The Use and Benefits of Lightweight Internal Floating
Covers and Aluminium Geodesic Domes
Installacja Koper, Slovenia 1993-2003
12 Gasoline and Fuel tanks 22-60m
The Use of Aluminium Geodesic Domes
Retrofitting of existing External Floating Roof Tanks Covering of Fixed Roof Tanks
Problems of the EFRT
• Sinking of the Floating Roof due to retention of rain water, snow, ice, dirt and sand
• Contamination of the product due to water ingress passing the Rim Gap Seals
• Failure of the Roof Drain System loss of product and possible contamination of the environment
• Requirement for large Seal Systems reduces the overall tank storage capacity
• Rim Gap Seal fires are very common• Rolling Ladders may snag and corrode• Standing Storage Losses
through Wind and Sunlight reduce profitability of the tank
Advantages of Aluminium Geodesic Dome Roofs on EFRT
• Eliminates effect of rain, wind and snow– No Roof Drain System required– Normally no Secondary Seal required– Seal fires very rare
• No Rolling Ladders required• No maintenance required• Reduces Standing Storage Losses by 90%
Problems of Fixed Roof Tanks with Steel Roofs
• Internal Roof Support Columns (Cone Roofs) - cause cracking on the tank floor- corrode at the product interface- reduce storage space- need regular inspection - trap product fire hazard during maintenance- increase significantly standing storage losses
• Roof Corrosion- requires expensive maintenance (painting, replacement of steel plates, significant down-time)- becomes a safety hazard
Advantages of Aluminium Geodesic Dome Roofs
• Fast and Easy to Erect• Shorter lead time in tank construction schedule
(FRT)• Free Span Structure (no Columns) • Meets the Requirements of API 650 App. G• All Bolted Construction and fully assembled with
no „Hot Work“• Does not Require Painting – EVER• Available ex works within 12 to 14 weeks of order• Prefabricated under Workshop Conditions• Total Quality Control
60m Aluminium Internal Floating Cover
The Use of lightweight Aluminium Internal Floating
Covers
• Reduction of Storage Losses up to 97%• Payback time 12-18 months
Loss calculation example
Based on API 2517 and API 2519• Calculation of Total (Standing + Withdrawal) Evaporation Loss• Tank Diameter: 30 meters (100 ft) - Product: Gasoline• Fixed Roof• Throughput: 1.5 million barrels/year • Avg. Amb. Temp. 16 Deg C (60 Deg F)• Avg. Wind Speed: 10 mls/hr
TOTAL LOSS OF PRODUCTwithout Internal Floating Roof:508.000 litres p.a.with Internal Floating Roof: 5.500 litres p.a.Saving: 502.500 litres p.a.
Seals on the VACONODECK
• The standard seal on the VACONODECK is a closed cell polyethylene single or double wiper seal
• „R“-Type mechanical seals with efficiencies >95% are also available.