Sea Water Cooling System
Note: A separate sea water cooling system should be provided for each engine.
Illustration 1 | g00745796 |
Typical arrangement (1) Sea water strainer (2) Auxiliary water pump (3) The diameter of the hose that connects to the sea water strainer is 32 mm (1.25 inch). (4) The diameter of the hose that connects to the valve for the sea water is 32 mm (1.25 inch). (5) The diameter of the valve for the sea water is 25.4 mm (1.00 inch). (6) The skin fitting has a diameter of 25.4 mm (1.00 inch). |
Illustration 2 | g00745850 |
The sea water strainer should be mounted so that the top of the sea water strainer is just above the level of the sea water. By having the sea water at this level, the sea water strainer can be easily cleaned. (1) Sea water strainer (2) Auxiliary water pump (5) Valve for the sea water (7) Level of the sea water |
The fitting for the sea water inlet (6) should not project below the bottom of the hull. The fitting for the sea water inlet should be installed away from rudders and shafts. This will prevent a problem with the flow of sea water at high speeds. The rear edge of the sea water inlet may project more than the front of the sea water inlet. The rear edge of the inlet for the sea water cannot project more than 6 mm (0.25 inch) from the front edge of the inlet for the sea water.
The fittings for the sea water inlet and the piping for the sea water inlet should have a minimum bore of 25 mm (1 inch). A valve for the sea water (5) must be installed. The valve for the sea water must have a full flow passage.
Between the fitting for the sea water inlet and the auxiliary water pump (2), a sea water strainer (1) should be installed. The sea water strainer should be easily accessible for the purpose of maintenance.
Illustration 3 | g00808369 |
Typical example of the naturally aspirated 3034 Marine engine (8) Supply for the lubrication of the propeller shaft (9) Supply for the sea water |
Illustration 4 | g00808371 |
Typical example of the turbocharged 3034 Marine engine (10) Supply for the lubrication of the propeller shaft (11) Supply for the sea water |
A pipe should be run from the sea water strainer to the inlet of the auxiliary water pump (9) and (11). The pipe may be rigid or flexible. The flexible pipe section should be reinforced in order to prevent a collapse. Rubber hose connections in the sea water inlet system should be kept as short as possible. Rubber hose connections should also be reinforced. The system must be flexible. This will permit the engine to move on the flexible engine mounts. The connection for the auxiliary water pump is for a 32 mm (1.25 inch) bore.
Some propeller shafts need water for lubrication. The supply for the lubrication of the propeller shaft (8) and (10) will suit a 10 mm (0.39 inch) bore.
The materials that are used in the sea water system must be compatible with each other. This will help prevent excessive corrosion because of electrolysis. The following metals can be used in a sea water system:
- Copper
- Cupronickel
- Stainless steel Type 316
- Gunmetal
- Silver solder
- Aluminum brass
The following metals should be avoided in a sea water system:
- Lead
- Iron
- Steel
- Zinc
- Magnesium
- Aluminum
- Alloys of aluminum
Keel Cooling System
Illustration 5 | g00808372 |
The naturally aspirated engine is shown. (1) Supply for the keel cooling system |
Illustration 6 | g00808373 |
The naturally aspirated engine is shown. (2) Return for the keel cooling system |
Both the naturally aspirated 3034 and the turbocharged 3034 Marine engines are suitable for a keel cooling system.
Requirements for Keel Cooling Systems for the Naturally Aspirated 3034 Marine Engine     | ||
    | Naturally Aspirated 3034 Marine Engine     | Turbocharged 3034 Marine Engine     |
Heat rejection at rated speed     | 40 kW (2300 Btu/min)     |
51 kW (2908 Btu/min)     |
Coolant temperature at the exit of the keel cooler     | 60 °C (140 °F)     |
60 °C (140 °F)     |
Coolant flow through the keel cooler     | 90 L/min (24 US gpm)     |
90 L/min (24 US gpm)     |
The connections for the keel cooling system require a 32 mm (1.25 inch) bore.
The length of the piping between the engine and the keel cooler must be as short as possible. To achieve a short distance, the piping must be as direct as possible. The piping must also be flexible so that the engine is allowed to move on the flexible engine mounts. Venting points should be installed so that air can be removed from the system.
The keel cooling system should have venting points. The venting points are used to remove air from the system.
The keel cooling system should use the correct mixture of water and antifreeze. Refer to the Operation and Maintenance Manual, "Cooling Systems Specifications" for more information on the correct mixture.
Connections for the Domestic Water Heater
Illustration 7 | g00812810 |
The naturally aspirated 3034 Marine engine is shown. (1) Supply for the domestic water heater |
Illustration 8 | g00812811 |
The naturally aspirated 3034 Marine engine is shown. (2) Return for the domestic water heater |
Fittings are available to supply a domestic water heater. If the fittings are not installed on the engine, then the fittings can be installed at a later time.
Radiator hose or heater hose must be used in order to connect the domestic water heater to the fittings. The hoses must be installed so that chafing will not occur.
NOTICE |
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The hoses that connect the domestic water heater to the engine are part of the closed engine cooling system. Failure of the hoses will lead to engine overheating. Engine overheating can lead to possible engine damage. |