Fire Suppression Systems

Marine fire suppression system servicing

Marine fire suppression system servicing covers the fixed systems, other than CO2 and foam, that protect machinery spaces, cargo pump rooms, accommodation, ro-ro decks, galleys and special hazards on board. These include high-pressure and low-pressure water mist, automatic sprinklers, water spray and drencher systems, local application systems over engines and boilers, clean agent and inert gas systems, condensed aerosol generators, dry chemical powder systems on gas carriers and galley deep-fat fryer systems.

These systems often sit unused for years, so their readiness depends on regular testing of pumps, valves, cylinders, nozzles and controls. vslSafety arranges a provider with the right maker knowledge at the vessel’s port. Fixed CO2 systems are covered by CO2 system servicing and foam systems by foam fire fighting system servicing.

Regulatory requirements and standards

• SOLAS chapter II-2, regulation 10, sets where fixed systems are required, and regulation 14 requires them to be maintained and ready for use.
• FSS Code chapter 5 (fixed gas systems), chapter 7 (fixed pressure water-spraying and water-mist systems) and chapter 8 (automatic sprinkler systems).
• MSC/Circ.848, as amended by MSC.1/Circ.1267, for equivalent fixed gas systems such as inert gas and clean agents in machinery spaces and cargo pump rooms.
• MSC/Circ.1165 (as amended) for equivalent water-based systems in machinery spaces and cargo pump rooms.
• SOLAS regulation II-2/10.5.6 requires fixed local application systems in certain category A machinery spaces above 500 m³, approved under MSC.1/Circ.1387, which superseded MSC/Circ.913.
• MSC.1/Circ.1270 for fixed aerosol systems in machinery spaces.
• SOLAS regulation II-2/10.6.4 for deep-fat cooking equipment, with ISO 15371 commonly used for galley systems.
• MSC.1/Circ.1315/Rev.1 for dry chemical powder systems on gas carriers installed on or after 1 July 2023.

Maintenance follows MSC.1/Circ.1432, as amended by MSC.1/Circ.1516 for sprinkler testing, plus the maker’s instructions. Some tasks can be done by competent crew; others, such as cylinder weighing, release testing and hydrostatic testing, are normally done by a trained service provider, often one authorised by the system maker. For ro-ro passenger ships, SOLAS amendments in force from 1 January 2026 add new fire protection requirements for vehicle, special category and ro-ro spaces, including fixed water-based protection of vehicle areas on weather decks.

Inspection and servicing intervals

Item	Requirement	Interval	Reference
Water mist, spray, sprinkler	Check panel indicators and alarms, pump unit and valve positions	Weekly	MSC.1/Circ.1432
Water mist, spray, sprinkler	Valve positions, tank levels, automatic pump start; test sample of section valves	Monthly	MSC.1/Circ.1432
Water mist, spray, sprinkler	Section tests, pump flow tests, alarms, strainers, sprinkler inspection	Annual	MSC.1/Circ.1432
Fixed gas (non-CO2)	Weigh or verify cylinders (above 95% of nominal charge); blow through piping	2 years	MSC.1/Circ.1432
Fixed gas and water systems	Internal inspection of control and section valves	5 years	MSC.1/Circ.1432
Fixed gas cylinders	Hydrostatic test of 10% (50% or all if failures); flexible hoses renewed	10 years	MSC.1/Circ.1432
Dry powder systems	Blow through with nitrogen, test controls, moisture sample, pressure test vessel	2 years	MSC.1/Circ.1432
Aerosol generators	Check replacement date; renew per maker	Annual; per maker	MSC.1/Circ.1432
Galley and deep-fat systems	Check per maker’s instructions	Annual	MSC.1/Circ.1432

What the service includes

• Review of system drawings, maker manuals, previous reports and cylinder test dates
• Functional testing of control panels, alarms, release stations, time delays and ventilation or fuel shut-offs
• Pump start and flow tests, relief valve checks and strainer cleaning on water-based systems
• Section valve tests, open-head section flow tests and automatic sprinkler or nozzle sample tests
• Weighing or level checking of clean agent and inert gas cylinders and pilot cylinders
• Blowing through of discharge pipework and nozzle checks
• Galley hood and fryer system inspection, including detection links, cartridges and power shut-off
• Replacement of expired aerosol generators, batteries and flexible hoses
• Arrangement of cylinder hydrostatic testing and recharging where due

Equipment and system types covered

Providers work on high-pressure and low-pressure water-mist systems (for example Marioff HI-FOG, Danfoss Semco and Ultra Fog), local application systems, wet-pipe and dry-pipe sprinklers, ro-ro drenchers, inert gas agents such as IG-541 and IG-55, chemical clean agents such as FK-5-1-12 and HFC-227ea, condensed aerosol generators, dry chemical powder skids on gas carriers and pre-engineered galley systems.

Common defects and PSC deficiencies

• Water-mist pump failing to start automatically, or low standby pressure
• Local application section valves isolated after maintenance, or nozzles painted over
• Sprinkler heads damaged, painted or obstructed by new ducting
• Clean agent cylinders below the weight tolerance or overdue for hydrostatic test
• Release cabinet alarms or ventilation stops not working
• Aerosol generators beyond their replacement date
• Galley system cartridge expired or fryer power not shutting off on release

Certificates and documents you receive

• Service report per system with test results, pressures and flow readings
• Cylinder weighing records and hydrostatic test certificates
• Record of parts replaced, including hoses, generators and batteries
• Defect list with recommended rectification
• Confirmation that the system has been returned to service

How to prepare the vessel

Share the system drawings, maker and model, and the last service report. Plan release testing with the chief engineer, since machinery may need to be stopped or ventilation isolated, and ensure the system is locked against accidental discharge during work. Provide fresh water for flushing and a safe route to land cylinders. Where a system is out of service, arrange alternative protection as expected by MSC.1/Circ.1432. Detection-triggered systems should be tested together with fire detection and alarm systems.

Information needed for a quotation

• Vessel name, IMO number, flag, class and ship type
• Port, ETA and ETD
• System types, makers and models, and protected spaces
• Number and size of agent and pilot cylinders and their hydrostatic test dates
• Number of aerosol generators and their replacement dates
• Last service date and any open findings
• Whether replacement cylinders or parts should be supplied

vslSafety coordinates a suitable provider at the vessel’s port. Cylinders due for testing can be handled through cylinder hydrostatic testing and recharging.

Frequently asked questions

How often should a marine water-mist system be serviced?

MSC.1/Circ.1432 sets weekly, monthly and annual checks, with internal inspection of control and section valves every five years and hydrostatic testing of gas and water pressure cylinders every ten years. The annual inspection includes section tests, pump flow tests and alarm checks, with the maker’s own instructions applied in addition.

What is a local application fire-fighting system?

It is a fixed water-based system that protects high-risk areas in category A machinery spaces, such as the fire-hazard portions of main engines, generators, boilers, purifiers and incinerators, without flooding the whole space. SOLAS regulation II-2/10.5.6 requires it in certain machinery spaces above 500 m³. Systems are approved under MSC.1/Circ.1387 and must be able to be released automatically and manually.

Does a clean agent or inert gas system need weighing like CO2?

Yes. MSC.1/Circ.1432 recommends that high-pressure agent and pilot cylinders are weighed, or their contents verified by other reliable means, every two years, and refilled if below 95% of the nominal charge. Inert gas cylinders are normally checked by pressure and temperature correction. At ten years, a sample of cylinders is hydrostatically tested, with further testing if any fail.

How long do aerosol generators last?

Condensed aerosol generators have a service life set by the maker, and MSC.1/Circ.1432 requires them to be renewed in line with the manufacturer’s recommendations. The replacement date should be checked annually. Generators cannot be refilled, so a ship with an older system should order replacements in good time and confirm that the new units are compatible with the approved system.

Is a galley fire suppression system mandatory?

SOLAS regulation II-2/10.6.4 requires deep-fat cooking equipment to have an automatic or manual extinguishing system, a primary and backup thermostat with alarm, automatic power shut-off when the system is released, a local alarm and clearly labelled manual controls. Systems for other galley equipment are optional unless class or the owner requires them.