Do not use a speed scoop or cup design intake through-hull strainer because it can cause a ramming effect and force water upward, past the seawater pump, and into the engine cylinders when the vessel is moving and the generator set is shut down.

Do not use hulls incorporating sea chests or other designs that provide a positive pressure to the raw water pump for the intake through-hull strainers. Positive pressure forces water past the raw water pump and into the engine. A sea chest is a concave molded-in-the-hull chamber that aligns to the vessel’s direction of travel. A sea chest configuration applies positive pressure similar to a scoop-type through-hull strainer.

3.2.2Seacock

Mount the seacock to the hull, assemble it to the intake, and ensure that it is accessible for operation. Figure 3-2 shows a typical installation.

Avoid overcaulking the seacock. Excess caulk reduces water flow and, in some cases, develops a barrier that can force water upward, past the seawater pump, and into the engine cylinders when the vessel is moving and the generator set is shut down.

3.2.3Seawater Strainer

Mount the seawater strainer to the seacock or permanent structure at a point not higher than the seawater pump. Ensure that the strainer is accessible for service. See Figure 3-4 for a typical installation.

Some seawater strainers include a seacock and an intake through-hull strainer.

Maximum seawater inlet pressure at the seawater pump is 34.5 kPa (5 psi). Excessive pressure will cause water ingestion.

1

2

3

1-789

1.Seawater pump

2.Seawater strainer

3.Seacock

Figure 3-4 Seawater Strainer

3.2.4Water Lines

Water lines from the seacock to the engine-driven seawater pump are usually constructed of flexible hose. Connect a flexible section of hose to the seawater pump to allow the generator set to vibrate during operation. Support a nonflexible water line within 102 mm (4 in.) of its connection to the flexible section.

Keep the seawater hose as straight and short as possible. If the hose is too long, usually over 4.6 m (15 ft.), water draw problems may occur. See Section 7 for the inlet water line hose size and the seawater connection to the seawater pump inlet. Avoid running the inlet pipe above the generator. See Figure 3-5 for the seawater hose connection to the seawater pump inlet.

 

1

1. Seawater pump inlet

TP-5586-6

 

Figure 3-5 Seawater Inlet Connection, Typical

3.2.5Closed Heat Exchanger

(4--125EFOZ/5--150EOZ Models)

A closed heat exchanger is the best cooling method for most applications. See Figure 3-6 or Figure 3-7 for a typical installation. Provide space to access the water-cooled exhaust manifold pressure cap.

3.2.6Direct Water Cooled (3.5EFOZ/4EOZ Models)

In a direct seawater cooling system, the impeller pump circulates the seawater around the cylinder and through the cylinder head. A thermostat controls the cooling water circuit temperature. Consult Figure 3-8 and the engine operation manual for the cooling water circuit diagrams.

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Section 3 Cooling System

TP-6069 6/03

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Image 16
Kohler 125EFOZ/150EOZ, 8.5EFOZ Seacock, Seawater Strainer, Water Lines, Closed Heat Exchanger 125EFOZ/5--150EOZ Models