2.1
Design filling rate is at least
the minimum nominal filling rate used during the approval tests.
2.2
Foam is the extinguishing medium
produced when foam solution passes through a foam generator and is
mixed with air.
2.3
Foam solution is a solution of
foam concentrate and water.
2.4
Foam concentrate is a liquid
which, when mixed with water in the appropriate concentration forms
a foam solution.
2.5
Foam delivery ducts are supply
ducts for introducing high-expansion foam into the protected space
from foam generators located outside the protected space.
2.6
Foam mixing ratio is the percentage
of foam concentrate mixed with water forming the foam solution.
2.7
Foam generators are discharge
devices or assemblies through which high-expansion foam solution is
aerated to form foam that is discharged into the protected space.
Foam generators using inside air typically consist of a nozzle or
set of nozzles and a casing. The casing is typically made of perforated
steel/stainless steel plates shaped into a box that enclose the nozzle(s).
Foam generators using outside air typically consist of nozzles enclosed
within a casing that spray onto a screen. An electric, hydraulic or
pneumatically driven fan is provided to aerate the solution.
2.8
High-expansion foam fire-extinguishing
systems are fixed total flooding extinguishing systems that
use either inside air or outside air for aeration of the foam solution.
A high-expansion foam system consists of both the foam generators
and the dedicated foam concentrate approved during the fire testing
specified in 3.1.3.
2.9
Inside air foam system is a fixed
high-expansion foam fire-extinguishing system with foam generators
located inside the protected space and drawing air from that space.
2.10
Nominal flow rate is the foam
solution flow rate expressed in l/min.
2.11
Nominal application rate
is the nominal flow rate per area expressed in l/min/m2.
2.12
Nominal foam expansion ratio is
the ratio of the volume of foam to the volume of foam solution from
which it was made, under non-fire conditions, and at an ambient temperature
of e.g. around 20ºC.
2.13
Nominal foam production is the
volume of foam produced per time unit, i.e. nominal flow rate times
nominal foam expansion ratio, expressed in m3/min.
2.14
Nominal filling rate is the ratio of nominal foam production to the area, i.e.
expressed in m/min.
2.15
Nominal filling time is the
ratio of the height of the protected space to the nominal filling
rate, i.e. expressed in minutes.
2.16
Outside air foam system is a
fixed high-expansion foam system with foam generators installed outside
the protected space that are directly supplied with fresh air.