Hebei Huayang Steel Pipe Co., Ltd is one of the most experienced manufacturers and suppliers of erw steel pipes for buried pipelines dn300 in China. Welcome to buy discount erw steel pipes for buried pipelines dn300 made in China here from our factory. Quality products and low price are available.
Product introduction
Product Description
ERW Steel Pipes For Water Transmission Pipelines DN400 are high-efficiency electric resistance welded steel pipes specially designed for municipal water supply, industrial water delivery, irrigation water conservancy, and underground water transmission projects. Manufactured strictly in accordance with GB/T 3091 (Welded steel pipes for low pressure liquid delivery), GB/T 9711 (Oil and gas industry steel pipes for pipeline transportation systems) and ISO 3183 standards, they adopt high-quality Q235B/Q355B carbon steel strips and advanced High-Frequency Induction Welding (ERW) technology. With a nominal diameter (DN) of 400mm (corresponding to outer diameter 426mm), the pipes feature excellent water tightness, high pressure-bearing capacity, good corrosion resistance, and smooth inner walls. They are perfectly suitable for long-term buried or above-ground water transmission, widely used in urban water supply trunk lines, industrial circulating water pipelines, farmland irrigation systems, and water conservancy project connecting pipelines, providing safe, efficient, and cost-effective pipeline solutions for global water transmission infrastructure.
Basic Product Specifications
Product Name: ERW Steel Pipes For Water Transmission Pipelines DN400
Executive Standard: GB/T 3091-2015, GB/T 9711.1, ISO 3183, compatible with AWWA C200 (for municipal water supply projects)
Manufacturing Process: ERW (Electric Resistance Welding), high-frequency induction welding, steel strip cold forming, weld annealing, water pressure testing, finishing
Steel Grade: Q235B, Q355B (core grades for water transmission), Q295B optional for high-pressure water projects
Nominal Diameter (DN): 400mm (fixed, mainstream specification for medium-sized water transmission pipelines)
Outer Diameter (OD): 426mm (matching DN400, consistent with standard pipe size)
Wall Thickness (WT): 6mm – 12mm, custom thick-wall up to 16mm for high-pressure water transmission
Standard Length: 6m, 12m (standard), custom fixed lengths available (matching water project construction needs)
Delivery Condition: Annealed (standard, to eliminate weld residual stress); hot-dipped galvanized optional for enhanced corrosion resistance
Surface Finish: Black bare steel with anti-rust oil; hot-dipped galvanized (Zn coating ≥80μm), 3PE/FBE anti-corrosion coating (for buried harsh environments)
Pipe End: Plain ends (standard for flange connection); 30°/45° beveled ends for field welding; threaded ends optional for small-caliber matching
Application: Municipal water supply trunk lines, industrial circulating water pipelines, farmland irrigation pipelines, water conservancy project connecting pipes, underground water transmission pipelines, residential district water supply main pipes, sewage treatment plant water delivery pipes
Grade & Process Explanation
Steel Grade Performance for Water Transmission: Q235B and Q355B are core carbon steel grades for water transmission pipes, with excellent weldability, pressure-bearing capacity and cost-effectiveness. Q235B (minimum yield strength ≥235MPa) is suitable for conventional low-to-medium pressure water supply projects (working pressure ≤1.6MPa). Q355B (minimum yield strength ≥355MPa) offers higher strength and impact toughness, ideal for high-pressure water transmission, long-distance water pipelines and cold-region water projects. Both grades adopt low-sulfur (≤0.045%) and low-phosphorus (≤0.045%) composition, effectively resisting corrosion from tap water, groundwater and irrigation water, avoiding scaling and rust accumulation in the pipe.
ERW Process Advantages for Water Pipes: Adopting high-frequency induction welding technology, the steel strip is cold-formed into a cylindrical shape and welded continuously, with high production efficiency and uniform weld quality. The post-weld annealing treatment eliminates residual stress, ensures the weld mechanical properties are consistent with the base metal, and enhances the pipe's water tightness-critical for water transmission to prevent leakage. The ERW process ensures smooth inner walls, reducing water flow resistance, improving water transmission efficiency, and avoiding energy loss during long-distance delivery.
Water-Oriented Special Design: Optimized for water transmission scenarios, focusing on water tightness, corrosion resistance and flow efficiency. The DN400 (OD426mm) specification matches the mainstream medium-sized water pipeline demand, balancing flow capacity and construction cost. Strict dimensional tolerance control ensures reliable connection with flanges, valves and water pipe fittings. Optional anti-corrosion coatings (hot-dipped galvanized, 3PE) adapt to buried, wet and chemical-containing water environments, extending the service life of the pipeline to over 25 years.
Dimensional Tolerance (GB/T 3091 & GB/T 9711 Standard)
|
Item |
Tolerance (DN400, OD426mm) |
|
Outer Diameter (OD) |
±1.0% of nominal OD (426mm), max ±4.26mm |
|
Wall Thickness (WT) |
+12% / −10% of nominal WT, min allowable WT ≥ 85% of nominal WT |
|
Out-of-Roundness |
≤1.0% of outer diameter (≤4.26mm for OD426mm) |
|
Straightness |
≤2.0 mm per meter, ≤24 mm for 12 m length |
|
Length |
+200 mm / −0 mm, custom ±50 mm available |
Mechanical Properties (GB/T 3091 Reference)
|
Property |
Q235B |
Q355B |
|
Minimum Yield Strength |
≥235 MPa |
≥355 MPa |
|
Tensile Strength |
375–500 MPa |
470–630 MPa |
|
Elongation |
≥26% |
≥21% |
|
Hydrostatic Test |
100% tested at 1.5× working pressure (minimum 2.4MPa), holding time ≥30 minutes, no leakage or permanent deformation |
|
|
Weld Tensile Test |
No weld separation, tensile strength ≥90% of base metal |
|
|
Bend Test |
No cracks or weld defects after bending, complying with GB/T 3091 requirements |
|
Note: For cold-region water transmission projects, the Charpy impact test (≥27J at 0℃) is optional to enhance low-temperature toughness and prevent pipe cracking in cold environments.
Chemical Composition (Max. %, GB/T 3091)
|
Element |
C |
Mn |
P |
S |
Si |
|
Q235B |
≤0.20 |
≤1.40 |
≤0.045 |
≤0.045 |
≤0.35 |
|
Q355B |
≤0.24 |
≤1.60 |
≤0.040 |
≤0.040 |
≤0.55 |
Residual elements: Cu ≤0.30%, Ni ≤0.30%, Cr ≤0.30% (max. %). Strict control of impurities and non-metallic inclusions prevents rust and scaling inside the pipe, ensuring the cleanliness of transmitted water and avoiding secondary pollution. The steel strip is subjected to surface derusting and cleaning before welding, further improving weld quality and corrosion resistance, adapting to long-term water immersion environments.
Manufacturing Process (ERW for Water Transmission Pipes)
Raw Material Inspection: Select high-quality Q235B/Q355B steel strips that comply with GB/T 3091 standard, and strictly inspect the chemical composition and mechanical properties before production. The steel strips undergo derusting, oil removal and cleaning to eliminate surface impurities, ensuring weld quality and avoiding water contamination.
Steel Strip Forming: The steel strips are continuously cold-formed into a cylindrical shape through precision forming rolls, with strict dimensional control to ensure uniform wall thickness and high roundness (out-of-roundness ≤4.26mm for OD426mm), meeting the requirements of water pipe connection and flow efficiency.
High-Frequency ERW Welding: Adopt high-frequency induction welding technology to achieve continuous welding of the steel strip joint. The weld seam is heated and melted uniformly, forming a dense weld with no pores or cracks. Post-weld annealing treatment (600-650℃) eliminates residual stress, ensuring the weld mechanical properties are consistent with the base metal and enhancing water tightness.
Weld Inspection: 100% online ultrasonic testing (UT) of weld seams to detect welding defects such as cracks, incomplete fusion and porosity; visual inspection of weld surface to ensure smoothness and no burrs, avoiding affecting water flow.
Hydrostatic Test: 100% pressure test is carried out at ≥1.5 times the working pressure, with a holding time of 30-60 minutes according to GB/T 3091 standard, ensuring no leakage or permanent deformation-critical for water transmission pipeline safety.
Anti-Corrosion Treatment (Optional): For buried or wet environments, hot-dipped galvanizing or 3PE/FBE anti-corrosion coating is applied. The galvanized layer (≥80μm) effectively resists rust and corrosion, while the 3PE coating isolates soil and water corrosion, extending the pipeline service life.
Finishing: Cut the pipes to standard lengths, process pipe ends (plain or beveled), apply anti-rust oil to the surface, and carry out clear marking to complete the production process.
Product Advantages
Strict Standard Compliance: Fully manufactured in accordance with GB/T 3091, GB/T 9711 and ISO 3183 standards, meeting municipal, industrial and water conservancy project acceptance requirements, suitable for global water transmission projects.
DN400 Standard Water Pipe Specification: Matches the mainstream medium-sized water transmission pipeline demand, balancing flow capacity (suitable for 1000-5000m³/h water delivery) and construction cost, widely used in urban and industrial water supply projects.
Excellent Water Tightness: ERW high-frequency welding + post-weld annealing, dense weld seams, 100% hydrostatic test, no leakage, ensuring safe water transmission and avoiding water waste.
Good Corrosion Resistance: Low-sulfur low-phosphorus steel composition + optional hot-dipped galvanized/3PE coating, adapting to underground, wet and chemical-containing water environments, extending service life to over 25 years.
Smooth Inner Wall & High Flow Efficiency: ERW process ensures smooth inner walls, reducing water flow resistance and energy loss, improving long-distance water transmission efficiency.
Stable ERW Weld Quality: High-frequency induction welding, uniform weld formation, low defect rate, weld mechanical properties consistent with the base metal, adapting to long-term water pressure and buried load.
Cost-Effective & High Efficiency: ERW process has high production efficiency, low manufacturing cost, and the pipes are lightweight and easy to transport and install, reducing project construction costs and cycle time.
Customizable for Water Scenarios: Accept custom wall thickness (up to 16mm), anti-corrosion coating type, and pipe length, adapting to different water transmission conditions (high-pressure, cold region, buried).
Main Applications
Urban municipal water supply trunk lines and branch pipelines (DN400 mainstream specification)
Industrial circulating water pipelines, factory water supply and drainage pipes
Farmland irrigation and water conservancy project pipelines
Underground water transmission and storage tank connecting pipelines
Residential district and commercial area water supply main pipes
Sewage treatment plant water inlet and outlet pipelines (anti-corrosion type)
Cold-region water transmission projects (with low-temperature impact resistance)
Water diversion and water replenishment projects for rivers and lakes
Quality Inspection & Certification
Dimensional Inspection: Full inspection of nominal diameter (DN400), outer diameter (426mm), wall thickness, length, straightness and out-of-roundness to meet GB/T 3091 standard, ensuring compatibility with water pipe components.
Mechanical Property Testing: Tensile test, bend test, weld tensile test, and hydrostatic test to verify product mechanical performance and water tightness, in line with GB/T 3091 technical requirements.
Non-Destructive Testing (NDT): 100% Ultrasonic Testing (UT) for weld seams; Radiographic Testing (RT) optional for high-safety water projects; visual inspection of weld surface and pipe body.
Chemical Analysis: Heat analysis to confirm chemical composition meets GB/T 3091 Q235B/Q355B grade requirements, strict control of harmful elements and non-metallic inclusions, ensuring water quality safety.
Certification: Mill Test Report (MTR) provided for each order, with full heat number traceability; third-party inspection (SGS, BV, CCS) available on request to meet global water transmission project acceptance standards.
Packaging & Delivery
Packaging: DN400 (OD426mm) pipes are bundled with heavy-duty steel strips (6-10 strips per bundle), wrapped with waterproof and dust-proof woven cloth to prevent rust and damage during transportation and on-site storage; high-strength plastic end caps are installed to protect pipe ends and internal surfaces, avoiding dust and moisture contamination (critical for water pipe cleanliness).
Marking: Each pipe is clearly marked with GB/T 3091, ERW, DN400 (OD426mm), steel grade, size (OD×WT), heat number, batch number, length, manufacturing date, and "Water Transmission Pipe" identification, facilitating on-site identification and management, complying with the marking requirements of GB/T 3091.
Trade Terms: FOB, CIF, CFR, DAP, DDU all available, supporting various international trade cooperation methods for global water transmission projects.
Shipping Ports: Major Chinese coastal ports (Tianjin, Qingdao, Shanghai, Ningbo), with professional loading equipment for DN400 large-diameter pipes, ensuring efficient and convenient global transportation, supporting timely delivery for water project schedules.
Customization: Accept customized wall thickness (6mm-16mm), anti-corrosion coating (hot-dipped galvanized/3PE/FBE), lengths (matching water project construction design), and pipe ends (plain/beveled/flanged) to meet specific water transmission pipeline project requirements.
Contact Us
For quotation, stock availability, delivery lead time, and customized solutions of ERW Steel Pipes For Water Transmission Pipelines DN400, please contact our sales team. We have rich experience in supporting municipal, industrial and water conservancy projects, providing standard-compliant DN400 ERW water pipes, and professional technical support for on-site installation, pressure testing, and anti-corrosion treatment, ensuring the safe, efficient and stable operation of your water transmission systems.
About us
Hebei Huayang Steel Pipe Co., Ltd. was founded in 2005, with a registered capital of 500 million yuan. The company covers an area of more than 1,000 mu, with annual sales of 10 billion yuan, more than 600 employees and an annual productivity of 2.75 million tons. The company has 17 new automatic steel pipe production lines and 14 high-frequency production lines, with a diameter of 73-660 mm; Three double-sided submerged arc welded steel pipe production lines with diameters of 406.4-1422.4mm;; 24 hot tube expanding production lines, with a diameter of 230-820mm; Two anticorrosion steel pipe production lines with a diameter of 73-1626 mm; 2 automatic painting production lines. With 3 branches and 5 offices, the products are sold to various cities and exported to more than 80 countries such as Southeast Asia, Middle East, Europe and America.
Packaging, transportation and delivery
Packaging, transportation and delivery
At Hebei Huayang Steel Pipe Co., Ltd., we apply standardized and reliable packaging solutions for all our steel pipe products. Our pipes can be securely packed by hexagonal bundling or circular bundling according to product diameter, wall thickness and customer requirements. Each pipe end is protected with high‑strength plastic pipe caps to avoid collision damage, dust and moisture during transportation and storage. The whole bundle is firmly wrapped with durable woven bags to enhance stability and prevent scratches or deformation.
We support a complete range of transportation methods to satisfy global customers, including road transportation, railway transportation, sea freight and container shipping. Based on our strategic location in Cangzhou, Hebei Province, we enjoy convenient access to major ports such as Tianjin Port, which greatly improves logistics efficiency and reduces transportation costs.
For standard specifications and normal order quantities, the general delivery time is about 30 days after order confirmation and deposit receipt. For large‑scale orders, special sizes or customized processing requirements, our production and sales team will formulate a detailed production plan and provide an accurate delivery schedule accordingly to ensure on‑time supply and stable performance for projects and clients worldwide.
Strict quality control
1. During and after the production, experienced quality inspectors randomly check the products to ensure that each steel pipe is qualified for production and application.
2. A nationally recognized laboratory with CNAS certification and certification by French Classification Society.
3. Have CNOOC access certificate, KOC oil company access network, ADNOC Abu Dhabi oil company access network, Petrobras access network, etc.
4. Accept the inspection by the third party designated/paid by the buyer, such as SGS and BV.
Certifications
API 2B
API 5L
GOST
ISO 9001
EN 10219
EN 10210
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