Figure 15-39.--Stowage of portable manifold for interim washdown system.
vented, the air required for drainage is taken in through
efficient drainage. Each secondary drainage system is
the vent line instead of through the drain receptacle of
independent of the main drainage system and has its
the fixture, and proper drainage of the trap will result.
own pumps or eductors and its own disposal
FUEL OIL SYSTEMS
Plumbing and deck drains are classified according
to their type; either as soil or sanitary waste drainage.
Naval ships now use a fuel oil known as fuel, naval
Drains from water closets, urinals, and similar fixtures
distillate as their primary fuel. This fuel oil meets the
flushed with seawater are soil drams. Most of the other
requirements of specification MIL-F-16884. Other
plumbing drains are waste drams.
NATO countries have similar, if not identical, naval
shipboard fuel specifications. Therefore, the NATO
Since shipboard flushing systems use salt water, the
code number F-76 was assigned to the fuel, naval
soil drainage piping is usually of a copper-nickel alloy.
corrosive effect of the salt water. The joints in
The use of F-76 has increased the amount of time
copper-nickel piping are silver-brazed. The sanitary
between fireside cleanings. Cleaning can be extended
waste drains are usually made up of brass or copper.
from one overhaul to the next, with periodic inspections
held during the operational period. Fireroom
All plumbing drainage systems must be vented. A
maintenance and topside maintenance is reduced, while
vent line prevents the siphonage of traps and allows
sewer gas to escape. As long as a system is properly