Marine Exhaust Systems
Marine exhaust systems are the products with in line component applications design to reduce the sound level as much as possible. System starts from output of the engine exhaust and to the transom of the boat into the air. There are two types of marine exhaust systems. Dry and wet exhaust systems.
Dry Exhaust System:
Dry exhaust system is the oldest system used. Old technology allows manufacturers to produce noise reduction dry exhaust systems in their categories. They make quality standards which originated policy set up intentionally. At that time, mostly they used stainless steel material in their marine exhaust systems including; elbows, manifolds, clamps, tubing & hose systems attached to the system.
The exhaust gasses were transport to outside of the boat without any form of cooling. This was the handicap of dry exhaust system. Real handicap was the excessive heat generated by the diesel engines. Even though they are isolated well, due to the heat, noise level was high and still is for the ones who use old system.
Reduction of exhaust gas temperature by injecting water come down to 40 to 50 degrees centigrade is achieved. Wet exhaust systems are born. When they tried to replace exhaust components from stainless steel to flexible rubber or synthetic material results are getting better and better.
Wet Exhaust System:
When gas and water mixed in the new system, lots of new components have to be added in order to make the system safe and sound. Wet exhaust system is made up of different components to support the system as a whole. These are water lock, muffler, exhaust hose, gooseneck, exhaust connections and air went. In this system the only problem in the design was the water lock, which creates excessive back pressure to the engine, which might damage consequences for the engine parts.
To reduce the exhaust gas temperature of the engine wet exhaust systems are used in order to reduce the speed of sound, which gains fast speed with hottest environment. Another reason to reduce the temperature of the exhaust gas is related with the sound level. As the speed of sound transmission reduces so the sound noise level, which human ear hears, reduces proportionately.
Wet exhaust systems are used wide range of yachts now a day. Flexible rubber materials used installing these systems onboard the yachts make easy to install and maintenance as well. Let me mention about wet system components in order to be understood well.
Water lock component:
Modern water lock components have two chambers, upper and lower. This structure creates dual stage construction. There is a tube in the center and two chambers rotate 360 degree individually in order to give flexibility to the system. Size of the chamber depends on the engine HP size. Two chambers water lock reduce the sound level to maximum level and give minimum back pressure to the engine. Upper chamber connected to the engine exhaust manifold while the lower chamber connected to the transom plate with flexible rubber hose systems. Same systems are combined with muffler as well as gooseneck to the water lock. This gives additional flexibility for usage of limited space like horizontal or vertical installment of the system in limited spaces in the yacht.
Muffler creates additional water mixing to further reduce the sound level of the exhaust gasses. It mixes the water inside the exhaust line, which results in even better noise reduction. The connection of the muffler causes almost no resistance to the free flow of the exhaust gasses.
Gooseneck prevents water back filling to the exhaust system. It is installed high points of the system and it gives curve to the system in order to make back filling impossible.
Air vent component:
If there is point the cooling water is injected into the exhaust system is less than 15 cm above the sea level, there is a risk that cooling water will siphon into the exhaust system and subsequently into the engine itself. Air vents are used on the highest elevated parts of the system to allow cooling water not to siphon back to the system.? They have self-contained anti siphon pressure valve. This creates more safety environment, however needs regular cleaning maintenance to get rid of sea salt crystals.
Transom Exhaust Connection component:
Rubber hose components:
These are high quality silicone based hose systems which display high resistance against the heat. Flexible material gives another ease in installation of the system.