 |
Boiler steel pipes includes medium pressure boiler pipe and high pressure boiler pipe, it is often manufactured in seamless procedures, welded steel pipe is not applicable.
It has been widely used at heat exchanger pipe and tubing services, tube exchanger bundle, high pressure boiler, economizer, super heater, petrochemical industry pipes, etc.
Types of boiler tubes
Fire Tube Boiler
Fire-tube boiler is a type of boiler in which hot gas passes from the fire through one or more pipes that pass through a sealed water container. The heat of the gas is transferred through the wall of the tube through heat conduction, heating the water and eventually generating steam. Fire tube boilers are the third of the four historical types of boilers: low-pressure tank or “haystack” boilers, flue boilers with one or two large flues, fire tube boilers and high-pressure boilers with many small tubes
Water Tube Boiler
Water tube boiler is a type of boiler in which water circulates in tubes heated externally by the fire. The fuel is burned in the furnace to produce hot gas, which heats the water in the steam generation tube. In smaller boilers, the additional power generation tubes are separated in the furnace, while larger utility boilers rely on water injection tubes that make up the furnace wall to generate steam. High-pressure water tube boiler: The hot water then rises into the steam drum. Here, saturated steam is drawn away from the top of the drum.
Boiler Pipe Manufacturing methods
The manufacturing method of medium and high pressure boiler steel pipe is same with the seamless steel pipe, but there are some key manufacturing processes shall be noted:
Fine drawing, surface bright, hot rolling, cold drawn, heat expansion
Heat treatment methods applied in the boiler pipes
Heat treatment is a method of changing the physical properties of high pressure boiler pipe by heating and cooling. Heat treatment can improve the microstructure of high pressure boiler pipe, so as to meet the required physical requirements. Toughness, hardness and wear resistance are obtained by heat treatment. In order to obtain these characteristics, it is necessary to adopt quenching, annealing, tempering and surface hardening.
1. Quenching
Hardening, also called quenching, is that high pressure boiler pipe is heated evenly to the appropriate temperature, then quickly immerse in water or oil for rapid cooling, and cooling in the air or in the freezing zone. So that the high pressure boiler pipe can obtain the required hardness.
2. Tempering
High pressure boiler pipe will become brittle after hardening. And the stress caused by quenching can make the high pressure boiler pipe tapped and broken. The tempering method can be used to eliminate brittleness. Although the hardness of high pressure boiler pipe is lighter reduced, its the toughness can be increased to reduce the brittleness.
3.Annealing
Annealing is the method to eliminate the internal stress of high pressure boiler pipe. The annealing method is that the steel parts need to be heated to the critical temperature, then put in dry ash, lime, asbestos or closed in the furnace, then let it cooling slowly.
We can produce all sizes of boilers tubes,according to European,Chinese,American,Japanese standard.With fast delivery time,supportive payment term.All tubes production processes are controlled strictly.with high level of quality requirement,all tubes are inspection before delivery,and also accept third party inspection before delivery.
Boiler steel pipes includes medium pressure boiler pipe and high pressure boiler pipe, it is often manufactured in seamless procedures, welded steel pipe is not applicable.
It has been widely used at heat exchanger pipe and tubing services, tube exchanger bundle, high pressure boiler, economizer, super heater, petrochemical industry pipes, etc.
Types of boiler tubes
Fire Tube Boiler
Fire-tube boiler is a type of boiler in which hot gas passes from the fire through one or more pipes that pass through a sealed water container. The heat of the gas is transferred through the wall of the tube through heat conduction, heating the water and eventually generating steam. Fire tube boilers are the third of the four historical types of boilers: low-pressure tank or “haystack” boilers, flue boilers with one or two large flues, fire tube boilers and high-pressure boilers with many small tubes
Water Tube Boiler
Water tube boiler is a type of boiler in which water circulates in tubes heated externally by the fire. The fuel is burned in the furnace to produce hot gas, which heats the water in the steam generation tube. In smaller boilers, the additional power generation tubes are separated in the furnace, while larger utility boilers rely on water injection tubes that make up the furnace wall to generate steam. High-pressure water tube boiler: The hot water then rises into the steam drum. Here, saturated steam is drawn away from the top of the drum.
Boiler Pipe Manufacturing methods
The manufacturing method of medium and high pressure boiler steel pipe is same with the seamless steel pipe, but there are some key manufacturing processes shall be noted:
Fine drawing, surface bright, hot rolling, cold drawn, heat expansion
Heat treatment methods applied in the boiler pipes
Heat treatment is a method of changing the physical properties of high pressure boiler pipe by heating and cooling. Heat treatment can improve the microstructure of high pressure boiler pipe, so as to meet the required physical requirements. Toughness, hardness and wear resistance are obtained by heat treatment. In order to obtain these characteristics, it is necessary to adopt quenching, annealing, tempering and surface hardening.
1. Quenching
Hardening, also called quenching, is that high pressure boiler pipe is heated evenly to the appropriate temperature, then quickly immerse in water or oil for rapid cooling, and cooling in the air or in the freezing zone. So that the high pressure boiler pipe can obtain the required hardness.
2. Tempering
High pressure boiler pipe will become brittle after hardening. And the stress caused by quenching can make the high pressure boiler pipe tapped and broken. The tempering method can be used to eliminate brittleness. Although the hardness of high pressure boiler pipe is lighter reduced, its the toughness can be increased to reduce the brittleness.
3.Annealing
Annealing is the method to eliminate the internal stress of high pressure boiler pipe. The annealing method is that the steel parts need to be heated to the critical temperature, then put in dry ash, lime, asbestos or closed in the furnace, then let it cooling slowly.
We can produce all sizes of boilers tubes,according to European,Chinese,American,Japanese standard.With fast delivery time,supportive payment term.All tubes production processes are controlled strictly.with high level of quality requirement,all tubes are inspection before delivery,and also accept third party inspection before delivery.
