Iveco VECTOR Series Technical And Repair Manual page 50

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SECTION 2 - FUEL
Single—stage pressure relief valve (item 5, Figure 18)
Fitted at one end of the rail, its function is to protect the system's components if any malfunctioning of the rail pressure sensor
or of the pump pressure regulator causes an excessive increase in the pressure of the high—pressure system.
The valve is a mechanical type and when the pressure in the high—pressure system reaches 1850 bar the valve opens to run fuel
off into the outlet line and accordingly reduce the pressure to acceptable values.
Figure 19
Single—stage pressure relief valve (item 4, Figure 18)
Fitted at one end of the rail, its function is to protect the system's components if any malfunctioning of the rail pressure sensor
or of the pump pressure regulator causes an excessive increase in the pressure of the high—pressure system.
The valve is a mechanical type and when the pressure in the high—pressure system reaches 1850 bar the valve opens to run fuel
off into the outlet line and accordingly reduce the pressure to acceptable values.
Flow limiters (item 2, Figure 18)
Located on the fuel outlet unions from the common rail, they protect the engine and vehicle in the event of larger fuel leakage
after the flow limiter (e.g. a jammed open nozzle) or external leakage (e.g. damage in high—pressure pipes).
Under this circumstance, cut off the fuel to the cylinder in question.
To reset the flow limiter it is necessary to stop the engine in order to zero the rail pressure.
!
However, if the cause of it switching on is not removed, the same fault will occur the next time the engine is started.
If the leakage is considerable, it will be impossible to restart the engine due to the lack of pressure in the rail.
Base - April 2006
VECTOR 8 ENGINES
or lower for the single—stage
valves
Print P2D32V001E