Understanding the operations and intricacies of machineries can be arduous and challenging task onboard ships. For every engineer officer, preliminary theoretical knowledge of day to day operations and piping systems is important for taking cognizance of complicated machinery operations. The hierarchy on board further defines and demands the engineers in their first stint onboard to trace the piping diagrams in order to have thorough understanding of different symbols and lines from the facsimiles provided onboard.
- Usually, a typical line diagram would look like a printed labyrinth and could be difficult to understand. It is hence suggested to keep them for reference and trace them physically.
- The junior rank is generally the in-charge of daily transfers related to sludge and bilge waters, under the directions of the second engineer and thus he should begin his enterprise with the same approach.
- To instigate with the process of plotting line diagrams, one should always start with the highest or lowest point in the system, specifically with a tank that supplies or is being drained to, taking all safety precautions.
- The tank being drawn without scale, should be marked with the outlet valves or inlet valves, along with the sophisticated remote closing devices having pneumatic control arranged for operations external to the engine room.
- The tanks should further be marked with the air pipes, thermometers, level gauges, overflow pipes and electronic high and low level alarms.
- Sounding pipes must be considered and their position in the tank must be thought of, whether in aft or forward of the tank.
- Manhole doors and other mountings aid the cleaning and inspection of particular tanks and they must also be drawn with a symbol representing important details. Tracing the mountings serve an additional aid to know abnormality and the normal operating parameters of the system. With any deviation, a problem can be encountered and dealt without chasing the track of breakdown maintenance.
- The point of the pipes leaving the tank should be noted. Further, the lines should be traced with the subsequent valves marked with their types ( some require turning the floor plates if they lie buried inside). This would help to know the leakages and get them rectified at the earliest.
- Special attention should also be paid to the lagging clad steam lines and valves which could cause a burn if handled carelessly. Valves placed below the floor plates could be difficult to identify and memorize, and thus should be marked with the respective names from the system diagram by a felt tip pen for future references.
- Moving further, each and every pump along with its auxiliary should be marked with strainers and filters. The change over lever in the duplex filter should be carefully noticed, along with the purging cock and drain respectively.
- The type of pump should be considered along with their application in handling different fluids in the particular system. The same should be studied and the reasons should be framed for their application in that system. Relief valves, if provided, on the discharge side of the pump must be looked upon, laying emphasis on the fact that they are not present on the discharge side of centrifugal or roto dynamic pumps.