46 C.F.R. § 32.56-60 Ventilation ducts—T/ALL.
Title 46 - Shipping
(a) Each duct for ventilation of Category A machinery spaces that passes through accommodation, service, or control spaces must be: (1) Constructed of steel and insulated to “A-60” Class; or (2) Constructed of steel, fitted with an automatic fire damper at each boundary where it enters and leaves the Category A machinery space, and insulated to “A-60” Class for a distance of 5 meters (16.4 feet) beyond each machinery space boundary. (b) Each duct for ventilation of accommodation, service, and control spaces that passes through Category A machinery spaces must be constructed of steel and be fitted with an automatic fire damper at each Category A machinery space boundary.
Title 46: Shipping
PART 32—SPECIAL EQUIPMENT, MACHINERY, AND HULL REQUIREMENTS
Subpart 32.56—Structural Fire Protection for Tank Ships With a Keel Laying Date On or After January 1, 1975
§ 32.56-60 Ventilation ducts—T/ALL.
