WNS automatic oil(gas)-fired steam/hot water boiler is the horizontal,three-return,fire-return,fire-tube boiler,mainlu consisting of housing,tank,diversion smoke chamber and fire tubes.Boiler can use light oil,heavy oil,natural gas,liquefied gas and urban coal gas.The wet-backj corrugated tank can effectively reduce the thermal stress and improve the safety and life of boiler.Heatingj areas are laid summetrically for reasonable pressure and expansion.Sound layout of heating areas ensure good water circulation and heat ecchange,optimizing the effect of heat transfer and increasing the heating efficiency.Steam boiler integrates the lower-level combustion chamber to expand the range of safe water level and stesm space in the boiler and to guarantee the good-quality steam.Full butt-welding wet-back structure can avoid the rear wall from damage of hot fume and provide the reliable operation of boiler.selec the worldly well-known burner and advanced automatic control systerm for more stable combustion,easier operation and safe and more reliable running.