ASTM A179 Seamless Carbon Steel Tubes
ASTM A179 covers seamless cold-drawn low-carbon steel tubes specifically for heat exchangers and condensers. These are tubes, not pressure piping for general fluid transport.
Key Features
| Feature | Description |
|---|---|
| Material | Low-Carbon Steel (Killed Steel) |
| Process | Cold-Drawn Seamless |
| Condition | As-drawn or annealed |
| Primary Use | Heat transfer surfaces in condensers, heaters, coolers |
Why A179?
Excellent Heat Transfer: Smooth surface from cold drawing
Good Formability: Easy to expand into tubesheets
Cost-Effective: Cheaper than alloy/cupronickel alternatives
Good Corrosion Resistance: In treated water/steam condensate
Chemical Composition
| Element | Composition (%) |
|---|---|
| Carbon (C) | 0.06 - 0.18 |
| Manganese (Mn) | 0.27 - 0.63 |
| Phosphorus (P), max | 0.035 |
| Sulfur (S), max | 0.035 |
| Silicon (Si) | ≥ 0.13 (Killed steel) |
Mechanical Properties
| Property | Requirement |
|---|---|
| Tensile Strength, min | 325 MPa (47,000 psi) |
| Yield Strength, min | 180 MPa (26,000 psi) |
| Elongation, min | 35% |
| Hardness, max | 72 HRB |
Applications
Primary Use: Heat Exchangers
Surface condensers (power plants)
Feedwater heaters
Evaporators & coolers
Refrigeration systems
Typical Industries:
Power Generation
Petrochemical
HVAC
Marine
Manufacturing Process
Hot-rolled seamless tube → 2. Pickling/Cleaning → 3. Cold Drawing → 4. Heat Treatment (if annealed) → 5. Final Processing
Cold Drawing Provides:
Smooth surface (better heat transfer)
Tight dimensional tolerances
Improved mechanical properties
Testing Requirements
| Test | Requirement |
|---|---|
| Hydrostatic Test | Mandatory (pressure per formula) |
| Flattening Test | Required |
| Flaring Test | Required |
| Hardness Test | Optional |
Hydrostatic Test Pressure:
text
P = 2St/D S = 60% of yield strength (min 1000 psi)
Comparison with Similar Standards
| Standard | Key Difference from A179 |
|---|---|
| ASTM A192 | For high-pressure boiler tubes |
| ASTM A214 | ERW (welded) heat exchanger tubes |
| ASTM A210 | Medium-carbon for superheater tubes |
| ASTM A106 | For high-temperature piping, not heat exchangers |
⚠️ Important Limitations
Not for Pressure Piping:
A179 is for heat exchanger TUBES, not general fluid piping
Use A106 or A53 for pressure piping systems
No pressure ratings for piping applications
Service Limitations:
Maximum temperature: ~400°C (750°F)
Corrosive fluids: Requires water treatment
High velocity: Erosion risk above ~2 m/s
Ordering Information
Typical Specification:
text
ASTM A179 Tubes 19.05 mm OD × 2.11 mm Wall × 6,000 mm Length Annealed condition For condenser service
International Equivalents
| Region | Equivalent Standard |
|---|---|
| Europe | EN 10216-2 P195GH |
| Japan | JIS G3461 STB340 |
| China | GB 5310 20G |
In summary: ASTM A179 specifies seamless cold-drawn carbon steel tubes specifically designed for efficient heat transfer in condensers and heat exchangers. Its smooth surface, good formability, and cost-effectiveness make it the standard choice for non-corrosive or properly treated water/steam applications. Remember: it's for heat exchanger tubes, not general-purpose piping.
