76-660mm Straight ERW Welded Pipe Underground Municipal Water Pipe

Product Description

76-660mm Straight ERW Welded Pipe Underground Municipal Water Pipe is dedicated buried municipal water supply straight seam high-frequency welded pipe, specially designed for urban underground tap water trunk lines, community water distribution pipelines, rural centralized water supply and municipal water renovation projects. The outer diameter covers the full range of 76mm to 660mm, produced strictly in accordance with GB/T3091, ASTM A53 Type E, EN10255 low-pressure fluid pipeline standards.

We adopt Q235B, ASTM A53 Grade B low-carbon water delivery special steel as raw materials, with stable uniform metallographic structure and low impurity content, meeting drinking water pipeline safety requirements. Adopting mature ERW/HFW high-frequency solid-state induction welding process, the weld realizes complete metallurgical fusion with the pipe body, equipped with online internal & external flash removal and weld normalization stress relief heat treatment to eliminate welding residual stress. All pipes pass 100% full-length hydrostatic tightness test and full weld eddy current/ultrasonic non-destructive inspection to eliminate underground water leakage hidden dangers.

For underground buried working conditions, we provide professional dual anti-corrosion matching solutions: outer wall 3PE three-layer polyethylene anti-corrosion, inner wall food-grade fusion bonded epoxy lining, effectively isolating soil corrosion, groundwater erosion and pipe inner wall scaling, compliant with NSF61 drinking water contact standards. With complete size series, stable pressure resistance, long anti-corrosion service life and complete third-party inspection certificates, this ERW water pipe is the mainstream supporting pipeline for global underground municipal water supply infrastructure projects.

## 1. Basic Product Specifications - \\Product Name\\: 76-660mm Straight ERW Welded Pipe Underground Municipal Water Pipe - \\Executive Standards\\: GB/T3091-2025, ASTM A53 Type E, EN10255, NSF61 drinking water lining standard - \\Outer Diameter Range\\: 76mm ~ 660mm full municipal buried water pipeline mainstream calibers - \\Conventional Wall Thickness\\: 2.75mm – 18mm, STD / SCH40 standard wall + custom thick wall for high-pressure water supply trunk lines - \\Steel Grades\\: Q235B, ASTM A53 Grade B low-carbon fluid transportation steel - \\Production Process\\: Hot rolled coil slitting → multi-roll precision forming → HFW ERW high-frequency welding → internal & external burr removal → weld normalization heat treatment → sizing & straightening → fixed-length cutting → full hydrostatic & NDT inspection → anti-corrosion coating processing - \\Standard Length\\: 6m / 9m / 12m; custom fixed length within 12m supported - \\Applicable Medium\\: Urban tap water, rural domestic water, reclaimed water, low-corrosion municipal circulating water - \\Design Working Pressure\\: 0.6–1.6MPa, matching conventional underground municipal water network pressure grade - \\Buried Service Environment\\: Ordinary soil, saline soil, coastal high-humidity area, rock backfill road crossing sections - \\Pipe End Options\\: 30°~37.5° standard beveled welding ends, plain flat ends, thick plastic anti-collision protective end caps - \\Anti-Corrosion Custom Matching (Core For Underground Use)\\: 1. External: 3PE three-layer polyethylene anti-corrosion (FBE primer + adhesive + HDPE outer layer) 2. Internal: Food-grade liquid epoxy lining, anti-scaling, non-toxic contact drinking water - \\Core Features\\: Full 76–660mm OD series, underground buried water dedicated design, defect-free stress-relieved ERW weld, 100% hydrostatic tightness test, internal & external dual anti-corrosion, food-safe inner lining, soil extrusion resistance, factory bulk supply for municipal water EPC projects

## 2. Core Product Advantages ### 2.1 Complete 76–660mm Full Caliber Series, One-Stop Municipal Water Centralized Procurement Covers all medium and large diameter specifications commonly used in urban underground water supply trunk and branch networks, fully compatible with GB/ASTM standard water pipe elbows, tees, flanges and reducers. Municipal engineering contractors can complete all diameter purchasing from one factory, simplify multi-supplier logistics coordination, reduce construction preparation cycle and overall supporting costs, suitable for large-scale urban water network reconstruction batch projects.

2.2 Special Low-Carbon Steel For Water Delivery, Safe For Domestic Drinking Water

Q235B / ASTM A53 Grade B steel strictly controls carbon, sulfur and phosphorus impurities, uniform fine grain structure, no harmful precipitation medium dissolution. Cooperated with food-grade internal epoxy lining that meets NSF61 standards, no secondary pollution to tap water, solving the hidden danger of rust and scaling in ordinary black steel pipes, fully compliant with municipal drinking water pipeline health and safety acceptance requirements.

2.3 HFW ERW Weld + Weld Normalization, Anti-Leakage For Long-Term Underground Burial

Flux-free high-frequency concentrated edge heating forms narrow heat-affected zone without coarse grain embrittlement. Independent online normalization heat treatment eliminates concentrated residual stress easily generated by buried pipes under long-term soil extrusion and alternating water pressure. 100% full-length hydrostatic pressure holding test (holding time ≥10s for OD＞219mm) and full weld scanning NDT completely eliminate underground pipeline water leakage risks, avoiding road collapse and water resource waste caused by pipe burst.

2.4 3PE External + Epoxy Internal Dual Anti-Corrosion, Ultra-Long Underground Service Life

Outer 3PE composite anti-corrosion: Three-layer integrated structure, strong resistance to soil electrochemical corrosion, rock scratch and extrusion damage, low water absorption, effectively block underground moisture and corrosive ions.

Internal food-grade epoxy lining: Smooth inner surface reduces water flow friction loss, inhibits mineral scaling and microbial adhesion, easy pipeline pigging cleaning. Combined dual anti-corrosion system extends underground service life to 40–50 years, far exceeding single asphalt coating ordinary pipes, greatly reducing later pipeline maintenance and excavation repair costs.

2.5 Smooth Inner Wall, Reduce Municipal Water Transmission Energy Consumption

Online mechanical full removal of internal welding flash forms flat smooth inner surface, lowering water flow resistance by more than 30% compared with unprocessed rough weld pipes. It reduces pump load of urban water plants, cuts long-term power consumption of water supply system, conforms to energy-saving design requirements of modern municipal infrastructure.

2.6 Strict Municipal Water Special Inspection Standard, Complete Acceptance Documents

All pipes adopt enhanced inspection standards for water supply projects: full root hydrostatic tightness test, full weld non-destructive inspection, 180° cold bending test without crack. We can provide complete MTR material report, weld inspection certificate, hydrostatic test record and anti-corrosion coating thickness/adhesion test report. Support SGS, BV third-party on-site sampling inspection required by municipal bidding projects, full batch raw material traceability system to smoothly pass government engineering acceptance.

## 3. Dimensional Tolerance Standard (GB/T3091 & ASTM A53) | Inspection Item | Standard Tolerance | | ---- | ---- | | Outer Diameter (76mm–168mm) | ±0.8% nominal OD | | Outer Diameter (168mm–660mm) | ±1.0% nominal OD | | Wall Thickness | +12% / −10% nominal thickness; tighter tolerance for high-pressure trunk lines | | Pipe Straightness | ≤1.5mm per meter | | Out-of-Roundness | ≤1.0% of outer diameter | | Cutting Length | +100mm / −0mm |

## 4. Mechanical & Chemical Properties (Water Supply Low Carbon Steel) ### 4.1 Mechanical Properties | Steel Grade | Min. Yield Strength | Tensile Strength | Min. Elongation | Mandatory Factory Test For Municipal Water Pipe | | ---- | ---- | ---- | ---- | ---- | | Q235B | ≥235MPa | 370–500MPa | ≥26% | 100% hydrostatic tightness test, full weld UT/ET NDT, 180° cold bending test | | ASTM A53 Grade B | ≥240MPa | ≥415MPa | ≥20% | Hydrostatic pressure test, reverse bend test, weld full inspection |

4.2 Maximum Allowable Chemical Composition (Mass %)

Note: All pipes pass flattening and cold bending test without weld crack; internal epoxy lining third-party food safety inspection report can be provided separately for drinking water projects.

## 5. Complete Manufacturing & Anti-Corrosion Process For Underground Water Pipe 1. \\Raw Material Inspection\\: Inspect chemical composition and tensile performance of certified hot rolled low carbon steel coils, eliminate raw materials with segregation and high impurity content unfit for water delivery. 2. \\Slitting & Edge Levelling\\: Precision slitting to matched width, grind strip edge oxide scale to guarantee uniform stable welding gap for leak-free water pipe weld. 3. \\Multi-Roll Continuous Precision Forming\\: Gradual rolling molding to ensure uniform roundness and consistent wall thickness of pipe blank, meet municipal pipeline dimensional tolerance limits. 4. \\HFW High-Frequency Induction Welding\\: Closed-loop automatic parameter control, concentrated edge heating to realize full penetration solid-state metallurgical weld without filler metal. 5. \\Internal & External Weld Burr Removal\\: Online mechanical scarving to clear welding flash for smooth inner pipe wall, reduce water flow resistance. 6. \\Weld Normalization Stress Relief Heat Treatment\\: Eliminate welding residual stress, improve weld anti-cracking performance under long-term underground soil extrusion and water pressure alternating load. 7. \\Sizing & Straightening\\: Precision sizing mill calibrate outer diameter to standard tolerance, straightener correct pipe linearity. 8. \\Fixed-Length Cutting\\: Neat burr-free cutting according to municipal project customized length requirements. 9. \\Water Pipe Standard Full Inspection\\: 100% hydrostatic tightness test, full weld ultrasonic non-destructive flaw detection, full dimensional reinspection. 10. \\Dual Anti-Corrosion Construction\\: Outer wall shot blasting → 3PE three-layer anti-corrosion coating; inner wall sand blasting → food-grade epoxy lining curing. 11. \\Finished Anti-Corrosion Inspection\\: Detect coating thickness, adhesion and pinhole leakage to ensure underground long-term anti-corrosion performance. 12. \\Laser Permanent Marking\\: Mark standard, steel grade, OD×WT, batch number, anti-corrosion type on each pipe body. 13. \\Municipal Engineering Export Packaging\\: Thick wear-resistant PE film wrapping to avoid scratch of 3PE and epoxy coating, bundled with high-strength steel strips, thick plastic anti-collision end caps to protect pipe ends during trenching and transportation.

## 6. Main Underground Municipal Water Pipeline Application Scope - Urban Main Water Supply Network: Underground buried trunk pipelines for urban central water plant delivery, cross-road water supply pipelines - Community Distribution Water Pipeline: Residential district buried branch water pipes, commercial complex underground water supply supporting pipelines - Rural Centralized Water Supply Project: Rural village buried domestic water pipeline, mountain reservoir diversion water delivery pipe - Municipal Water Reclamation System: Underground reclaimed water transmission pipeline for road greening irrigation - Global Municipal Infrastructure EPC Projects: Overseas underground buried tap water supply pipeline projects complying with GB, ASTM and EN international standards

## 7. Quality Inspection & Municipal Engineering Certification - Fully compliant with GB/T3091, ASTM A53, EN10255 underground water supply welded pipe standards, internal lining meets NSF61 drinking water safety standard - ISO 9001 quality management system certified full HFW production line, dedicated municipal water pipe anti-corrosion workshop - Dual independent inspection system: base pipe hydrostatic & full weld NDT inspection + finished internal & external anti-corrosion coating performance inspection - Complete set of municipal bidding official MTR test documents, weld inspection certificates and anti-corrosion test reports supplied per shipment - Support SGS, BV third-party on-site sampling inspection required by government municipal bidding projects - Full batch traceability system covering steel coil raw material to finished buried water pipe delivery to construction sites

## 8. Packaging & Municipal Bulk Delivery Arrangement - \\Packaging\\: Anti-corrosion water pipes wrapped with double-layer wear-resistant PE protective film to prevent coating scratch during excavation and transportation, bundled with high-strength steel strips, thick plastic anti-collision caps installed at both pipe ends. - \\Product Marking\\: Laser permanent marking including execution standard, steel grade, outer diameter × wall thickness, batch number and internal/external anti-corrosion type. - \\Trade Terms\\: FOB, CIF, CFR, DAP global sea and land bulk delivery, support inland truck transport to city municipal construction sites - \\Shipping Ports\\: Tianjin, Qingdao, Shanghai, Ningbo, support full container centralized loading for large urban water network reconstruction bulk orders - \\Customization Service\\: Custom fixed length, adjustable wall thickness for high-pressure trunk lines, customized anti-corrosion coating thickness, standard beveled pipe end processing - \\Delivery Cycle\\: Conventional stock water pipe specifications 7–12 working days; customized thick wall + reinforced 3PE + food epoxy lining pipes 12–18 working days

## 9. Why Choose Our Underground Municipal Water ERW Pipe 1. Professional municipal buried water pipe production line, supporting matched internal food epoxy lining + external 3PE dual anti-corrosion dedicated for underground long-term burial 2. Complete 76–660mm outer diameter full series, one-stop bulk supply for urban trunk, branch and rural water supply all buried pipeline specifications 3. Water-dedicated low-carbon steel + safe inner lining, no secondary pollution to tap water, pass drinking water safety acceptance 4. Weld normalization treatment + 100% hydrostatic tightness test, eliminate underground pipe burst and water leakage hidden danger 5. Diversified anti-corrosion thickness customization, adapt to ordinary soil, saline coastal and rock backfill various buried geological environments 6. Factory direct bulk supply without intermediate markup, stable mass delivery capacity and complete bidding documents, long-term cooperative supplier for municipal infrastructure EPC projects

## Contact Us For factory bulk wholesale quotations, detailed GB/ASTM technical data sheets, food-grade lining safety test reports, anti-corrosion coating inspection certificates, municipal project large order discounts and mass delivery schedules of \\76-660mm Straight ERW Welded Pipe Underground Municipal Water Pipe\\, please contact our professional municipal infrastructure sales team. We supply full OD range buried ERW water supply welded pipes and one-stop internal & external dual anti-corrosion customized solutions for global urban underground tap water, rural centralized water supply and municipal water network reconstruction bulk procurement projects.

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