Low Carbon Cold Drawn ASTM A179 Seamless U Bend Tube For Power Plant Boilers

Low-Carbon Cold Drawn ASTM A179 Seamless U-Bend Tube For Power Plant Boilers

ASTM A179 U-bend tubes are seamless cold-drawn low-carbon steel tubes that have been thermally or mechanically bent into a U-shape for use in heat exchangers, condensers, and boilers. The U-bend design allows for thermal expansion and efficient heat transfer in confined spaces.

Key Features of ASTM A179 U-Bend Tubes:

1. Material Composition (Same as ASTM A179 Straight Tubes)

Note: Small amounts of residual elements (Cu, Ni, Cr, Mo) may be present but are not specified.

2. Mechanical Properties

Cold-Drawn Process: Ensures a smooth surface finish and tight dimensional tolerances.

Heat Treatment: Typically supplied in the annealed or stress-relieved condition for better ductility.

Key Characteristics of ASTM A179 material:

✅ Excellent Thermal Conductivity (due to low carbon content)
✅ Good Weldability & Formability (suitable for bending and flaring)
✅ Smooth Internal Surface (minimizes fouling in heat exchangers)

3. U-Bend Specifications

Bending Process:

Cold bending (for tighter radii)

Induction/heat-assisted bending (to prevent cracking)

Bend Radius: Typically 1.5x to 3x the tube OD (e.g., for a 19mm tube, bend radius ≈ 28.5–57mm)

Wall Thinning: ≤ 10–15% (post-bending)

Surface Finish: Smooth, free from cracks or deformities

4. Advantages of U-Bend Tubes

✅ Compact Design – Saves space in heat exchangers.
✅ Thermal Expansion Handling – Absorbs stress from heating/cooling cycles.
✅ Reduced Leak Points – Fewer welded joints compared to straight tubes.
✅ Efficient Heat Transfer – Smooth inner surface minimizes fouling.

5. Comparison: U-Bend vs. Straight Tubes

6. Common Defects & Quality Checks

Cracking at the bend (due to improper bending technique)

Excessive wall thinning (must be within 10–15%)

Ovality (deformation) – Should meet ASTM tolerances

7. Testing Methods:

Hydrostatic Test (checks for leaks)

Eddy Current Test (detects surface defects)

Dimensional Inspection (OD, wall thickness, bend radius)

Applications of ASTM A179 U-Bend Tubes:

ASTM A179 U-bend tubes are primarily used in heat exchangers and condensers where efficient heat transfer, compact design, and thermal stress resistance are critical. Their seamless, cold-drawn, low-carbon steel construction makes them ideal for moderate-temperature and pressure environments.

1. Heat Exchangers (Most Common Use)

Shell & Tube Heat Exchangers – U-bend tubes allow for thermal expansion and reduce the need for expansion joints.

Compact Design – The U-shape minimizes space requirements while maximizing heat transfer efficiency.

Fluid Types:

Water, steam, oil, refrigerants, and chemicals.

Industries:

✔ Power Plants (condensers, feedwater heaters)
✔ Oil & Gas (refineries, petrochemical processing)
✔ HVAC & Refrigeration (chillers, evaporators)

2. Condensers

Used in power plant condensers to convert steam back into water.

Advantages:

High thermal conductivity (due to low carbon content).

Smooth inner surface reduces fouling.

3. Boilers & Feedwater Heaters

Low-pressure boilers (not for high-temperature/pressure applications like A192/A213 tubes).

Feedwater heaters (pre-heat water before entering boilers).

4. Industrial Process Equipment

Chemical Processing – Heat transfer in reactors, distillation columns.

Food & Beverage – Pasteurizers, sterilizers.

Pharmaceuticals – Clean steam systems, heat recovery.

5. Marine & Offshore Applications

Shipboard condensers & coolers (due to corrosion-resistant treatments).

Yuhong Holding Group has more than 35 years experience for pipeline products, till now we have 3 big joint venture factories, the total production area more than 130000 square meters, and more than 600 workers with 106 production lines give our clients excellent supporting always. The factories already got certificates like : ABS, LR, DNV-GL, BV, KR, CCS, ASME, ISO 9001, ISO14001, ISO18001, ect.

Our factories main products as below :
Factory 1th: Stainless steel seamless tube, Duplex steel seamless tube, Super duplex steel seamless tube, Nickel alloy steel seamless tube;

Factory 2th: Carbon steel seamless tube, Alloy steel seamless tube; Enhanced Heat Tranfer Tube, low fin tube ,U bending workshop;
Factory 3th: High frequency welding fin tube(HFW fin tube, Solid Fin tube, Studded Tube, Serrated Fin tube, Longitudinal welding fin tube), Wound fin tube(L type fin tube, LL type fin tube, KL type fin tube), Embedded G type fin tube , Extruded fin tube, low fin tube, U bend & 180deg. Return;

Yuhong Holding Group also has gained rich experience for project package( products contain:Pipes, Fittings, Flanges, heat exchanger, furnace, fired heater, air cooler, boiler) , YUHONG brand has marked its global presence in more than 85 countries, like, Korea, USA, Canada, Mexico, Colombia, Bolivia, Chile, Argentina, Brazil, Ecuador, Austria, New Zealand, Singapore, Malasyia, Indonesia, Thailand, Vietnam, Ukraine, Turkey,Sauid Arabia, Qatar, U.A.E,Israel,India, UK, France, Italy, Gernmany, Poland, Spain,... We have successfully implemented the orders of Cross Country Pipelines for our valuable customers. In addition, we have also developed a huge network of contacts and strategic alliances with most important manufacturers as stockists around the world.