Additional features include automatic ventilation
Navy ships to provide protection for galley deep-fat
shutdown, actuation of local and remote predischarge
and doughnut fryers and their exhaust systems.
alarms, manual time delay bypass, automatic
A q u e o u s p o t a s s i u m c a r b o n a t e i s s p e c i fi c a l l y
ventilation closures (if installed), and Halon
formulated to extinguish fire in the reservoirs by
discharged indicator light.
combining with the hot cooking-oil surface to form a
An AFFF bilge sprinkling system normally
combustion-resistant soap layer, thereby cutting off
supplements Halon 1301 systems in machinery spaces
the grease from its source of oxygen. There is little or
and pump rooms. The AFFF bilge sprinkling system,
no cooling with APC. A typical APC
where installed, should be actuated at the same time as
fire-extinguishing system is shown in figure 6-19. For
the Halon system. AFFF bilge sprinkling systems are
more information about the APC fire extinguishing
not installed if the bilge is too shallow.
system, refer to the technical manual NAVSEA
REVIEW QUESTIONS
S9555ARMMO010, Fire Extinguishing System,
Deep-Fat and Doughnut Fryer.
Q15.
Halon systems are used to extinguish fires
COMPONENTS
that are beyond the capacity of portable fire
extinguishing equipment, and where
Each APC system includes one or two cylinders
abandonment of the space is necessary.
filled with a solution of potassium carbonate in water
1.
True
pressurized with compressed nitrogen (N2). Discharge
2.
False
piping from the cylinder(s) leads to one or more
nozzles which spray the solution into the cooking oil
Q16.
The full discharge of the gas from a Halon
reservoirs, along the galley hood plenum, or up into the
1301 system into a protected space is
galley hood exhaust duct. A spring-tensioned cable
completed in how many seconds?
keeps the system inactive. When this tension is
1.
10
released, the system is activated and N2 is released
2.
20
from a pressurized cartridge. This action opens the
lever control heads, releasing the aqueous potassium
3.
30
carbonate.
4.
40
OPERATION
Q17.
What type of system normally supplements
Halon 1301 systems in machinery spaces and
Operation of the APC fire-extinguishing system is
pump rooms?
normally fully automatic. Manual backup modes of
1.
APC
operation are provided at the cylinder assembly,
2.
PKP
pressure release control box, and the remote manual
control box.
3.
AFFF
4.
Magazine sprinkler
Automatic Operation
Excessive heat on one of the fusible links melts the
link and releases the cable tension. The extension
AQUEOUS POTASSIUM CARBONATE
spring in the pressure-control box pulls the lever,
(APC)
which activates the pressure release cartridge. N2 gas
from the pressure-release cartridge activates the lever
Learning Objective: Recall the location, design
control head(s), causing the cylinder(s) to discharge.
components, and operation of a typical installed
aqueous potassium carbonate (APC) fire-extinguishing
Manual Operation
system.
The aqueous potassium carbonate (APC) system
Aqueous potassium carbonate (APC)
has three manual modes of operation:
fire-extinguishing systems (fig. 6-19) are installed in
6-17
