As the second engineer onboard a tanker, presenting a main boiler for survey involves a detailed and structured approach to ensure all components are thoroughly inspected and maintained according to classification society standards. The following steps outline the procedure:

Planning:

• Inform the classification society beforehand and decide on a suitable date and location for the survey.
• Calculate the time required for the survey and ensure it fits within the available time frame.
• Confirm that adequate manpower is available for the task.
• Check for necessary spare parts and place orders to ensure timely delivery.
• Arrange all required tools.
• Review the boiler manual for specific procedures and special instructions.
• Gather all past maintenance, inspection, and survey records.
• Conduct a meeting with all personnel involved to discuss the work and procedures.
• Perform any special checks required before shutting down the boiler.

Before stopping the boiler:

• Inform the duty officer on the bridge about the commencement of work.
• Switch over the boiler, main engine, and diesel generators to Low Sulphur Marine Gas Oil (LSMGO).
• Perform a boiler soot blow to clean the boiler tubes.
• Stop all auxiliary machinery that consumes steam.

Stopping the boiler:

• Change the boiler to manual control.
• Stop boiler firing and carry out post purging for at least five minutes.
• Isolate the boiler.
• Shut the main steam stop valve
• When the boiler pressure drops to 3-4 bar, perform a scum blowdown to remove floating impurities.
• Conduct a bottom blowdown to drain the water
• Before the pressure drops to 2 bar open the vent valve.
• Allow the boiler to cool down sufficiently.
• Once the boiler is confirmed to be drained completely, carefully open the manhole door.

Precautions for entry:

• Ventilate the boiler and check for oxygen and gas content.
• Conduct a risk assessment and follow safe entry procedures as per the company's Safety Management System (SMS).
• Prepare an enclosed space entry permit and obtain signatures from all concerned parties.

Inspection:

Boiler Cleaning:

• Thoroughly clean the boiler on water side, fire side and refractory.

Inspection on Gas side and refractory:

• Check the condition of refractory material for any damage and cracks
• Check for high temperature cracks in front of burner i.e. the back wall of furnace
• Check the floor for any cracks and oil contamination
• Check for signs of overheating near burner surface
• Check for leaks at boiler tube at the plate entry
• Check for carbon deposits/ soot deposits
• Check for restriction of gas passage
• Check the soot blower nozzle.
• Examine the condition of tubes.
• Check the exterior for corrosion, leakage, cracks, and overheating.
• Inspect the condition of insulation, pipes, valves, refractory, and burning equipment.

Waterside Inspection:

• Check the internal condition for scale, sludge and corrosion
• Check the bottom blow-down and scum blow-down pipe from the inside of the boiler for any signs of erosion
• Check for any distortion of boiler bottom plate
• Check for steam bubbling pitting on tubes and wall
• Check for oxygen pitting at waterline and steam space
• Check condition of manhole door, mudhole/ handhole door from the inside of boiler.
• Examine pipelines and valves.

External inspection:

• Check the condtion of boiler support (top bracing)
• Remove insulation and check for corrosion
• Check boiler mounting attachment to the shell
• Check the condition of boiler gauge glass connection
• Check for any leaks from steam gasket

Additional Inspections:

• Overhaul and inspect all boiler mountings.
• Inspect and overhaul safety valves.
• Calibrate pressure gauges.
• Check the condition of Forced Draft (FD) fans, dampers, and linkages.
• Inspect foundation bolts for tightness, corrosion, and fretting.
• Inspect the uptake.
• Measure tube thickness.

Post inspection:

• Reassemble the boiler and follow the proper procedure for firing it up.
• Test and set the safety valve.
• Test all alarms and trips.
• Prepare detailed measurement and inspection reports.
• Ensure all reports are signed by the classification surveyor.

Prepare three copies of the report, duly signed by the classification surveyor:

• One copy is retained by the surveyor.
• One copy is sent to the company.
• One copy is placed in the ship survey file.