Webasto Air Top 3500 Installation Instructions Manual page 11

Visit www.butlertechnik.com for more technical information & downloads.
fuel extracting
sealing ring
device
tank fitting
Fig. 12: Fuel Extraction From the Plastic Tank
(Extraction Via Tank Fitting)
NOTE:
The fitting must be made of sheet steel!
Fuel Lines
Only steel, copper and plastic pipes made of plasticized,
light-resistant and temperature-stabilized PA 11 or PA 12
(e.g. Mecanyl RWTL) in accordance with DIN 73378 may
be used as fuel lines. As in the majority of cases it is not
possible to route the lines in a continuous upward pitch,
the inside diameter must not exceed a given dimen-
sion.Starting with an inside line diameter of 4mm, air or
gas bubbles will accumulate resulting in malfunctions of
the combustion operation if lines sag or are routed with a
downward pitch. When the diameters shown in Fig. 8 are
used, you can be sure that no unwanted bubbles will be
formed.
The lines leading from the metering pump to the heater
should not be routed in a downward pitch.
To prevent the fuel lines from sagging, freely suspended
lines must be secured. Mounting should be performed in
such a manner that the lines are protected against flying
thermal influence
stones and (exhaust pipe).
To prevent the fuel lines from slipping off they are to be se-
cured at the joints by means of hose clamps.
Connecting Two Pipes Using a Hose
The proper connection of fuel lines using a hose is shown
in Fig. 13.
Check for leakage!
correct
clamp
incorrect
bubble
bubble
Fig. 13: Pipe/Hose Connection
www.butlertechnik.com
Air Top 3500/5000
Metering Pump
The metering pump is a combined delivery/metering and
shutoff system and is subject to certain installation criteria
(see Figs. 8, 14 and 15).
Air Top 3500/5000, 12-volt Petrol
preferably
15°-90°
Fig. 14: Metering Pump DP 2
Installation Position
Air Top 3500/5000 D. 12-volt and 24-volt Diesel
Fig. 15: Metering Pump DP 30
Installation Position
9