You must obtain the specific safety pre-cautions for a given engine from the appropriate NAVSEA technical manual. In addition to the guidelines in the NAVSEA technical manual, you should observe the following precautions when operating or maintaining a diesel engine.

Relief Valves

If a relief valve on an engine cylinder lifts (pops) several times, stop the engine immediately. Determine the cause of the trouble and decide upon the correct solution. Except in an emergency, NEVER lock a relief valve in the closed position. Pressure-relief mechanisms are fitted on enclosures in which excessive pressures may develop.

Fuel

When fuel reaches the injection system, it should be absolutely free of water and foreign matter. You must thoroughly centrifuge the fuel before using it, and you must keep the filters clean and intact. Remember, fuel leakage into the lubricating oil system will cause dilution of the lubricating oil with a consequent reduction in viscosity and lubricating properties.

Cooling Water

Do NOT allow a large amount of cold water, under any circumstances, to enter a hot engine suddenly. Rapid cooling may crack a cylinder liner and head or may cause a piston to seize within a cylinder. Reduce the load or, when ordered to do so, stop the engine when the volume of circulating water cannot be increased and the temperatures are too high. In freezing weather, you must carefully drain all passages and pockets in the engine that contain fresh water and that are subject to freezing, unless an antifreeze solution has been added to the water.

Starting Air

When engines are stopped, you must vent all starting-air lines. Serious accidents may result if pressure is left on. Intake air must be kept as clean as possible. Accordingly, you must keep all air ducts and passages clean.

Cleanliness

Cleanliness is essential to efficient operation and maintenance of diesel engines. You must maintain clean fuel, clean coolants, clean lubricants, and a clear exhaust. You must also keep the engines clean at all times, and take steps to prevent oil or fuel from accumulating in the bilges or in other areas to prevent fire hazards.