What is Welded Steel Pipe?
Welded steel pipe is one type of steel pipe welded with steel plates or steel strips. There are round, square and other shapes, and the steel pipe has a welding seam on its surface.
With the rapid development of high quality strip continuous rolling production and the advancement of welding and inspection technology, the quality of welding seams improve continually. The varieties and specifications of welded steel pipes are increasing, and they have replaced seamless steel pipes in more and more fields. Compared with seamless steel pipe, welded steel pipe has lower cost and higher production efficiency.
Our manufacturing plant was established in 1982, which is able to meet the needs of both private and public projects. If you are interested in our products, you can contact any of our sales representatives to discuss the exact specifications required for their welded steel pipes. Our team of experts can help you order rolled and welded steel pipes to suit your project needs. We ensure on-time delivery so you can complete your project on schedule.
Welded Steel Pipe type by welding method
Welded Steel Pipe Type By weld shape
Spiral welded steel pipe
In general, the strength of the spiral welded steel pipe is higher than that of straight seam welded steel pipe. The welded steel pipe with larger diameter can be produced with narrower billets, and a different diameter welded steel pipe can be produced with billets of the same width.
Applications
Transmission pipelines: Welded steel pipe is widely used to transport fluids, such as oil, natural gas and water.
Structural pipes: Welded steel pipe has the advantages of good load-bearing capacity and earthquake resistance, which is used in building structures, bridges, steel frames, supports and other engineering fields.
Machinery manufacturing: Welded steel pipe can be used to manufacture various mechanical parts, such as shafts, brackets, conveyor rollers and so on.
Oil and gas drilling: Welded steel pipe can be used to manufacture oil and gas drilling, and oil production equipment, such as drill pipes, casing, etc.
Technical Specifications
The weight of the welded steel pipe: kg/m = (Od - Wt) * Wt * 0.02466. (Note："Od" is the outer diameter, "Wt" is the wall thickness.)
| Nominal Size | Ordinary Pipe | Thickening Pipe | ||||
| （mm） | （in） | Out Diameter （mm） | Wall Thickness（mm） | Weight （kg/m） | Wall Thickness（mm） | Weight
（kg/m） |
| 6 | 1/8″ | 10 | 2.00 | 0.39 | 2.5 | 0.46 |
| 8 | 1/4″ | 13.5 | 2.25 | 0.62 | 2.75 | 0.73 |
| 10 | 3/8″ | 17 | 2.25 | 0.82 | 2.75 | 0.97 |
| 15 | 1/2″ | 21.25 | 2.75 | 1.26 | 3.25 | 1.45 |
| 20 | 3/4″ | 26.75 | 2.75 | 1.63 | 3.5 | 2.01 |
| 25 | 1″ | 33.5 | 3.25 | 2.42 | 4 | 2.91 |
| 32 | 1 1/4 | 42.25 | 3.25 | 3.13 | 4 | 3.78 |
| 40 | 1 1/2 | 48 | 3.5 | 3.84 | 4.25 | 4.58 |
| 50 | 2″ | 60 | 3.5 | 4.88 | 4.5 | 6.16 |
| 65 | 2 1/2 | 75.5 | 3.75 | 6.64 | 4.5 | 7.88 |
| 80 | 3″ | 88.5 | 4 | 8.34 | 4.75 | 9.81 |
| 100 | 4″ | 114 | 4 | 10.85 | 5 | 13.44 |
| 125 | 5″ | 140 | 4 | 13.42 | 5.5 | 18.24 |
| 150 | 6″ | 165 | 4.5 | 17.81 | 5.5 | 21.63 |
Comparisons
| Items | Our advantages | Other suppliers |
| Raw material | Famous steel pipe factories TPCO, Bao Steel etc | Local small factories |
| Production test | 100% test | Sampling test |
| Non-conforming products | Reject | Repair |
| NDT | 100% inspect | Sampling test |
| Heat treatment | 100% proceed | May not be done |
| Final inspection | 100% inspect | Sampling test |
Quality Assurance
1) How to detect the internal defects of Welded steel pipe? Now is generally the use of non-destructive testing methods, such as magnetic testing, ultrasonic testing, X-ray testing, penetration testing and so on.
2) Ultrasonic can test and welding material or defects on any part, it can find the location easily but more difficult to confirm the shape or size.
3) X-Ray test: it’s need to have 100% x-ray test, by imagine processing system to ensure the sensitivity of detection.
4) Coating and corrosion protection: The qualified welded steel pipe shall be anti-corrosion treatment and coated according to the user's requirements.