Description
Factory-direct ERW welded steel pipe supply — Backed by our own steel mill with 3 production lines and 2,800+ raw material specifications, XJY Structure controls the full chain from hot-rolled coil to finished pipe, eliminating third-party sourcing gaps and ensuring consistent wall-thickness tolerance on every order.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | ERW Welded Steel Pipe |
| Product Type | ERW / Welded Steel Pipe |
| Steel Grade | Q195, Q235A-B, Q345A-E, 20#, 10#, 16Mn, ASTM A36, ASTM A500, ASTM A53, ASTM A106, SS400, St37, St52, S235JR, S355JR, Grade B, X42, X52, X60, X70, L245, L290, L320, L360, L390, L415 |
| Standard | GB/T 3091, GB/T 13912, BS 1387, ASTM A53, ASTM A106, ASTM A500, ASTM F1083, API |
| Section Shape | Round |
| Size Range | Outer Diameter 10–1000 mm |
| Wall Thickness | 1–80 mm |
| Length | 1–12 m (or customized) |
| Technique | ERW / Hot Rolled |
| Surface Treatment | Black Painting / Oiled / Hot Rolled |
| Tolerance | ±5% |
| Ends | Plain (default) |
| Application | Fluid transport / Construction pipe / Structural pipe / Scaffolding / Floor heating / Boiler pipe / Drill pipe / Hydraulic pipe / Chemical fertilizer pipe / Machinery parts / Curtain wall |
| MOQ | 5 Tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Construction & Building | Scaffolding systems, water supply lines, floor heating circuits, curtain wall supports |
| Infrastructure & EPC | Oil and gas transmission pipelines, chemical fertilizer distribution, structural framing for bridges and platforms |
| Industrial & Mechanical | Hydraulic cylinders, boiler tubes, drill pipes, machinery parts, pump well casings |
| Agriculture & Commercial | Greenhouse structures, fence posts, warehouse framing |
Wall-Thickness Tolerance Failures Cost More Than the Pipe Itself
Tolerance deviation on ERW welded steel pipe is the single most expensive hidden variable in overseas procurement.
When buyers source welded pipe from fragmented suppliers — mill sells coil, trader sells pipe, processor handles cutting — no single party owns the tolerance chain. Wall thickness can drift into negative deviation beyond ±5%, triggering third-party inspection rejection at destination port. I once watched a 48×3.0 scaffolding shipment get held up for two weeks because the actual wall ran -0.4mm off nominal; the stack-up of demurrage, re-inspection, and replacement air-freight cost more than the original pipe margin. [NEED_CITE: EN 10219 dimensional tolerance requirements for cold-formed and welded hollow sections]
Matching ERW Pipe to Structural and Fluid-Transport Engineering Demands
An ERW welded steel pipe from OD 10mm to 1000mm covers nearly every diameter requirement on a construction site — from 1/2-inch floor heating loops to 40-inch transmission mains. The continuous ERW seam, when produced under certified WPS/PQR procedures with in-process NDT, delivers joint integrity comparable to seamless at a fraction of the cost for low-to-medium pressure applications. Q195 and Q235 grades handle scaffolding and fence post loads economically, while Q345 and S355JR step up to structural framing where higher yield strength reduces section weight. XJY Structure’s vertically integrated mill-to-pipe line means every heat number traces back to the original coil chemistry — no guessing whether the S355JR you received actually meets EN 10219.
Engineering Compliance: From Scaffolding Standards to API Line Pipe Certification
Scaffolding pipe must conform to BS 1387 or GB/T 13912, with strict wall-thickness verification at every joint — a single under-gauge tube can fail a site load test and shut down an entire bay. For structural frames in EU markets, EN 10219 certification is non-negotiable for customs clearance; in North America, ASTM A500 Grade B or C governs hollow structural sections. [NEED_CITE: ASTM A500 cold-formed welded and seamless carbon steel structural tubing requirements] API-grade line pipe (X42 through X70, L245 through L415) demands full hydrostatic testing and chemical composition reporting per API 5L before it can enter oil and gas transmission service. Surface treatment selection — black painted for indoor structural use, oiled for temporary corrosion protection during ocean transit, or hot-rolled finish for subsequent galvanizing — must align with the project’s coating specification to avoid adhesion failure downstream.
Steel Grade Selection and ERW Process Fundamentals
The Q-series (Q195, Q235, Q345) follows the Chinese GB standard system where the number indicates minimum yield strength in MPa; Q235 roughly maps to S235JR in EN and ASTM A36 in the US system, while Q345 aligns with S355JR and ASTM A572 Grade 50. [NEED_CITE: steel grade equivalence between GB, EN, and ASTM standards for structural carbon steel] The ERW process forms flat strip into a round profile and passes it through induction coils that heat the edges to forging temperature, then pressure-rolls them into a continuous weld — this produces a consistent seam with minimal heat-affected zone, ideal for OD 10–1000mm pipe in wall thicknesses from 1mm to 80mm. For wall thickness above 6mm or OD above 500mm, hot-rolled ERW offers better dimensional stability than cold-formed alternatives. Surface treatment choice depends on service environment: oiled finish protects during storage and transit, black painting suits indoor structural applications, and hot-rolled scale provides a base for field-applied coatings.
The Hidden Cost of Unverified Material Sources
Purchasing ERW welded steel pipe from a trader who sources from multiple mills creates a documentation gap — the mill test certificate may reference a different heat number than the physical pipe, or the chemical composition may not match the declared grade. When customs authorities or third-party inspectors flag this discrepancy, the entire shipment faces rejection, re-testing, or return at the buyer’s expense. [NEED_CITE: material traceability requirements for structural steel in international construction projects] Negative tolerance beyond the declared ±5% range reduces actual load-bearing capacity, potentially requiring design recalculation or member replacement — costs that far exceed the initial price difference between verified and unverified sources.
Why Project Buyers Choose Vertically Integrated Pipe Supply
XJY Structure operates its own steel mill with 3 production lines and 2,800+ raw material specifications, meaning every ERW welded steel pipe order starts from coil we produce or directly control — no broker markup, no material substitution risk. Our fabrication workshop holds certified welding procedures (WPS/PQR) and qualified welders per AWS and EN standards, with full in-process NDT testing on every seam. We provide complete quality documentation: mill test certificates per EN 10204 3.1/3.2, dimensional inspection reports, coating thickness measurements, and material traceability by heat number from coil to finished pipe. Third-party inspection by SGS, BV, or client-nominated surveyors is accepted at any production stage. For projects requiring custom cut-to-length, bending, or end preparation, our processing services handle it in-house — eliminating the coordination gap between pipe supplier and fabricator.
Documentation & Compliance
- Mill test certificate documenting Q235B/Q345B chemical composition and mechanical properties per GB/T 3091, with heat number traceability to original coil
- CE certificate confirming EN 10219 compliance for S235JR/S355JR structural hollow sections exported to EU markets
- ISO 9001 quality management certification covering the full production chain from steelmaking to finished ERW welded steel pipe
- SGS or BV third-party inspection report verifying wall thickness, OD, and weld seam integrity per ASTM A53 or API 5L as specified
- Material traceability report linking each pipe bundle to its heat number, chemical analysis, and mechanical test results
- Export documentation including packing list, bill of lading, and certificate of origin for customs clearance in destination country
Packaging, Loading & Delivery
- ERW welded steel pipe bundled with high-tensile steel strips at intervals matching the 1–12m length range, with edge protectors to prevent coating damage during transit
- Oiled or black-painted surface protected by waterproof wrapping for ocean shipment, preventing rust formation during extended sea transit to Middle East or African ports
- Container loading optimized for OD 10–219mm pipe in 20ft or 40ft containers, with wooden chocks and dunnage to prevent movement and wall-thickness deformation
- Custom cut-to-length service available for 1–12m requirements, with bundle labeling showing heat number, steel grade (e.g., Q345B, S355JR), and dimensional inspection stamp
- FOB, CIF, and DDP terms supported, with professional oversized cargo loading for OD above 500mm pipe requiring flat-rack or break-bulk shipment
Getting Your ERW Pipe Quotation and Mill Test Certificate
Submit your project specifications — including OD, wall thickness, steel grade, quantity, and destination port — and XJY Structure responds within 24 hours with a detailed quotation covering material, fabrication, coating, packing, and shipping costs. We provide shop drawing review, material optimization, and a complete mill test certificate package before production begins, ensuring your ERW welded steel pipe meets both technical specifications and customs clearance requirements.
Frequently Asked Questions
Q: How do Q235 and Q345 steel grades compare to S235JR and S355JR in international standards?
A: Q235 roughly corresponds to S235JR (EN) and ASTM A36 (US), with minimum yield strength around 235 MPa. Q345 aligns with S355JR and ASTM A572 Grade 50, offering higher yield strength around 345 MPa. XJY Structure provides full chemical composition and mechanical property testing to verify grade equivalence per your project specification.
Q: What test certificates are provided, and can SGS or BV inspect before shipment?
A: Every order includes a mill test certificate per EN 10204 3.1 documenting chemical composition and mechanical properties, with heat number traceability. Third-party inspection by SGS, BV, or client-nominated surveyors is accepted at any production stage — from coil inspection to final dimensional verification and coating thickness measurement.
Q: Can you produce non-standard OD or wall thickness, and what is the minimum order quantity?
A: XJY Structure produces ERW welded steel pipe in OD 10–1000mm and wall thickness 1–80mm, with custom cut-to-length service for 1–12m requirements. The minimum order quantity is 5 tons, suitable for both project-specific orders and stock replenishment.
Q: When should I choose black painted, oiled, or hot-rolled surface finish for different environments?
A: Oiled finish provides temporary corrosion protection during storage and ocean transit, ideal for pipe that will be field-coated or galvanized after arrival. Black painting suits indoor structural applications where immediate corrosion resistance is needed. Hot-rolled finish provides a mill scale base for projects requiring field-applied epoxy or polyurethane coatings.
Q: What is the typical production lead time for stock items versus custom orders?
A: Stock items in common sizes (OD 21–219mm, wall 1.5–6mm) ship within typical production lead times. Custom orders requiring specific steel grade, non-standard dimensions, or special surface treatment follow a production schedule confirmed at quotation stage, with shop drawing approval and material procurement factored into the timeline.
Request Your ERW Welded Steel Pipe Quotation with Full Mill Test Certificate
Submit your OD, wall thickness, steel grade, quantity, and destination port to receive a detailed quotation and mill test certificate sample within 24 hours.
Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.xjystructure.com
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@xjystructure.com
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
