Welcome to ALLLAND Steel Pipe Co., Ltd.
Welcome to ALLLAND Steel Pipe Co., Ltd.
ALLLAND Steel Pipe Supply
Welcome to ALLLAND Steel Pipe Manufacturing.GB/T 3091 Q235 steel pipes are commonly used carbon steel welded pipes manufactured in accordance with the Chinese national standard GB/T 3091, “Welded Steel Pipes for Low-Pressure Fluid Conveyance.” Q235 refers to the steel grade, which has a minimum yield strength of 235 MPa and offers good weldability, formability, and cost-effectiveness.
These steel pipes are primarily produced using ERW (high-frequency resistance welding), SSAW (spiral submerged arc welding), and LSAW (longitudinal submerged arc welding) processes, and are widely used in water conveyance, fire protection systems, building structures, and general industrial low-pressure piping applications.
Alllandsteel is a steel pipe manufacturer based in China with 25 years of experience.
The facility spans 22,000 square meters, represents a RMB 700 million investment, and operates four production lines (JCOE, ERW, SMLS, SSAW) alongside five coating lines.
With an annual production capacity of 250,000 tons, the factory covers specifications ranging from Ø406 to Ø1524 and holds multiple international certifications (API/ASTM/EN/ISO/JIS). Focused on steel pipes, creating value for you!
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GB/T 3091 Q235 is the most commonly used carbon structural steel grade combination in the Chinese national standard “Welded Steel Pipes for Low-Pressure Fluid Conveyance.” Here, “Q235” is the steel grade, indicating that the material has a yield strength of ≥235 MPa.
In the steel pipe industry, GB/T 3091 Q235 typically refers to:
O.D.:
10.3 mm – 660 mm
W.T.:
1.2 mm – 25 mm
Length:
3 m – 12 m, available in fixed or multiple lengths; custom lengths per project requirements.
Manufacturing Process:
ERW / HFW / SSAW / LSAW
Standards:
GB/T 3091
Steel Grades:
Q235 / Q235B
Tube Ends& Surface Treatment:
Square, Chamfered; Black Skin, Pickled, Painted/Oiled for Rust Prevention
Delivery Conditions:
Grade, Specification, Furnace Number, Standard
DN25
DN500
GB/T 3091 Welded Steel Pipes for Low-Pressure Fluid Conveyance primarily specifies:
| Symbol | Meaning |
| Q | Yield Strength |
| 235 | Minimum Yield Strength 235 MPa |
Common Grades:
Q235B is the most commonly used grade for welded steel pipes.
The above dimensions are commonly used specifications for GB/T 3091 Q235 welded steel pipes. Exact OD, wall thickness and length can be customized according to project requirements.
| Property | Requirement |
| Yield Strength | ≥235 MPa |
| Tensile Strength | 375-500 MPa |
| Elongation | ≥22% |
Key Advantages:
1. Good weldability
2. Cost-effective performance
| Element | Content |
| C | ≤0.20% |
| Si | ≤0.35% |
| Mn | ≤1.40% |
| P | ≤0.045% |
| S | ≤0.045% |
For example:
GB/T 3091 is specifically designed for welded steel pipes used in low-pressure fluid conveyance; therefore, it is not suitable for harsh environments such as high-pressure oil and gas transmission.
| Item | GB/T 3091 Q235 | ASTM A53 |
| Standard | China | USA |
| Material | Q235 | Grade A/B |
| Application | Low pressure fluid | General piping |
| Manufacturing | Welded | Welded/Seamless |
* Both of these standards are widely used for carbon steel pipes, but they follow different technical specifications and should not be considered identical.
ALLLAND Steel Pipe specializes in the manufacture of GB/T 3091 Q235 welded steel pipes using advanced ERW (high-frequency resistance welding), SSAW (spiral submerged arc welding), and LSAW (longitudinal submerged arc welding) production lines.
With strict quality control, anti-corrosion coating capabilities, and extensive experience in international exports, ALLLAND provides reliable piping solutions for water supply, construction, and industrial projects worldwide.
Q235 and ASTM A36 are similar carbon structural steels with comparable applications, but they are not completely equivalent. Q235 follows Chinese standards, while ASTM A36 follows American standards. Material substitution should be confirmed according to project requirements and specifications.
GB/T 3091 Q235 pipes are commonly manufactured by:
Q235 is a standard carbon structural steel with a minimum yield strength of about 235 MPa, while Q345 is a higher-strength low-alloy steel with a yield strength of about 345 MPa. Q345 is typically selected for projects requiring higher load-bearing capacity.
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