NFPA – 11
Sharks Foam Fire Suppression Systems are the ideal solution for fire protection of flammable liquids. For years, foam has been used as a fire extinguishing medium for flammable and combustible liquids. Unlike other extinguishing agents such as water, dry chemical, CO2, etc., a stable aqueous foam can extinguish a flammable or combustible liquid fire by the combined mechanism of cooling, separating the flame/ignition source from the product surface, suppressing vapors and smothering. It can also secure against re-flash or reignition for extended periods of time. Water, if used on a standard hydrocarbon fuel, is heavier than most of those liquids and if applied directly to the fuel surface, will sink to the bottom, having little or no effect on extinguishment or vapor suppression. If the liquid fuel heats above 212°F, the water may boil below the fuel surface throwing the fuel out of the contained area and spreading the fire to nearby areas. For this reason, foam is the primary fire-extinguishing agent for all potential hazards or areas where flammable liquids are transported, processed, stored or used as an energy source.
Fixed/ Semi Fixed Foam System For Floating/Fixed Roof Storage Tanks
Fixed Foam System: is a complete installation in which foam is piped from a central foam station and discharged through fixed delivery outlets on the hazard being protected with permanently installed pumps where required.
Semi Fixed System: is an installation in which the hazard is equipped with fixed discharge outlets connected to piping that terminates at a safe distance.
Foam Sprinkler System for Chemical Storage/Processing Areas and Critical Machines
Foam Water Sprinklers are installed overhead to protect the risk where foam is required to be uniformly applied. This is followed with plain water in a standard sprinkler pattern. Foam Water Sprinklers protect the loading and unloading area in the event of a spill fire with low expansion foam system. These are useful in applications such as Air Craft Hangars, critical industrial equipments, chemical stores etc.
Pre action foam system can also be considered for protection of sensitive areas.
Foam Fire Protection for Aircraft Hangars
NFPA - 409
Fixed foam systems are required to protect housed aircrafts in many commercial and military aircraft hangars. Variable factors that affect system design and component selection include hangar floor area, type of hangar construction, aircraft access door height, type and size of housed aircraft, aircraft quantity and parking arrangement, and floor drainage details. Additional information on aircraft hangar protection is covered in NFPA 409 “Standard on Aircraft Hangars.”
There are four types of foam fire protection systems suitable for the protection of an aircraft hangar. These systems may be used separately or they may be combined.
Rim Seal Protection for Floating Roof Oil Storage Tanks
Rim Seal floating roof tank fires represent one of the most dangerous threats for chemical and petrochemical storage farms. Industry data shows that the oil industry has experienced several rim seal fires worldwide and some of them have developed into largescale disasters. Such disasters start with a rim seal fire that breaks out and grows undetected to a point that it spreads over the whole seal area such that the floating roof tank is surrounded by fire.
In the worst case scenario, the intense heat radiated is absorbed partially by the tank shell and the pontoon till the metal sheets lose their mechanical stability. In such conditions, the roof is no longer capable of floating normally and can incline causing the roof to sink under the fuel resulting in full surface fire. The most efficient way to contain such fire is to install a fire detection and suppression system.
Such systems specified by NFPA 11 provide well proven methods of firefighting on floating roof tanks. However, the reaction time from fire detection to suppression of such systems is a cause of concern for many oil companies. It is in fact paramount that a fire on a floating tank roof is suppressed as soon as possible. It is for this reason that an additional system is supplied and integrated with floating tank roof in order to provide early fire detection and instantaneous fire suppression within the rim seal zone. Such systems are capable of instantaneously detecting a fire outbreak in the rim seal zone and discharging, in seconds, a charge of fire extinguishing agent directly on the zone where fire has started.