1. **What is ASTM A179 material?**
ASTM A179 is a standard specification for **seamless cold-drawn low-carbon steel tubes** used primarily in **heat exchangers, condensers, and similar heat transfer equipment**. It's known for good thermal conductivity, weldability, and formability.
2. **What size is ASTM A179?**
ASTM A179 covers tubes with **Outside Diameters (OD) from 3/8 inch (9.5 mm) to 3 inches (76.2 mm)**. Wall thicknesses are typically specified using the **Birmingham Wire Gauge (BWG)** system, ranging from **BWG 12 (0.109" / 2.77mm) to BWG 22 (0.028" / 0.71mm)**, or their decimal/inch equivalents. Other wall thicknesses meeting the tolerance requirements are also possible.
3. **What is the tolerance of ASTM A179?**
Key tolerances per ASTM A179:
* **Outside Diameter (OD):** ±0.005 inches (±0.13 mm) for tubes under 1 inch OD. Tighter tolerances (±0.004" or ±0.003") can be specified.
* **Wall Thickness:** ±10% of the specified nominal wall thickness.
* **Straightness:** Maximum deviation of 1/8 inch (3.2 mm) in any 5-foot (1.5 m) length.
* **Length:** Tolerances depend on whether tubes are ordered to random or exact lengths.
4. **What is SA 179 specification?**
**SA 179 is identical to ASTM A179.** The "SA" prefix indicates it's been adopted by the ASME (American Society of Mechanical Engineers) Boiler and Pressure Vessel Code (BPVC) for use in pressure equipment construction. The technical requirements (material, dimensions, tolerances, testing) are the same as ASTM A179.
5. **What is the difference between SA 214 and SA 179?**
**In essence:** Both are low-carbon steel tubes for heat exchangers. **SA 179 is seamless, SA 214 is welded.** Seamless (SA 179) offers potentially higher strength and reliability for demanding service, while welded (SA 214) is a cost-effective option for less severe conditions.
