SCE group PC009 SCE group title Fired Heaters Gas or oil fired heaters. To prevent fire and explosion in Fired Heaters. At item level i.e. per heater SCE group PC010 SCE group title Gas Tight Floor Walls (Offshore only) Gas tight floors designed to prevent spread of gas into critical areas. To provide a vapour containing barrier that minimises the migration of toxic or hydrocarbon gases from the storage / ballast water system into the normal occupied area of the leg Gas-tight floors of gravity base structures preventing vapours from oil in the storage cells from entering the leg Some walls in closely constructed Facilities to limit gas spread during an incident. At module and elevation level