Why are High and Low suction fitted on F.O Service Tank?

The high and low suctions are a safety feature to prevent shutdown of main engine, generators and boilers due to water contamination of the fuel.

Normally the low suction is kept in used if any water should find its way into the fuel and service tank, it will gradually separate towards the tank bottom when it becomes apparent water is present by finding it at the tank drains or by operation of the engine, it is possible to bring the high suction into operation and avoid shutdown.

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Bilge Injection Valve

Bilge Injection is a valve that enables the engine room bilges to be pumped out directly overboard in the event of an emergency such as flooding. The valve is normally fitted to the end of a branch connection with the main sea water suction line. This enables large main seawater cooling pumps to be used as a bilge pump in an emergency. Emergencies like fire and flooding involve the use of seawater. If there is a fire, seawater is the biggest resource of water available in the sea. Similarly, if it involves flooding of the engine room, cargo spaces or any other place on the ship for that matter; you would again require pumping the sea water out of the ship. In both these cases, you require pumps. There are two valves in close proximity namely main injection valve and bilge injection valve. Both of them have their own independent controls. The diameter of the bilge injection valve is kept nearly 66% of the main valve diameter which draws water directly from the sea th...

Difference Between A, B & C-Class Divisions?

IMO Symbol A Class Division IMO Symbol B Class Division SOLAS has tables for structural fire protection requirement of bulkheads and decks. The requirements depend on the spaces in question and are different for passenger ships and cargo ships. The Administration has required a test of a prototype bulkhead or deck in accordance with the Fire Test Procedures Code to ensure that it meets the above requirements for integrity and temperature rise. Types of Divisions: "A" Class "B" Class "C" Class "A" Class: "A" class divisions are those divisions formed by bulkheads and decks which comply with the following criteria: They are constructed of steel or equivalent material They are suitably stiffened They are constructed as to be capable of preventing the passage of smoke and flame to the end of the one-hour standard fire test. they are insulated with approved non-combustible materials such that the average tempera...

Why do we blow through engine before starting ?

The engine is blown through on air before starting it : a) To Blow out through indicator cock any residual exhaust gas or other products of combustion trapped inside the cylinder after shutting the engine. b) To check if any jacket cooling water from cylinder head or turbocharger or any other source, has leaked while the engine was shut and collected on top of piston. If while blowing through, water comes out of indicator cock or relief valve, we need to investigate and rectify the fault before starting the engine. It is imperative that the engine is blown through before starting. There have been cases where the generator engine has been started from control room without bothering to blow th...

Marine Engineering

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