Fuel-gas boilers should be monitored for any water accumulation at the bottom of the steam drum during operation to prevent damp rot of the base. Additionally, it is not allowed to extinguish the flame with positive pressure smoke in the furnace chamber, as this is very prone to damaging the extinguisher. However, if the extinguisher is found to be violently vibrating, the machine should be stopped for inspection.
Fuel-gas boiler thermal cracks are cracks that occur during the cooling process of the weld, predominantly in the low-temperature stage, and are primarily located within the weld metal, with a large number occurring in the vicinity of the weld. They can be categorized into crystalline (condensation) cracks, liquefaction cracks, and polygonal cracks. Crystalline cracks are rare and are particularly found in welds of carbon steel with high levels of impurities, single-phase austenitic stainless steel, aluminum, and its alloys. Key influencing factors include welding tensile stress, low melting point eutectic (chemical composition of the weld metal), and the extent of welding overheating.
After every 36 months of operation, fuel-gas boilers should be shut down for a comprehensive maintenance, which includes the following tasks: cleaning the soot and ash on the fire surface, and removing the scale and sediment from the boiler exterior and the water-cooled wall. Additionally, rinse the surfaces clean with clean water. Pay attention to inspect for signs of corrosion on the welding plates inside and outside the boiler, and immediately repair any significant defects. If any suspicious areas are found that do not affect safety production, make a timely record for future reference. After the inspection, apply boiler paint on the fire surface to prevent corrosion.
