61
S
ince January 2015, ships operating in designated
emission control areas (ECAs) have been required
to utilise fuel oil with a sulfur content of no more
than 0.10%, against a previous limit of 1.0%.
Since these rules were introduced under the
International Convention for the Prevention of Pollution
From Ships (MARPOL) Annex VI (Regulations for the
Prevention of Air Pollution from Ships), the use of LNG
as a marine fuel has become more attractive to ship
owners, due to its low emissions and sulfur content.
ECAs under MARPOL Annex VI for SO
x
include the
Baltic Sea area, the North Sea area, the North American
area (covering designated coastal areas off of the US
and Canada), and the US Caribbean Sea area (around
Puerto Rico and the US Virgin Islands).
The first ships to use LNG as a marine fuel were
small ferries, cruise ships and offshore vessels. Now,
however, a much wider variety of ships are using LNG
as their main fuel.
Of the LNG fuel gas systems (FGSs) produced so
far, the majority have been low pressure systems with
a maximum system pressure of 10 bar pressure. There
are a wide range of companies that can supply
cryogenic valves for these systems. However, with the
introduction of MAN Diesel & Turbo’s ME-GI
two-stroke gas engine, high pressure FGSs are
becoming a familiar sight in the engine rooms of a
variety of ships. The supply of equipment for high
pressure FGSs is a much more specialist area, as these
systems operate at 370 bar pressure and higher.
Meeting
marine
demands
Duncan Gaskin,
Parker Bestobell Marine,
UK,
looks at how the
wider adoption of LNG as
a marine fuel is leading to
demand for high pressure
cryogenic valves.
