Aalborg OC-I 0.5t/10bar

Common issues

• Burner nozzle/atomizer fouling or coking causing poor combustion and smoke
• Waterside scale buildup from inadequate feedwater treatment
• Fireside soot deposits on tubes reducing heat transfer efficiency
• Safety valve seat leakage or wire-drawing
• Refractory cracking or erosion around the burner throat
• Feed pump or level control malfunction leading to low-water trips

Inspection checklist

• Check flame condition and combustion quality (smoke, color) at the burner
• Test the low-low water level alarm and cutout
• Inspect the safety valve for correct set pressure and lift per class requirement
• Check boiler water treatment dosing and test results (alkalinity, chlorides, TDS)
• Inspect fireside tube surfaces for soot/scale at each opening
• Inspect waterside surfaces for scale, pitting, or sludge accumulation
• Check refractory condition around the burner and furnace
• Verify the burner control sequence (purge, ignition, flame failure trip)
• Inspect mountings, gauge glass, and pressure gauge for correct function

Service intervals

Typical intervals for this design class, not the manufacturer’s figures for your model. The manufacturer’s manual is binding.

Typical wear limits

Ranges are typical for this design class. Always confirm against the manufacturer documentation for your serial number.

Critical spares

• Burner nozzle/atomizer
• Safety valve or repair kit
• Feed check/non-return valve
• Water level gauge glass set
• Ignition electrodes
• Flame scanner/photocell

Safety

• Pressurized steam system - follow lockout/tagout and allow cooling before internal inspection
• Low water level is a critical hazard - never bypass low-water cutouts, as tube/shell overheating can lead to failure
• Hot surfaces on the casing, steam lines, and burner front
• Fuel oil under pressure and heated (HFO) - burn/fire risk at the burner and fuel line connections
• Safety valve discharge path must be clear and correctly routed

Class survey

Composite/auxiliary boilers of this size are examined internally and externally at Special Survey (often also at intermediate surveys for older units), with mandatory safety valve testing and thickness gauging of representative tube/shell areas. Boiler water treatment logs and safety valve test records should be maintained for survey.