High Frequency ERW Pipe 76mm-660mm Water Gas Transmission Carbon Pipe

Product Description

HFW Straight Seam Welded Tube 76~660mm Q235 Construction Structural Pipe is a high-frequency straight seam welded structural pipe specially developed for building construction, steel structure engineering, mechanical manufacturing and municipal supporting projects. Adopting premium Q235 carbon structural steel as raw material, the product covers a complete outer diameter range from 76mm to 660mm, with standardized wall thickness specifications, fully compliant with national and international structural pipe standards.

Manufactured by advanced HFW (High Frequency Welded) integrated molding technology, the pipe features uniform wall thickness, high roundness and straightness, smooth inner and outer wall without burrs. The welding seam achieves complete metallurgical fusion with the pipe body, with stable structural strength and excellent bending, twisting and pressure resistance performance. All finished pipes pass strict flattening test, bending test and weld non-destructive inspection, with no welding defects. Optional black anti-rust oil, hot dip galvanized, painting and other surface treatments effectively prevent oxidation and corrosion. With stable mechanical performance and ultra-high cost performance, this Q235 structural welded pipe is widely recognized as the preferred steel material for global construction and structural engineering projects.

1. Basic Product Specifications

Product Name: HFW Straight Seam Welded Tube 76~660mm Q235 Construction Structural Pipe

Executive Standard: GB/T 700, GB/T 3091, EN10219, ASTM A500

Outer Diameter Range: 76mm – 660mm full complete structural sizes

Conventional Wall Thickness: 2.75mm – 20mm, customized thickness available

Steel Grade: Q235B (Mainstream), Q235A

Production Process: HFW high-frequency straight seam welding, online internal & external burr removal, weld stress relief treatment

Standard Length: 6m / 9m / 12m; custom fixed length within 12m supported

Applicable Scenarios: Building structural support, steel frame engineering, mechanical equipment chassis, bridge auxiliary structure, municipal guardrail, pipeline support

Service Characteristics: Static load bearing, structural support, non-pressure structural use

Pipe End Treatment: Plain ends, burr-free cutting, plastic anti-collision end caps

Surface Treatment Options: Black anti-rust oil, red/gray anti-rust paint, hot dip galvanized, spray painting

Core Features: Full 76–660mm size range, Q235 reliable structural steel, HFW high-integrity weld, high dimensional accuracy, strong bearing capacity, low cost, easy processing and welding

2. Core Product Advantages

2.1 Complete 76–660mm Full Size Series

Covers all mainstream medium and large diameter structural pipe specifications, fully matching various structural design standards. One-stop supply of all calibers eliminates the trouble of multi-supplier procurement, greatly simplifies project purchasing procedures and shortens construction preparation cycle, suitable for large-scale batch structural engineering projects.

2.2 Premium Q235 Carbon Steel Stable Structural Performance

Q235 low-carbon structural steel has uniform internal texture, moderate strength, excellent plasticity and toughness, and superior cold bending, welding and cutting performance. It is not easy to deform or crack during processing such as bending, drilling and welding, fully meeting the mechanical load-bearing requirements of building structures, mechanical frames and municipal engineering structures.

2.3 Advanced HFW Welding Technology, Integrated Pipe Body

Adopting fully automatic high-frequency resistance welding technology, no welding filler is required. The weld and base metal realize integrated metallurgical fusion with consistent strength. Online weld stress relief treatment eliminates welding residual stress, avoiding structural deformation and weld cracking in later use. 100% weld flaw detection ensures zero welding defects and stable overall structural performance.

2.4 High Dimensional Accuracy & Excellent Assembly Performance

Precision rolling and sizing process ensures ultra-low tolerance of outer diameter, wall thickness and straightness. The pipe has smooth inner and outer walls without burrs, flat cutting end faces, no deformation. It is highly compatible with on-site assembly, welding and installation, effectively improving construction efficiency and reducing on-site secondary processing costs.

2.5 Diversified Surface Anti-Rust Customization

Multiple surface protection processes are optional according to project environment: anti-rust oil for short-term storage and indoor structures; anti-rust paint for outdoor conventional structural protection; hot dip galvanized treatment for coastal, humid and corrosive environments, effectively extending the service life of structural pipes and reducing later maintenance costs.

2.6 Ultra-High Cost Performance for Structural Engineering

Compared with seamless pipes, HFW welded structural pipes have lower procurement cost while meeting all structural load-bearing standards. With stable batch quality, low defective rate and no frequent maintenance required in later stage, it is the most cost-effective mainstream structural steel pipe for civil construction, municipal engineering and mechanical manufacturing projects.

3. Dimensional Tolerance Standard

4. Mechanical & Chemical Properties (Q235B)

4.1 Mechanical Properties

4.2 Chemical Composition (Max Mass %)

Note: Q235B material has excellent room-temperature impact resistance, suitable for most conventional construction and municipal structural projects; all pipes pass mandatory flattening and bending tests to ensure structural safety.

5. Manufacturing Process

Raw Material Inspection: Adopt qualified Q235 hot rolled steel strips, strictly inspect chemical composition and mechanical properties to ensure compliance with structural steel standards.

Slitting & Edge Finishing: Precision slitting according to pipe specifications, smooth edge treatment to ensure uniform welding gap.

Multi-Roll Continuous Forming: Gradual rolling molding to ensure uniform roundness, consistent wall thickness and smooth pipe surface.

HFW High-Frequency Welding: Automatic closed-loop parameter control to realize full penetration weld with high bonding strength.

Internal & External Burr Removal: Online mechanical scarving to remove welding flash, ensuring flat and smooth inner and outer pipe walls.

Weld Stress Relief Treatment: Eliminate welding residual stress, improve weld toughness and overall structural stability.

Sizing & Straightening: Precision sizing and straightening to control dimensional tolerance within standard range.

Fixed-Length Cutting: Neat burr-free fixed-length cutting according to customer requirements.

Full Performance Inspection: Weld non-destructive testing, flattening test, bending test and full dimensional re-inspection.

Surface Treatment & Marking: Anti-rust oil spraying, painting or galvanizing treatment; laser permanent marking of specifications, grade and batch number.

Export Standard Packaging: Waterproof PE wrapping, steel strip bundling, plastic end caps protection for long-distance transportation.

6. Main Application Scope

Building Construction: Steel structure frame, building support pipe, foundation structural pipe, workshop steel frame engineering

Municipal Engineering: Road guardrail, municipal support frame, landscape structure, bridge auxiliary supporting pipe

Mechanical Manufacturing: Mechanical equipment chassis, support bracket, conveyor frame, engineering machinery structural parts

Pipeline Engineering: Pipe support, cable protection pipe, non-pressure structural auxiliary pipeline

Warehouse & Logistics: Steel structure warehouse support, shelf base structural pipe, factory building auxiliary steel structure

Global Structural EPC Projects: Overseas civil construction, municipal and mechanical structural engineering supporting pipes

7. Quality Inspection & Certification

Compliant with GB/T 3091, GB/T 700, EN10219 and other international structural pipe standards

ISO 9001 quality management system certified production

100% weld non-destructive inspection + flattening & bending mechanical test

Complete Mill Test Report (MTR) and factory qualification certificates provided

Support SGS, BV third-party sampling inspection and project acceptance

Full batch traceability from raw materials to finished product delivery

8. Packaging & Delivery

Packaging: Black pipes coated with anti-rust oil, wrapped with waterproof PE film, bundled with high-strength steel strips; galvanized/painted pipes with reinforced wear-resistant packaging, plastic end caps for protection.

Product Marking: Laser permanent marking including size, Q235 grade, standard, batch number and production date.

Trade Terms: FOB, CIF, CFR, DAP global sea and land delivery

Shipping Ports: Tianjin, Qingdao, Shanghai, Ningbo

Customization Service: Custom fixed length, spray painting, hot dip galvanized, special end processing

Delivery Cycle: Conventional stock sizes 3–7 working days; customized processed pipes 7–15 working days

9. Why Choose Our Q235 HFW Structural Pipe

Full Size Coverage: Complete 76–660mm caliber series, one-stop solution for all structural pipe specifications

Reliable Q235 Structural Performance: Stable strength and toughness, suitable for all kinds of structural load-bearing and processing requirements

High-Quality HFW Weld: Integrated weld structure without defects, ensuring long-term structural safety and stability

High Dimensional Precision: Strict tolerance control, convenient for on-site assembly and construction

Flexible Customization: Various surface anti-rust treatments and fixed-length processing to meet diverse project needs

Factory Direct Supply: No intermediate markup, competitive bulk price and stable delivery capacity

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