Installation Instructions
Seite/Page 66 - Kaptitel/Chapter 6: Installation Instructions
9.2.16
b) Position of the venting valve is too far from the ships’ center line. The water reaches the exhaust area when the
ship is tilted.
c) The venting valve does not work, because it jams or it is clotted. (The venting valve’s function needs to be
checked regularly.)
As it consistently happens that functioning risks are not realised during the laying of the exhaust hose, the following
explanations refer explicitly to the exhaust hose. Here, the location, the size and the position of the „waterlock“ play
a very decisive role:
6.7.2 Installation area of the waterlock
Concerning a water-cooled exhaust system, it must be regarded that - under no circumstances - cooling water from
the exhaust hose can get into the exhaust elbow area at the engine. If this happens, the cooling water can get into
the combustion chamber via an open discharge valve. This would lead to irreparable damage at the engine.
In addition to that, one has to reckon with possible tilted positions of sailing yachts, which makes the position of the
waterlock even more important. In general one could say that:
The deeper the waterlock is located underneath the generator, the better the protection from entering water into the
combustion chamber.
The picture below shows that the distance between the critical point at the exhaust elbow and the maximum
permissible water level in the exhaust hose is stated with 600 mm. This distance should be understood as a
minimum distance.
6.7.3 The volume of the waterlock
The waterlock must be measured so large, that it can take the entire amount of water flowing back from the exhaust
hose. The amount of water depends on the hoses’ length (L) and its cross section. While the diesel engine is
running, cooling water is continuously injected into the exhaust system and is carted outside with the emissions by
the exhaust gas pressure. When the engine is turned off, the number of revolutions sinks quite fast. By doing so, the
point is reached where the exhaust gas pressure does not suffice anymore to cart the cooling water out. All cooling
water remaining in the hose at that point flows back into the waterlock. At the same time, the diesel engine itself
continues to cart cooling water through the cooling water pump, as long as it keeps on rotating.
The waterlock must necessarily be measured large enough that it can take the entire amount of cooling
water and, at the same time, does not exceed the prescribed vertical height of 600 mm up to the critical
point at the exhaust elbow.
Fig. 6.7.3.0-1: Volume of the waterlock