Marine Rose Box
The Marine Rose Box, also commonly referred to within the industry as a raw water intake filter, bilge water filter box or strum box, is a specialised seawater/bilge water filtration device within a ship's piping system
Overview
Basic Characteristics and Functions
Core Function: Installed at the suction end of a vessel’s bilge water, ballast water and seawater cooling pipelines, it filters out silt and debris from seawater to prevent impurities from entering pumps and other downstream equipment, thereby avoiding blockages or damage.
Suitable Media: Seawater, bilge water, ballast water and other common fluids found in marine piping systems.
Standard Size Range: DN40–DN300; mainstream products cover the full range of specifications from DN50 to DN200.
Standards
Japanese Standard: JIS F7206-1998, currently the most widely applied standard in the industry, which specifies technical requirements for different materials such as galvanised carbon steel and stainless steel.
Chinese National Standard: CB623-80, the traditional general standard for the domestic shipbuilding industry.
Core Technical Parameters
The ratio of the total filter mesh area to the nominal cross-sectional area of the suction pipe is greater than 3, ensuring that the suction flow rate is not significantly affected.
The ratio of the filter mesh area to the total area of the orifice plate is greater than 0.33, balancing filtration precision with flow efficiency.
Standard mesh aperture sizes range from 5–10 mm and can be customised according to filtration requirements.
Common materials: hot-dip galvanised carbon steel (with a zinc coating of not less than 600 g/m²), SUS304 stainless steel, and copper alloys.
Key Points for Routine Maintenance
Dismantle and clean the filter screen regularly to prevent the long-term accumulation of seawater sediment and sand, which can block the filter pores and impair the flow efficiency of the pipework.
In the event of faults such as water leaks or deformation of the filter screen, repair or replace components promptly to ensure the normal operation of the bilge water system.
Equipment that is out of service for extended periods must be protected against rust to prevent structural failure caused by seawater corrosion.
Main Types:
Round
Square
