Fuel Supply; Information On Fuel Supply; Removing Fuel At Vehicle's Fuel Supply; And Return Pipe - Webasto Air Top Evo 40 Installation Instructions Manual

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
p [bar]
p (bar)
h [m]
1
L
1
0
L
1
h
[m]
2
p (bar)
Fig. 09: Permissible pressure at fuel take-off point
Parameter
Inside diameter of fuel line
L Length of fuel line (intake side)
1
L Length of fuel line (pressure side)
2
L + L Total length of fuel line
1 2
Height difference between heater and fuel pump
H
1
(heater above fuel pump)
Height difference between heater and fuel pump
H
2
(heater below fuel pump)
Fuel level (tank above fuel
pump), h1 [m]
h = 0
1
h = 0 to 1
1
h = 1 to 2
1
Fuel level (tank below fuel
pump), h2 [m]
h = 0 to 1.3
2
Air Top Evo 40 | Air Top Evo 55
L
H
2
0
L
H
2
Value
2 mm
max. 5 m
max. 10 m
max. 12 m
max. 3 m
max. 1m
Maximum permissible fuel pres-
sure at take-off point, p [bar]
-0.1 to +0.5
-0.1 to +0.4
-0.1 to +0.3
Maximum permissible fuel pres-
sure at take-off point, p [bar]
-0.1 to +0.5
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
Use only the genuine Webasto fuel extractor.
X X
Make sure that the installation location satisfies the require-
X X
ments.
Fuel take-off from return pipe:
X X
– 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.
Fuel take-off from swirl pot:
X X
[m]
1
– Make sure that the swirl pot is not completely emptied.
5.3

Removing fuel from vehicle fuel tank

[m]
The Webasto fuel extractor can be installed on the fuel delivery
2
unit.
CAUTION
Risk of fire by fuel escaping from leaking fuel
tank
Skin burns
Do not drill into fuel tank.
X X
When retrofitting the fuel take-off system on a
X X
plastic tank: Install the Webasto fuel extractor only
on the vehicle's fuel delivery unit.
12