In general, industrial boilers can be classified into two types, one is water tube boiler and the other is fire tube boiler. This article will introduce you the differences between water tube boiler and fire tube boiler from the following aspects.

Design

Water tube boiler and fire tube boiler are essentially opposite in design. In a water tube boiler, water travels through tubes which are surrounded by the by-products of combustion, or flue gas. In a fire tube boiler, the flue gas travels through the tubes, which are surrounded by hot water. Fire tube boilers are typically designed with either three or four sets of tubes (three- or four-pass boilers). Every set of tubes that the flue gas travels through is considered a “pass”. Boilers designed for three-passes have the stack at the rear, and boilers designed for four-passes have the stack at the front. A boiler with more passes has a higher heat extraction rate and is more efficient then one with less passes. 

Steam pressure

The steam pressure of the water tube boiler and fire tube boiler is also different. Steam pressure limit of the fire tube boiler is lies between 20-30 bar and the pressure limit of the water tube boiler is much more than the fire tube boiler and is unlimited within the design limits.

Unit Output

Unit output of the boilers mainly depends on the design limits. Unit output of the fire tube boiler is 20 MW and that of the water tube boiler is unlimited.

Efficiency

Normal efficiency of the fire tube boiler is about 80 to 85 % but this can be increased or decreased by using different accessories. Efficiency of the water tube boiler is more than that of fire tube boiler and lies within the range of 85 to 90 %. Efficiency of water tube boiler can also be increased by using different accessories.

Application

Fire tube boiler are usually used for the heating purposes while water tube boiler is used for power and heat supply.

Inspection requirements

Fire tube boiler need for regular inspection than that needed for the water tube boiler.

Erection

Fire tube boiler is packed and ready for the work at working site while water tube boiler is need to be shop assembled and erected at site.

ZG Boiler is an industrial boilers manufacturer in China with 70 years’ history and we have water tube boilers and fire tube boilers to meet customers’ demand. Both of them have oil & gas fired boiler, coal fired boiler, biomass fired boiler and customers can choose the most suitable one according to its application and the local fuel.