Silicone-based sealant stops fire advancing through pipes, bulwarks

July 1, 2003
Long used in the North Sea, FireSeal's silicone-based fire protection system is moving into the Gulf of Mexico.

Long used in the North Sea, FireSeal's silicone-based fire protection system is moving into the Gulf of Mexico. The company recently received US Coast Guard approval to use the seal in the Gulf of Mexico. The approval was in time to install the foam on BP's Mad Dog truss Spar for Green Canyon block 782.

The sealant originated from efforts in the nuclear field to prevent fire, smoke, and toxic fumes from spreading from compartment to compartment. It was adapted for offshore and marine applications in the 1980s. FireSeal Export Sales Manager Bo Ohlsson said the silicone foam's pedigree also traces itself back to the beginnings of the space age. The material was developed to improve spacecraft safety on re-entry into the earth's atmosphere, he said. Related silicone material serves as an insulator and ablative that burns away on re-entry.

The heat-activated seal is gas-tight and water-tight, and stops smoke and fire from spreading through passages in bulkheads. On a platform, however, hydrocarbons can complicate the picture.

In addition to fire, there is a risk of hydrocarbon blasts caused by gas leakages, he said, adding it depends on how the hydrocarbons are stored on the platform. It is therefore essential to have a good separation between these compartments.

Platforms must carry a fire rating to preserve life in the event of a fire onboard. A one-hour fire-rating means the fire protection onboard can hold off advancing flames for one hour, enabling rescue from the unit.

"But it isn't sufficient to have the fire rating only," Ohlsson said, citing the Piper Alpha tragedy in July 1988, when 167 people died. Of that number, as many as 80 died of gas inhalation in a supposed "safe haven."

Stockholm-based FireSeal designs the fire protection and sells the material, and performs training courses for those who install the FireSeal material. In most cases, the material is installed during construction, with the platform builder as the customer. The material can also be installed during retrofits or upgrades.

When heat rises to a certain temperature, it triggers a reaction in the sealant. The FireSeal cures into a spongy, resilient form, creating a gas-tight and fire-tight seal. Ohlsson said the activated seal is also strong enough to withstand firefighting, so pressure from the water hoses will not puncture the material or dislodge the foam.

Multiple penetrations

FireSeal's FS-03 is a two-component silicone foam that offers a flexible seal. The company said it resists large movements and vibrations without cracking or loss of adhesion. FS-03 is useful for complicated penetrations with irregular or bunched cabling, according to the company. The FS-Flex D sealing system incorporates silicone sealant and ceramic fiber. It allows movements of the penetrating items simultaneously by achieving a high degree of mechanical and pressure resistance. This system is meant for use in cable or pipe applications above and below the waterline.

For more information, contact Bo Ohlsson, FireSeal. Tel: +46 155 26 80 40, fax: +46 155 28 41 10, [email protected],