One strip width serves many diameters — the reason spiral pipe wins on large-diameter water, oil and gas lines. Wall 5–25.4 mm, lengths up to 14.5 m, 3PE / TPEP / FBE coating and cement-mortar lining available in the same factory.
Coiled strip is uncoiled, levelled and edge-milled, then continuously formed into a spiral by the forming unit at a preset angle; the inner and outer submerged-arc welds are completed in one pass on the same line. Because the seam runs spirally, stress is distributed around the circumference.
Changing the forming angle changes the diameter, so one coil serves DN600 through DN3000 without new tooling — short lead times and high material yield. Lengths up to 14.5 m cut site welds by more than half compared with 6 m pipe.
| Standards | GB/T 9711 (PSL1 / PSL2) · GB/T 3091 · SY/T 5037 · API 5L · EN 10217 · ASTM A53 / A135 |
| Outside diameter | DN200 – DN3800（Φ219 – Φ3820 mm） |
| Wall thickness | 5 – 25.4 mm (up to 30 mm on request) |
| Length | 6 – 14.5 m |
| Steel grade | Q235B · Q355B · L245 – L450（Gr.B – X65） |
| Welding | Double-sided SAW (inner + outer), spiral seam |
| Pipe ends | Plain end · Bevel 30°–37.5° · Flanged |
| Inspection | Hydrostatic test · UT · X-ray · Dimensions & appearance |
| Coating | Bare · 3PE · 2PE · FBE · TPEP · Epoxy coal-tar |
| Lining | Cement mortar · IPN8710 · Epoxy resin · Rubber |
Third-party inspection (SGS / BV / TÜV) and mill test certificates available; every pipe is traceable by heat number.
Municipal and industrial water trunk lines, most common above DN800.
Storm and sewage mains, usually with cement-mortar lining.
PSL2 grade with 3PE coating and 100% NDE.
Pile casings and jacking sleeves, wall selected by load.
Outer casing for pre-insulated district-heating pipe.
Factory and bridge foundations, temporary support.
0.6–2.5 MPa for water mains; 6.4 MPa and above for oil & gas to PSL2 with 10–25.4 mm wall, subject to hydrostatic test and wall-thickness calculation.
One strip width can produce many diameters by changing the forming angle, so material yield is high and no die change is needed; straight-seam pipe needs a plate width matched to each diameter.
Normally one 20 ft container (about 25–28 t); smaller lots negotiable. 7–15 days for standard sizes, 15–25 days with 3PE coating, 25–35 days for large diameters or special grades.
Replace with our spiral forming unit and simultaneous inner/outer welding — what buyers most want to see.
Replace with hydrostatic testing, UT/X-ray inspection and bundled finished pipes.
Replace with a site photo of our spiral pipe in service — jacking, trunk lines or piling.
Technical proposal and quotation within one working day.
