Webasto Thermo 50 Installation Instructions Manual page 43

Fuel supply
7.1. Fuel lines
Only steel, copper and plastic lines of plasticised, light and temperature-
stabilised PA 11 or PA 12 (e.g. Mecanyl RWTL) in accordance with
DIN 73378 may be used for the fuel lines.
NOTE:
The hose clips must be tightened with a torque of 1.0 + 0.4 Nm.
Leaking fuel must be removed before starting the engine or heater.
IMPORTANT:
If PME (vegetable oil methyl ester) is used as fuel, care must be taken
to ensure that the fuel lines and fuel filter are resistant to PME.
Do not use an angle cutter to cut a Mecanyl fuel line!
Since the lines normally cannot be routed with a constant uphill gradient,
the inside diameter must not be allowed to exceed a certain size. Air or
gas bubbles will accumulate in lines with an inside diameter of more
than 4 mm and cause malfunctions if the lines sag or run downwards.
The diameters specified in Fig. 7 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. The
lines must be installed in such a way that they cannot be damaged by
flying chippings and high temperatures (exhaust line).
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7.2. Connecting 2 pipes with a hose
The correct procedure for connecting fuel lines with a hose is illustrated
in Fig. 11.
Ensure that there are no leaks!
Right
Clip
Wrong
Bubble
Fig. 11: Pipe / hose connection
Thermo 50
Bubble