Section 38.20-10 - Ventilation-T/ALL(a) A power ventilation system shall be provided for compartments containing pumps, compressors, pipes, control spaces, etc. connected with the cargo handling facilities. These compartments shall be ventilated in such a way as to remove vapors from points near the floor level or bilges, or other areas where vapor concentrations may be expected. The compartments shall be equipped with power ventilation of the exhaust type having capacity sufficient to effect a complete change of air in not more than 3 minutes equal to the volume of the compartment and associated trunks.(b) The power ventilation units shall not produce a source of vapor ignition in either the compartment or the ventilation system associated with the compartment. Inlets to exhaust ducts shall be provided and located at points where concentrations of vapors may be expected. Ventilation from the weather deck shall be provided. Ventilation outlets shall terminate away from any openings to the interior part of the vessel a lateral distance at least equal to that specified in § 38.20-1(a) . These outlets shall be so located as to minimize the possibility of recirculating contaminated air through the compartment.(c) Means shall be provided for purging the following spaces of cargo vapors:(1) The space surrounding nonpressure vessel type tanks, i.e., within the secondary barrier.(2) The space surrounding pressure-vessel type tanks whose piping connections are below the weather deck in accordance with § 38.10-1(h) .(3) The space surrounding tanks whose manhole openings are below the weather deck in accordance with § 38.05-10(f) .(d) Power ventilation shall be provided for each auxiliary machinery or working space located on and accessible from the cargo handling deck. Such ventilation systems shall be designed to preclude the entry of cargo vapors into the space via the open access or the ventilation system itself.CGFR 66-33, 31 FR 15269, Dec. 6, 1966, as amended by CGFR 68-65, 33 FR 19985, Dec. 28, 1968