Blow-by gas recirculation diagram)

BLOW-BY GAS RECIRCULATION DIAGRAM)

Crankcase emissions are made up of a mixture of air, diesel and burnt gases which leak through the piston rings, in addition to lubrication oil vapour.

This mixture is defined "blow-by" or "vent" gas.

Vent gases from the crankcase and cylinder head flow through pipe (3) to separator (2) where they lose part of their oil content in the vortex. This falls back to the sump through pipe (4) in the form of droplets (4).

The remaining gases flow through pipe (5) and are directed to the intake circuit.

Cylinder head gas outlet pipe (1) contains a flap trap (6) to prevent the pipe catching fire due to flame flash-back.