INTRODUCTION
OF
The
Fire Hydrant System unlike the Portable (First – Aid) Fire Extinguishers
basically uses water as extinguishing media.
A
raging fire without a proper extinguishing system can be devastating. Hence
there is an emphasis on provision of a Fire Hydrant System.
In the Fire Hydrant System, the Water in
large quantum is pumped continuously with tremendous force and velocity so as
to reach the seat of fire. Hydrant valves are located at strategic points.
These are work as outlets of water through the Fire Hose.
1.1 Automatic Fire Hydrant System
In the case of the Automatic Fire Hydrant
system the piping network is pressurized with water at a definite pressure and
is maintained in readiness for any eventuality. Once the Hydrant valve is
manually opened during fire, the fall in pressure in the pipe line is sensed by
the pressure switches activating the pumps, thereby ensuring continuous supply
of water and pressure at the outlets (Hydrant Points)
1.2
Water for Fire Fighting
Generally, the water is stored in underground sumps, underground Water Tanks or Overhead reservoirs. The capacity of these tanks can be derived based on the nature of Buildings and Hazard i.e., Ordinary; Light; Medium & High Hazard Occupancies as per TAC.
1.3 Pumping Facility
The Pumping facility may consist of multiple
pumps at centralized locations, close to and drawing water from the Fire
fighting reservoir. These pumps are driven with suitable prime movers at
required speed to pump the required quantity of water from the reservoir in to
the piping system and finally out of the Hydrants, to fight the fire.
The pumps are located in level with the
floor of the Tank sump or reservoir, so that a flooded suction is achieved,
which is called the positive suction, or it can be placed above the top level
of the water and the pump sucks the water. This scheme is called the negative
suction of the pump. Pumps can be selected to throw water at required
velocities, the required quantities at the required sequence – on occurrence of
fire.
The main pump is generally provided with a
standby pump of same capacity to cater to a break down during fire.
In our case it is positive suction pump and
it consist by one Jockey pump for maintaining the line pressure, main pump for
sprinkler & Hydrant System & Diesel engine operated pump as standby
pump.
1.4 Piping Network
The piping network runs partly underground
and partly over ground but, finally emerges out of ground at various points of
utility. The network of piping carries
water from the point it is pumped into, till the hydrant and is designed to
cater to the pressure within the pipes.
1.5
Hydrants Points
Hydrants are generally seen in close
vicinity of the protected buildings. These are painted red in color for easy
identification. The stand post of the hydrant is an 80 NB dia pipe projecting out
of ground and fixed with a Hydrant valve with an outlet hand wheel for
operating the valve. Hydrants also
consist of a glass - fronted cabinet housing hoses and branch pipe with nozzle
to direct the water to the base of fire.
Hydrant points are located at required span
between each other, at strategic points so as to be able to combat the fire
from all sides. Near each hydrant point, a hose box is provided with a set of
fire hoses & branch pipe with nozzle to direct the water to the base of
fire.
Hydrants and its components are designed keeping in mind that no time is wasted from the time the fire is detected and the fire fighting commences.
2.0 INTRODUCTION ABOUT
2.1 System
Description
General: Provide a complete, ,
[addressable], Microprocessor-based fire
alarm system with [initiating devices], [notification appliances,] [and]
monitoring and Control devices] as indicated on the drawings.
Software: The fire alarm system shall
allow for loading and editing instructions and operating sequences as
necessary. The system shall be capable of storing, and downloading while the
system is in operation, a second set of operating software resident in the
control panels as backup in case primary operating software is corrupted.
In addition, the system shall be capable of on-site programming to
accommodate system expansion and facilitate changes in operation. All software
operations shall be stored in a non-volatile programmable memory within the
fire alarm control unit. Loss of primary and secondary power shall not erase
the instructions stored in memory.
History Logs: The system shall provide a
means to recall alarms and trouble conditions in chronological order for the
purpose of recreating an event history. A separate alarm and trouble log shall be
provided.
Reference
Conventional Operation. Each addressable device on the
communication channel is continuously interrogated for status condition such
as: normal, off-normal, alarm, supervisory, or trouble. Sophisticated poll and
response communication techniques ensure supervision integrity operation. The
device LED blinks to indicate. Receipt of a communications poll and is steady
on to indicate an alarm (or trouble) condition.
CPU bay system power supply (SPS) provides an IDNet signaling line
circuit (
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