46 C.F.R. § 154.708 Cargo boil-off as fuel: Valves.
Title 46 - Shipping
(a) Gas fuel lines to the gas consuming equipment must have two fail-closed automatic valves in series. A third valve, designed to fail-open, must vent that portion of pipe between the two series valves to the open atmosphere. (b) The valves under paragraph (a) of this section must be arranged so that loss of boiler forced draft, flame failure, or abnormal gas fuel supply pressure automatically causes the two series valves to close and the vent valve to open. The function of one of the series valves and the vent valve may be performed by a single three-way valve. (c) A master gas fuel valve must be located outside the machinery space, but be operable from inside the machinery space and at the valve. The valve must automatically close when there is: (1) A gas leak detected under §154.706(a)(2) or §154.706(b); (2) Loss of the ventilation under §154.706(a)(2) or §154.707(c); or (3) Loss of inert gas pressure within the double-walled piping system under §154.706(a)(1).
Title 46: Shipping
PART 154—SAFETY STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES
Subpart C—Design, Construction and Equipment
Cargo Pressure and Temperature Control
§ 154.708 Cargo boil-off as fuel: Valves.
