Fire-Fighting System Operation
AFFF concentrate before it is pumped into the
The fire-fighting system provides the dual
fire-fighting capability of an onboard AFFF system
· AFFF tank Stores 60 gallons of AFFF con-
augmented by three 20-pound Halon 1211 portable
bottles (fig. 13-6). AFFF can be dispersed from both the
turret nozzle and a 100-foot long handline with nozzle.
· Pressure-relief valves PRV12 is set at 275 psi
They can be operated at the same time or
and it protects the AFFF concentrate side of the
independently. Maximum flow rate from the turret
back pressure regulating valve and relieves the
nozzle is 500 gpm while the flow rate for the handline is
AFFF back to the tank. PRV11 is set at 225-250
psi and it relieves head pressure at the turret
flow-control valve by dumping water/AFFF
Water is pumped from the main water tank by the
onto the deck.
centrifugal water pump. A butterfly isolation valve
controls the flow of the water from the tank to the
· Check valves Protects the AFFF concentrate
pump. This valve is opened and closed by a hydraulic
cylinder, which is activated by the standby/off switch
flow in one direction only. They are located in
on the main control panel. When open, the isolation
the turret piping and in the handline.
AFFF LINES DRAIN VALVE HANDLE
WATER LINES DRAIN VALVE HANDLE
TURRET AFFF SHUTOFF VALVE
Figure 13-6.--Controls and indicators.