What is Seam Pipe?

Seam pipe (also known as welded pipe) refers to the strip or plate bending round, square and other shapes and then welded into the surface jointed pipe. Seam pipe is using a blank plate or strip.

With the advancement of high-quality steel rolling production as well as the rapid development of welding and inspection techniques, and continuously improve the quality of welds, pipe joints increasing varieties and specifications, and in more and more areas instead of seamless steel tubes. Seam pipe is lower than seamless steel pipe on cost, high production efficiency.

According to different welding methods can be divided arc welded pipe, high-frequency or low frequency electric resistance welded pipe, gas pipe, stove pipe, Bundy tubes.
Press seam shape classification can be divided into longitudinal and spiral welded pipe.
By end-use is divided into general welded pipe, galvanized pipe, oxygen blowing pipe, wire casing, metric pipe, roller tube, deep well pump tube, automotive tube, transformer tube, welding thin-walled tube, welding shaped tube and spiral welded pipe.

Press the end of the shape classification is divided into circular pipe and shaped (square, flat, etc.) pipe.

Seamed pipes are made of carbon steel that is easy to weld. Their nominal sizes range from DN15 to DN100, with a maximum nominal diameter of DN150 (6). Welded steel pipes are commonly used for the transportation of hot and cold water and gas, so they are also called water-gas pipes. Galvanized welded steel pipes are customarily called white iron pipes on construction sites, while ungalvanized welded steel pipes are called black iron pipes. The blanks used for welded steel pipes are steel plates or strips.

In the case of Ni-containing welded steel pipe containing Ni, the corrosion resistance is strong in an acidic environment. In the environment containing sulfuric acid or hydrochloric acid, the higher the content of Ni in the T-welded steel pipe, the stronger the corrosion resistance. In the general environment, it is only necessary to add Cr to the T-welded steel pipe to prevent corrosion. Poor edge conditions on the strip are another important cause of misalignment. The effect of mass flow, heat flux density and structural parameters (ratio of the diameter of the spiral curvature and the diameter of the T-welded steel pipe Dc/D) on the saturated bubble boiling heat transfer coefficient in the vertical spiral tube. In the production of T-welded steel pipes, there are many factors influencing the wrong side. In the production practice, the steel pipe is often downgraded by the dry and wrong side. Therefore, it is necessary to analyze the causes of the wrong side of the spiral steel pipe and its preventive measures.

Advantages of seamed pipes:

Compared with seamless steel pipes, seamed pipes (welded pipes) have significant advantages in cost, production efficiency, and size flexibility, and are widely used in construction, machinery, energy, transportation and other fields.

1. Low production cost and good economy
High raw material utilization: Steel plates or steel strips are rolled, which saves more materials than seamless steel pipes (which need to be perforated and rolled).
High production efficiency: The automated welding production line has a high speed (such as ERW welded pipes can reach 20-50 meters per minute), which is suitable for large-scale production.
Price advantage: The price of welded pipes is usually 20%~40% lower than that of seamless steel pipes of the same specifications, which is suitable for budget-sensitive projects.

2. Flexible size and various specifications

Wide diameter range:
ERW welded pipe: Φ20mm~Φ610mm (suitable for small-diameter precision pipes)
LSAW welded pipe: Φ406mm~Φ1600mm (suitable for large-diameter high-pressure pipes)
SSAW welded pipe: Φ219mm~Φ3000mm (super-large diameter, used for pile foundations and water delivery)

Controllable wall thickness: thin wall (1mm) to thick wall (25mm+) can be produced to meet different pressure requirements.

3. High welding strength and stable performance
Modern welding technology (such as high-frequency resistance welding and submerged arc welding) makes the weld strength close to the parent material, and the quality can be ensured by ultrasonic and X-ray detection.
Good cold processing performance: welded pipes are easy to bend, stamp, and expand, suitable for complex structures (such as automobile exhaust pipes and furniture frames).

4. Lightweight and design adaptability
Thin-walled welded pipes are light in weight and suitable for light steel structures (such as scaffolding and shelves).
Special-shaped pipes (square pipes, rectangular pipes, elliptical pipes) can be produced to meet special needs such as architectural decoration and mechanical design.

5. Environmental protection and sustainability
The production energy consumption is lower than that of seamless steel pipes, reducing carbon emissions.
Recyclable, in line with the trend of green buildings.

Typical application areas of seamed pipes:

1. Building and steel structure
Building frame/roof truss/scaffolding/door and window guardrails

2. Energy and pipeline engineering
Transportation of oil and gas/municipal engineering water supply and drainage/water conservancy engineering/thermal pipe network centralized heating system

3. Machinery and automobile manufacturing
Construction machinery/auto parts/agricultural machinery and equipment

4. Transportation and infrastructure
Bridge construction (pier support, guardrail)/subway tunnel/port terminal (steel pipe pile foundation)

5. Home and daily use
Furniture/home appliances/sports equipment

Selection suggestions:
Preferably choose seamed pipes: cost-sensitive, large-caliber, lightweight structure (such as construction, ordinary fluid transportation).
Select seamless pipes: ultra-high pressure, high temperature, strong corrosive environment (such as chemical pipelines, aviation hydraulic systems).

Read more: Types and uses of welded steel pipe or Seam pipe vs Seamless pipe