Gas fired boilers are fueled by natural gas, city gas, coke oven gas, liquefied petroleum gas or biogas. Gas fired boilers include gas fired steam boiler and gas fired hot water boiler. Gas fired hot water boiler is also called gas fired heating boiler.

Gas fired boilers are the popular choices in areas of the country with easy access to gas sources. Unlike coal fired boiler, gas fired boilers require a burner to inject the gas fuel into the boiler furnace, it is burned in a fire chamber without the use of grate. Since gas fired boilers do not produce ash after combustion, so they do not need slag remover. If the gas injected into the furnace is mixed with the air within a certain range, it is easy to explode. Therefore, gas fired boilers require an automated combustion and control system. Gas fired boilers are compact in structure; the boiler body and its ventilation, water supply, control and auxiliary equipment are all arranged on one distribution box, and the large and medium-sized ones can also be assembled.

• The main pressure components of fire tube boiler: shell, tube sheet, furnace, and fire pipe;
• The main pressure components of water tube boiler: drum, water wall, boiler tube bundle, serpentine tube, header;
• The connection mode of main pressure components: welded or expanded tube joint.