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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.
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.
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.
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.
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.