Operational Guide · Registers & Logbooks

# Boiler Operations

The auxiliary boiler is often the least-monitored unit in the engine room, until a defect in its safety devices suddenly makes it the top priority.

boiler auxiliary boiler SOLAS II-1 pressure

## Operational Explanation

The auxiliary boiler supplies steam for heavy fuel oil heating, general services and, on some ships, the operation of auxiliary turbogenerators: although not the main propulsion unit, its sudden malfunction — especially of the pressure safety devices — represents a serious risk to the crew.

SOLAS Chapter II-1, Regulation 26 establishes the general principle that machinery, boilers and other pressure vessels, together with their associated piping and fittings, must be of a design and construction adequate for the service for which they are intended and installed and protected so as to reduce to a minimum any danger to persons on board. The boiler survey comprises a thorough external examination (supports, stays, uptakes, funnel base) and a complete internal examination of the boiler, superheater, superheat control, air heater and economizer, if fitted, verifying correct operation and correct setting of the safety devices under working conditions.

## Regulatory Reference

SOLAS Chapter II-1, Regulation 26 (Machinery): general principle of adequate design and construction for boilers and pressure vessels; survey requirements of the applicable Classification Society for periodic external and internal examination of the boiler and verification of safety devices.

## Scope of Application

Every ship fitted with an auxiliary boiler (combustion-fired or exhaust gas economizer) for producing steam for general services, fuel heating or auxiliary turbogenerators.

## Procedure / How to Complete It

1. Carry out the external examination of the boiler, checking the condition of supports, stays, uptakes and funnel base.
2. Carry out the complete internal examination of the boiler, superheater, superheat control, air heater and economizer according to the applicable maintenance and survey programme.
3. Verify correct operation and correct setting of the safety valves under working conditions, not only with the boiler shut down.
4. Maintain chemical treatment of the feed water according to manufacturer specifications, periodically checking the parameters (hardness, pH, dissolved oxygen).
5. Document every anomaly found during periodic examinations and schedule the corrective intervention before the next survey cycle.

## Practical Example

Example verification: during the periodic internal examination of the auxiliary boiler, slight localized corrosion is found on the superheater tubing; the corrective intervention is scheduled and completed before the survey deadline, preventing the defect from worsening to the point of compromising system integrity.

## Real Cases

Serious failures of boiler pressure safety devices, documented in several industry cases, have been traced to safety system maintenance treated as a secondary activity relative to steam production, with functional checks under working conditions carried out less frequently than necessary.

## Common Mistakes Mistake Library

Mistake | Consequence | How to avoid it
--- | --- | ---
Safety device verification limited to a visual check, without a functional test under working conditions | Safety valve malfunction not detected until a critical event | Always test safety devices under actual working conditions, not only with visual inspection
Chemical treatment of feed water not monitored regularly | Accelerated corrosion or internal scaling, not detected until the periodic internal examination | Regularly monitor the chemical parameters of feed water between one survey and the next
Minor anomalies found during periodic examinations not scheduled for correction | Worsening of the defect until the next survey | Always schedule a corrective intervention for every anomaly found, however minor

## PSC Observations

PSCOs may verify the documentation of the boiler's last surveys and, in case of doubts about the general safety of the engine room, request evidence of the operation of safety devices.

## Operational Tips

- Always test the boiler's safety devices under actual working conditions, don't limit yourself to visual inspection.
- Regularly monitor the chemical parameters of feed water, not only at the time of the periodic survey.
- Always schedule the corrective intervention for every anomaly found during examinations, even if apparently minor.

## Checklist

- External boiler examination completed (supports, stays, uptakes)
- Internal examination of boiler, superheater, air heater and economizer completed
- Safety devices functionally tested under working conditions
- Chemical parameters of feed water monitored regularly
- Anomalies found documented and scheduled for correction

## FAQ

What does SOLAS Regulation II-1/26 require for boilers?
That machinery, boilers and other pressure vessels, together with their associated piping and fittings, be of a design and construction adequate for the intended service and installed and protected so as to minimize any danger to persons on board.
Why test safety devices under working conditions rather than only with the boiler shut down?
Because only under real working conditions is it possible to verify that the safety valve correctly activates at the intended set pressure, a condition not replicable with a static visual check.
What does the periodic internal boiler examination cover?
A thorough examination of the boiler itself, the superheater, the superheat control, the air heater and the economizer, if fitted, checking the general condition and correct setting of the safety devices.
🎬 Additional photos, videos and interactive diagrams for this topic will be available in a future version of the platform.

## Related Topics

Planned Maintenance System Blackout and Failure Management

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