ASTM A179 Irregular Carbon Steel U Bend Tube Heat Exchanger Tube Boiler Tube
ASTM A179 Heat Exchanger Tube Low Carbon Steel Seamless U Bend Tube
The effect of irregular bend structures in oscillating heat pipes (OHPs) on thermal performance and unidirectional flow can be analyzed through several key mechanisms:
Thermal Performance
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Oscillation Dynamics:
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Disruption vs. Enhancement: Irregular bends may disrupt regular oscillatory motion, potentially dampening oscillations and reducing heat transfer efficiency. Conversely, they could introduce turbulence or chaotic mixing, enhancing heat transfer by breaking thermal boundary layers.
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Local Pressure Variations: Non-uniform bends create asymmetric pressure gradients, affecting vapor-liquid phase distribution. Sharp bends may increase pressure drops, while smoother sections could aid flow recovery, influencing thermal resistance.
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Fluid Distribution and Dry-Out:
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Irregular geometries might lead to uneven fluid distribution, increasing the risk of dry-out in regions with poor fluid return. However, strategic irregularities could promote capillary-driven fluid replenishment in critical areas.
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Heat Transfer Mechanisms:
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Enhanced nucleation sites in irregular bends might improve boiling/evaporation efficiency. Conversely, stagnant zones due to flow separation could reduce effective heat transfer areas.
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Unidirectional Flow
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Directional Bias:
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Asymmetrical bends can act as passive check valves, favoring net flow in one direction. This mimics a hybrid OHP-traditional heat pipe behavior, potentially reducing start-up time and improving heat transport under high loads.
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Oscillation vs. Circulation:
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Moderate irregularities may sustain oscillations while promoting a directional bias. Excessive asymmetry might suppress oscillations, converting the OHP into a less effective continuous-flow system.
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ASTM A179 Carbon Steel Seamless Tube Chemistry Composition:
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C, %
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Mn, %
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P, %
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S, %
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0.06-0.18 |
0.27-0.63
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0.035 max
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0.035 max
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ASTM A179 Carbon Steel Seamless Tube Mechanical Properties:
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Tensile Strength, MPa
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Yield Strength, MPa
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Elongation, %
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Hardness, HRB
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325 min
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180 min
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35 min
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72 max
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ASTM A179 Carbon Steel Seamless Tube Outside Diameter & Tolerance
| Outside Diameter, mm | Tolerance, mm |
| 3.2≤OD＜25.4 | ±0.10 |
| 25.4≤OD≤38.1 | ±0.15 |
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38.1＜OD＜50.8 |
±0.20 |
| 50.8≤OD＜63.5 | ±0.25 |
| 63.5≤OD＜76.2 | ±0.30 |
| 76.2 | ±0.38 |
ASTM A179 Carbon Steel Seamless Tube Wall thickness & Tolerance
| Outside Diamter, mm | Tolerance, % |
| 3.2≤OD＜38.1 | +20/-0 |
| 38.1≤OD≤76.2 | +22/-0 |
Other Available Materials
| Standard | Steel grade | Tensile(MPa) | Yield(MPa) | Elongate(%) | Hardenss |
| 20MnG | 20MnG | ≥415 | ≥240 | ≥22 | |
| 25MnG | 25MnG | ≥485 | ≥275 | ≥20 | |
| 15CrMoG | 15CrMoG | 440～640 | ≥235 | ≥21 | |
| 12Cr2MoG | 12Cr2MoG | 450～600 | ≥280 | ≥20 | |
| 12Cr1MoVG | 12Cr1MoVG | 470～640 | ≥255 | ≥21 | |
| 12Cr2MoWVTiB | 12Cr2MoWVTiB | 540～735 | ≥345 | ≥18 | |
| 10Cr9Mo1VNb | 10Cr9Mo1VNb | ≥585 | ≥415 | ≥20 | |
| ASME SA210 | SA210A-1 | ≥415 | ≥255 | ≥30 | ≤143HB |
| SA210C | SA210C | ≥485 | ≥275 | ≥30 | ≤179HB |
| ASME SA213 | SA213 T11 | ≥415 | ≥205 | ≥30 | ≤163HB |
| SA213 T12 | SA213 T12 | ≥415 | ≥220 | ≥30 | ≤163HB |
| SA213 T22 | SA213 T22 | ≥415 | ≥205 | ≥30 | ≤163HB |
| SA213 T23 | SA213 T23 | ≥510 | ≥400 | ≥20 | ≤220HB |
| SA213 T91 | SA213 T91 | ≥585 | ≥415 | ≥20 | ≤250HB |
| SA213 T92 | SA213 T92 | ≥620 | ≥440 | ≥20 | ≤250HB |
| DIN17175 | ST45.8/Ⅲ | 410～530 | ≥255 | ≥21 | / |
| 15Mo3 | 15Mo3 | 450～600 | ≥270 | ≥22 | |
| 13CrMo44 | 13CrMo44 | 440～590 | ≥290 | ≥22 | |
| 10CrMo910 | 10CrMo910 | 480～630 | ≥280 | ≥20 |
Applications:
- Pharmaceutical Equipment
- Chemical Equipment
- Sea Water Equipment
- Heat Exchangers
- Condensers
- Pulp and Paper Industry
- Off-Shore Oil Drilling Companies
- Power Generation
- Petrochemicals
- Gas Processing
- Specialty Chemicals
- Pharmaceuticals
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