Seamless Carbon Steel Tubes For Efficient Heat Transfer
Astm a192 u-bend tubes are seamless carbon steel tubes designed for high-pressure boilers and heat exchangers.
Seamless Carbon Steel Tubes For Efficient Heat Transfer
Astm a192 u-bend tubes are seamless carbon steel tubes designed for high-pressure boilers and heat exchangers. offering excellent corrosion resistance and thermal efficiency, they ensure durable pipeline performance.
ASTM A192 U-Bend Tubes are seamless carbon steel tubes engineered for high-pressure service in boiler tubes and heat exchanger tubes. Conforming to ASTM A192/ASME SA192 specifications, these U-shaped tubing solutions are ideal for applications in power generation, petrochemical, and industrial plants, where corrosion resistance and pipeline durability are critical. The U-bend design enhances heat transfer efficiency and acts as a thermal expansion absorber, reducing stress in high-temperature systems.
Manufactured through a seamless, cold-drawn process, ASTM A192 U-Bend Tubes feature a minimum wall thickness ranging from 1.65mm to 2.77mm and outer diameters from 12.7mm to 38.1mm. The tubes can be customized with bend radii from 1.5 times the outer diameter to 1250mm and leg lengths up to 26 meters, catering to specific project requirements. Post-bending heat treatment at a minimum of 650°C ensures optimal mechanical properties, while protective argon gas filling during heat treatment prevents oxidation. Surface treatments like varnishing or pickling further enhance corrosion resistance.
These boiler tubes undergo stringent testing, including hydrostatic, flattening, flaring, and hardness tests, to comply with ASTM A450/A450M standards. With a minimum tensile strength of 325 MPa and yield strength of 180 MPa, they are designed to withstand pressures up to 9.8 MPa and temperatures between 450°C and 650°C. The U-bend configuration minimizes thermal stress and eliminates the need for expansion joints, making them space-efficient and cost-effective for heat exchanger tubes in compact designs.
The ASTM A192 U-Bend Tubes are particularly suited for high-pressure boilers, superheaters, economizers, and reheaters, offering reliable performance in harsh environments like coal, thermal, and oil power plants. Their carbon steel composition (0.06-0.18% carbon, 0.27-0.63% manganese) ensures good weldability and formability, allowing for bending and flanging without cracking. Compared to ASTM A179 tubes, A192 tubes are optimized for higher-pressure applications, while their seamless construction ensures leak-free performance.
Addressing challenges like pipeline wear, corrosion, and thermal stress, ASTM A192 U-Bend Tubes provide a robust solution for engineers seeking durable and efficient boiler tubes. Their high thermal conductivity and long service life make them a preferred choice for critical applications in demanding industrial settings.
| Element | Composition (%) |
|---|---|
| Carbon (C) | 0.06–0.18 |
| Manganese (Mn) | 0.27–0.63 |
| Silicon (Si) | ≤0.25 |
| Phosphorus (P) | ≤0.035 |
| Sulfur (S) | ≤0.035 |
| Property | Value |
|---|---|
| Tensile Strength, min (MPa) | 325 |
| Yield Strength, min (MPa) | 180 |
| Elongation, min (%) | 35 |
| Hardness (HBW) | ≤137 (for ≥5.1 mm wall thickness) |
The ASTM A192/ASME SA192 standard is applicable to seamless carbon steel pipes used for boilers and superheaters in high-pressure environments, with a focus on meeting the minimum wall thickness necessary for these applications.
ASTM A 192 boiler tube equivalent EN 10216-2, DIN 17175, BS 3059 Part II, NF A 49-213, NBR 5594 ASTM (American Society for Testing Materials standard) A192 and ASME (American Society of Mechanical Engineers standards) SA192. Equivalent Materials 1010, St35.
| Feature | ASTM A192 | ASTM A179 | ASTM A210 Grade A1 |
|---|---|---|---|
| Material Type | Carbon Steel | Carbon Steel | Carbon Steel |
| Application | High-Pressure Boilers & Superheaters | Low-Pressure Heat Exchangers | Medium-Pressure Boiler Tubes |
| Manufacturing Process | Seamless, Hot/Cold Finished | Cold Drawn | Hot Rolled or Cold Drawn |
| Tensile Strength (MPa) | ≥325 | ≥325 | ≥415 |
| Yield Strength (MPa) | ≥180 | ≥180 | ≥255 |
| Elongation (%) | ≥35 | ≥35 | ≥30 |
| Temperature Service Range | High (Steam & Pressure) | Low to Medium | Medium |
| Corrosion Resistance | Good (With Coatings) | Moderate | Moderate |
| Key Advantage | High-pressure capability & structural durability | High thermal conductivity for heat exchangers | Cost-effective for general boiler use |
U-bend tubes are widely used in heat-exchanger systems. Heat-exchanger equipment on the basis of seamless stainless U-tubes is essential in strategically important and critical fields — nuclear and petrochemical machine building.
a...................The difference in length between two straight pipe
sections
c..............The tangent spacing of the outer wall of the elbow
Da............nominal steel pipe outer diameter
E..............The distance between the outer diameters of the two straight
ends
f...............the distance between the ends of the two straight ends
l............... straight tube length
Lg............. straight pipe section plus total length of pipe
Rm...........nominal bending radius
S.............nominal wall thickness
Smin.......The minimum wall thickness at the back of the elbow
t...............the bend deviates from the horizontal distance
So...........Standard minimum wall thickness
| Item | Condition (when) | Tolerance |
|---|---|---|
| Ovality | Nominal bend radius ≤ 2 x nominal OD | less than or equal to 12% |
| 2 x nominal OD < Nominal bend radius ≤ 4 x nominal OD | less than or equal to 10% | |
| Nominal bend radius > 4 x nominal OD | less than or equal to 5% | |
| Nominal bend radius ≤ 2 x nominal OD | 0.75 x nominal wall | |
| Minimum wall thickness | 2 x nominal OD < Nominal bend radius ≤ 4 x nominal OD | 0.8 x nominal wall |
| Nominal bend radius > 4 x nominal OD | 0.9 x nominal wall | |
| Nominal bend radius ≤ 8" (200mm) | +/-3/64"(1mm) | |
| Bending Radius | 8" (200mm) < Nominal bend radius ≤ 16" (400mm) | +/-1/16"(1mm) |
| Nominal bend radius >16" (400mm) | +/-5/64"(1mm) | |
| Distance between legs | - | Max 1/16"(1.5mm) |
| Wall thinning of bending area | - | Max 17% |
| Difference between leg lengths at the ends | Leg length ≤ 16' (4.88m) | +1/8"(3mm) |
| Leg length > 16' (4.88m) | +3/16"(5mm) | |
| Deviation from plane of bend | - | ≤ 3/16"(1.5mm) |
| Flattening on bend | - | ≤ 10% nominal diameter |
| Straight leg length | ≤5m | +1/8"(3mm) |
| >5m | +3/16"(5mm) | |
| Total tube length including radius | ≤6m | +3/16"(5mm) |
| >6m | +5/16"(8mm) |
U-Tube heat exchangers are known for their distinctive U-shaped tubes that offer several advantages and also come with certain limitations.
The U-tube heat exchanger features a single tubesheet with both ends of the tubes secured to it. This design allows the tubes to expand and contract freely, avoiding thermal stress and offering excellent thermal compensation. A double tube pass is utilized, providing a lengthy process path, high flow rates, and superior heat transfer performance with robust pressure resistance. The tube bundle is removable from the shell for convenient maintenance and cleaning, presenting a simple structure and low cost.
Limitations imposed by the elbow's curvature radius restrict the arrangement of heat exchange tubes. This results in a larger inner tube spacing within the tube bundle and a lower utilization rate of the tube sheet. The shell-side fluid is prone to short-circuiting, which can impede heat transfer. When a tube leaks or sustains damage, only the U-shaped tubes on the outer part of the bundle can be readily replaced. Damage to the inner heat exchange tubes is not as easily repairable and may require blocking off. Furthermore, the damage to a single U-shaped tube equates to the loss of two tubes, leading to a higher scrap rate.
U-bend tubes are used to transfer heat between fluids.
Transfers heat between fluids, allowing return flow at 180° in a compact space.
Used in heat exchangers, chemical & petrochemical, food processing, and refrigeration industries.
Applied in heat exchangers at Oil & Gas, petrochemical plants, refineries, and power plants.
Handles aggressive fluids like sodium hydroxide + sodium hypochlorite safely.
Allows pipeline expansion without buckling; flexible or sliding options available.
Enhances heat transfer when the outside coefficient is lower than the inside, improving efficiency.
U-bent heat exchanger tubes ensure efficient heat ...
Titanium alloy u-bent tubes offer unmatched corros...
U-shaped monel 400 tubes offer exceptional corrosi...
Sa-213 tp347h u-bend tubes offer exceptional corro...
U-shaped heat exchanger tubes offer superior corro...
Alloy steel u-tubes provide superior strength and ...