Product Manual

3.13.3 Fuel extraction for heaters with inlet pressure resistant
metering pump up to 2.0 bar (diesel)
Fuel extraction using T piece from the fuel return line laid
between the vehicle engine to the tank fitting
1
2
5
6
8
b
6
7
7
7
9
3
4
Picture 21
1 Fuel return line from the vehicle's tank fitting
2 Fuel flow line from the vehicle's tank fitting
3 Metering pump (inlet pressure resistant up to 2.0bar) marked with
a green nameplate
4 T-piece
5 Fuel filter – only required for contaminated fuel
6 Fuel pipe, 4 x 1 (di = Ø2mm, blue)
7 Fuel hose, 3.5 x 3 (di Ø 3.5mm), approx. 50mm long
8 Adapter ( Ø 4.5 / 3.5mm)
9 from the vehicle engine to the tank fitting
Permissible line lengths
Intake side: a = max. 2 m
Pressure side: b = max. 6 m
Note
 Items 4 and 5 are not included in the “Universal installation kit”
scope of supply. Order No.
see page 11.
 Connect fuel pipe (Item 6) to the heater using adapter (Item 8). The
adapter (Item 8) with diameter 4.5 mm fits on the fuel sockets of
the heater. The smaller diameter 3.5mm fits on the fuel pipe.
 Installation of a fuel filter (Item 5) requires two adapters Ø5 / 3.5,
Order No.
see page 11.
 When installing tank connection (Item 1), maintain a minimum
distance of 5
±2
mm from the end of the riser to the bottom of the
tank.
 Check pressure in the fuel return line before installing.
Allowable pressures:
Æ for standard metering pump: max. 0.2 bar
Æ for inlet pressure-compatible metering pump: max. 2.0 bar
Warning!
Safety instructions for fuel supply!
 It is not permitted to extract fuel downstream of the vehicle's own
fuel pump.
 If using a T-piece in a plastic pipe, always insert support sleeves in
the plastic pipe.
 Always insert the T-piece in the fuel return line.
 Connect the T-piece and the plastic pipe with the relevant fuel
hoses and secure with hose clips.
 If the pressure in the fuel line is higher than 2.0 bar up to max.
4.0 bar, use a pressure reducer (Order No. 22 1000 20 08 00) or a
separate tank connection.
 If the pressure in the fuel line is above 4.0 bar or if there is a
non-return valve in the return line (in the tank), a separate tank
connection must be used.
 The vehicle must be delivered with an almost empty vehicle tank.
 After cutting the fuel return line, with the vehicle engine switched
off, use suction to check whether fuel extraction from the vehicle
tank without air bubbles is ensured. This ensures that the fuel
return line ends just above the bottom of the tank and no non-
return valve is installed. If this is not applicable, a separate tank
connection must be made or the fuel extraction must be estab-
lished using an adapter.
25.2933.90.0001.0A EN | 06.2018 27
Technical Description | Hydronic S3 Economy