Webasto Air Top 3500 ST Installation Instructions Manual page 17

Air Top 3500 ST / Air Top 5000 ST
Plastic tank
Sealing ring
Fig. 12: Fuel pickup from the plastic tank
(Pickup via tank drain screw)
Tank connector
Tank fitting
Fig. 13: Fuel pickup from the plastic tank
(Pickup via tank fitting)
NOTE:
The tank fitting must be made from metal!
7.4.
Only steel, copper and plastic lines of plasticised, light and temperature-
stabilized PA 11 or PA 12 (e.g. Mecanyl RWTL) pursuant to DIN 73378
may be used for the fuel lines. Since the lines normally cannot be routed
with a constant rising gradient, the internal diameter must not be allowed
to exceed a certain size. Air or gas bubbles will accumulate in lines with
an internal diameter of more than 4 mm and these will cause
malfunctions whilst the heater is operating if the lines sag or are routed
downwards. The diameters specified in Figure 9 will ensure that bubbles
do not form.
The lines should not be routed downwards from the metering pump to
the heater.
Unsupported fuel lines must be secured to prevent them sagging. They
must be installed in such a way that they cannot be damaged by flying
Sealing ring
road chippings and high temperatures (exhaust line). The fuel lines must
be secure at the connections using hose clips to prevent their slipping.
Fuel lines
Fuel supply
49