Marine pumps are critical equipment that can be found on almost all ships, but for many novice ship owners, they may have no knowledge of the functions of marine pumps. The function of a marine pump is to discharge accumulated water from the bottom of the ship. Usually on large yachts, cooling water is discharged to the outside through a well-developed drainage system, but on small vessels, cooling water can only be discharged to the bottom of the cabin; Water may also flow into the bottom of the cabin through some small pipe gaps, such as leakage of the shaft seal of a straight shaft engine, especially due to ship cracking caused by impact, or water pipe cracking caused by high engine temperature. Appropriate and sufficient marine pumps can accelerate the drainage speed, preventing it from sinking quickly, in order to save time for maintenance or waiting for rescue.

Install at least one marine pump at the lowest point of the hull. For large vessels, one should be installed in each enclosed compartment, and the drainage pipe must be at least 20cm above the waterline. All compartment pumps should be located in a convenient location for personnel to operate, in order to check the status of the pump and its float switch, and to remove any debris sucked in around the pump. If the cabin pump is located in an inaccessible or inaccessible location, such as under the stern shaft engine, please consider changing the position of the cabin pump in this situation, i.e., how and when to start the cabin pump? The switch of marine pumps is usually configured as "automatic" and "manual". When water accumulates at the bottom of the cab and reaches the set water level, the cab pump float switch will automatically turn on. When the water level drops to the set level, the float switch automatically stops; Generally speaking, small boats only have manual pumps, as shown in the following figure. It is very important to regularly check for debris around the pump that may block the pump opening. In particular, new yachts need more attention because various construction wastes, sawdust, glass fiber dust, foam plastic fragments, epoxy resin fragments, and even screws may enter the bilge. Regularly check the function of the float switch. After a long time, it may freeze or corrode.

The distribution of the bottom pump drainage pipe should be concentrated above to keep it away from the wet bottom of the cabin.

If the bilge pump is not always on, a small amount of water can be injected into the bilge water to check its function. This not only confirms the performance of the automatic switch of the bilge pump, but also observes its drainage route and selects the appropriate bilge pump for your vessel. The rated power of the bilge pump is determined by its pumping capacity. The unit is gallons per hour. However, power is relative because the length, height, and type of pumping pipeline can affect the pumping rate of the pump in the cabin. The industry experience standard is that if a marine pump can pump 60% of the approved power, it is considered qualified; If the discharge hose is bent, replace it with a straight hose, which can increase the pumping capacity by 30%. A small vessel equipped with a small flow pump is sufficient "may sound logical, but the fact is quite the opposite: when there are leaks or other more serious maritime accidents in the hull, the impact of seawater on small vessels is much faster than that on large vessels.