Straight Seam Welded Pipe
The Straight Seam Welded Pipe Manufacturer!
Gnee Steel Group is a supply chain-integrated enterprise including steel plate, coil, profile, outdoor landscape design and processing. Products include: API 5L Line Pipe, Seamless Steel Pipe, Welded Steel Pipe, OCTG, Stainless Steel Pipe, Coated Steel Pipe, Galvanized Steel Pipe, Pipe Fittings.
Why choose us
Production Capacity
The company has 19 API 5L line pipe lines, 10 API 5CT casing lines, 5 API 5D drill pipe lines and 2 pipe fitting lines.
Quality Guaranteed
Gnee has a strict procurement and quality inspection team carefully selects high-quality raw materials; an advanced science and technology team improves production and reduces costs for customers; an excellent design and processing team strives for excellence.
Broad Market
The company's products are exported to more than 70 countries around the world, with a total of more than 800 global cooperative enterprises, including 15 shipbuilding companies, 143 engineering project companies, and 23 boiler machinery manufacturers.
|
Steel grade |
C max |
Si |
Mn |
P |
S |
|
A45 |
0.17 |
/ |
0.98 |
0.035 |
0.035 |
|
A50 |
0.22 |
/ |
|||
|
CA55/A55 |
0.28 |
/ |
|||
|
B55 |
0.20 |
0.13~0.45 |
|||
|
CB60/B60 |
0.24 |
||||
|
CB65/B65 |
0.28 |
||||
|
CB70/C70 |
0.31 |
1.30 |
|||
|
C55 |
0.18 |
0.55-0.98 |
|||
|
CC60/C60 |
0.21 |
||||
|
CC65/C65 |
0.24 |
0.79-1.30 |
|||
|
CC70/C70 |
0.27 |
Advantages of Straight Seam Welded Pipe
Cost-effectiveness:
One of the most significant advantages of straight seam welded pipes is their cost efficiency. The manufacturing process involves less material waste compared to other types of pipes, making them a budget-friendly option for large-scale projects. Their affordability does not compromise quality, as they are built to withstand high pressure and extreme conditions.
High strength and durability:
Straight seam welded pipes are known for their exceptional strength. The welding process creates a continuous seam that enhances the pipe's structural integrity, allowing it to handle high-pressure applications without risk of failure. This durability makes them ideal for transporting liquids and gases in demanding environments.
Versatility:
These pipes are available in various sizes and thicknesses, making them suitable for a wide range of applications. Whether you need pipes for residential plumbing, industrial manufacturing, or large-scale infrastructure projects, straight seam welded pipes can be tailored to meet your specific requirements.
Ease of installation:
The uniformity of straight seam welded pipes simplifies the installation process. Their consistent dimensions allow for easy alignment and connection, reducing installation time and labor costs. This ease of use is particularly beneficial in projects with tight deadlines.
Corrosion resistance:
Many straight seam welded pipes are treated with protective coatings or made from corrosion-resistant materials, ensuring longevity even in harsh environments. This feature is crucial for applications involving water, chemicals, or other corrosive substances, as it minimizes maintenance and replacement costs.
Smooth interior surface:
The welding process results in a smooth interior surface, which reduces friction and allows for efficient fluid flow. This characteristic is essential for applications in the oil and gas industry, where minimizing pressure loss is critical for operational efficiency.
Classification of straight seam welded pipes
Straight seam submerged arc welded pipe
Straight seam submerged arc welded pipe (LSAW) is generally made of steel plate as raw material and undergoes different forming processes, using double-sided submerged arc welding and post-welding expansion to form welded pipes.
Straight seam high-frequency welded pipe
It is a welded pipe that uses high-frequency alternating current to heat the surface of the steel plate, quickly reaching the melting point and pressing to form. Compared with resistance welded pipes, high-frequency welded pipes have more stable quality, higher production efficiency, and a wider range of applications. The price of high-frequency welded pipes is slightly higher than that of resistance welded pipes.
Acceptance steps for straight seam steel pipes
The approval procedure for batch acceptance of straight seam steel pipes should comply with the corresponding product standards.
Straight seam steel pipes should comply with the corresponding product standards including inspection items, sampling quantity, sampling location and test methods. With the consent of the buyer, batch sampling of hot-rolled seamless steel pipes can be carried out according to rolling root rows.
If there are items that do not meet the requirements of product standards, the unqualified items should be selected, and double samples should be taken from the same batch of straight seam steel pipes to review the unqualified items. If the re-inspection results do not meet the standards, the batch of straight seam steel pipes shall not leave the factory.
Straight seam steel pipes that do not meet the standards (including items whose organization does not meet the standards and are not allowed to be re-inspected) should be submitted to the supplier for acceptance one by one, or a new batch of reheat treatment (reheat treatment no more than twice) should be recommended for acceptance.
If there are no special provisions in product standards, the chemical composition of straight seam steel pipes shall be accepted according to the melting composition.
Production process of straight seam welded steel pipe
Plate probe
After entering the production line, ultrasonic inspection is first carried out to manufacture steel plates for large-diameter submerged arc welding straight seam steel pipes.
Edge milling
Use an edge milling machine to perform double-sided milling on the two edges of the steel plate to achieve the required plate edge parallelism, plate width and groove shape.
Pre-bending
Pre-bending the edge of the plate with a pre-bending machine to make the edge of the plate meet the requirements.
Forming
First, on the forming machine, half of the pre-bent steel plate is pressed into a J-shape through multiple stepping stamping, and then the other half of the steel plate is also pressed into a C- shape, and finally an O-shape with an opening is formed.
Pre-welding
Seam welding the formed straight seam welded steel pipe and continuous welding with gas shielded welding.
Internal welding
Welding is carried out on the inner side of the straight seam steel pipe, using longitudinal multi-wire submerged arc welding, up to four wires.