Fire tests should be carried out in accordance
with the following paragraphs 3.8.1 - 3.8.7 below.
_____________
NOTE :
The fire tests of section 3.8 are more expensive and time
consuming than the other tests of these guidelines. It is
recommended that fire tests should be carried out at the end of
the test programme, so as to avoid expense of unnecessary
testing of foam concentrates which do not comply in other
respects.
3.8.1 Environmental
conditions
.1 Air temperature: (15 +/- 5) degrees C
.2 Maximum wind speed: 3
m/s in proximity of the fire tray.
Records
During
the fire test, record the following:
.1 indoor or outdoor test
.2
air temperature
.3 fuel temperature
.4 water temperature
.5 foam solution temperature
.6 wind speed
.7 extinction
time. 3.8.3 Foam solution
.1 Prepare a foam solution, following the
recommendations from the supplier for concentration, maximum premix
time, compatibility with the test equipment, avoiding contamination
by other types of foam, etc.
.2 The test should be carried out with sea water at
about 20 degrees C. Simulated sea water with the characteristics
stated in 3.6.3 may be used. 3.8.4 Apparatus.1 Fire tray:
Circular fire tray of steel
with dimensions as follows:
diameter at rim:
(1,480 +/- 15) mm
depth: (150 +/- 10) mm
normal thickness of steel wall: 2.5 mm _______
NOTE : The tray has an area of approximately
1.73 m**2.
.2 Foam-making equipment:
In
accordance with subparagraph 3.6.2.1. 3.8.5 Fuel
Use an aliphatic hydrocarbon
mixture with physical properties according to the following
specification:
.1 distillation range: 84-105 degrees
.2 maximum difference
between initial and boiling points: 10 degrees C
.3 maximum aromatic content: 1%
.4 density at 15 degrees:
(707.5 +/- 2.5) kg/m**3
.5 temperature: about 20 degrees C. __________
NOTE : Typical fuels meeting this specification
are n-hepthane and certain solvent fractions sometimes referred
to as commercial hepthane. The Administration may require
additional fire tests using an additional test fuel.
3.8.6 Test procedure
3.8.6.1 Place the tray
directly on the ground and ensure that it is level. Add
approximately 30L of fresh water and (55 +/- 2) L of fuel, to give a
nominal freeboard of 100 mm.
3.8.6.2 Not later than 5 minutes after adding of a
fuel, ignite the fuel and allow it to burn free for a period of not
less than 180 s after the full involvement. Set up the foam
equipment at a height which is equal to the upper edge of the rim as
it is shown at figure 1. 200 +/-5 s after full involvement of the
surface into the fire, apply foam along the wall of the tray for a
period of 120 +/- 2 s. Record the extinction time as the period from
start of foam application to extinction.
3.8.7 Permissible limits
Extinction time % not more than
120 s.