flammability test data in risk assessment

72
THE ANNALS OF UNIVERSITY “DUNĂREA DE JOS“ OF GALAŢI
FASCICLE VIII, 2008 (XIV), ISSN 1221-4590
TRIBOLOGY
and the procedure. Even if the test is, in principle,
simple and the results are quantified in only three
possible ways, the procedure was well established in
order to obtain repeatability, a desired characteristic
of the test results but hard to obtain for test involving
fire or flammability characteristics [26]. Discussions
at ISO/TC 28 from 2000 also set the test parameters
accuracy, in order to give the possibility of ranking
fluids based on a well established procedure. For
instance, there was introduced three temperature
sensors, with imposed position on the manifold (two
on its opposite sides – near the ends of the rod and
one at the center of it), and not one as in the first
version of the standard, in order to have a better
control of the temperature uniformity that has to be at
all these three points within 700°C±5°C (or other
selected temperature, but with same accuracy)
Several specifications are related to the fluid
sample: the temperature, the volume and the state
(including the fact that “any air bubbles which may
have arise on mixing shall be allowed to escape from
the fluid before testing”). It is interesting to notice
that the majority of comments were done by countries
that are big manufac-turers and users of hydraulic
fluids (United Kingdom, Canada) [45].
This international test method and tester has the
highest degree of resemblance to the American Hot
Manifold Ignition Test (Federal Test Method 791,
Method 6053.1) [40], the results of the test being also
quantified in a similar way (Tab. 2). Even the tester
dimensions are very close to those of the tester
describes in EN ISO 20823:2003.
This ISO testing method is mainly used for
assessing the resistance to ignition of the fire-resistant
fluids that are, by definition, difficult to be ignited.
The procedure given in this standard is also specified
in ISO 12922-1999, Lubri-cants, industrial oils and
related products (class L). Family H (hydraulic
systems). Specifications for categories HFAE, HFAS,
HFB, HFC, HFDR and HFDU.
Many specifications related to hydraulic fluids
and oils include the results of some others tests
concerning the fire resistance and flammability, the
shear stability and the determination of extremepressure
and anti-wear properties, taking into account
other standards than those involved in this study [20,
21, 43]
The FM Standard 6930 [2] was intended to test
only hydraulic fluids. A sample of the hydraulic fluid
being tested was pressurized to 6.89MPa and heated
to a fixed temperature starting from 60°C. There were
performed four tests: test for determining the
chemical heat release rate of the fluid, flame
propagation test, test for measuring critical heat flux
for ignition, hot surface ignition test. The latest was
designed to mimic hydraulic fluid leaking under high
pressure from a hose in an environment where hot
surfaces are common. Hydraulic fluid was sprayed
from a nozzle onto a steel surface heated to 700°C.
FM will also work with the American Petroleum
Institute to include the new specification test
standard within a new hydraulic fluid flammability
standard being developed by the International
Organization for Standardization (ISO) [34].
The objectives of the grant CEEX-M4-452
includes applicative research concerning the three
testing methods that now are not performed in our
country for technical fluid assessment conformity by
taking into account the requirements of the European
directives [6-9, 14]. As far as the authors could have
investigated, the test included in SR EN ISO
20823:2004 has not been not performed in Romania
till nowadays. This affirmation is based on the
negative answers received from 10 laboratories
having RENAR (Asociatia de Acreditare din
Romania, Romanian Accreditation Association)
accreditation for analysing, testing and research on
fuels, oils, lubricants. These laboratories confirm that
they can not perform any one of the three tests under
the requirements of the European standards, as imposed
by the Directive 92/104 [7]. These laboratories
are: ICERP SA Ploieşti, ICMET Craiova, INCERP -
CERCETARE SA Ploieşti, LAREX CNIEP - Centrul
Naţional pentru Încercarea si Expertizarea Produselor,
ROMPETROL QUALITY CONTROL SRL,
PETROTEL LUKOIL SA Ploieşti, RULMENTUL
SA, PETROM SA (ARPECHIM).
Some laboratories explain the reasons why they
could not do these tests, especially the absence of the
necessary equipment and some of them could do one
or two of these tests but in accordance to other
standards. For instance, Total Lubrifin SA can
perform two of the above-mentioned tests but
following the requirements of ASTM standards.
4. THE TESTER
The tester design meets the requirements
imposed by SR EN ISO 20823:2004, comprising (fig.
2) a robotic system 1 that automatically ensures the
positioning of the fluid dispenser 5 above the
simulated manifold, at a position desired by the
operator, within a high temperature enclosure 4. The
manifold is made of corrosion resistant steel and it
could be heated by an electric system up to 700°C.
The temperature control is done by the help of three
digital thermocouples mounted on a transversal
guiding system 3 that allow them to be in contact
with the manifold and then withdrawn during the
fluid dropping. All the above mentioned subsystems
are enclosed in the ventilated enclosure 2.
5. PRELIMINARY RESULTS
Table 3 presents three tests done at elevated
temperature and in the last column there are presented
comments that could give supplementary
characteristics of the tested fluids. For instance, a