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FUEL SYSTEM
FUEL TANKS--GENERAL
It is very important that the design, construction and
installation of all fuel system components meet the highest
possible standards. Use only products specified for marine
applications.
Fuel tanks for diesel engines and generators may be made of
fiberglass, aluminum or stainless. Fuel tanks for gasoline
engines and generators may be made of only fiberglass or
aluminum; stainless is not appropriate for gasoline because
improper welding can remove carbon leaving only steel,
which will rust and then leak.
If the tank is made of fiberglass, be certain that the interior is
gel-coated to prevent fibers from contaminating the fuel
system. Copper or galvanized fuel tanks should not be used.
The nominal thickness of a fuel tank depends on the material
used. Any fitting or opening must be at the top of the tank. A
drain plug at the bottom of the tank is not acceptable.
Avoid the use of fittings made of copper-based alloys such as
brass as they will deteriorate the aluminum fittings.
Fastenings for an aluminum tank should be 300 series stain-
less steel.
It is not necessary to mount the tank above the engine level,
as the fuel lift pump provided will raise the fuel from the
tank. The amount of lift should be kept to a minimum 6 ft
(1.8 mm). If a tank is already installed above engine level, it
can be utilized in this position.
Cleanliness and care are especially important when the fuel
tank is installed because any dirt left in the tank will cause
fouling when the engine is started for the first time.
A
CAUTION:
Make sure the fuel tank filler is
properly sealed to prevent water re-entry should it
become awash. The fuel tank's vent should be routed
so as to prevent water entry as well.
The fuel tank's fuel pickup tube should be clear and
unobstmcted, without screens or gauze strainers. Make sure
that all fittings are sufficiently tightened to prevent leaking.
Fuel tanks that are located below the engine's fuel system
level must have their fuel return connection at the tank
extending down into the tank in the same manner as the
pickup tube; otherwise, air will replace fuel siphoning out of
the engine's fuel system through the return. (Diesel Models).
The fuel tank's vent should be located so that its discharge
route cannot allow water to enter through to the fuel tank(s).
Moisture must not be allowed to accumulate in the vent's line.
Mount the fuel tank and secure it into position. The NFPA
recommends that the bottom tanks be installed on slatted
wooden platforms to help prevent moisture condensation.
Cylindrical tanks should be set in chocks or cradles and
securely fastened.Insulate all wood or metal surfaces from
the tank surface with a non-abrasive and non-absorbent
material.
FUEL TANKs-GASOLINE
Tanks must be labeled with the manufacturer's name, tank
material and capacity. They also must be marked that they
have been pressure tested to the requirements of Title 33
CPR, sub part J. If either the fuel-fill fitting or the tank is
metallic, it will need to be grounded. A 10-gauge or larger
stranded copper wire must be fastened from the metal com-
ponents to the boat's ground.
Design the fuel tank vent line so that gasoline cannot spill
onto the boat. A loop in the vent line from the top of the tank
to the underside of the deck and then to the through-hull fit-
ting will prevent this. The line should drain back to the tank
with no traps. The vent line should be no less than 9116 in
(14.3 mm) I.D .. The through-hull vent fittings must be
equipped with a flame arrestor.
24
Fuel Tanks Located Above the Engine/Generator
A carburetor float valve cannot be trusted to hold back fuel in
an installation having a fuel tank located at or above the
engine/generator's fuel system. This type of system, with
some or all of the fuel supply line to the carburetor routed
below the level of the fuel tank's top, requires a shut-off
valve to shut off the fuel supply to the engine or generator
when the engine isn't running.
GENERATOR
USE EITHER ANTI-SIPHON V.tlVES
OR ElECTRICALLY OPERATED
FUEL STOP VALVES
PROPUlSION
ENGINE
FUEL TANKS LOCATED ABOVE THE ENGINE/GENERATOR
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