Installation Instructions
9.12.14
Kapitel/Chapter 7: Installation Instructions - Seite/Page 75
7.7
.
Installation of the waterlock
Note!:
Pay attention to the right flow direction throught the
waterlock.
Unfortunately, it can occasionally occur that, because of an disadvantageous mounting position of the waterlock, sea
water gets into the diesel engines’ combustion chamber. This disables the diesel engine by irreversible damages.
Quite frequently, this leads to discussions during which the parties involved in the yachts’ construction or the
installation of the generator have to explain themselves.
One point in this situation can be clarified definitely:
If sea water gets into the inner section of the engine, this is not possible due to constructional defects of the
generator or to malfunctions on the engine itself. It can only reach the combustion chamber via the exhaust hose
and thus get into the engine.
Thereby, the position of the generator and the waterlock, as well as the arrangement of the cooling water and
exhaust hoses play the decisive role.
If the waterlock is arranged in an unfavourable position, the cooling water flowing back in the exhaust hose can rise
so high, that it reaches the exhaust stack. Since at least one discharge valve is always open when the engine is shut
off, the sea water has free access to the combustion chamber. By capillary action, this sea water then flows past the
cocks and even reaches the engine oil in that way. (In fact, a surprisingly high oil level is a first indication of an
upcoming catastrophe).
If an usual high oil level can be detected and/or the oil is of a greyish colour, the engine must not be used
anymore. This is a certain sign for cooling water that got into the oil pan. If the engine is started under these
conditions, the water and the oil are mixed into an emulsion. The oil will quickly become so viscous that one
will have to call it a paste. In this phase the fine oil hoses are blocked and a few moments later the machine
gets destroyed because of insufficient lubrication. Before this happens, an immediate oil change should be
made. Since the water can only reach the engine via the combustion chamber, it can be assumed that the
compression rings will start to corrode. These effects have to be discussed with an engine expert. It will
certainly be reasonable to immediately inject plenty penetrating oil through the intake stack and to slowly
turn the engine with the starter motor.
The cooling water can reach the exhaust area via the exhaust hose as well as via the cooling water feed.
7.7.1 Possible cause for water in the exhaust hose
7.7.1.1 Possible cause: exhaust hose
If the cause is the exhaust hose itself, the following points are to be checked at the hose:
a) Position of the waterlock is too high. The water reaches the exhaust hose.
b) Position of the waterlock is too far away from the middle of the generator. The water reaches the exhaust hose in
tilted position.
c) The waterlock is too small relating to the length of the exhaust hose.
7.7.1.2 Possible cause: cooling water hose
If the generator is not clearly installed 600 mm over the water line, the cooling water feed must be equipped with a
„venting valve“ which is at least led out 600 mm over the water line. (This position must also be assured in every
tilted position. Therefore, the venting valve should be located in the ships’ center line, so that it cannot move in tilted
position).
a) Position of the venting valve is too low. The water flows into the exhaust area when the ship is tilted.
