High-strength Piping Solutions For Diverse Industries
Seamless pipes for oil and gas, power generation, petrochemicals, and construction, offering high strength and corrosion resistance for high-pressure applications.
Seamless Pipes by Applications are engineered for demanding industrial environments, offering superior strength, durability, and corrosion resistance. Manufactured without welds, these pipes ensure uniform structure and reliability under high-pressure and high-temperature conditions, making them ideal for oil and gas piping, boiler tubes, petrochemical piping, and construction piping. Seamless pipes are used across industries like power generation, petrochemicals, oil and gas, and infrastructure for their leak-proof performance and longevity.
Seamless Pipes are produced through hot-rolling or cold-drawing processes, with outer diameters ranging from 6 mm to 914 mm and wall thicknesses from 1 mm to 100 mm. Lengths are available in standard (6m, 12m) or customized options (up to 18m) to meet project specifications. Heat treatments like normalizing, quenching, or tempering enhance mechanical properties, ensuring performance in extreme conditions. The absence of welds eliminates weak points, making these pipes suitable for high-pressure piping applications where safety and reliability are critical.
The chemical composition of seamless pipes varies by grade (e.g., carbon steel, alloy steel, or stainless steel), typically including carbon (0.08–0.30%), silicon (0.10–0.50%), manganese (0.30–1.50%), phosphorus (≤0.040%), and sulfur (≤0.040%), with alloying elements like chromium or molybdenum for enhanced corrosion resistance. Rigorous testing, including tensile, hydrostatic, flattening, and nondestructive tests (ultrasonic or eddy current), ensures compliance with standards like ASTM, JIS, or DIN. Surface treatments such as galvanizing, 3LPE, or epoxy coatings protect against pipeline wear, while plain, beveled, or threaded ends facilitate installation.
Seamless pipes excel in applications requiring high-pressure resistance, such as oil and gas pipelines, boiler systems, heat exchangers, and structural frameworks. Compared to welded pipes, seamless pipes offer superior strength and uniformity, making them the preferred choice for critical applications in refineries, power plants, and construction projects. Their versatility supports diverse industries, from transporting corrosive fluids to supporting heavy structural loads.
These pipes address challenges like high-pressure containment, corrosion, and thermal stress in industrial systems. Their seamless construction and compliance with international standards make them a reliable choice for engineers seeking durable industrial piping solutions, ensuring safety, efficiency, and extended service life in demanding environments.
Withstands extreme pressures in oil and gas, boiler, and petrochemical systems.
Performs reliably at high temperatures, ideal for boiler tubes.
Resists corrosion with coatings, suitable for harsh environments.
Uniform structure eliminates weld defects for leak-proof performance.
Long-lasting materials reduce maintenance and replacement costs.
Certified with rigorous testing to meet industry standards.
Explore the dimensional ranges and common applications of various seamless pipe types.
| Type | Outer Diameter | Wall Thickness | Length | Applications |
|---|---|---|---|---|
| Hot-Rolled Seamless | Above 32 mm | 2.5 – 200 mm | Up to 12 m | General industrial, structural |
| Cold-Rolled Seamless | 6 – 650 mm | 0.25 – 50 mm | Up to 12 m | Precision applications |
| Thin-Walled Pipe | 5 – 100 mm | Less than 0.25 mm | Up to 6 m | Instrumentation, automotive |
| Heavy Wall Pipe | 50 – 650 mm | 10 – 200 mm | Up to 12 m | High pressure, structural |
| DN | NB (inch) | OD (mm) | Nominal Wall Thickness (mm) | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| SCH10 | SCH20 | SCH30 | STD | SCH40 | SCH60 | XS | SCH80 | SCH100 | SCH120 | SCH140 | SCH160 | XXS | |||
| 15 | 1/2" | 21.3 | 2.11 | 2.41 | 2.77 | 2.77 | 3.73 | 3.73 | 4.78 | 7.47 | |||||
| 20 | 3/4" | 26.7 | 2.11 | 2.41 | 2.87 | 2.87 | 3.91 | 3.91 | 5.56 | 7.82 | |||||
| 25 | 1" | 33.4 | 2.77 | 2.90 | 3.38 | 3.38 | 4.55 | 4.55 | 6.35 | 9.09 | |||||
| 32 | 1.1/4" | 42.2 | 2.77 | 2.97 | 3.56 | 3.56 | 4.85 | 4.85 | 6.35 | 9.70 | |||||
| 40 | 1.1/2" | 48.3 | 2.77 | 3.18 | 3.68 | 3.68 | 5.08 | 5.08 | 7.14 | 10.15 | |||||
| 50 | 2" | 60.3 | 2.77 | 3.18 | 3.91 | 3.91 | 5.54 | 5.54 | 8.74 | 11.07 | |||||
| 65 | 2.1/2" | 73 | 3.05 | 4.78 | 5.16 | 5.16 | 7.01 | 7.01 | 9.53 | 14.02 | |||||
| 80 | 3" | 88.9 | 3.05 | 4.78 | 5.49 | 5.49 | 7.62 | 7.62 | 11.13 | 15.25 | |||||
| 90 | 3.1/2" | 101.6 | 3.05 | 4.78 | 5.74 | 5.74 | 8.08 | 8.08 | |||||||
| 100 | 4" | 114.3 | 3.05 | 4.78 | 6.02 | 6.02 | 8.56 | 8.56 | 13.49 | 17.12 | |||||
| 125 | 5" | 141.3 | 3.4 | 6.55 | 6.55 | 9.53 | 9.53 | 12.7 | 15.88 | 19.05 | |||||
| 150 | 6" | 168.3 | 3.4 | 7.11 | 7.11 | 10.97 | 10.97 | 14.27 | 18.26 | 21.95 | |||||
| 200 | 8" | 219.1 | 3.76 | 6.35 | 7.04 | 8.18 | 8.18 | 10.31 | 12.7 | 12.7 | 15.09 | 18.26 | 20.62 | 23.01 | 22.23 |
| 250 | 10" | 273 | 4.19 | 6.35 | 7.8 | 9.27 | 9.27 | 12.7 | 12.7 | 15.09 | 18.26 | 21.44 | 25.4 | 28.58 | 25.4 |
| 300 | 12" | 323.8 | 4.57 | 6.35 | 8.38 | 9.53 | 10.31 | 14.27 | 12.7 | 17.48 | 21.44 | 25.4 | 28.58 | 33.32 | 25.4 |
| 350 | 14" | 355.6 | 6.35 | 7.92 | 9.53 | 9.53 | 11.13 | 15.09 | 12.7 | 19.05 | 23.83 | 27.79 | 31.75 | 35.71 | |
| 400 | 16" | 406.4 | 6.35 | 7.92 | 9.53 | 9.53 | 12.7 | 16.66 | 12.7 | 21.44 | 26.19 | 30.96 | 36.53 | 40.19 | |
| 450 | 18" | 457.2 | 6.35 | 7.92 | 11.13 | 9.53 | 14.27 | 19.05 | 12.7 | 23.83 | 39.36 | 34.93 | 39.67 | 45.24 | |
| 500 | 20" | 508 | 6.35 | 9.53 | 12.7 | 9.53 | 15.09 | 20.62 | 12.7 | 26.19 | 32.54 | 38.1 | 44.45 | 50.01 | |
| 550 | 22" | 558.8 | 6.35 | 9.53 | 12.7 | 9.53 | 22.23 | 12.7 | 28.58 | 34.93 | 41.28 | 47.63 | 53.98 | ||
| 600 | 24" | 609.6 | 6.35 | 9.53 | 14.27 | 9.53 | 17.48 | 24.61 | 12.7 | 30.96 | 38.89 | 46.02 | 52.37 | 59.54 | |
| 650 | 26" | 660.4 | 7.92 | 12.7 | 9.53 | 12.7 | |||||||||
| 700 | 28" | 711.2 | 7.92 | 12.7 | 15.88 | 9.53 | 12.7 | ||||||||
| 750 | 30" | 762 | 7.92 | 12.7 | 15.88 | 9.53 | 12.7 | ||||||||
| 800 | 32" | 812.8 | 7.92 | 12.7 | 15.88 | 9.53 | 17.48 | 12.7 | |||||||
| 850 | 34" | 863.6 | 7.92 | 12.7 | 15.88 | 9.53 | 17.48 | 12.7 | |||||||
| 900 | 36" | 914.4 | 7.92 | 12.7 | 15.88 | 9.53 | 19.05 | 12.7 | |||||||
Seamless Pipes
Seamless pipes, available in various wall thicknesses, are designed for precise applications, with cold-rolled thin-walled pipes achieving thicknesses as low as 0.25 mm or less.
The outer diameter of hot-rolled seamless pipe is generally greater than 32mm, the wall thickness is 2.5-200mm, the outer diameter of cold-rolled seamless steel pipe can be 6mm, the wall thickness can be 0.25mm, the outer diameter of thin-walled pipe can be 5mm, and the wall thickness is less than 0.25mm, cold rolling
The ability to produce seamless pipes with ultra-thin walls and controlled ovality makes them critical for industries like automotive, hydraulics, and petrochemicals, ensuring reliability and performance.
| NPS/ DN/ OD | Permissible Variations in Outside Diameter | |||
|---|---|---|---|---|
| Over | Under | |||
| in. | mm | in. | mm | |
| NPS 1/8 to 1½, incl DN 6 to 40 OD 10.3 to 48.3, mm |
1/64 | 0.4 | 1/64 | 0.4 |
| Over 1½ to 4, incl DN 40 to 100 OD 48.3 to 114.3, mm |
1/32 | 0.8 | 1/32 | 0.8 |
| Over 4 to 8, incl DN 100 to 200 OD 114.3 to 219.1, mm |
1/16 | 1.6 | 1/32 | 0.8 |
| Over 8 to 18, incl DN 200 to 450 OD 219.1 to 457, mm |
3/32 | 2.4 | 1/32 | 0.8 |
| Over 18 to 26, incl DN 450 to 650 OD 457 to 660, mm |
1/8 | 3.2 | 1/32 | 0.8 |
According to the production method, seamless tubes are divided into hot - rolled tubes, cold - rolled tubes, cold - drawn tubes, extruded tubes, jacking tubes, etc. The maximum diameter is 650 mm and the minimum diameter is 0.3 mm. Depending on the application, there are thick - walled tubes and thin - walled tubes. Seamless steel tubes are mainly used as petroleum geological drilling tubes, cracking tubes for petrochemical industry, boiler tubes, bearing tubes and high - precision structural steel tubes for automobiles, tractors and aviation. In the plate, Q345B seamless steel pipe belongs to the low - alloy series.
Among the low - alloy materials, this kind of material is the most common. The outside diameter of hot - rolled seamless pipe is usually more than 32mm, the wall thickness is 2.5 - 200mm, the outside diameter of cold - rolled seamless steel pipe can be 6mm, the wall thickness can be 0.25mm, the outside diameter of thin - walled pipe can be 5mm, and the wall thickness is less than 0.25mm, cold rolling has higher dimensional accuracy than hot rolling.
A consolidated overview of international seamless pipe standards, their materials, and applications.
| Standard System | Standard Code | Material Type | Typical Applications |
|---|---|---|---|
| ASTM / ASME (USA) |
ASTM A53 | Carbon Steel | General-purpose piping, structural |
| ASTM A106 | Carbon Steel | High-temperature service | |
| ASTM A179 | Low Carbon Steel | Heat exchangers, condensers | |
| ASTM A333 | Carbon/Alloy Steel | Low-temperature service | |
| ASTM A335 | Alloy Steel | High-temperature, pressure piping | |
| ASTM A213 / A209 | Alloy/Stainless Steel | Boilers, superheaters | |
| ASTM A312 | Stainless Steel | Corrosion-resistant piping | |
| ASTM A519 | Carbon/Alloy Steel | Mechanical tubing (e.g., SAE 1026) | |
| ASTM A790 | Duplex Stainless Steel | High-strength, corrosion-resistant service | |
| API (Oil & Gas) |
API 5L | Carbon Steel | Oil & gas pipelines |
| API 5CT | Carbon Steel | Casing & tubing for wells | |
| JIS (Japan) |
JIS G3454/G3455/G3456 | Carbon Steel | Pressure piping service |
| JIS G3460 | Carbon Steel | Boilers, heat exchangers | |
| JIS G3429 | High-strength Steel | High-pressure gas cylinders | |
| GB (China) |
GB 3087 | Carbon Steel | Low & medium pressure boilers |
| GB 5310 | Carbon Steel | High-pressure boiler pipes | |
| GB/T 8163 | Carbon Steel | Fluid and structural use |
Seamless pipes are critical in various industries thanks to their excellent strength, temperature resistance, and structural uniformity. They ensure safe and efficient performance in demanding environments.
Used in steam pipelines, boiler tubes, superheaters, and heat exchangers for high-temperature and high-pressure conditions in power plants.
Transports crude oil, natural gas, and petroleum products in pipelines and refinery units, handling high-pressure and corrosion.
Handles chemicals, gases, and hazardous substances in reactors and heat exchangers, ensuring safe processing.
Applied in automotive systems and machinery for fluid conveyance and precision components requiring strength and accuracy.
Used in structural support, water and sewage systems, and building frameworks for strength and corrosion resistance.
Utilized in hydraulic and engine systems onboard, resisting corrosion in marine environments.
Employed in aircraft and military equipment for hydraulic systems and structural components.
Stainless pipes for hygienic transport of food and pharmaceutical products, maintaining sterility.
Designed for transporting slurries and chemicals in mining, withstanding abrasion and harsh conditions.
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