Webasto Air Top Evo 40 Installation Instructions Manual - 5 Fuel Supply
12
Air Top Evo 40 | Air Top Evo 55
5 Fuel supply
5.1 Information on fuel supply
The fuel can be taken off at the following points:
■
Fuel supply or return pipe on vehicle engine
■
Vehicle fuel tank
■
Separate fuel tank
The fuel line consists of an intake and pressure side:
■
Intake side: Connection between fuel tank and fuel pump
■
Pressure side: Connection between fuel pump and heater
Permissible pressure at fuel take-off point
5.2 Removing fuel at vehicle's fuel supply
and return pipe
Installation location requirements:
The installation location must satisfy the following requirements:
■
The pressure at the fuel take-off point is within the permissible
range.
Installing fuel extractor
X
X
Use only the genuine Webasto fuel extractor.
X
X
Make sure that the installation location satisfies the require-
ments.
X
X
Fuel take-off from return pipe:
–
Make sure that the return pipe is not closed off by a non-re-
turn valve.
–
Make sure that the return pipe extends to the base of the
fuel tank.
X
X
Fuel take-off from swirl pot:
–
Make sure that the swirl pot is not completely emptied.
5.3 Removing fuel from vehicle fuel tank
0
H
2
[m]
H
1
[m]
0
h
1
[m]
h
2
[m]
L
1
L
2
L
2
L
1
p [bar]
p (bar)
p (bar)
Fig. 09: Permissible pressure at fuel take-off point
Parameter
Value
Inside diameter of fuel line
2 mm
L
1
Length of fuel line (intake side)
max. 5 m
L
2
Length of fuel line (pressure side)
max. 10 m
L
1
+ L
2
Total length of fuel line
max. 12 m
H
1
Height difference between heater and fuel pump
(heater above fuel pump)
max. 3 m
H
2
Height difference between heater and fuel pump
(heater below fuel pump)
max. 1m
Fuel level (tank above fuel
pump), h1 [m]
Maximum permissible fuel pres-
sure at take-off point, p [bar]
h
1
= 0
-0.1 to +0.5
h
1
= 0 to 1
-0.1 to +0.4
h
1
= 1 to 2
-0.1 to +0.3
Fuel level (tank below fuel
pump), h2 [m]
Maximum permissible fuel pres-
sure at take-off point, p [bar]
h
2
= 0 to 1.3
-0.1 to +0.5
The Webasto fuel extractor can be installed on the fuel delivery
unit.
CAUTION
Risk of fire by fuel escaping from leaking fuel
tank
Skin burns
X
X
Do not drill into fuel tank.
X
X
When retrofitting the fuel take-off system on a
plastic tank: Install the Webasto fuel extractor only
on the vehicle's fuel delivery unit.