Distribution Manifold
The distribution manifold shown in Figure 4-6
requires eight valves. You seldom need to
open or close any but the generator valves (to
equalize fuel usage), but it is not always ap-
parent exactly which combination of valves
to switch when you have an emergency or
need to equalize tanks. All valves should be
clearly labeled.
There should also be a clear diagram of
the fuel system schematic mounted on a plas-
tic placard right next to the fuel manifold. At
the dock, you have plenty of time to ponder
which combination of valves to open or close
to make the correct selection, but under-
way—in an emergency or in heavy weather—
it’s another story altogether.
In addition, there should also be a warn-
ing placard reading:
“Always open valves in combination to
takeoff and return to the same tank.”
Of course, the required placard warning that
oil discharge overboard is illegal must be
posted as well.Diesel Day-Tank Piping
Though the twin-tank diesel system is per-
fectly adequate, the day-tank system is supe-
rior for long-range cruising and all larger
diesel craft. Here the main port and star-
board fuel tanks (the “wing tanks”) feed a
single smaller, day tank. The engines and the
generator draw off this day tank, and the re-
turn lines go to the day tank as well. Addi-
tionally, you can set up to have optional
draw direct from the wing tanks; the piping
is straightforward, though installing a plac-
ard of the piping schematic is still highly
recommended.
For the serious voyager, routine filling of
the day tank gives a good regular reckoningChapter 4: Fuel Piping and Fuel System Bonding
Figure 4-6. Fuel-
piping or distri-
bution manifold