WL steam boiler has high efficiency in steam cycling and heat exchange. Its thermal efficiency is 90% or above and the fume discharge meets the European EN 267 standards. It is an E.P. and energy-saving product. This boiler has reached the international industrial standards in the aspects of safety, environment protection, and economical technology. The boiler has a rationally designed structure, and the area of heat exchange surface is twice of the boilers of the same model. It is able to produce sufficient power and is very durable. It has lower operational shock and noise. No equipment foundation is required since it can be positioned at liberty and easily erected. Inside the steam boiler is the high-efficient steam-water separator, which reaches the dryness of 98% or above. This enables the boiler to operate under the steam conditions anytime. The furnace arrayed by several conduits has radiative heat transfer and high coefficient of convective heat transfer. Meanwhile, the WL steam boiler adopts the high header and high water-level technologies and has large water volume. It only takes 5 to 10 minutes for the boiler from cold position to operation at full load in the room with sufficient steam. In addition, it has stable steam supply and good load-impact resistance, which is particularly welcomed for the working condition where the shutdown and re-start is very frequent and steam load is not very stable