30 CFR § 36.47 Tests of exhaust-gas cooling system.
(a) The adequacy of the exhaust-gas cooling system and its components
shall be determined with the engine operating at the maximum allowable
liquid fuel rate and governed speed with 0.5±0.1 percent, by volume, of
natural gas in the intake air mixture. All parts of the engine and
exhaust-gas cooling system shall be at their respective equilibrium
temperatures. The cooling spray, if any, shall be operated, and all
compartments designed to hold cooling water shall be filled with the
quantity of water recommended by the applicant. No cooling air shall be
circulated over the engine or components in the cooling system during the
(b) Determinations shall be made during the test to establish the
cooling performance of the system, the cooling water consumption, high-water
level when the system sprays excess water, and low-water level when the
cooling system fails.
(c) The final exhaust-gas temperature at discharge from the cooling
system, and before the exhaust gas is diluted with air, shall not exceed
170° F. or the temperature of adiabatic saturation, if this temperature is
(d) Water consumed in cooling the exhaust gas under the test
conditions shall not exceed by more than 15 percent that required for
adiabatic saturation of the exhaust-gas at the final temperature. Water in
excess of that required for adiabatic saturation shall be considered as
entrained water. Enough water shall be available in the cooling system or in
reserve supply compartments for sustained satisfactory operation for at
least 2 2/3 hours under the test conditions.
NOTE: This amount is enough to cool the exhaust for an 8-hour shift at
one-third load factor.
(e) The adequacy of the automatic fuel shutoff actuated by the
temperature of the final exhaust shall be determined with the engine
operating under test conditions by withdrawing water until the cooling system
fails to function. The final exhaust-gas temperature at which the liquid fuel
to the engine is automatically shut off shall be noted. This temperaure
shall not exceed 185° F.
(f) Following the automatic fuel shutoff test in paragraph (e) of
this section, the temperature of the control point shall be allowed to fall
to 170° F. At this temperature and with the water replenished in the cooling
system, it shall be possible to start the engine.
NOTE: If the cooling system includes a reserve supply water tank, the line or
lines connecting it to the cooling compartment may require a suitable flame
(g) The effectiveness of the automatic engine shut-off, which will
operate when the water in the cooling jacket(s) exceeds 212° F., shall be
determined by causing the jacket temperature to exceed 212° F.