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GB/T 14291 Q235A/Q235B Welded Steel Tube for Mine Liquid Service with 4–1200 mm Diameter Range

Basic Properties
Place of Origin: China
Brand Name: TORICH
Certification: ISO 9001,ISO 14001,TS 16949
Model Number: GB/T14291
Trading Properties
Minimum Order Quantity: 3 Tons
Price: USD 500-900 Tons
Payment Terms: L/C,D/A,D/P,T/T,Western Union,MoneyGram
Supply Ability: 50000Tons/year
Product Summary
GB/T 14291 Q235 Welded Steel Tubes For Mine Liquid Service Product Overview GB/T 14291 Q235 welded steel tubes are straight-seam ERW carbon steel tubes specifically designed for mine liquid and auxiliary fluid service applications. These tubes are engineered for use in mine pressured-air lines, ...

Product Details

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welded steel pipe

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electric resistance welded steel tube

Material: Carbon Structural Steel / Low-alloy Structural Steel
Standard: GB/T 14291 Welded Steel Tubes For Mine Liquid Service
Steel Grade: Q235A, Q235B; Optional Q295A/Q295B/Q345A/Q345B By Order
Outside Diameter: 4–1200 Mm Commercial Supply Range
Wall Thickness: 0.3–200 Mm Commercial Supply Range
Length: 1–12 M Customized; 4–12 M Common Supply Range
OD Tolerance: D ≤ 48.3 Mm: ±0.50 Mm; 48.3 < D ≤ 273 Mm: ±1%D; D > 273 Mm: ±0.75%D
Wall Thickness Tolerance: ±10%S
Heat Treatment: Normally Supplied As-welded/as-rolled; Heat Treatment Or Stress Relief Only When Specified
Product Description
GB/T 14291 Q235 Welded Steel Tubes For Mine Liquid Service
GB/T 14291 Q235A/Q235B Welded Steel Tube for Mine Liquid Service with 4–1200 mm Diameter Range 0
Product Overview

GB/T 14291 Q235 welded steel tubes are straight-seam ERW carbon steel tubes specifically designed for mine liquid and auxiliary fluid service applications. These tubes are engineered for use in mine pressured-air lines, drainage systems, gas-drainage lines, and slurry transportation. Manufactured primarily from Q235A/Q235B mild steel, with optional higher-strength grades including Q295 and Q345 for projects requiring increased yield strength. GB/T 14291 comprehensively defines dimensions, shape, weight, technical requirements, test methods, inspection rules, packaging, marking, and quality certification for this specialized tube category.

Technical Specifications
Parameter Specification
Material Carbon structural steel / low-alloy structural steel
Standard GB/T 14291 Welded Steel Tubes for Mine Liquid Service
Steel Grade Q235A, Q235B; optional Q295A/Q295B/Q345A/Q345B by order
Outside Diameter 4-1200 mm commercial supply range
Wall Thickness 0.3-200 mm commercial supply range
Length 1-12 m customized; 4-12 m common supply range
OD Tolerance D ≤ 48.3 mm: ±0.50 mm; 48.3 < D ≤ 273 mm: ±1%D; D > 273 mm: ±0.75%D
Wall Thickness Tolerance ±10%S
Straightness Commercially controlled for mine pipeline installation; stricter straightness can be agreed in purchase specification
Surface Condition Black, oiled, varnished, painted, or galvanized by agreement
Heat Treatment Normally supplied as-welded/as-rolled; heat treatment or stress relief only when specified
Key Characteristics
  • Q235A/Q235B pipe mechanical baseline under GB/T 14291: tensile strength not less than 375 MPa, lower yield strength not less than 235 MPa, elongation not less than 15% for D ≤ 168.3 mm and not less than 20% for D > 168.3 mm
  • Precise dimensional control for mine pipe fitting: OD tolerance is ±0.50 mm for D ≤ 48.3 mm, ±1%D for 48.3 < D ≤ 273 mm, and ±0.75%D for D > 273 mm; wall thickness tolerance is ±10%S
  • Comprehensive inspection aligned to mine-service risk: chemical composition checked by furnace, tensile testing by batch, with hydraulic testing, ultrasonic examination, and eddy-current flaw detection as standard inspection items
  • Q235 mild carbon structural steel with density of approximately 7.85 g/cm³, commonly used without heat treatment where moderate strength, weldability, and formability are required
Quality Advantages
  • Superior leakage control: Each pipe undergoes hydraulic-test control and weld-seam inspection according to agreed inspection plans, utilizing GB/T 241 hydrostatic testing, GB/T 18256 ultrasonic testing, or GB/T 7735 eddy-current testing as required
  • Transparent tolerance specifications: We quote against declared GB/T 14291 tolerance bands and accommodate project-specific requirements including fixed length, beveled ends, coating thickness, marking format, and third-party inspection
  • Complete material traceability: Comprehensive material records based on heat analysis, furnace identification, batch tensile testing, and quality certificate requirements, referencing GB/T 700 for carbon structural steels and GB/T 1591 for high-strength low-alloy structural steels
International Standards Compliance
Standard System Applicable Standard Description
GB GB/T 14291 Primary standard for welded steel tubes used in mine liquid service
GB GB/T 700 Material reference for Q235 carbon structural steel
GB GB/T 1591 Material reference for Q295/Q345 low-alloy structural steel
ASTM ASTM A53/A53M Comparable standard for black or hot-dip galvanized welded/seamless steel pipe
EN EN 10217-1 Welded non-alloy steel tubes for pressure purposes with specified room-temperature properties
JIS JIS G 3452 Carbon steel pipe for ordinary piping at comparatively low working pressure
GOST GOST 10705 Electric-welded steel pipes for pipelines, structures, and general-purpose products
Primary Application

Underground mine slurry drainage pipeline systems for transporting water mixed with coal fines or mineral particles from working areas to drainage sumps.

Chemical Composition
Grade Standard C Si Mn P S Other Elements
Q235A GB/T 700 ≤0.22 ≤0.35 ≤1.40 ≤0.045 ≤0.050 Rimmed or killed
Q235B GB/T 700 ≤0.20 ≤0.35 ≤1.40 ≤0.045 ≤0.045 Rimmed or killed
Q295A GB/T 1591-1994 ≤0.16 ≤0.55 0.80-1.50 ≤0.045 ≤0.045 Ti 0.02-0.20; V 0.02-0.15; Nb 0.015-0.060; Cr/Ni/Cu ≤0.30 each
Q295B GB/T 1591-1994 ≤0.16 ≤0.55 0.80-1.50 ≤0.040 ≤0.040 Ti 0.02-0.20; V 0.02-0.15; Nb 0.015-0.060; Cr/Ni/Cu ≤0.30 each
Q345A GB/T 1591-1994 ≤0.20 ≤0.55 1.00-1.60 ≤0.045 ≤0.045 Ti 0.02-0.20; V 0.02-0.15; Nb 0.015-0.060; Cr/Ni/Cu ≤0.30 each
Mechanical Properties
Grade Tensile Strength Rm, MPa min. Lower Yield Strength ReL, MPa min. Elongation A, % min. D ≤ 168.3 mm Elongation A, % min. D > 168.3 mm
Q235A 375 235 15 20
Q235B 375 235 15 20
Q295A 390 295 13 18
Q295B 390 295 13 18
Q345A 470 345 13 18
Product Gallery
GB/T 14291 Q235A/Q235B Welded Steel Tube for Mine Liquid Service with 4–1200 mm Diameter Range 1 GB/T 14291 Q235A/Q235B Welded Steel Tube for Mine Liquid Service with 4–1200 mm Diameter Range 2 GB/T 14291 Q235A/Q235B Welded Steel Tube for Mine Liquid Service with 4–1200 mm Diameter Range 3 GB/T 14291 Q235A/Q235B Welded Steel Tube for Mine Liquid Service with 4–1200 mm Diameter Range 4 GB/T 14291 Q235A/Q235B Welded Steel Tube for Mine Liquid Service with 4–1200 mm Diameter Range 5 GB/T 14291 Q235A/Q235B Welded Steel Tube for Mine Liquid Service with 4–1200 mm Diameter Range 6 GB/T 14291 Q235A/Q235B Welded Steel Tube for Mine Liquid Service with 4–1200 mm Diameter Range 7 GB/T 14291 Q235A/Q235B Welded Steel Tube for Mine Liquid Service with 4–1200 mm Diameter Range 8
Frequently Asked Questions
Q: Are you trading company or manufacturer?
A: We are a manufacturer, but we can also handle trading operations.
Q: How long is your delivery time?
A: Generally speaking, delivery time is 10-15 days if the goods are in stock, or 30-40 days if the goods are not in stock, depending on the order quantity.
Q: Do you provide samples? Is it free or extra?
A: Yes, we offer samples free of charge, but customers need to pay the freight costs.
Q: What is your terms of payment?
A: Payment terms: For orders ≤2000 USD, 100% payment in advance. For orders ≥2000 USD, 30% T/T payment in advance, with balance due before shipment.

If you have any other questions, please feel free to contact us.

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