46 C.F.R. § 108.437 Pipe sizes and discharge rates for enclosed ventilation systems for rotating electrical equipment.
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(a) The minimum pipe size for the initial charge must meet table 108.441 and the discharge of the required amount of CO2 must be completed within 2 minutes. (b) The minimum pipe size for the delayed discharge must be at least 1.25 centimeters ( (c) The pipe used for the initial discharge must not be used for the delayed discharge, except systems having a volume of less than 57 cubic meters (2,000 cubic feet).
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PART 108—DESIGN AND EQUIPMENT
Subpart D—Fire Extinguishing Systems
Fixed Carbon Dioxide Fire Extinguishing Systems
§ 108.437 Pipe sizes and discharge rates for enclosed ventilation systems for rotating electrical equipment.