GB/T 14291 Spiral Submerged Arc Welded Steel Pipe (SSAW)
Basic Overview
GB/T 14291 is the Chinese national standard for "Welded steel pipes for mine fluid service" (full title: "矿粉矿浆输送用电焊钢管" / "矿用流体输送焊接钢管") . This standard specifically covers welded steel pipes used in mining applications for transporting fluids such as water, slurry, air, and gas .
The standard applies to spiral submerged arc welded (SSAW) pipes, also known as helical submerged arc welded (HSAW) pipes, which are manufactured by spiral forming and double-sided submerged arc welding .
Key Specifications
| Attribute | Description |
|---|---|
| Standard Number | GB/T 14291 (current version: GB/T 14291-2016; previous: GB/T 14291-1992/1993) |
| Standard Title | "Welded steel pipes for mine fluid service" / "矿粉矿浆输送用电焊钢管" |
| Current Status | GB/T 14291-2016 is active (effective July 1, 2017) |
| Previous Version | GB/T 14291-1993 (withdrawn/obsolete) |
| Primary Application | Mine fluid transportation – dewatering, ventilation, gas drainage, slurry transport |
| Pipe Types | Spiral submerged arc welded (SSAW/HSAW), straight seam welded (ERW), and seamless |
| Materials/Grades | Q195, Q215, Q235, Q295, Q345 (carbon and low-alloy steels) |
| Key Feature | Specifically designed for abrasive mining environments (ore pulp, slurry, mineral powder) |
Chemical & Mechanical Properties
| Grade | Tensile Strength (min) | Yield Strength (min) | Elongation % |
|---|---|---|---|
| Q235A / Q235B | 375 MPa | 235 MPa | 15-20% |
| Q295A / Q295B | 390 MPa | 295 MPa | 13-18% |
| Q345A / Q345B | 470 MPa | 345 MPa | 13-18% |
Source:
Manufacturing Process
Spiral submerged arc welded (SSAW) pipes under GB/T 14291 are produced using the following process :
Raw Material: Hot-rolled steel coil or strip (grades Q195, Q215, Q235, Q295, Q345)
Forming: The steel strip is continuously spiral-formed at room temperature
Welding: Double-sided automatic submerged arc welding (inside and outside) creates the spiral seam
Testing: 100% ultrasonic or X-ray inspection of weld seam; hydrostatic testing
Finishing: End preparation and coating as required
Applications
GB/T 14291 spiral welded pipes are specifically designed for mining environments :
| Application | Description |
|---|---|
| Mine Dewatering | Pumping groundwater out of mine workings |
| Ventilation Systems | Air supply and exhaust in underground mines |
| Gas Drainage | Methane/coal seam gas extraction (mine gas drainage) |
| Slurry Transport | Ore pulp, mineral powder, and tailings transport |
| Compressed Air Lines | Powering pneumatic mining equipment |
| Fire Protection | Mine fire suppression systems |
Key Features & Advantages
| Feature | Description |
|---|---|
| Abrasion Resistance | Designed for abrasive mining environments (ore pulp, slurry) |
| Corrosion Resistance | Suitable for mine water and corrosive fluids |
| Large Diameter Capability | SSAW process enables large-diameter pipes up to 4000mm |
| Cost-Effective | More economical than seamless for large diameters |
| High Strength Options | Q345 grade provides 470 MPa tensile strength |
Dimensional Tolerances
| Parameter | Tolerance |
|---|---|
| Outside Diameter (D ≤ 48.3mm) | ±0.50 mm |
| Outside Diameter (48.3mm < D ≤ 273mm) | ±1% D |
| Outside Diameter (D > 273mm) | ±0.75% D |
| Wall Thickness | ±10% S |
Source:
Testing Requirements
| Test Type | Requirement | Frequency |
|---|---|---|
| Chemical Analysis | Per GB/T 20066, GB/T 223, GB/T 4336 | Each heat |
| Tensile Test | Per GB/T 228 | Each batch |
| Hydrostatic Test | Per GB/T 241 | Each pipe |
| Ultrasonic Examination | Per GB/T 18256 | Each pipe |
| Eddy Current Flaw Detection | Per GB/T 7735 | Each pipe |
| Bend Test | Per GB/T 244 | Two per batch |
| Flattening Test | Per GB/T 246 | Four per roll |
Related Standards
| Standard | Application |
|---|---|
| GB/T 3091 | Low-pressure fluid transmission (water, gas, steam) |
| SY/T 5037 | Spiral submerged arc welded pipe for low-pressure fluid pipelines |
| GB/T 9711.1 / 9711.2 | Petroleum and natural gas pipeline transportation |
| API 5L | International line pipe standard |
| ASTM A53 | General piping standard (US) |
Important Notes
1. Standard Versions
GB/T 14291-2016 is the current version (effective July 1, 2017)
Older versions: GB/T 14291-1993, GB/T 14291-1992 are obsolete
2. Primary Application Focus
GB/T 14291 is specifically for mining applications (mine dewatering, ventilation, gas drainage, slurry transport)
For general low-pressure fluid transmission (water, gas, steam), GB/T 3091 is more appropriate
3. SSAW vs. ERW
The standard covers both spiral submerged arc welded (SSAW) and straight seam welded (ERW) pipes
Spiral welding is preferred for larger diameters (typically > 219mm)
4. Material Grades
Common grades include Q235B (most common), Q295, and Q345 for higher strength applications
For more demanding mining environments, Q345 is recommended for its higher tensile strength (470 MPa)
Summary
GB/T 14291 spiral submerged arc welded steel pipe is specifically designed for mining fluid transportation applications including dewatering, ventilation, gas drainage, and slurry transport .
Key features:
Manufactured by spiral submerged arc welding (SSAW) process
Available in grades Q235B, Q295, Q345
Suitable for abrasive mining environments (ore pulp, slurry, mineral powder)
Produced in large diameters (up to 4000mm)
Requires 100% non-destructive testing of weld seams
Active standard: GB/T 14291-2016 (effective July 2017)
When ordering, specify: GB/T 14291, Grade (Q235B/Q295/Q345), SSAW (spiral submerged arc welded), Size (OD x WT), Length, End Finish, and Coating Requirements.
