A fire tube steam boiler is a boiler where the combustion gases from the burner are channeled through tubes that are surrounded by the fluid to be heated. The boiler body is the pressure vessel and contains the fluid. In most cases, this fluid is water that will circulate for heating purposes or become steam for use in processing.
Each set of tubes through which the combustion gas passes, before making a turn, is considered a "step". Consequently, a three-step boiler will have three sets of pipes with the outlet located at the rear of the boiler.
1. In terms of boiler body structure, WNS series gas-fired (oil-fired) boilers are fire tube boilers; SZS series gas-fired (oil-fired) boilers are water tube boilers;
2. In terms of boiler working pressure, if the boiler pressure is below 1.6Mpa, the choice is usually the WNS series gas-fired (oil-fired) boiler, if the boiler pressure is above 1.6Mpa, the SZS series gas-fired (oil-fired) boiler may be a better solution. Some high-pressure boilers also adopted SZS series gas-fired (oil-fir...