Investigating gas explosions: an expert describes his experience

Investigating gas explosions:

an expert describes her experience

[A NUMBER OF GAS EXPLOSIONS over the past few years have resulted in over 170 injuries and a dozen deaths. Those explosions come from a variety of sources, including fuel piped directly to a property or delivered in bulk transport, and fuel stored on a property.

Gas fuel systems can exasperate a building fire as the initial fuel source for the fire when it escapes from piping, storage or appliances; as the initial ignition source because of its low ignition energy; or by being both the fuel and the ignition source. Gas can also be a contributing factor that influences the fire growth rate and spread when the fuel system is attacked by a fire.

Understanding the role played by gas in fires and explosions requires careful consideration from an expert. Rose Campbell, risk analyst and expert services manager with CEERISK Consulting Ltd, has investigated many incidents where gas played a key role in the inception of a fire or explosion and the extent of the damage.

In her experience, investigation of gas fires and explosions requires careful analysis of all factors. Depending on the extent of the damage, which can be made worse by the presence of gas, that can be particularly tricky.

Rose Campbell explained: “A good place to start is looking at the compliance of all aspects of working fuel gas systems to ensure they comply with local codes and standards. That also includes review of the design, manufacturing specification, construction, installation and other various components.

“The source of any gas leak must be determined as well. Leaks can occur from many areas, including pipe junctions, unlit pilot lights or burners, uncapped outlets, malfunctioning appliances and malfunctioning controls. The failure of gas regulators is also a contributing factor to gas leaks, as internal faults can cause the regulators to fail to reduce pressure to acceptable levels.

“One of the most common sources of gas leaks is corrosion, caused by rusting metal pipes or electrolysis between similar metals, metal and water, and metal and soil. Corrosion accounts for about 30% of known gas leaks. “Other sources of gas escape include physical damage, which can occur during installation or as a result of impact during construction works, such as is the case when underground pipes are pierced during investigation.” q • Rose Campbell is risk analyst and expert services manager with CEERISK Consulting Ltd, specialists in supporting experts investigating major incidents including gas explosions and building fires.