Custom stainless steel filter block for boat: solution against sea salt haze (5100 m³/h) 

When operating ships on the high seas, one of the main problems is the penetration of sea salt haze into ventilation systems. The corrosive environment quickly destroys standard galvanized filter blocks, which leads to equipment failure and costly repairs.

In May 2025, TC Filter Group engineers received an order to design and manufacture a custom filter unit for a vessel. The customer’s key requirement is maximum corrosion resistance while maintaining specified aerodynamic characteristics.

Technical characteristics and operating conditions

The following input data were determined for this project:

Air flow:​ 5100 m³/h (under normal conditions)

Fan total static pressure:​ 4500 Pa

Operating temperature:​ room (up to +40°C)

Case material:​ stainless steel (AISI 304), completely eliminating the risk of salt corrosion

Overall dimensions (according to drawing):​ 900 × 420 × 620 mm

Inlet:​ Ø610 mm

Filtering configuration

The filter unit is designed according to a two-stage scheme to effectively protect the ship's ventilation systems from salt aerosols and mechanical particles.

Stage I - coarse filter (synthetic fiber panel):

Retains large particles of salt, sand and fibers

The material is resistant to moisture and salt environments

Easy to replace without tools

Stage II - aluminum mesh (metal filter with small cells):

Cell size ~1–2 mm, effectively retains fine salt haze

Completely resistant to corrosion, does not require replacement - only periodic cleaning

Operates over a wide temperature range

Design features and sealing

Particular attention was paid to fastening the filters and sealing the housing:

Case material: AISI 304 stainless steel, welded seams machined and polished

Sealing: EPDM seals, salt, UV and marine resistant

Filter fastening: stainless steel bolts with washers (see Fig. 4), ensure reliable fixation even with vibrations typical for marine transport

Flanges: custom profile, compatible with marine ducts

Handles and locks: stainless steel, resistant to sea corrosion