What is Drenching System_Exposure Protection of Explosive Buildings

Identification of Hazard for Drenching system:

Hazardous Material Present Explosives are chemical substances, which by nature are liable to be initiated by spark, friction and percussion. Once these catches fire, they create sudden and intense pressure on its surroundings, with heat, sound and flash. 

Consequently, any fire involving explosives might lead to disastrous consequences as a result of mass fire unless dealt with speedily and effectively. As such manufacture, processing and storage of explosives in any building is always associated with serious fire and explosion hazard. Unlike other combustible or flammable substances/liquids, the explosives once involved in a fire do not give any time for making a ‘sizeup’ of the situation and any action needed to avoid catastrophe must be preplanned and embodied in well laid-down procedures. 

It may, however, be noted that all the explosives in use are not of similar characteristics and behaviour. As such with a view to dealing with fires involving explosives very effectively, a knowledge of the behaviour/characteristics of the different explosives/ammunition when involved in a fire is very much essential. Besides the knowledge on the behaviour of explosives, a knowledge on the application of proper fire-fighting measures in accordance with the behaviour of the explosives when involved in a fire is also very much essential. 

For fire-fighting purposes, explosives are divided into 4 fire divisions from Fire Division 1 to Fire Division 4 in accordance with their behaviour when involved in a fire.

 Placement of Drenching System:

In general, ammunition without its means of initiation and ignition can be exposed to a fire for several minutes (depending upon classification of explosives) before it explodes. 

Drenchers are provided on exterior of a building to protect against a fire from a neighbouring building. In order to prevent the hazardous material catches fire from heat radiation coming from adjacent building which is on fire, drenching system are provided for roofs, over windows, and all openings on external wall.