Rotax 912 i Series Installation Manual page 103

Return line
Connection thread on fuel pressure regulator: 9/16-18 UNF. The return
line must have a minimum inner diameter of 7,5 mm (0.3 in.)
(AN-6 or 3/8").
To speed up the venting of the fuel system install a restricted bypass line
Bypass line
between the inlet (pressure side of the fuel pump module) and the return
line. In this bypass line a restricted jet must be installed so that there is
control over the fuel flow rate.
The positioning and dimension of the jet is up to the aircraft manufac-
turer.
NOTE:
Secure fuel lines with suitable screw clamps or by crimp connection.
Screw clamp
Effectivity: 912 i Series
Edition 1/Rev. 2
BRP-Powertrain
INSTALLATION MANUAL
With the engine switched off (throttle at idle and with
NOTICE
WARNUNG
both fuel pumps switched on), the pressure on the
output of the fuel pressure regulator must not exceed
0.5 bar (10.15 psi) (relative to ambient pressure).
If no bypass line is installed, the pressure release in
NOTICE
WARNUNG
the fuel lines is very slow. This must be noted accord-
ingly in the manuals of the aircraft manufacturer (fuel
lines are possibly under full operating pressure even
after engine stop).
The fuel lines must have a minimum inner diameter of
7,5 mm (0.3 in.) (AN-6 or 3/8").
For better heat dissipation select fuel lines made of
Tip
WARNUNG
metal whenever practicable (except for flex hoses to/
from engine).
The switching between several fuel tanks at power loss
due to fuel shortage must be given within a defined period
of time and without falling below the minimum perfor-
mance limit and must be ensured by the aircraft manufac-
turer. Refer to the latest requirements such as FAR or EA-
SA.
73-00-00
Page 7
January 01/2014