(a)Purpose. The purpose of this test shall be to determine
the flammability of a hydraulic fluid when it is sprayed over three different
sources of ignition which are described in paragraph (b)(4) of this
(b)Description of apparatus. (1) A 3-quart pressure vessel,
with the necessary connections, valves, and heating elements, shall be used
for containing and heating the fluid under the test conditions as specified
(2) An atomizing round-spray nozzle, having a discharge
orifice of 0.025-inch diameter, capable of discharging 3.28 gallons of water
per hour with a spray angle of 90 degrees at a pressure of 100 p.s.i., shall
be connected to the pressure vessel.
(3) A commercial pressurized cylinder, containing nitrogen
with the customary regulators, valves, tubing, and connectors, shall be used
to supply nitrogen to the pressure vessel described in paragraph (b)(1) of
(4) Three igniting devices shall provide three different
sources of ignition as follows:
(b)(4)(i) A metal trough with a metal cover in which cotton
waste soaked in kerosene is ignited.
(b)(4)(ii) An electric arcing device in which the arc is
produced by a 12,000-volt transformer.
(b)(4)(iii) A propane torch--Bernzomatic or equivalent.
(b)(4)(5) A means of measuring distances from the nozzle tip
to the igniting device shall be provided.
(c)Test procedures. (1) A 2 1/2-quart sample of the fluid
shall be poured into the pressure vessel and heated to a temperature of 150°
F. The temperature shall be maintained at not less than 145° F. or not more
than 155° F. during the test.
(2) Nitrogen shall be introduced into the vessel at 150
(3) The fluid shall be sprayed at each igniting device,
described in paragraph (b)(4) of this section, which is moved along the
trajectory of the spray. Each igniting device shall be held in the spray at
different distances from the nozzle tip for one minute or until the flame or
arc is extinguished (if less than one minute) to determine this
fire-resistant characteristic of the fluid.
(d)Appraisal of tests. If the test procedures in paragraph
(c) of this section do not result in an ignition of any sample of fluid or if
an ignition of a sample does not result in flame propagation for a time
interval not exceeding 6 seconds at a distance of 18 inches or more from the
nozzle tip to the center of each igniting device, it shall be considered fire
resistant, according to the test requirements of this section.
U.S. Department of Labor | Mine Safety and Health Administration (MSHA) | 1100 Wilson Boulevard, 21st Floor | Arlington, VA 22209-3939 www.msha.gov | Telephone: (202) 693-9400 | Fax-on-demand: (202) 693-9401