CD Pre-treatment Unit

Verify Oil Content Meter (OCM / 15 ppm bilge alarm) calibration and function test using the manufacturer-approved test solution (e.g. Marinfloc WBS function test solution) at intervals required by class.

Inspect and replace filter cartridges (coalescence and polishing filters) according to service bulletin intervals or when differential pressure exceeds the specified limit; check for wrong filter material as per SB 17.

Check dosing pump hoses, flocculant chemical levels, and chemical dosing system operation; verify approved chemicals are in use per the manufacturer's approved chemical list.

Inspect all tank internals (oil descaler, flocculation tank, flotation tank) for corrosion, scaling, and sludge build-up; flush and clean as required — especially critical in high-chloride or high-temperature bilge water conditions (SB 01, SB 12, SB 24).

Verify the three-way overboard/recirculation valve operation and confirm correct sampling point arrangement and recirculation facility per SB 23 and MARPOL requirements.

Check the compressed air supply system (pressure, moisture, oil-free quality) used for dissolved air flotation; inspect air distributor non-return valves as per SB 14 and settings for backflush timing per SB 13.

Review the Oil Record Book entries, WhiteBox / discharge monitoring unit logs, and confirm the 15 ppm alarm activates the automatic stop-and-recirculate function before any overboard valve opens.

Inspect all pump seals, piping connections, and magnetic flow meter installation for leaks or air ingress that could affect flow measurement accuracy (SB 18); test automatic oil-sensing and oil-release valve to sludge tank.