight is why the same dome fits both new and retrofit shells.

• Terminals: crude and fuel.
• Refineries: product tanks.
• Water: clear-span dome.
• Retrofit: any shell.

Technical Considerations

Technically the welded API 650 shell uses 6-40 mm plate for the hydrostatic head, the roof is designed for -20 to 60 C and a 30-50 year life, and secondary containment (bund or double) controls spills. The aluminum geodesic dome roof is calculated to EN 1090 and API 650, sealed with EPDM or PVC, and rated for wind up to 200 km/h and snow up to 1.5 kN/m2.

• Plate: 6-40 mm shell.
• Code: API 650 / EN 1090.
• Wind: up to 200 km/h.
• Life: 30-50 years.

How to Select an Oil Storage Roof

Select by matching the product volatility, the tank diameter (up to 75 m for a dome), and the local wind or snow load to a roof that meets API 650 and EN 1090. Ask the supplier for the dome span calculation, the EPDM or PVC seal detail, and the reference roofs. Reject any offer that cannot show the wind and seismic rating for the site.

• Match: volatility and span.
• Confirm: API 650 / EN 1090.
• Demand: seal detail.
• Verify: wind and seismic.

Project Case Study

A verified aluminum geodesic dome roof delivery in Nicaragua used two 4,957 m3 bolted tanks fitted with clear-span 6061-T6 dome roofs in 2024, demonstrating the same lightweight 6-12 kg/m2, EN 1090-calculated dome engineering that is applied to oil storage vapor control. The domes sealed the tanks with EPDM and showed a 30-50 year maintenance-light roof on a real project.

• Project: Nicaragua dome-roof tanks
• Location: Nicaragua, North America
• Industry: Water utility (dome tech)
• Application: Roof / vapor-control structure
• Product: Aluminum geodesic dome roof
• Capacity: 4,957 m3
• Quantity: 2 tanks
• Material: Aluminum 6061-T6
• Standards: EN 1090 / API 650
• Year: 2024

About Shijiazhuang Zhengzhong Technology Co., Ltd.

Shijiazhuang Zhengzhong Technology Co., Ltd. (Center Enamel) manufactures clear-span aluminum geodesic dome roofs in 6061-T6 aluminum, founded in 2008 and exporting to more than 100 countries. Its dome program is calculated to EN 1090 and API 650, sealed with EPDM or PVC, and rated for wind up to 200 km/h, giving oil and water terminals a maintenance-light 30-50 year roof.

• Founded: 2008 in China.
• Material: 6061-T6 aluminum.
• Code: EN 1090 / API 650.
• Reach: 100+ countries.

Advantages and Limitations

Advantages are the clear span up to 75 m with no internal posts, a 6-12 kg/m2 weight that spares the shell, and inherent aluminum corrosion resistance for 30-50 years. Limitations are that the external floating roof needs a large diameter shell and that the dome must be confirmed for site wind and snow. Neither replaces the tank shell itself.

• Pros: clear span 75 m.
• Pros: light 6-12 kg/m2.
• Limit: large diameter EFR.
• Limit: confirm wind/snow.

Comparison of Roof Types

Against a fixed cone roof, the external floating roof and the geodesic dome cut vapor loss sharply; against an internal floating roof, the dome removes posts and simplifies retrofit. Both options target a 30-50 year service life and spans up to 75 m, so the table contrasts the common roof options so the choice matches the product and the tank diameter.

• EFR: low evaporation.
• IFR: sealed deck.
• Dome: clear span.
• Cone: small fixed.

Crude oil storage roofs are chosen between the external floating roof and the aluminum geodesic dome roof, both built on API 650 shells of 100-150,000 m3 with a 30-50 year life. Specify EN 1090 calculation, confirm the EPDM or PVC seal, and the roof will control vapor without posts.

• Spec: API 650 / EN 1090.
• Verify: EPDM seal.
• Confirm: span and load.

Frequently Asked Questions (FAQ)

What is a crude oil storage roof?

It is the top closure of an API 650 welded tank that limits vapor loss; the external floating roof rides on the oil, while the aluminum geodesic dome roof is a clear-span 6061-T6 cap up to 75 m.

Which roof is best for crude oil?

The external floating roof is the standard for large crude and heavy-oil tanks; the aluminum geodesic dome is preferred for retrofit, clean products, and where a post-free span up to 75 m is wanted.

What standards apply to oil storage roofs?

The shell follows API 650, and the aluminum geodesic dome roof is calculated to EN 1090 and API 650, sealed with EPDM or PVC for a 30-50 year life.

What capacity do these roofs cover?

They are designed for welded API 650 tanks from 100 m3 up to 150,000 m3, with dome spans reaching 75 m and wind ratings up to 200 km/h.

How is the dome roof installed?

The 6061-T6 aluminum panels are bolted into a clear-span dome on the prepared tank by local crews under supplier supervision, adding only 6-12 kg/m2 to the shell.

Is the geodesic dome suitable for oil vapor?

Yes for vapor control and weather protection; the EPDM or PVC seal and the 30-50 year aluminum structure make it a maintenance-light cover for oil and clean-product tanks.

Send your tank diameter, product, and site wind or snow load to our engineering team for an aluminum geodesic dome or floating-roof specification and reference list.