Figure 6-5. Typical high capacity single-speed pump system.
AFFF Sprinkler System
a pump, a motor, and a reduction gear (except 12 gpm
that is direct drive), coupled together with flexible
AFFF Transfer System
couplings and mounted on a steel base. The pump is
AFFF Testing Equipment
fitted with an internal relief valve, which opens to
prevent damage to the pump. The injection pump and
AFFF Generating Equipment
the injection station piping are sized to produce a
6 percent nominal concentration at peak demand by
Installed AFFF generating equipment is usually
i n j e c t i n g A F F F c o n c e n t r a t e i n t o t h e s e awa t e r
located in main machinery spaces, JP-5 pump rooms,
distribution system. AFFF concentrate is supplied
on flight decks, and in hangars and helo bays. The
from an AFFF tank. In some installations there is a
reason for this is that research has revealed that these
1-1/2-inch hose connection between the pump and the
are the places where class Bravo fires most often occur.
pump cutout valve. This hose connection is used to
There are two types of pumps used with the
transfer AFFF concentrate to other tanks by
installed AFFF system. They are the AFFF
connecting hoses between the pump and fill lines of the
single-speed injection pump and the AFFF two-speed
other tank. AFFF is transferred by manually starting
injection pump.
the injection pump that is used to supply the washdown
countermeasure system with AFFF. This action allows
AFFF Single-Speed Injection Pump
the system to be used as a fire-extinguishing system for
flight decks, fantail, and helicopter landing flight
The AFFF single-speed injection pump (fig. 6-6) is
d e c k s a n d p l a t f o r m s . B e s i d e s wa s h d ow n
a permanently mounted, positive displacement,
countermeasure systems, injection pumps also supply
electrically driven, sliding-vane type of pump. These
AFFF to reentry hose reels, well decks, and fueled
pumps are provided in capacities of 12, 27, and
vehicle stowage decks.
60 gallons per minute (gpm). The pump unit consists of
6-5
