The engine needs cooling water, more cooling lines for the external exhaust manifold, and the slot has an exhaust line, usually a copper tube, from the tank to the fuel pump, and then another hose is connected to the fuel hose of the fuel filter. From there, another hose needs fuel for carbohydrate or fuel injection systems on diesel engines, and there is a return line to take unnecessary fuel back to the tank!
Compared with the cost of system service and protection of metal hoses at least once a year, some hoses have a service life of 2-3 years. After a long time of use, vibration, heat and fatigue seasons, replace all hoses and use comfortable new clips, and all double clips passing through the rubber hose body. The hose only needs to meet the minimum SAE specifications and survive within the warranty period, which is usually only 1 year. Some hoses have a 2-year, 3-year or 5-year warranty. When you enter the high-end flexible silicone exhaust hose, there is a 10-year warranty, but that does not mean you can ignore the hose for 10 years.
Almost all yacht inboard engines send their exhaust and cooling water through high-temperature hoses and full exhaust pipes in the crossbeam, or through the drive unit and through the propeller hub. For all hoses and pipe joints, if the metal hose is equipped with tap water at the head of the kitchen, the cockpit refreshment center or the ice maker on the bridge. All of these hoses are vital for the circulation of liquids and gases that make your rubber hoses work.