For the purpose of these Interim Guidelines, unless expressly
provided otherwise, the following definitions should apply.
3.1
Natural gas hydrate pellets (NGHPs) means
artificially formed pellets of "natural gas hydrate". Natural gas
hydrate is a crystalline solid which consists of molecules of natural
gas (mainly methane) each surrounded by a cage of water molecules.
3.2
International Gas Carrier Code (IGC Code)
means the International Code for
the Construction and Equipment of Ships Carrying Liquefied Gases in
Bulk as adopted by the Maritime Safety Committee of the Organization
by resolution MSC.5(48), as amended by resolutions MSC.17(58), MSC.30(61), MSC.32(63), MSC.59(67), MSC.103(73), MSC.177(79) and MSC.220(82).
3.3
Cargo hold is a space intended
for the stowage of NGHPs.
3.4
Cargo hold cover space is a space
above cargo holds which may be filled with natural gas.
3.5
Cargo hold cover is a structure
constituting cargo hold cover space for maintaining gas-tightness.
3.6
Gas machinery room is a space
containing equipment for natural gas handling.
3.7
Hatchway cover is a cover for
the opening of a cargo hold, which provides gas-tightness between
a cargo hold and a cargo hold cover space, as necessary.
3.8
MARVS is the maximum allowable
relief valve setting of a cargo hold.
Area classification (Zones 0, 1 and 2) is
based on the standard IEC 60079 (Electrical apparatus for explosive
gas atmospheres).