Roll-Over Valve Check - PIAGGIO Beverly 250 USA Workshop Manual

Maintenance
Characteristic
Standard opening vacuum
200 ÷ 260 mbar

Roll-over valve check

The valve should allow the following results:
• Tank aeration when running (ambient air enters into the tank based on the volume of fuel used).
• Tank pressurization (the tank internal temperature may rise when running or while stopped. The valve
should pressurize the tank so to limit the amount of fuel vapors departing towards the Canister).
Prevent the liquid fuel pollution of the Canister (if the vehicle falls, the valve should interrupt the con-
nection to the Canister).
The valve must be removed from the vehicle upon
inspection.
A MITYVAC pump and a length of pipe are needed
for the inspection; proceed as follows:
• Attach the MITYVAC pump to the lower joint to
the safety valve (white).
• Set the pump control onto "vacuum" and, whilst
keeping the valve aligned with its vertical axis,
check that air may be sucked in without observing
any movements on the manometer needle gauge.
• Set the pump onto "pressure" and, whilst keeping
the valve aligned with its vertical axis, check that
the valve can be pressurized to values slightly be-
low 0.1bar (~60mbar).
N.B. The calibration pressure can be easily rec-
ognized as, when reached, the valve will start to
discharge air thus emitting a weak noise.
• Align the valve with its horizontal axis and check
that it can be pressurized to values much higher
than the calibration pressure (e.g. 0.5bar without
it necessarily being maintained).
Replace the valve if anomalies are found.
N.B. Any valve failure may cause the fuel tank to
deform or increase of the Canister operating re-
quirements.
MAIN - 24
Beverly 250 USA