Bristell B23
Airplane Maintenance Manual
Chapter 28
Issue: 30-Sep-2020
Chapter 28 Page 3
Checking Fuel System Tightness
NOTE
Tightness is checked by pressurized air or fuel. When performing a
specific tightness check, outside temperature fluctuations must not
be bigger than ±13°C (8°F). Reseal found out leakage by
a suitable
method
–
by tightening, by using a suitable sealing.
Checking Airplane Fuel System Tightness by Air
DANGER Explosion and fire hazard!
▶
Working on the fuel system is only allowed to persons
who are fully instructed and familiarized with safety
instructions.
▶
Do not work on the fuel system
during rain and storm
in a closed space
when the engine is operating or
with electric system switched on.
▶
Do not work on the fuel system nor allow any person to
stay next to the aircraft, when wearing polyester clothing
or any clothing from a material which creates static
electricity.
▶
Do not smoke or handle with open fire nor allow any
person to do so.
▶
Ensure airplane is grounded.
▶
Drain fuel system.
▶
Disconnect fuel line from mech. Fuel pump (1)
▶
Disconnect fuel return line from fuel manifold(2)
▶
Close the fuel return line; the fuel filler neck and the fuel
vent line with appropriate plugs
▶
Choose the correct tank to test and select with the fuel
selector valve.
▶
Pressurize the system at the fuel feed line (at the mech.
Fuel pump) with 2 psi.
▶
Shut the air pressure supply. During 15 minutes there
must not be any loss in pressure. Find out leakage by
listening to and by soap water.
▶
Fuel selector valve
–
OFF position.
