The use of FOAMGLAS PFS fire suppression systems, which are passive systems that remain in place to assist in providing immediate and automatic control of LNG pool fires without delays, are a proven safeguard for any LNG containment pit

Industrial fire safety is more important now than ever before. Production demands require oil and gas facilities to run continuously without fear of costly safety issues.

Many companies are also assigning a greater priority to communicating their successful safety records both internally and externally. In a liquefied natural gas (LNG) facility, a commitment to fire safety includes ancillary applications of insulation materials which may contribute to mitigation of catastrophic fire potential.

When reviewing an insulation material’s fire endurance, three factors must be considered: fire resistance, toxicity and performance in the presence of combustible chemicals. It can be said that FOAMGLAS® cellular glass insulation has proven to be totally non-combustible, non-toxic and non-absorptive of combustible fluids, says Peter Bakker, regional manager Middle East Countries, Pittsburgh Corning Europe.

Because FOAMGLAS® insulation is 100 per cent glass, without binders or fillers, it simply cannot burn, even when in direct contact with intense flame. "Thermal insulation" is usually considered as a material limited to helping maintain operating system temperatures, while acknowledged as having a potentially active role in fire propagation. However, in the case of FOAMGLAS® insulation, it can actually serve to protect piping and equipment from fire damage, retard fire spread and help safeguard personnel, says Bakker.

The commitment to fire safety is evident in testing requirements such as UL 723 for flame spread and smoke development. The UL 723 test evaluates the spread of flame over a material surface and the density of the smoke developed when exposed to a test fire to establish a basis for burning characteristics of different materials. Full scale and small scale fire exposure is covered by UL 1709, which is specific to hydrocarbon fire exposure. More often than not, these two testing methods are listed in specifications relative to insulation for pipe and vessels in hydrocarbon processing facilities. Facility engineers are tasked with ensuring that the proper fire credentials remain in place and that these cannot be compromised, he says.

FOAMGLAS® Insulation, as an insulating material, is considered one of the best in a hydrocarbon processing facility based on its thermal and fire resistant properties. Because the material will not burn, promote flame spread or produce toxic smoke, it is ideal for fire attenuation.

LNG run-off pit

Such is the case with the pooling of LNG in the event of a breach in the vessels or pipes storing or transporting the liquefied material within the facility itself. With fire safety as a priority, the need for safeguards is paramount for hydrocarbon processing facilities. From mechanical equipment to the choice of pipe and tank insulation, each area must be designed with fire safety in mind. One critical area of an LNG plant regarding exposure to catastrophic fire, are the pools or pits, as they are sometimes referred, put in place to contain LNG from spreading in the event of a leak from a pipe or storage tank, he says.

Once the LNG is contained in a pit, the danger of pool fire is still present and must be considered as a potential safety risk. Traditional fire attenuating equipment is not always enough if a pool fire should occur.

The use of FOAMGLAS® PFS™ fire suppression systems, which are passive systems that remain in place to assist in providing immediate and automatic control of LNG pool fires without deployment delays, are a proven safeguard for any LNG containment pit. The FOAMGLAS® PFS™ systems contain specially formulated low-density cellular glass cubes that have a combination of physical properties not found in traditional fire suppressant foams. Made of cellular glass, the material is both extremely buoyant and non-flammable. The pool fire suppressant module system is non-corrosive and resistant to water and vermin. It is also fibre-free, and has a high compressive strength, Bakker explains.

Damaged or post incident waste materials can be disposed of as standard refuse, and can be compacted for reduced waste volume.

Suppression methods for potential fires are designed to reduce hazards such as radiant heat and flame height. Based on past research, high expansion foam was regarded as the primary technology in suppressing LNG pool fires. It should be noted that a FOAMGLAS® PFS™ system is not a stand-alone product. It is designed as a passive system specifically to provide a first line of defense and is supplemented by the typical foam (or other proven material) extinguishing materials.

FOAMGLAS® PFS™ pool fire suppression systems complement any safety programme by delivering a reliable, low cost, low maintenance passive solution for the reduction of thermal radiation and flame height in contained liquid natural gas (LNG) fires. FOAMGLAS® PFS™ systems are easy to install and can provide immediate mitigation of the thermal flux, rate of combustion, view and overall size of an LNG pool fire. Because FOAMGLAS® PFS™ systems are highly buoyant, the pool fire suppressant modules rise immediately to the surface of the LNG to provide an insulating cap that can aid in reducing vapourisation.

Vapour and Fire Control Testing commissioned by Total and conducted under the supervision of Resource Protection International at the Centro Jovellanos concluded that FOAMGLAS® PFS® systems were effective in reducing radiant heat flux and controlling fire from LNG and LPG pool fires.

In scale tests conducted by Shell Research Ltd, a depth of 200 mm (8 inches) of FOAMGLAS® PFS™ cubes, assisted in providing an immediate and automatic control of the fire at a level comparable with that provided of 1-2 metres (3.3-6.6 ft) of high-expansion foam. Results of large scale experiments performed at the Emergency Services Training Institute of Texas A&M University have shown that the view factor of an LNG pool fire suppressed by a FOAMGLAS® PFS™ system is comparatively lower than that of high expansion foam, providing real protection from thermal radiation for exposed equipment or personnel. With maximum flame height significantly reduced at a steady state, the thermal radiation is limited to the visible fire within the much lower temperature range of 200˚C to 500˚C (392˚F to 932˚F).

Field extinguishing trials conducted were successful in demonstrating the system’s performance. These trials, performed on an LNG test pit of 100 square feet, showed that fire-fighters equipped with a single 20 lb dry chemical extinguisher were able to directly approach the edge of the containment pit and extinguish the flames within seconds with only a partial charge.

FOAMGLAS® cellular glass insulation is the result of more than a half-century of proven performance and continual product improvement. From its use on pipes, tanks and vessels to PFS™ systems, FOAMGLAS® Insulation is the right choice for industrial applications requiring fire safe characteristics and performance, adds Bakker.