Awwa C200 Spiral Welded Steel Pipe

Spiral welded steel pipe, also known as SSAW pipe, is manufactured by spirally coiling steel strip and welding the seam with a double submerged arc process. The spiral seam distributes circumferential stress more evenly than a straight longitudinal seam, which improves the pipe's structural performance under internal pressure and external soil loads. The continuous coil-fed production method also delivers higher dimensional consistency across long production runs, making spiral welded pipe particularly well-suited for large-diameter water mains, transmission mains, and aqueducts where uniform wall thickness and accurate diameter are critical to installation efficiency and long-term service life.

Polyurethane lining is specified where water chemistry is aggressive, including high chloride, high total dissolved solids, or desalinated water service. Polyurethane is smoother than cement mortar, with a Hazen-Williams C factor of approximately 140 to 150, which reduces pumping energy. However, polyurethane lining is less tolerant of installation damage than cement mortar and requires more careful handling on site.

At Cangzhou Spiral Welded Pipe Manufacturing Group, anchor pattern depth is measured and recorded for every production batch in accordance with the applicable coating standard and our approved coating procedure. Coating adhesion is tested using the pull-off method in our CNAS certified laboratory. The test data is submitted with the mill test certificate for each order.

Coil Preparation: Steel strip is uncoiled, leveled, and edge-milled to the required width for the target pipe diameter. Strip edges are cleaned to remove rust and contaminants that could cause porosity or lack of fusion during welding.

Spiral Forming: The strip is fed into a forming machine at a controlled angle, creating the spiral seam geometry. The forming machine controls the spiral angle and strip alignment to prevent misalignment, which weakens the weld's pressure-bearing capacity.

Welding: The spiral seam is welded using the double submerged arc welding process. An initial penetrating weld is made on the inside seam, followed by a second weld along the outside seam. This two-pass weld creates a pipe structure in which the weld is as strong as or stronger than the parent metal.

Weld Inspection: Every length of pipe receives 100 percent ultrasonic testing of the weld seam. In-line continuous UT is supplemented by off-line X-ray radiography. End welds at both pipe ends receive additional 100 percent manual ultrasonic re-inspection because stress conditions during forming are less stable at the ends than in the middle of the pipe.

Hydrostatic Testing: Every pipe receives a hydrostatic test before coating application. The test pressure is specified by the project; if no pressure is specified, the mill applies a standard test pressure and records the pressure-time graph with the mill test certificate.

End Preparation: Pipe ends are machined to the specified configuration. Butt-welded joint ends receive machine-beveled ends per ASME B16.25. Rubber gasket joint ends receive bell and spigot forming with K10 or K20 steel rings for mechanical coupling systems.

Coating Application: Lining and coating are applied in the same facility under the same quality management system. Cement mortar lining is applied by centrifugal or spray method. 3LPE external coating is applied by side extrusion or powder spray. FBE is applied by electrostatic spray.

Certified Welding Inspectors: The mill employs Certified Welding Inspectors (CWI) qualified under AWS QC1. CWIs perform 100 percent visual examination of every weld as a minimum requirement.

Laboratory Testing: The CNAS certified laboratory performs chemical analysis, tensile testing, Charpy V-notch impact testing, and coating adhesion testing on every production heat. Test reports are traceable to the heat number and pipe mark number.

Mill Test Certificates: Each shipment is accompanied by EN 10204 3.1 mill test certificates containing chemical composition, tensile properties, elongation, and hydrostatic test results. Charpy impact test results are included when specified. Pressure-time graphs for hydrostatic testing are retained and available upon request.

Dimensional Verification: OD tolerance, ovality, straightness, end squareness, and bevel angle are measured for every pipe. Shop fit tests are performed to verify that joints assemble correctly and that annular space between spigot and bell meets AWWA C200 requirements.

Third-Party Access: Buyers or their designated inspection agencies may access the production areas relevant to their order. Advance notice allows scheduling of witnessed hydrostatic testing and coating inspection.

Traceability: The mill maintains heat number traceability from steel coil through finished pipe. Welding procedure specifications, procedure qualification records, and welder qualification records are maintained for every welding process and every welder.

Production Scale: 13 spiral welded pipe production lines with a combined annual capacity of 400,000 tons. This capacity allows parallel scheduling of large-diameter orders, reducing delivery lead time compared to single-line mills.

CNAS Certified Laboratory: Chemical, mechanical, and coating adhesion testing are performed in-house. Pre-shipment test data is available without waiting for third-party laboratory scheduling, which shortens the inspection and release cycle.

Experience with International Water Projects: The mill has supplied AWWA C200 spiral welded pipe to water transmission projects in Southeast Asia, the Middle East, and South America. Project references are available upon request.

Full Traceability Documentation: Every pipe is traceable to its steel heat number. Mill test certificates, welding procedure records, welder qualification records, and coating test reports are compiled for each order.

Pipe outside diameter and wall thickness

Total quantity in meters or tons

Lining type and thickness

External coating type

Pipe end configuration

Destination port

Quotations are provided within 24 hours of receiving complete specifications.