ASTM A178 / ASME SA178 Grade A Carbon Steel Welded Boiler Tube Heat Exchanger Tube

ASTM A178 / ASME SA178 Grade A Carbon Steel Welded Boiler Tube Heat Exchanger Tube

This specification ASTM A178/ASME SA178 covers minimum-wall-thickness, electric-resistance-welded tubes made of carbon steel and carbon-manganese steel intended for use as boiler tubes, boiler flues, superheater flues, and safe ends. The welding process of the tube is mainly manufactured using resistance welding (ERW) technology, which is suitable for high temperature and high pressure environments.

ASTM A178 GR. A carbon steel welded boiler tubes and heat exhcanger tubes are usually delivered in a cold worked state and require stress relief annealing (if required by the application scenario). Welding seams require 100% eddy current or ultrasonic testing to ensure no defects, and require individual water pressure testing. The pressure is calculated based on the wall thickness and diameter to ensure sealing.

ASTM A178/ ASME SA178 Carbon Steel Welded Tubes Chemical Composition

ASTM A178 Gr.A Carbon Steel Welded Boiler and Heat Exchanger Tube Mechanical Properties

The low carbon content of ASTM A178/ASME SA178 Gr. A carbon steel welded boiler tube and heat exchanger tube can improve welding performance and reduce the risk of embrittlement in the heat affected zone. At the same time, it has moderate strength and excellent plasticity, suitable for cold bending and expansion processing.

ASTM A178/ASME SA178 Gr.A Carbon Steel Welded Boiler Tube and Heat Exchanger Tube Core Application Areas

(1) Boiler system

ASTM A178 Gr. A carbon steel welded tube is a commonly used material for medium and low pressure boiler tubes, especially suitable for water/steam environments with temperatures ≤ 450 ℃. Specific applications include:

• Water Walls: Located on the heating surface of the boiler furnace, they need to directly absorb radiant heat. The welding performance and plasticity of Gr. A carbon steel welded tubes can meet the processing requirements of dense tube rows.
• Economizers: Economizers use flue gas waste heat to preheat boiler feedwater, with a working temperature mainly in the low temperature range (usually<300 ℃). Gr. A carbon steel welded tubes have advantages in corrosion resistance and economy in this low temperature range.
• Steam Drum Connection Tube: In low-pressure steam cycle systems, pipelines need to withstand periodic thermal stress, which poses a risk of high fatigue and cracking. Gr.A carbon steel welded tubes have good ductility and can reduce the risk of fatigue cracking.

 (2) Heat exchange equipment

• Condensers: ASTM A178 carbon steel welded tube can be used for steam condensation in power plants or ships, and Gr. A tubes perform well in freshwater or low salinity cooling water environments.
• Petrochemical heat exchanger: ASTM A178 GR. A carbon steel welded tube is suitable for heat exchange in non corrosive media such as oil and gas, such as preheaters in refineries and natural gas coolers.
• Waste heat recovery system: ASTM A178 GR. A carbon steel welded tube industrial waste heat boiler recovers low-temperature waste gas waste heat (such as steel plants, cement plants), and Gr. A has significant cost-effectiveness advantages.