Sea Water Circuit - FNM HPE Series Installation Manual

Do not use pipes or fittings with a passage diameter
less than 8 mm (5/16 in). The engine can be
damaged.
It is good practice to use pipes with a larger diameter in the
case of long distances between the tank and the engine to
remedy the reduction in flow rate due to deposit of impurities
along the tube.
It is recommended to use hoses to the fuel circuit to prevent
breakage of the tubes during operation. Avoid stopping the
tubes with solutions that can result in damage cause by cutting
or rubbing profiles and sharp edges. Avoid sharp bends
(excessive angle).
In case of twinned installations (two engines) use separate
tubes both for delivery and for the return of fuel from each of
the engines up to the tank.
All components of the circuit must be properly tested and
manufactured for use with diesel fuel complying with EN590.
Do not use components of the fuel circuit which are
not suitable for the passage of fuel type EN590. The
breakage of one of these can lead to fuel losses in
the circuit and potential risks for the safety and
health of users of the boat, as well as to damage to
the engine.
5.2.2 Fuel filter
The fuel filter (see Figure 20 on page 21) is supplied with the
engine and can be installed on the engine itself or on a
bulkhead in the engine compartment.
The normal filter provided may be insufficient to stop the fuel
contamination resulting from the growth of algae.
In this regard, it is recommended to install an additional fuel
filter in series (e.g. Racor 500) with the following
characteristics:
Possibility of water discharge
-
Filtering capacity: minimum 2 μm
-
Fittings diameter; minimum 20 mm (¾ in)
-
Maximum flow rate: minimum 4.5 l/min (1 gal/min)
-
The presence of the additional fuel filter is required
in some areas of the world where the proliferation of
algae in the tank is common.
Install the additional filter between the engine filter and the
tank. The filter must be permanently attached, and must be
easy to inspect.
22 – FNM® Series HPE – Installation Manual
It is also possible to use additives for diesel fuel that contrast
the growth of algae, especially in very hot climates. Since the
chemical composition and the method of use of these
additives can vary, CMD cannot guarantee that it does not
affect the performance of the engine or cause damage to its
operation.
The use of fuels or additives that do not meet the
specifications for which the engine is designed
involve the engine failure and it will void the
warranty.
5.2.3 Connecting the engine to the fuel circuit
Connect the fuel delivery from the tank to the engine directly to
the low-pressure electric pump mounted on the engine. The
pump position varies from engine to engine and is identified by
the following table (or refer to paragraph 3.3 - Engine elements
on page 8).
Engine
1.3/1.9/2.4HPE
3.0HPE
Connect the fuel return pipe from the engine to the tank
directly on the return fitting which is located on the high
pressure pump or near the rail (diesel fuel high pressure
distributor).

5.3 Sea water circuit

The system of sea water intakes and pipes must be sufficient
to ensure a correct supply of sea water to the engine. Water is
necessary for the proper operation of the engine.
The absence of a proper sea water intake to the
engine causes the immediate heating of the
propulsion unit. Operating the engine without sea
water in the circuit will irreparably damage the pump
impeller, as well as the whole engine, and may void
the engine warranty.
The minimum flow rate of sea water to the engine and the
minimum diameter of the pipes are indicated in the following
table:
Position of the fuel low pressure
electric pump
On the bell housing, left side.
The lower end of the intercooler, near
the bell (left side)