Boiler accessories vary by type. For example, in an oil-gas steam boiler, the auxiliary components include chimneys, gas separators, feed water pumps, computer control cabinets, daily oil tanks, automatic water treatment systems, oil and gas burners, valves, and instruments. In a coal-fired steam boiler, the auxiliary components consist of speed regulators, blowers, induced draft fans, chimneys, flues, membrane tanks, descalers, water separators, computer control cabinets, dust collectors, gas collectors, and coal feeders. The auxiliary components for an oil-gas organic heat carrier boiler include oil auxiliary equipment, gas auxiliary equipment, valves, instruments, circulating oil pumps, gear oil injection pumps, filters, oil-gas separators, chimneys, computer control cabinets, expansion tanks, oil storage tanks, oil burners, and gas burners. The auxiliary components for a hot air boiler include speed regulators, high-pressure blowers, induced draft fans, computer control cabinets, chimneys, flues, slag discharge machines, coal feeders, and heat exchangers.