25 October 2004
Figure 4-11. MK-48 refueling hood.
Ductwork. Follow criteria as specified in paragraph 2-4.1 for both MK-46
and MK-48 shops and the following:
a. Fabricate all ductwork in contact with Otto Fuel II vapors with (black)
carbon steel. Require all joints be either butt welds or flanges.
b. Size the duct to maintain a minimum transport velocity of 12.7 m/s (2,500
Fans. Select fans as specified in paragraph 2-4.2.
Weather Stack Design and Location
. Proper dispersion from the stack
is critical because Otto Fuel II exhaust is not filtered. See paragraph 2-4.3.
Air Cleaning Devices
to the quantities and types
generated by these processes, there is no requirement for air pollution control
Replacement Air. Design replacement air systems to maintain a
pressure (relative to the atmosphere) ranging from -5.0 to -14.9 Pa (-0.02 to -0.06
inches wg) in the spaces with a potential for personnel exposure. Maintain the spaces
with a low potential for personnel exposure at a differential pressure ranging from 2.49
to 12.4 Pa (+0.01 to +0.05 inches wg).
Quantity and Distribution. Distribute air to produce laminar flow of air
from supply to exhaust in the workspace. Use vertical supply distribution method as