Full Surface Tank Fires

A large UAE based oil company has constructed a crude oil pipeline from Abu Dhabi to Fujairah. Oil delivered from the pipeline is stored in 110m diameter floating roof tanks, which are protected by Angus Fire Engineering Foam Systems. These systems provide various levels of protection.

The first level of protection is by Rimseal foam systems. These systems are for extinguishing fires in the tank rimseal area with the foam only being applied in the annular ring area between the tank wall and foam dam. Due to the comparatively low flow of this system it would not be capable of fighting a full surface fire.

In the case of a full surface fire there are two additional levels of protection:

1) Full Surface Foam Pourers and Nozzles located at the top of the tank shell.

wp20141113009460The Full Surface Foam Pourers ensure the outside area (approximately 30m from the tank wall) of the tank roof is quickly covered with foam at an application rate of approximately 6 l/min/m2.

Foam is delivered to the middle area of the tank at an application rate of approximately 10 l/min/m2 using the monitor nozzles.

The design of the pourer and nozzle system is semi-fixed with the pourers and nozzles hard piped to an inlet connection outside the bund wall. Foam solution is supplied by a portable skid mounted turbine driven proportioning system that is connected to the firewater ringmain via Angus 12” Super Aquaduct hoses.

2) Big Flow Foam Monitors

The Big Flow Monitors are rated at approximately 38,000 l/min and will apply foam at an application rate of approximately 12 l/min/m2 over the complete roof surface. Because these monitors will need to direct foam into the tank from outside the bund area they are design to have a foam throw of greater than 140m.

The monitors are wheeled and form part of an integrated system including turbine driven foam proportioning skids, Angus 12” Super Aquaduct hose and 25,000 litre foam concentrate tankers.

The total system has been successfully commissioned/tested by the Angus Fire Commissioning team.