CLASSIFICATION OF BOILERS:
1. Water Tube Boiler: a type of boiler in which water circulates in tubes heated externally by the fire.
Fuel is burned inside the furnace, creating hot gas which heats water in the steam-generating tubes. In
smaller boilers, additional generating tubes are separate in the furnace, while larger utility boilers rely
on the water-filled tubes that make up the walls of the furnace to generate steam.
2. Fire Tube Boiler: is a type of boiler in which hot gases pass from a fire through one or (many) more
tubes running through a sealed container of water. The heat of the gases is transferred through the
walls of the tubes by thermal conduction, heating the water and ultimately creating steam.
KINDS OF BOILERS:
1. Power Boiler: The purpose of a power boiler is to create steam by applying heat energy to water.
2. Portable Boiler: Complete portable boiler rooms in easily transportable containers. 100% external
connections.
3. Locomotive Boiler: A locomotive boiler is a device which is used to create steam from water by using
heat energy. It is a horizontal drum axis, multi-tubular, natural circulation, artificial draft, forced
circulation, mobile, medium pressure, solid fuel fired fire tube boiler that has an internal fire furnace. It
is capable of producing high steam rate and hence it is used for railway locomotive engines and in
marines.
4. Miniature Boiler: The idea is that you use it to teach children how to be safe if they happen to find
themselves unattended in a building that's like 200 years old.
5. Low Pressure heating boiler: Are either steam boilers that operate with no more than 15 psi steam
pressure or hydronic (water) boilers that operate with no more than 160 psi water pressure and no
more than 250°F operating temperature.
6. Hot Water Supply Boiler: A boiler used to heat water for purposes other than space heating.
7. Unfired Pressure Vessel: is any type of pressure vessel that is not fired. This means that they are not
exposed to combustion or burner fire. Since it is an unfired vessel, there is a lesser risk of overheating.
8. Reinstalled Boiler: When a boiler or pressure vessel is moved and reinstalled
9. Second Hand Boiler: a used boiler
10. Condensed Boiler: Condensing boilers are water heaters fueled by gas or oil. They achieve high
efficiency (typically greater than 90% on the higher heating value) by condensing water vapor in the
exhaust gases and so recovering its latent heat of vaporisation, which would otherwise have been
wasted.
BOILER AND IT’S ACCESSORIES
1. Air Preheater: is any device designed to heat air before another process (for example, combustion in a
boiler) with the primary objective of increasing the thermal efficiency of the process. They may be used
alone or to replace a recuperative heat system or to replace a steam coil.
2. Baffles: are flow-directing or obstructing vanes or panels used in some industrial process vessels
(tanks), such as shell and tube heat exchangers, chemical reactors, and static mixers.
3. Blowdown Valve: Blowdown valves are useful in fossil fuel fired boilers for continuous or intermittent
use to drain dissolved solids from the boiler water. These valves are fitted on the drain lines of the
boilers.
4. Breeching: A duct through which the products of combustion are transported from the furnace to the
stack; usually applied in steam boilers.
5. Burner: Burner may refer to: Gas burner, Coal burner or oil burner, a mechanical device that burns a
gas or liquid fuel into a flame in a controlled manner
6. Draft Fans: a type of pressurized fan that gives off positive pressure within a system.
7. Economizer: a device designed to make a machine or system more energy-efficient
8. Feedwater Heater: A feedwater heater is a power plant component used to pre-heat water delivered
to a steam generating boiler
9. Feedwater Pump: A boiler feedwater pump is a specific type of pump used to pump feedwater into a
steam boiler. The water may be freshly supplied or returning condensate produced as a result of the
condensation of the steam produced by the boiler. These pumps are normally high-pressure units that
take suction from a condensate return system and can be of the centrifugal pump type or positive
displacement type.
10. Furnace: an enclosed structure in which material can be heated to very high temperatures, e.g. for
smelting metals.
11. Fusible Plug: is a threaded metal cylinder usually of bronze, brass or gunmetal, with a tapered hole
drilled completely through its length. This hole is sealed with a metal of low melting point that flows
away if a pre-determined, high temperature is reached.
12. Gage Glass: the glass tube of a water gauge by which the water level in a boiler or tank is observed
13. Pressure Gage: A pressure gauge is a fluid intensity measurement device. Pressure gauges are
required for the set-up and tuning of fluid power machines and are indispensable in troubleshooting
them. Gauges help to ensure there are no leaks or pressure changes that could affect the operating
condition of the hydraulic system.
14. Safety Valve: Safety valve is a valve that act as a protection of equipment from exploding or
damaging and it is mainly installed in pressure vessels such as chemical plants, electric power boilers
and gas storage tanks.
15. Soot Blower: A soot blower is a device for removing the soot that is deposited on the furnace tubes
of a boiler during combustion.
16. Temperature Gage: Temperature gauges measure the thermal state of a homogeneous substance.
The measuring system must be brought as closely together as possible with the body to be measured.
The most widely used measuring methods rely on temperature-dependent physical and material
characteristics.
17. Water Walls: furnace wall that is comprised of refractory and tubes in a water-tube boiler. The tubes
are evenly spaced and generally connect to headers which in turn are connected back to the main
generating bank of the boiler.