API Publ 4740-2005 pdf free download

API Publ 4740-2005 pdf free download.In- situ Burning A Decsion-maker’s Guide to In- situ Burning.
What is lt? In-situ means“in place.” In-situ burning refers to the controlled burming of oil spilled from a vessel, facility, pipeline, or tank truck close to where the spill occurred (ASTM, 2003a). For spills on open water, responders usually have to collect and contain the oil using fire-resistant booms, because the oil has to be a minimum thickness to be ignited and sustain burning. In ice-infested waters, the ice can act as a natural boom, keeping the oil thick enough to burn. In-situ burning can also refer to burning of oil inside a vessel before it discharges. In-situ burning of spills on land occurs more often than on water because the oil doesn’t emulsify, submerge, or spread into thin sheens as quickly, and the oil is usually more accessible. Most of the time, in-situ burning on land is conducted shortly after a spill is discovered, when the oil is still thick. lgnition Sources A fire can be started with a range of ignition sources, from a simple match to more sophisticated equipment (see Figure 4 and 5). The ignition source is used to provide enough heat for a long enough period so that some of the oil vaporizes and the vapors ignite. Heavy oils require longer heating time and a hotter flame to ignite, compared to lighter oils. A key goal during an on-water burn is to ignite as much of the oil surface as possible, so that the oil is heated enough to form vapors and sustain the burn. Snecialized ionition sources include the“Helitorch”an incendiarv a. Those constructed of steel; b. Those constructed from fire- resistant fabrics; and C. Those employing active water cooling systems. For spills in ice-covered waters, the oil often accumulates in the spaces between the ice and can be readily burned without using boom. It may be necessary to cut holes in the ice where the oil is trapped under the ice away from natural breaks. Operational Guidelines For spills on open water, in-situ burning is ideally accomplished in the following steps (Buist, 1998): 1. Two vessels collect a patch of oil in fire-resistant boom that is towed until the oil fills about one-third of the area inside the boom (see Figure 7). 2. The boom is towed a safe distance from other patches of oil. 3. The oil inside the boom is ignited (see section above on ignition sources). The boom is slowly towed into the wind, to keep the oil toward the back of the boom and so that the smoke will go behind it. 4. The oil burns until the fire goes out. If there is a problem, it is possible to let one end of the boom go, allowing the oil to spread into a thin slick and the fire goes out quickly. 5. Any floating oil residue is collected (see Figure 8), and the boom is inspected for damage. 6. The boom is towed to pick up the next batch of oil. If the oil is continually leaking from a source, such as a well blowout, the fire-resistant boom can be positioned to capture the oil a safe distance from the source. The oil is burned as it accumulates inside the boom.