installation directiVe
1
N40 ENT M25
N60 ENT M37-M40
MAY 2006
1
2
3
5
4
8
6
04_072_N
7
7. FUEL LINE
For the installation, the following connections are required:
- from the tank to the pre-filter
- from the pre-filter to the pump inlet
- from the fuel discharge outlet to the tank
Pre-filter
The pre-filter with priming pump, supplied separately from
the engine, must be fastened near the tank, in a relatively low
point of the line to allow for easy replacement of the filtering
cartridge and/or the operation of the hand pump. Avoid the
use of additional mesh or paper filters along the feed lines
between pre-filter and engine. To avoid introducing impuri-
ties in the feeding lines inside the engine, do not place filter
cartridges pre-filled with fuel in the system.
Materials’ Characteristics
The fuel tank and the suction and return assembly must
withstand the continuous abrasion caused by a flow of fuel
oil of 250 l/h at a temperature of 120 °C without noticeable
deformation or wear or release of material. Use of metal
tanks, preferably made of iron alloys, is allowed, provided
they are connected to the negative terminal of the battery
to prevent the accumulation of electrostatic charges.
Tanks must be provided with vents to avoid exceeding an
internal pressure of ± 5kPa (± 0.5 m of H
2
O column); their
shape and the suction assembly must be such as to assure a
suction at the maximum longitudinal and transverse inclina-
tion allowed for the boat, with a residual quantity of fuel oil
considered “reserve”.
The suction inlet should be positioned in such a way as to
avoid taking in sludge. The return flow must be in such a way
as to facilitate the mixing of the returning fuel with the fuel
in the tank. If the tank is lower than the filter, then the return
pipe must always be submerged. The pipes and union fittings
of the fuel line must withstand a fuel oil flow rate of 250 l/h
at a temperature of 120 °C and a pressure of 3 bar (300
kPa) without noticeable deformation, wear or release of
material. Metal tubes, preferably made of iron alloys, are rec-
ommended, taking care to connect each individual segment
to engine ground to avoid the accumulation of electrostatic
charges and inserting a vibration damper elastic joint on each
segment. The pipes used must be certified according to the
relevant Countries’ rules or to the standards issued by clas-
sification Bodies.
1. Fuel filter - 2. Common rail - 3. Electro-injector - 4. Electro-injector return loop pressurization valve - 5. Rail overpressure valve -
6. High and low pressure pump - 7. Priming pump - 8. Settling pre-filter.
Figure
High pressure
Low pressure
Содержание NEF N40-ENT-M25
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