Coating Uniformity: Inspect whether the zinc layer on the steel pipe surface provides complete coverage, free from missed plating, nodules, or noticeable color variations. Inferior products often exhibit zinc layer peeling or localized darkening.
Surface Finish: High-quality galvanized pipes feel smooth to the touch, without burrs or unevenness; low-grade products may retain rust spots due to incomplete acid pickling.
Marking Clarity: Reputable manufacturers clearly mark specifications, standard numbers (e.g., GB/T 3091), and company names on the pipe body. Be wary of blurred or missing markings.
Additionally, cut a sample to inspect the cross-section. A high-quality zinc coating adheres tightly to the base pipe without delamination.

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