WELDED STAINLESS STEEL TUBE classification

Welded stainless steel tubes, as an indispensable material in modern industry, are widely used in various fields such as petroleum, chemical industry, construction, and medical. With diverse types and varied characteristics, they meet the diversified needs of different industries for pipeline materials. This article will delve into the classification and characteristics of welded stainless steel tubes, aiming to provide readers with a comprehensive and clear understanding.

Classified welded stainless steel tube by shape

In terms of end shape classification, welded stainless steel tubes are divided into round welded tubes and profile (square, flat, etc.) welded tubes.

Classified by welding method

Firstly, there is the arc welded stainless steel tube, which is widely used in fields such as petroleum drilling and mechanical manufacturing due to its stable welding process and reliable quality.
Secondly, there is the high-frequency or low-frequency resistance welded tube, which offers high efficiency and energy savings in the welding process, making it suitable for mass production.
Next, there is the gas welded stainless steel tube, which utilizes a gas flame as a heat source, offering flexibility in welding and commonly used in on-site operations and small-scale production.
Furthermore, the furnace welded tube is also an important classification, known for its high welding quality and fast production efficiency, widely used in areas such as water and gas pipelines. Large-diameter straight-seam welded tubes are favored for their strong pressure-bearing capacity and are commonly used in high-pressure oil and gas transmission systems.
Lastly, the spiral welded stainless steel tube, with its excellent mechanical properties and welding efficiency, plays an irreplaceable role in large-scale engineering projects such as oil and gas transportation, pipe piles, and bridge piers.

Classified by weld seam

Straight Seam Welded Tube:
The simple production process, high production efficiency, and low-cost lead to rapid development.
Spiral Welded Tube:
- Generally higher strength compared to straight seam welded tubes.
- Can produce larger diameter tubes using narrower billets, and tubes of different diameters using billets of the same width.
- However, compared to straight seam tubes of the same length, the length of the weld seam increases by 30-100%, and the production speed is lower.
- Therefore, straight seam welding is mostly used for smaller-diameter tubes, while spiral welding is preferred for larger-diameter tubes.
- Spiral seam welded steel tubes are divided into two types: automatic submerged arc welded steel tubes and high-frequency welded steel tubes.
  - a) Spiral seam automatic submerged arc welded steel tubes are classified into Class A and Class B tubes based on the pressure of the conveyed medium. Class A tubes are generally made of ordinary carbon steel such as Q235, Q235F, and ordinary low-alloy structural steel such as 16Mn. Class B tubes are made of steel such as Q235, Q235F, Q195, etc., and are used for low-pressure fluid transportation.

- - b) Spiral seam high-frequency welded steel tubes: There is no unified product standard yet. Generally, they are made of ordinary carbon steel such as Q235 and Q235F.

Classified by other ways

GB/T3091-1993 (Galvanized Welded Stainless Steel Tubes for Low-Pressure Fluid Transport): Mainly used for conveying water, gas, air, oil, heating hot water, or steam with low pressure and other general fluids. The representative material is Q235A steel.
GB/T3092-1993 (Galvanized Welded Stainless Steel Tubes for Low-Pressure Fluid Transport): Primarily used for conveying water, gas, air, oil, heating hot water, or steam with low pressure and other general fluids. The representative material is Q235A steel.
GB/T14291-1992 (Welded Stainless Steel Tubes for Mining Fluid Transport): Used for mine pressure wind, drainage, and gas drainage with straight seam welded steel pipes. Representative materials are Q235A and Q235B steel.
GB/T14980-1994 (Large Diameter Welded Stainless Steel Tubes for Low-Pressure Fluid Transport): Mainly used for conveying water, sewage, gas, air, heating steam, and other low-pressure fluids. The representative material is Q235A steel.
GB/T12770-1991 (Welded Stainless Steel Tubes for Mechanical Structures): Mainly used for machinery, automobiles, bicycles, furniture, hotel and restaurant decoration, and other mechanical components and structural parts. Representative materials include 0Cr13, 1Cr17, 00Cr19Ni11, 1Cr18Ni9, and 0Cr18Ni11Nb.
GB/T12771-1991 (Welded Stainless Steel Tubes for Fluid Transport): Mainly used for conveying low-pressure corrosive media. Representative materials include 0Cr13, 0Cr19Ni9, 00Cr19Ni11, 00Cr17, 0Cr18Ni11Nb, and 0017Cr17Ni14Mo2.

The classification of welded stainless steel tubes is diverse, with each type having its unique application scenarios and advantages. When selecting stainless steel welded tubes, factors such as material, process, performance, and environmental conditions should be fully considered to ensure they meet engineering requirements. Moreover, with the advancement of technology and process improvement, the types and applications of stainless steel welded tubes will continue to expand, injecting more vitality into industrial development.

Huaxiao Metal understands the importance of welded stainless steel tubes and is committed to providing customers with stainless steel welded tubes of different sizes and grades to meet various complex engineering needs. Whether you need high-strength, highly corrosion-resistant pipelines or precision-engineered, aesthetically pleasing decorative tubes, we can provide you with high-quality products and professional services. Choosing Huaxiao Metal means choosing quality and reliability.