UFC 3-410-04N 25 October 2004 Figure 4-11. MK-48 refueling hood.
4-3.2.6 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 fpm). 4-3.2.7
Fans. Select fans as specified in paragraph 2-4.2.
4-3.3 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. 4-3.4 Air Cleaning Devices. Due to the quantities and types of contaminants generated by these processes, there is no requirement for air pollution control equipment. 4-3.5 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). 4-3.5.1 Quantity and Distribution. Distribute air to produce laminar flow of air from supply to exhaust in the workspace. Use vertical supply distribution method as 4-10