Air at high pressure, i.e. at 25 bar or more, is required for starting main and auxiliary engines in motorships. Air at low pressure, say at 6 bar or less is required for much remote or temperature or pressure controlled equipment, for which purpose it must be clean and oil-free

Open systems using gravity tanks, etc., are rarely met nowadays and Figure 1.8 shows a characteristic arrangement of pressure tanks, calorifiers and pumps for a large ship. The fresh water pumps are self-priming, drawing from storage tanks and discharging through filters to a rising main, branched to give a cold supply and a hot supply in closed circuit through a calorifier. A tank kept under pressure by an external supply of compressed air rests on the system and provides the head necessary

Learning Objectives The main objectives of this section are to make all engineers familiar with: Pre-treatment of marine fuels. Design criteria, or problems related to settling and service tanks. Draining of settling tanks. Preheating. Separation, purifier and clarifier. Sludge and sludge handling

The main objective of this section is to make you acquainted with the relevance of fuel parameters on: Abnormal ignition and combustion. Wear, piston ring collapse and breakage. Gas leakage. Ignition, combustion and exhaust gas emission. Engine damages and operational problems. Prevention of engine damages with off spec. fuels and to recognize their impact on the operation of marine diesel engines

3.2 Treatment of detergent type lubricating oils The main function of detergent lubricating oil is to keep solid contaminations in suspension and prevent both their agglomeration and deposition in the engine. This function reduces ring sticking, wears of piston rings and cylinder liners, and generally improves the cleanliness of the engine. agglomeration

3.4 ALFA-LAVAL Separator MAPX 207S-20 general information 3.4.1 MAPX information Contents – Correct installation, suitable treatment of the liquid before and after the passage through the machine, – correct operation and handling of the machine according to the directions given in instruction book, – cleanliness, carefulness and methodical overhaul are factors of the greatest importance for ensuring the best machine function and intended results

To ensure good combustion in diesel engines and reduce wear and corrosion in this type of engine it may be necessary to remove certain impurities from fuel and lubricating oils. These include ash, various salts and water present in fuel oil and carbonaceous matter, metals, acids and water present in used lubricating oil. carbonaceous

Cleaning, overhaul, lubrication. Satisfactory functioning cannot be ensured unless the parts in contact with liquid are carefully cleaned before assembly. This applies particularly to seal rings, sliding surfaces, guiding and contact surfaces, and threads. Also take care that no burrs are knocked up on the metal parts when handling them. Follow the directions given in chapter 5.4 and 4.5

The principle of separation by which all commercially available oil/Water separators is the gravity differential between oil and water. In oily water mixtures, the oil exists as a collection of almost spherical globules of various sizes. The force acting on such a globule causing it to move in the water is proportional to the difference in weight between the oil particle and a particle of water of equal volume. This can be expressed as:

6.2 Pumping considerations Since the rate of separation depends on the oil globule size it will be appreciated that any disintegration of oil globules in the oily feed to the separator should be avoided and this factor can be seriously affected by the type and rating of the pump used. Tests were carried out by a British government research establishment some years ago on the suitability of various pumps for separator feed duties (Double vane, Triple screw and Single vane )