U5C
Wilhelmsen Unitor U5C — Portable CO2 Fire Extinguisher for Class B & C fires.
Inspector Detail
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Common issues
- Gradual loss of charge (weight loss) over time from valve seal seepage
- External corrosion of the cylinder in the salt/humid marine environment
- Damaged or missing discharge horn
- Broken or missing safety pin/tamper seal
- Corroded or failed mounting bracket
- Overdue hydrostatic test or servicing tag
Inspection checklist
- Weigh the cylinder and compare against the nameplate charged (gross) weight - this is how a CO2 extinguisher's charge is verified, not by a pressure gauge
- Safety pin and tamper seal intact
- Discharge horn present and undamaged
- Mounting bracket secure, corrosion-free and in the designated location
- External cylinder corrosion/pitting
- Hydrostatic test date within the current interval (stamped test pressure 150 bar on this unit)
- Service tag current and legible
- Location marking/signage visible and access not obstructed
- Correct extinguisher type for the space it protects (this is a B/C-rated unit, not suitable as the sole protection for Class A ordinary combustibles)
Service intervals
| Visual inspection and weight check | annually, per SOLAS/flag/class requirement |
| Full service (valve overhaul) and hydrostatic test | typically every 5-10 years depending on flag administration and manufacturer's schedule - confirm against SOLAS Ch. II-2, the flag state, and Wilhelmsen's service schedule for this model |
Typical wear limits
| Cylinder weight loss | commonly used trigger for service/recharge is roughly 10% below the nameplate charged weight - confirm the exact tolerance against the data plate and Wilhelmsen's service instructions |
Ranges are typical for this design class. Always confirm against the manufacturer documentation for your serial number.
Critical spares
- Discharge horn assembly
- Safety pin and tamper seal
- Mounting bracket
- Recharge/valve service is normally a shore facility job, not a shipboard spares item
Safety
- CO2 discharge displaces oxygen - even a portable unit discharged in a small, enclosed space can create a localised asphyxiation risk
- The discharge horn becomes extremely cold during use - direct contact risks cold burns/frostbite
- Cylinder is stored under high pressure (test pressure 150 bar) - keep away from heat sources and do not attempt to open or service the valve onboard
Class survey
Portable fire extinguishers are checked against the fire control plan for correct type, rating and count, current service tags, accessibility, and mounting at each annual and renewal survey under SOLAS fire safety systems requirements.
Components & Design
Component data being added…
Technical Data
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Common failures & inspection points
Verify pressure gauge needle is within green zone. Check for corrosion or damage to gauge glass/needle. Confirm pressure reading matches expected range per manufacturer specifications (typically 1-2 bar below minimum discharge pressure indicates need for servicing).
Inspect body for dents, rust spots, leaks, bent handle, missing or damaged nameplate. Check hose/horn for cracks, kinks, blockage, or deterioration. Verify CO2 cartridge (powder/foam models) is not corroded and remains firmly secured. Examine CO2 horn/nozzle for ice buildup or operational obstructions.
Confirm safety pin is intact and properly inserted through handle and discharge lever. Verify lever moves freely without sticking or obstruction. Check discharge nozzle (foam/powder) or horn (CO2) can rotate or aim freely. Test lever spring tension by light pressure - should resist but not be stuck.
Weigh extinguisher and compare to specification nameplate weight for full/loaded unit. For CO2 models, weight loss >5% from manufacture weight indicates potential leakage. For powder models (P-series), verify no settling/compaction by listening for powder movement when gently shaken. Foam models (E-series) must show full liquid level without separation.
Verify current service tag/certificate dated within 12 months from certified service provider. Confirm MED (Marine Equipment Directive), PED (Pressure Equipment Directive), EN 3 or EN 866 certifications are visible on nameplate. Check hydrostatic test date for wheeled/larger units (P25/P50/E45A) - maximum 5-year intervals required per SOLAS. Verify manufacturer date code on body.
Type-general inspection and maintenance points for this equipment category — not model-specific.
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