- Excessive wear of the liner
- The piston rings wear out
- Broken piston rings or rings gets seized in the groove
- Dirty scavenge place
- Poor combustion takes place due to leaking fuel valve
- Inadequate or surplus cylinder lubrication
What are the Indications of Scavenge Fire
- Loss of power happens and irregular running of engine and reduction in rpm takes place.
- Abnormal exhaust temperature of equivalent unit.
- The high local temperature in scavenge tank.
- Surging of turbocharger happens.
- Sparks and smokes coming out from the drain box.
- Smoky exhaust comes out
- The paint may blister on the scavenge doors due to the high temperature.
What Actions to be taken
Action taken vary upon the kind of fire whether minor or major
For minor fire
- Start reducing the engine rpm to slow or dead slow
- Increase the cylinder lubrication of the affected unit considering that these don’t feed the fire.
- In case of increase of fire lubrication not to be reduced. The fire can be due to a leaky valve so it can be cut off for the affected unit
- Keep monitoring the scavenge or exhaust temperatures
For major fire
- Immediately stop the engine
- Quench the fire with a permanent fire fighting system and boundary cooling of the scavenge manifold maybe necessary to prevent distortion
- After confirmation that fire is extinguished and scavenge place is opened and is inspected to find out the cause and same is to be rectified.
Following steps should be taken for prevention of fire.
- Regular cleaning of the under piston area and the scavenge manifold is required to avoid scavenge fire.
- The under piston drain valve and drain should be cleared out regularly to avoid the accumulation of sludge in those areas.
- The piston rings should be regularly inspected for their proper functioning.
