Introduction

Steel plate rolled pipes are made by rolling and welding steel plates. These pipes are divided into two main types: straight seam rolled welded steel pipes and spiral seam rolled welded steel pipes.

Straight Seam Rolled Welded Steel Pipe

Straight seam rolled welded steel pipes are typically manufactured on-site or commissioned to processing plants, as most professional steel pipe factories do not produce them. The steel plate materials used include Q235A, No. 10, No. 20, 16Mn, and 20g. The specification range for these pipes is nominal diameters from 200 mm to 3000 mm, with the largest being 4000 mm. Wall thickness generally ranges from 4 mm to 16 mm.

The length of a single pipe with a nominal diameter of 200-900 mm is 6.4 meters, while for diameters between 1000 and 3000 mm, the length is 4.8 meters. The applicable working temperature for Q235A is -15 to 300°C, and for No. 10, No. 20, 16Mn, and 20g, it is -40 to 450°C. These pipes are suitable for low-pressure applications.

Spiral Welded Steel Pipe

Spiral welded steel pipes are produced by professional steel pipe manufacturers. The materials used are Q235A and 16Mn. The specifications range from a nominal diameter of 200 mm to 700 mm, with wall thickness between 7 mm to 10 mm. The length of a single pipe is generally between 8 and 18 meters. The applicable working temperature for Q235A is -15 to 300°C, while for 16Mn, it is -40 to 450°C. The operating pressure for Q235A is 2.5 MPa and for 16Mn, it is 4 MPa.

Spiral welded steel pipes are commonly used for transporting media at low temperatures, low pressures, and with low corrosion, such as underground circulating water, low-pressure steam, coal gas, and oil. The longer length of a single spiral welded steel pipe makes it particularly suitable for long-distance transmission pipelines.

Copper Tubes and Brass Tubes

Copper tubes are manufactured from high-purity copper materials, such as T2, T3, T4, and TUP, with copper content exceeding 99.7%. Brass tubes are made from alloys of zinc and copper, such as H62 and H68, with copper content between 60.5% to 63.5%.

The manufacturing methods for copper tubes include drawing and extrusion. The outer diameter of drawn copper tubes ranges from φ3 to φ200 mm, while extruded copper tubes have an outer diameter range of φ32 to φ280 mm. The wall thickness typically ranges from 1.5 mm to 5 mm. The specification range for copper plate-coiled copper tubes is from φ155 to φ505 mm in outer diameter, with options for both single and coiled supply methods.

The applicable working temperature for copper tubes is generally below 250°C, and they are often used in oil pipelines, insulation accompanying pipes, and air separation oxygen pipelines.