Floating-roof tanks

40°C and igniteiTthe vapoi cormrig out of the vent the fire flashed back 

Workers should not go onto floating-roof tanks to extinguish rim ThiJ6t tiF3il.dfgcffliMi isnte)fip, e i lMT 2 ft 

To prime the hose and establish a siphon, the hose was connected to the 

The water level outside the dike rose because the dike drain valve had been left open, and the dike wall was damaged by the 

Keep plant modifications under control and keep drawings up to date (see Chapter 2). 

---

To reduce these losses, the crude oils are stored in floating roof tanks. 

Storage of Flammable Materials. The preferred storage for flammable Hquids or gases is in properly designed tanks. Floating roof tanks frequently are used in the petroleum industry for flammable cmdes and products (see Tanks and pressure vessels). The vents on cone roof tanks should either be equipped with flame arrestors or the vapor space above the contents should be inerted with a nonflammable gas or vapor, unless the flash point is weU above the maximum ambient temperature, the contents are not heated above the flash point, and the tank is not exposed to other tanks containing flammable Hquids. 

Vapor recovery systems floating roof tanks pressure tanks vapor balance painting tanks white Cyclones-precipitator-CO boiler cyclones-water scrubber multiple cyclones Vapor recovery vapor incineration Smokeless flares-gas recovery... 

Cone roof and floating roof tanks are usually correlated using vs. volume, w ith materials of construction as another variable. The cost of internal heat exchangers, insulation, unusual corrosion allowance, and special internals should be separated from the basic cost of the tank in the correlations. 

These tanks are designed to reduce evaporation and vapor emission. Two distinct designs are those with and those without an additional fixed roof. Of the former types, known as internal floating roof tanks, various provisions... 

Any source of ignitable hydrocarbons, such as separators or floating roof tanks, should be at least 60 m from the base of the flare stack. 

Figure 5-15. Oil trapped in the leg of a floating-roof tank caught fire during demolition.

Do not take floating-roof tanks off-float except when they are being emptied for repair. 

Evaporation Loss from External Floating Roof Tanks... 

The open-top floating roof tank design eliminates the potential for BLEVE. Further, the material being handled has no potential for chemical reactions or for condensed-phase explosions. Thus, these types of explosions can also be eliminated from consideration. 

In the storage of flammable liquids, if the composition of the vapour-air mixture above the liquid surface falls within the flammability limits, a floating roof tank would be used or the tank blanketed with inert gas. Check if the vapour composition for liquids listed below will fall within their flammability range, at atmospheric pressure and 25°C. 

Liquids are usually stored in bulk in vertical cylindrical steel tanks. Fixed and floating-roof tanks are used. In a floating-roof tank a movable piston floats on the surface of the liquid and is sealed to the tank walls. Floating-roof tanks are used to eliminate evaporation losses and, for flammable liquids, to obviate the need for inert gas blanketing to prevent an explosive mixture forming above the liquid, as would be the situation with a fixed-roof tank. 

Floating roof tank seal area ignited from flare carbon particles from 350 foot away 15,000,000 loss... 

Submerged floating roof tank of gasoline caught fire while foam was being applied. Fire spread to 3 other tanks. 12,000,000 loss... 

Floating roof tanks, both internal and open top are constructed with a circumferential seal to allow the roof to rise and fall. A single seal will allow some vapors to escape. However, recent environmental practice is to provide a secondary seal over the first seal, which provides additional mitigation against the release of most of the vapors. 

Most fires on floating roof tanks are small rim fires caused by vapors leaking through the seals. The source of ignition is normally lightning strikes. With proper seal maintenance and inspection, coupled with adequate shunt straps across the seal at every meter or so will reduce the probability of a tank fire. 

Floating, coating film defect, 7 122-123 Floating-roof tanks, 24 289-292 Floating solids, entrainment of, 16 694-696 Floating zone technique, fabrication... 

Petrolenm Liqnid Storage in External Floating Roof Tanks Petrolenm Liqnid Storage in Fixed Roof Tanks Petrolenm Refinery Eqnipment Leaks... 

---