Marine Installation Manual
2021-08
4-60
4 Ancillary Systems
4.4 Fuel gas system
X72DF
4.4.10
Fuel gas leak test
After first-time system assembly or maintenance work on the fuel gas piping, a
leak test of the fuel gas pipe on the engine side and plant side is required to ensure
that the fuel gas pipe is tight and that the components in the gas piping are
working properly. The fuel gas leak test can be carried out with compressed air
from the starting air system. The air pressure must be reduced to the fuel gas
supply pressure as defined in section
. A temporary connection
must be arranged (please refer to the MIDS drawing,
).
The fuel gas leak test can be activated from the engine’s LDU. The test is auto
-
matically done sequentially for the three sections of the fuel gas pipe, as shown in
Figure 4
-
35 Gas leak test sequence (engines with iGPR)
Figure 4
-
36 Gas leak test sequence (engines with GVU)
NOTE
If the inert gas pressure is equal to or higher than the design fuel gas
supply pressure, then it can be used instead of compressed. This can
be carried out by means of a pressure reduction valve. In this case, a
branch connection from the starting air system to the gas fuel piping is
not necessary.
SM-0249
Section 1 - From gas supply to shut-off valves on the engine
Section 2 - Gas manifolds and GAV’s on fuel side
Section 3 - Gas manifolds and GAV’s on exhaust side
iGPR
Gas feed
system
From starting
air system
(temporary)
Vent
I
P
I
P
SM-0248
Section 1 - From the GVU inlet to the shut-off valves on the engine
Section 2 - Gas manifolds and GAVs on fuel side
Section 3 - Gas manifolds and GAVs on exhaust side
GVU
Gas feed
system
From starting
air system
(temporary)
Inert gas
supply
Vent
I
P
I
P
