Description
Factory-Direct ERW Pipe Mill — We produce GR.B ERW welded steel pipe and apply 3PE anti-corrosion coating in our own facility, eliminating third-party sourcing gaps from raw steel to finished coated pipe.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | API ERW Welded Steel Pipe with 3PE Anti-Corrosion Coating |
| Product Type | ERW Welded Steel Pipe |
| Steel Grade | GR.B |
| Standard | API, ASTM |
| Section Shape | Round |
| Wall Thickness | 2–36 mm |
| Length | 5.8–12 m (6 m / 6.4 m / 12 m available) |
| Technique | ERW (Electric Resistance Welded) |
| Surface Treatment | 3PE Anti-Corrosion Coating |
| Tolerance | ±1% |
| Application | Oil and gas transport, fluid pipeline, sewage transport, chemical fertilizer pipeline, boiler pipe, drill pipe, hydraulic pipe, structure pipe |
| Certifications | API, ASTM, CE, ISO 9001 |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Oil & Gas | Onshore and offshore hydrocarbon transport pipelines, gathering lines, flow lines |
| Municipal Infrastructure | Sewage conveyance mains, stormwater drainage, reclaimed water distribution |
| Chemical & Fertilizer | Process fluid lines, fertilizer plant piping networks, boiler feed systems |
| Industrial Plumbing | Hydraulic conveyance systems, cooling water circuits, plant utility piping |
Where 3PE Coating Adhesion Decides Whether a Pipeline Survives Burial
A pipe that passes mill inspection but fails adhesion testing at the trench site costs more than the pipe itself.
Overseas buyers sourcing coated pipe from fragmented suppliers face a recurring problem: the steel arrives, the coating looks intact, but peeling starts within months of burial. The root cause is rarely the polyethylene itself — it is the bond between the epoxy primer and the steel surface, and whether the applicator controlled surface preparation, heating temperature, and curing time consistently across every meter. When fabrication and coating happen at separate facilities, accountability splits between two quality systems, and traceability breaks at the handoff point. An API ERW welded steel pipe 3PE anti-corrosion supplier that controls both the pipe mill and the coating line eliminates that gap entirely [NEED_CITE: 3PE coating adhesion testing per DIN 30670].
How GR.B ERW Pipe Matches Pipeline Pressure and Corrosion Demands
GR.B is the workhorse grade for API 5L pipeline applications, offering adequate yield strength for medium-pressure oil and gas transport while maintaining weldability in the field. The ERW process produces a longitudinal seam with consistent fusion quality, making it suitable for diameters where seamless alternatives become cost-prohibitive. The 3PE coating system — fusion-bonded epoxy primer, copolymer adhesive, and polyethylene outer layer — provides mechanical protection against soil stress and cathodic disbondment resistance for buried service. With wall thickness from 2 mm to 36 mm and lengths up to 12 m, this API ERW welded steel pipe 3PE anti-corrosion supplier delivers configurations that reduce field weld joints and accelerate installation schedules.
Engineering Compliance for Buried and Submerged Pipeline Service
Pipeline design codes require documented proof that both the steel body and the coating system meet specified standards before trenching begins. For ASTM-designated projects, GR.B pipe must conform to the chemical composition and testing requirements of the applicable API specification, while the 3PE coating must satisfy adhesion, cathodic disbondment, and impact resistance criteria [NEED_CITE: 3PE coating requirements for buried steel pipelines per SY/T 0413 and DIN 30670]. Third-party inspectors verify coating thickness uniformity, holiday detection at specified voltages, and peel strength at ambient and elevated temperatures. The ±1% wall thickness tolerance ensures that nominal pressure ratings hold across the full production run, which matters when engineers calculate corrosion allowance into their design life.
Understanding GR.B Grade and ERW Welding for Pipeline Use
GR.B belongs to the API 5L line pipe grade system, positioned as a standard-duty grade for transmission pipelines carrying oil, gas, and water. The “B” designation indicates a step above Grade A in minimum yield strength, providing a wider safety margin for pressure surges and external loading. ERW welding forms the longitudinal seam by passing current through the heated strip edges and forging them under pressure — no filler metal is added, which means the weld zone chemistry matches the base metal. This process suits the 2–36 mm wall thickness range well, delivering consistent seam integrity for diameters commonly used in gathering lines and distribution networks. The 3PE coating applied over the ERW seam requires careful surface profiling to ensure the epoxy primer bonds to both the pipe body and the weld bead without disbondment at the seam line [NEED_CITE: ERW weld seam quality requirements for 3PE coating application].
Hidden Costs When Coating Quality Falls Short at Site Inspection
Specifying GR.B pipe with 3PE coating from a supplier who cannot provide full material traceability creates risk at multiple stages. If the mill test certificate does not link each pipe to its heat number, customs authorities or project owners may reject the entire shipment. If coating thickness varies beyond acceptable limits, holiday detection testing reveals voids that require expensive field repair — or replacement. If the epoxy primer was applied outside its temperature window, adhesion failure may not surface until the pipe is buried and backfilled, at which point excavation and recoating multiply the original pipe cost many times over [NEED_CITE: material traceability requirements for API line pipe].
Why Sourcing from an Integrated Mill Changes the Quality Equation
Our facility operates its own steel production lines alongside the ERW pipe mill and the 3PE coating line, meaning every pipe carries one heat number from slab to coated finish. We maintain over 2,800 raw material specifications in inventory, so GR.B pipe orders do not depend on third-party coil procurement that introduces certification gaps. Every shipment includes a complete quality documentation package — chemical composition, mechanical test results, coating thickness reports, and holiday detection records — prepared against the same API and ASTM standards the pipe was produced to. Third-party inspection by SGS or BV is welcomed and coordinated at our facility before loading. For international projects, we handle export documentation, oversized cargo packing, and container loading plans optimized for 5.8 m to 12 m pipe lengths.
Documentation & Compliance
- Mill Test Certificate documenting GR.B chemical composition and mechanical properties per API 5L, linked to individual heat numbers for full material traceability
- API certification confirming compliance with line pipe manufacturing and testing requirements for GR.B grade ERW welded pipe
- ISO 9001 quality management system certificate covering the integrated production process from steelmaking through 3PE coating application
- SGS or BV third-party inspection report covering dimensional checks, coating thickness measurement, holiday detection, and adhesion testing per DIN 30670
- Coating inspection report documenting 3PE layer thickness, peel strength, and cathodic disbondment test results for each production batch
- Export documentation set including packing list, bill of lading, and certificate of origin for customs clearance at destination port
Packaging, Loading & Delivery
- ERW welded steel pipes bundled with steel strip ties and separated by rubberized spacers to protect the 3PE coating surface from abrasion during transit
- Coated pipe ends fitted with plastic caps to prevent moisture ingress and protect beveled or plain ends from damage during ocean freight
- Container loading plans optimized for 5.8 m, 6 m, 6.4 m, and 12 m lengths to maximize payload per 40ft open-top or flat-rack container
- Each pipe marked with heat number, GR.B grade designation, wall thickness, and length for on-site identification and traceability verification
- FOB, CIF, and DDP delivery terms available with professional export packing and complete shipping documentation for project cargo
Start Your Procurement With Drawings and Specifications
Share your project requirements — pipe dimensions, wall thickness, GR.B grade, 3PE coating specification, quantity, and destination port — and receive a detailed quotation including material cost, fabrication, coating, packing, and freight within one business day. Our engineering team will review your specifications, confirm coating standards compliance, and provide a production schedule aligned with your project timeline.
Request a Quotation with Full Mill Test Documentation
Submit your GR.B ERW pipe specifications and 3PE coating requirements to receive pricing, material certifications, and delivery schedules.
Mobile/WhatsApp/WeChat: +86 188 5315 7756 | Email: admin@xjystructure.com
Frequently Asked Questions
Q: What 3PE coating standards does your GR.B ERW pipe comply with?
A: Our 3PE anti-corrosion coating system is applied per DIN 30670 and SY/T 0413 standards, covering three layers — fusion-bonded epoxy primer, copolymer adhesive, and polyethylene outer layer. Coating thickness, adhesion strength, and cathodic disbondment resistance are tested per these specifications, and results are included in the quality documentation package.
Q: How does GR.B compare to other API 5L grades for pipeline applications?
A: GR.B is a standard-duty line pipe grade in the API 5L system, offering higher minimum yield strength than Grade A while maintaining good weldability for field joint welding. It is widely specified for onshore oil and gas gathering lines, water transmission, and industrial fluid pipelines where extreme high-pressure service is not required.
Q: Can third-party inspection be arranged before shipment?
A: Yes. We welcome SGS, BV, or other internationally recognized inspection agencies to conduct dimensional checks, coating thickness measurement, holiday detection testing, and adhesion testing at our facility prior to loading. Inspection reports are included in the shipment documentation package.
Q: What material traceability documentation is provided with each order?
A: Every pipe is traceable from raw steel heat number through ERW welding, 3PE coating application, and final inspection. The Mill Test Certificate includes chemical composition, mechanical test results, and coating inspection data linked to specific heat numbers, ensuring full chain-of-custody documentation for project compliance.
Q: What lengths and loading options are available for international shipment?
A: GR.B ERW pipes are available in 5.8 m, 6 m, 6.4 m, and 12 m standard lengths. Loading plans are optimized for 20ft, 40ft, and 40ft open-top containers depending on pipe diameter and length. FOB, CIF, and DDP delivery terms are available with complete export documentation.
