Seamless Stainless Steel Tubing

Stainless steel seamless tube is a kind of long steel with a hollow cross section and no seams around it. The thicker the wall thickness of the product, the more economical and practical it is, and the thinner the wall thickness, the processing cost of it will rise substantially. The process of the product determines its limited performance, general seamless steel pipe precision is low: wall thickness is not uniform, low brightness of the inner appearance of the tube, high cost of sizing, and the inner appearance of the pockmarks, black spots are not easy to remove; its detection and shaping must be processed offline. Therefore, it reflects its superiority in high-pressure, high-strength, mechanical structure materials.

Manufacturing Methods

Seamless tube / pipe manufacturing process

1. Seamless Hot Rolling Processes

Round Pipe Billet → Heating → Perforation → Three Roll Skew Rolling, Continuous Rolling or Extrusion → Off Pipe → Sizing (Or Reducing Diameter)→ Cooling → Billet → Straightening → Water Pressure Test ( Or Flaw Detection) → Marking → Storage

2. Seamless Cold Rolling (Cold drawn) Processes

Round Pipe Billet → Heating → Perforation → Head → Annealing → Pickling → Oil (Copper) → Multi Pass Drawing (Cold Rolling) → Billet → Heat Treatment → Straightening → Water Pressure Test → Marking → Storage

Calculation Formula

• Wall Thickness

  

  Among them:
  t: Wall Thickness (mm)
  P: Design Pressure (MPa)
  D: Outer Diameter (mm)
  S: Permissible Material Stress (MPa)
  E: Weld Coefficient (1 FOR SEAMLESS PIPE)
  Y: Material Coefficient

• Weight

  

  Among them:
  W:Weight (kg)
  D:Outer Diameter (mm)
  t: Wall Thickness (mm)
  L: Length (m)
  ρ: Density Of Stainless Steel (kg/m³, USUALLY 7930)

Dimension Range

Seamless stainless steel tubes are available in a wide range of sizes including outside diameter, wall thickness and length.

Outer Diameter Range

    Seamless Stainless Steel Pipe has a wide range of outer diameters, covering from small to large caliber:
Small caliber: 6mm to 20mm are common, such as 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm, etc.
Medium caliber: 20mm to 100mm, such as 22mm, 25mm, 28mm, 30mm, 32mm, 34mm, 38mm, 40mm, 42mm, 45mm, 48mm, 50mm, 51mm, 57mm, 60mm, 63mm, 65mm, 70mm, 73mm, 76mm, 80mm, 83mm, 89mm, 90mm, 95mm, 100mm and so on.
Larger caliber: 100mm to 300mm, such as 102mm, 108mm, 114mm, 121mm, 127mm, 133mm, 140mm, 146mm, 152mm, 159mm, 168mm, 170mm, 180mm, 192mm, 194mm, 200mm, 219mm, 245mm, 250mm, 273mm and so on.
Large caliber: above 300mm, such as 325mm, 355mm, 377mm, 406mm, 426mm, 457mm, 508mm, etc.

Wall Thickness Range

Wall thickness varies according to the outer diameter:
Thin wall: 0.4mm to 2mm, common for small diameter pipes.
Medium wall thickness: 2mm to 10mm, commonly found in medium caliber pipes such as 3mm, 4mm, 5mm, 6mm, 8mm, 10mm, etc.
Thick wall: 10mm to 30mm or even thicker, commonly found in large caliber pipes, such as 12mm, 14mm, 15mm, 16mm, 18mm, 20mm, 22mm, 25mm, 30mm, 34mm, etc.

Length Range

length of seamless stainless steel pipe varies depending on the production process:
Hot rolled steel pipe: the length is usually 1.5m to 10m.
Hot extruded steel pipe: the length is usually more than 1m.
Cold-drawn (rolled) steel pipe: the length is 1.0-7m for wall thickness 0.5-1.0mm; the length is 1.5-8m for wall thickness greater than 1.0mm.

Standards and grades

Application scenarios of seamless stainless steel pipes

• Oil and Gas Industry: Oil and gas drilling, subsea pipelines, refinery heat exchangers, and high-pressure transmission systems.

• Chemical Equipment: Chemical reactor piping, chemical fluid transport systems, chemical heat exchange equipment, etc.

• Marine Engineering and Shipbuilding: Marine piping, ballast water systems, fire protection systems, subsea pipelines, wellhead systems, seawater cooling, etc.

• Power and Energy Industry: High-pressure boiler tubes, heat exchanger piping, power generation equipment piping, etc.

• Food and Pharmaceutical Industry: Food processing equipment, beverage production equipment, pharmaceutical production piping, etc.

Packaging and shipping

Stainless steel pipes undergo extremely careful handling during packaging and transportation to ensure they are not damaged during transit. The following is a detailed description of the packaging and transportation process:

Packaging:

Protective Coating: Stainless steel pipes are typically coated with a protective oil or film before packaging to prevent surface corrosion and damage.

• Bundling: Pipes of similar size and specifications are carefully bundled together and secured with straps, ropes, or plastic bands to prevent movement during bundling.

• End Caps: Plastic or metal end caps are installed at both ends of the pipes to further protect the pipe ends and threads.

• Padding and Cushioning: Padding materials such as foam, bubble wrap, or corrugated cardboard are used to provide cushioning and prevent damage from impacts during transportation.

• Wooden Crates or Boxes: In some cases, the pipes may be packaged in wooden crates or boxes to provide additional protection against external forces and damage during handling.