What is meant by Emergency bilge suction in Engine room?

‘Bilge injection system’ is same as ‘direct suction’ referred in SOLAS and is understood to mean ‘Emergency bilge suction’, which is used to discharge overboard large quantities of sea water accumulated in engine room bilges using the main circulating pump or another suitable pump as permitted by regulation. This is mainly fitted to take protection against flooding engine room.
The emergency bilge valve is normally maintained in a closed position.
A non-return device is installed in the emergency bilge piping.
The emergency bilge suction piping is located inboard of a shell valve that is fitted with the control arrangements required by SOLAS.
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