Foam Fire System

medium 120 models total

A fixed foam system smothers flammable-liquid fires by starving them of oxygen under an expanding foam blanket, rather than cooling them the way water does, which is why it is the standard defence for cargo pump rooms, machinery space bilges and helidecks rather than accommodation.

Read more — Foam Fire System explained ▾

What sets a foam system apart from other fixed suppression

Water and water mist fight fire mainly by cooling; CO2 fights fire by displacing oxygen from an enclosed space and cannot be used where people might be present. Foam does something different again: it forms a blanket of bubbles over a burning or spilled flammable liquid, cutting off the oxygen supply at the surface and suppressing vapour release, which makes it the preferred system wherever oil, fuel or other liquid hydrocarbons are the main fire risk, cargo pump rooms on tankers, engine room bilges and fuel-handling areas, and helidecks where aviation fuel spills are the design case. It is generally unsuitable for fires deep in solid combustibles or in energised electrical equipment, where CO2 or water mist do a better job.

Fixed foam fire system flow — Flow diagram of a fixed foam fire-fighting system showing the sea water supply feeding a foam pump, a foam concentrate tank feeding a proportioner where concentrate is inducted into the water stream, the foam solution main running to a deck monitor, and the resulting foam blanket falling on a protected deck area.

Main components

Foam concentrate tank

Stores the concentrate, commonly a synthetic or protein-based foam, or an aqueous film-forming foam (AFFF), which is proportioned into the water stream rather than used neat.

Proportioning system

A fixed ratio or balanced-pressure proportioner meters concentrate into the firemain flow, typically at 1-6% concentration depending on the foam type, to produce the correct foam solution.

Foam generators or monitors

Fixed foam monitors on deck or helidecks, or foam generators (branch pipes with an air-aspirating nozzle) in machinery spaces, expand the solution into finished foam at the point of application.

Distribution piping and valves

Dedicated piping runs from the proportioning system to each protected space or deck monitor, with remote-operated valves allowing activation from outside the space itself, essential where the fire may have already made the space inaccessible.

Selection and sizing

Foam type matched to the fuel risk; AFFF performs well on hydrocarbon spills, but its environmental persistence has pushed many operators toward fluorine-free alternatives.
Application rate and concentrate quantity sized to cover the largest single protected area for the required discharge duration, not an average across all spaces.
Helideck systems sized specifically to IMO and offshore-industry helideck firefighting standards rather than generic machinery space rules.
Compatibility of the foam concentrate with the firemain's seawater supply, since some formulations degrade with saltwater dilution.

Regulations and class

SOLAS Chapter II-2 sets fixed fire-fighting system requirements for machinery spaces and cargo pump rooms on tankers, with specific regulations covering fixed foam systems as an alternative or addition to fixed gas systems. The IMO Fire Safety Systems (FSS) Code, Chapter 6, sets detailed performance requirements for fixed foam extinguishing systems, including discharge rate and duration. Helideck foam provision follows IMO helicopter facility guidance alongside class notation requirements where applicable. Class surveys the system periodically, and foam concentrate itself is shelf-life limited and must be sampled or replaced within the manufacturer's stated interval.

Typical faults

Fault	Cause	Consequence
Foam concentrate degraded	Storage past shelf life or contamination	System discharges but foam blanket fails to form correctly
Incorrect proportioning ratio	Proportioner valve fouled or maladjusted	Weak foam solution, reduced suppression effectiveness
Blocked foam generator screen	Debris or corrosion in piping	Reduced or no foam expansion at the point of application
Remote valve fails to operate	Actuator corrosion from a rarely-tested system	System cannot be activated from outside the affected space

What to look for in a supplier

Foam concentrate with a documented shelf life and a testing regime the crew can actually perform on board.
Clear guidance on fluorine-free foam options given tightening environmental restrictions on AFFF in several jurisdictions.
Availability of concentrate replenishment in the vessel's normal trading ports, since a discharged or degraded system with no local resupply leaves a real gap in fire protection.

Sample and test foam concentrate at the manufacturer's stated interval rather than assuming an unopened tank stays good indefinitely; degraded concentrate is invisible until the one time the system is actually needed, and by then it is too late to find out.

Inspector Mode Show All 120 total

10 manufacturers · 120 models

Skum/Tyco

36 ✓ 36 verified

FJM-MAN ✓ verified

Application

Manual fog/jet monitor for portable foam/water discharge

Common Failures & Inspection Points

Area: Proportioner foam ratio accuracy deviation beyond tolerance (target: 0 to +30% or +1 percentage point maximum)
Check: Annual foam solution sampling and laboratory ratio analysis; proportioner functional test at maximum and minimum design flow rates per EN 13565-1
Area: Bladder tank integrity compromise (pressure loss, corrosion, elastomer degradation)
Check: Visual inspection of tank exterior for rust, corrosion, or damage; pressure test of tank shell at 1.5x design pressure; bladder elastomer condition assessment; check relief valve operation
Area: Foam concentrate deterioration, sludging, or chemical stratification in storage
Check: Annual tank inspection for sludge accumulation; foam concentrate sampling and laboratory quality testing; check for separation or discoloration; verify storage temperature maintained within -2 to +60°C limits
Area: Monitor nozzle blockage or fouling preventing proper fog/jet pattern adjustment
Check: Manual nozzle actuation test through full fog-to-jet range; visual inspection of nozzle orifice for debris or crystallization; flush test with clean water; verify elevation and rotation movement smoothness
Area: System piping corrosion or blockage reducing flow and pressure delivery
Check: Hydrostatic pressure test of main and branch piping at 1.5x operating pressure; measure water pressure at proportioner inlet, monitor connection, and deluge valve; flush entire piping system annually; inspect for rust or mineral deposits

Typ-universelle Inspektionspunkte fuer Fixed Fire Suppression (verifiziert, 2026-06).

Foam Fire System

What sets a foam system apart from other fixed suppression

Main components

Foam concentrate tank

Proportioning system

Foam generators or monitors

Distribution piping and valves

Selection and sizing

Regulations and class

Typical faults

What to look for in a supplier

10 manufacturers · 120 models

Skum/Tyco

Survitec

Wilhelmsen Unitor

NK

Solberg

NAFFCO Marine

Kidde Marine / Carrier

Viking Group (Fire)

Wilhelmsen Ships Service

Minimax Marine