ASTM A178/A178M and ASME SA178/SA178M are standards for resistance welded carbon and carbon manganese steel boiler and superheater tubes. These standards specify the manufacturing requirements for pipes to ensure their suitability for a variety of industrial applications, particularly in high temperature and pressure environments.
ASTM A178 Welded Pipe is primarily intended for minimum wall thickness resistance welded pipe made from carbon steel and carbon manganese steel. ASTM A178 straight seam steel pipe is mainly used in key parts such as boiler tubes, boiler flues, superheater flues and safety ends. These pipes must meet certain size and thickness requirements to ensure they can withstand high temperatures and pressures and have sufficient strength and durability.
| Element | Grade A, | Grade C, | Grade D |
| Low-Carbon Steel | Medium-Carbon Steel | Carbon-Manganese Steel |
| Carbon | 0.06-0.18 | 0.35max | 0.27max |
| Manganese | 0.27-0.63 | 0.08max | 1.00-1.50 |
| Phosphorus, max | 0.035 | 0.035 | 0.03 |
| Sulfur, max | 0.035 | 0.035 | 0.015 |
| Silicon | … | … | 0.01 min |
A178 Straight seam welded pipe
Standard: ASTM A178, ASME SA178
Grade: Grade A, Grade C, Grade D
Technique: Electric-Resistance-Welded
Delivery Condition: Annealed, Normalized, Tempered, Heat Treatment, BK, BKS
Section Shape: Round
Surface Treatment: Varnish
Size: (mm)
OD: 12.7mm to 127mm
Wall thickness: 1.5mm to 6.0mm
Length: 6m-25m
Ends: Plain ends or bevel ends
Packaging:Loose / Bundle / Wooden Pallet / Wooden box-a / Plastic Cloth Wraps / Plastic End Caps / Beveled Protector
Transportation:By Road - Truck / Train, By Sea - Break-bulk Conventional Vessel / FCL (Full Container Load)
ASTM A178 Class C and Class D ERW steel pipes not suitable for forged welded safety ends shall be of size and thickness within the standard range of 1⁄2 to 5 in. (12.7 to 127 mm) outside diameter with a minimum wall thickness of 0.035 to 0.360 inches (0.9 to 9.1 mm). Other sizes of pipe are available provided they meet all other requirements of the specification.
During the production process, D-grade steel should be killed and the pipes should be made by resistance welding. After welding, all tubing should be heat treated at 1650°F (900°C) or higher and then cooled in air or in the cooling chamber of a controlled atmosphere furnace. For cold drawn tubing, heat treatment should be performed at 1200°F (650°C) or higher after the final cold drawing pass.
