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Today most buildings and structures have some degree of fire protection in order to protect lives, delay possible structural collapse allowing for evacuation, provide areas of temporary refuge in the case of fire, and ensure the integrity of escape routes by preventing or delaying the escalation of a fire and protect high-value assets.
There are two basic types of fire protection: active and passive. Active fire protection includes alarms and detection systems, sprinklers and water deluge systems, firefighting equipment and foam and powder extinguishers. Passive fire protection involves components of structural methods and materials such as concrete, mineral fiber boards, vermiculite cements and intumescent coatings. This article will describe how intumescent coatings can achieve passive fire protection in many structure types including offshore constructions, ships and commercial buildings.
Intumescent coatings have been used to protect the steelwork in buildings and other structures from fire for approximately 40 years. These coatings work by swelling up in the event of fire and physically creating a barrier between the steel and the fire for up three hours. Steel loses its structural strength at about 500 C and these coatings can delay the time it takes to reach this temperature (Fig. 1). Intumescents are often referred to as thin-film or thick-film coatings. Thin-film intumescents can be solventor water-based products and have dry film thicknesses (DFTs) of less than 5 millimeters. Thick-film coatings are typically solvent-free, epoxy-based with DFTs of up to 25 millimeters. Thickfilm epoxies can also be used to form castings, typically in two halfshells to protect narrow diameter pipework where spraying would create large volumes of overspray.
The acceptance and use of intumescent coatings increased dramatically in Europe in the 1970s as the major oil companies learned of their ability to protect structural steel from the extreme heat caused by hydrocarbon fires, including jet fires caused by leaking hydrocarbons.
In 1988 an explosion and subsequent oil and gas fires at the Piper Alpha, a North Sea oil production platform, resulted in the deaths of 167 people and £1.7 billion ($3.4 billion) in damage. The severity of this disaster, considered the worst offshore oil disaster at the time, prompted increased development and use of intumescent coatings for protection against hydrocarbon fires. The coatings developed tended to be thick-film...