Fire Protection System PDF

LECTURE 3 FIRE PROTECTION SYSTEM A method of fire protection involves the conveyance of water pipes to extinguish fire within a building falls into the field of plumbing. Water may be supplied through riser pipes or standpipes. A riser or standpipes with hose connections in a tall building may be fe...

LECTURE 3 FIRE PROTECTION SYSTEM A method of fire protection involves the conveyance of water pipes to extinguish fire within a building falls into the field of plumbing. Water may be supplied through riser pipes or standpipes. A riser or standpipes with hose connections in a tall building may be fed from storage tank, from pump or from a mobile pumping engine in the street connected to a breaching or ‘Siamese Post’ Water & Water Supply for Fire Fighting Supplying Water for Fire Protection Systems: The Elevated Water Tank The Underground Water Reservoir Types of Fire Protection Systems: Dry Standpipe System Wet Standpipe System Wet Standpipe System with Siamese Connection Automatic / Sprinkler System Dry Standpipe System No longer being utilized in new buildings, provided other systems are employed (otherwise must be installed in buildings 4 levels or more) The standpipe is a pipe installed in buildings not as part of the water supply or waste disposal system but primarily for use as water conveyor in case of fire How it works: a standpipe is connected to the building exterior (max ht.= 1.20M) for connection to fire department As much as possible, standpipes should be located in stairway landings Wet Standpipe System How it works: a piping network (line is directly connected to the main water line) connects to all levels of a building (at least 1 standpipe on each level) Wet standpipes shall be constructed of wrought iron or galvanized steel The number of wet standpipes shall be determined so that all portions of the building are within 6.00 meters of a nozzle attached to a hose 23 meters long The minimum diameter for a wet standpipe is 51mm for those less than 15 meters form the fire service connection. For those more than 15 meters from the fire service connection, the minimum diameter is 63mm Fire Hose Standard fire hose is made up of rubber lined cotton fibre 65 mm in dia, capable of standing routine test pressure of 14 kg/sqcm. Sometimes unlined or rubber lined or rubber cotton hose may be used for this purpose. The fire hose is housed in a special made glass cabinet Wet Standpipe System with Siamese Connection How it works: a piping network directly connected to the main water line, connects to all levels of a building; additionally, a Siamese Connection is located outside the building for additional water supply Automatic / Sprinkler System The installation of sprinkler system requires special planning in new building design and usually involves an extensive renovation of an existing building. The sprinkler system may be installed in the following types of buildings or sections of a building as a first aid assistance. i.e. apartment houses, club houses, colleges, dormitories, hospitals, hotels, office buildings, and the basement used as car parking's. Automatic sprinklers are connected to a water distribution system. A sprinkler nozzle is closed by a fusible plug that melts at a predetermined temperature, above normal room temperature, releasing water to fall on the source of heat. There are two general types of Automatic Sprinkler Systems: the Automatic Wet System and Automatic Dry System Automatic Sprinkler System Sprinklers have the advantage of quickly supplying water to fire before it gain dangerous headway and of preventing the access of air to the fire by smothering it with water. In some cases, an open head sprinkler system for the protection of the interior of the building is provided. Smoke Detectors & Sprinkler Heads Types of Sprinkler Heads Upright- used above piping when piping is exposed Pendent- projects through a finished ceiling when piping is exposed Fire Escapes A fire escape is a special kind of emergency exit, usually mounted to the outside of a building or occasionally inside but separate from the main areas of the building. It provides a method of escape in the event of a fire or other emergency that makes the stairwells inside a building inaccessible. Fire escapes are most often found on multiple-story residential buildings, such as apartment buildings. At one time, they were a very important aspect of fire safety for all new construction in urban areas; more recently, however, they have fallen out of common use. Fire Extinguisher Methods of Fire Extinguishing Cooling effect: The rapid expansion of liquid to gas when carbon dioxide is released from storage cylinder produces a refrigerating effect that converts part of the carbon dioxide into snow. This snow, which has a temperature of 80 0C soon sublimes into gas, absorbing heat from the burning material and surrounding atmosphere. Alarm Gong The sounding of alarm should occur shortly after the opening of a sprinkler head. An alarm valve which is a type of back pressure valve, should be fitted on the main supply pipe immediately above the main stop valve. The alarm gong should be close to the main stop valve, but should be sited outside the building in a position where it will readily be audible to the police and other petrol's. In order to avoid false alarm caused by fluctuations in the pressure of supply, a device is necessary in most types of alarm systems to permit of such temporary fluctuations without lifting of the alarm.