What Is A Boiler Tube ? How They Made It

Boiler tubes are seamless tubes made of carbon steel or alloy steel. In steam boilers, power plants, fossil fuel plants, industrial processing plants, electric power plants, etcThey are widely used. A boiler tube can either be a medium-pressure boiler tube or a high-pressure boiler tube.

In a boiler, boiler tubes are metal tubes that heat water in order to create steam. Tube boilers come in two major types: water-tube boilers and fire-tube boilers.

With the advent of high-pressure water tubes, it has become possible to heat water in tubes externally by means of gases. Fuel is burned within the furnace, generating hot gas that heats water in the tubes to produce steam. Smaller Boiler tubes are isolated by external heating tubes, while larger Boiler tubes rely on water-filled tubes that run along the walls of the furnace to create steam.

There are two major types of tube Boiler tubes: water-tube Boiler tubes and fire-tube Boiler tubes

Water-tube Boiler tubes. …

Fire-tube Boiler tubes. …

Materials used for Manufacturing of Boiler Tubes.

In water-tube boilers, water circulates inside the tubes and is heated externally by hot gases created by the furnace. In fire-tube boilers, hot gas is passed through one or more tubes which, through thermal conduction, heat the water surrounding them. Certain mechanisms can damage boiler tubes, including:

boiler feed water corrosion

graphitization

thermal fatigue

corrosion fatigue

The heat treatment methods used in boiler pipes

Heat treatment involves heating and cooling a high pressure boiler pipe to change its physical properties. The microstructure of a high pressure boiler pipe can be improved by heat treatment to meet the required physical requirements. By heat treating, toughness, hardness and wear resistance can be obtained. Quenching, annealing, tempering, and surface hardening are required to achieve these characteristics.

A. Quenching

In hardening, also called quenching, a high-pressure boiler pipe is heated evenly to the appropriate temperature, quickly immersed in water or oil for rapid cooling, and cooled in the air or in the freezing zone. In order for the high pressure boiler pipe to achieve the required hardness.

B. Tempering

After hardening, high pressure boiler pipes become brittle. By quenching, the high pressure boiler pipe can be broken and tapped. Brittleness can be eliminated by tempering. While the hardness of the high pressure boiler pipe is reduced, the toughness can be increased to reduce the brittleness.

C. Annealing

Annealing is a method of removing the internal stress from a high-pressure boiler pipe. In the annealing process, steel parts are heated to the critical temperature, then placed in dry ash, lime, asbestos or enclosed in a furnace and allowed to cool slowly.