Application description

Widely used in water supply and drainage systems, fire sprinkler lines, gas pipelines, scaffolding, fence posts, greenhouse frames, handrails, and structural supports. Also suitable for electrical conduit, industrial cooling lines, and agricultural irrigation. The zinc coating provides long-lasting corrosion protection for both indoor and outdoor installations.

Production description

The process begins with steel coil (for welded pipes) or billet (for seamless pipes). For welded pipes, the coil is slitted, roll-formed, and welded longitudinally (ERW) into a black pipe. For seamless pipes, a billet is pierced and cold drawn. The black pipe is then cleaned, fluxed, and immersed in a molten zinc bath at approximately 450°C. The zinc coating bonds metallurgically to the steel surface. Air knives or centrifuge controls coating weight (Z60–Z500). After galvanizing, the pipe is cooled, passivated, and inspected for coating uniformity, thickness, and adhesion. Optional threading, coupling, or grooving is then applied. Finished pipes are bundled, capped, and packed for shipment.

Shipping Packaging

For export, galvanized pipes are bundled with plastic end caps, wrapped in VCI paper and moisture-proof polyethylene, packed in steel or wooden crates (or on ISPM-15 pallets), secured with steel straps, and fitted with edge protectors. Labels include grade, size, length, quantity, and heat number for safe sea freight.

Why Choose Us?

1.Factory Strength:Direct manufacturer with ERW welding, seamless drawing, and in-line hot-dip galvanizing lines, ensuring consistent coating weight (Z60–Z500), uniform finish, and stable supply.

2.Quality Assurance:Strict control of zinc coating adhesion, thickness uniformity, and thread accuracy; 100% hydrostatic or eddy current testing; compliant with ASTM A53, BS 1387, EN 10255, JIS G3444, GB/T 3091.

3.Certifications & Reports:Mill test certificates (MTC) with each shipment; third-party inspections (SGS, BV) and salt spray test reports available upon request.

4.Customization & Service:Wide grade range (Q195–Q345, S235JR–S355JR, GR.B, STK400), shapes (round, square, rectangular), sizes (OD 21.3–609.6mm, wall 1.0–16.0mm), custom lengths, threading, coupling, grooving with fast lead times.

5.Export Packaging:Plastic end caps + VCI paper + moisture-proof wrapping + steel/wooden crates + ISPM-15 pallets + edge protectors for safe sea freight and damage-free delivery.

FAQ

1. How to store galvanized pipes to prevent white rust before use?
Store on dry, elevated racks under cover. Keep original end caps and wrapping intact. Avoid contact with wet ground, acids, or dissimilar metals. Good ventilation helps prevent condensation.

2. Can galvanized pipes be welded without damaging the coating?
Welding burns off zinc near the weld zone. Use low-heat input and apply cold-galvanizing spray or zinc-rich primer to restore corrosion protection on welded areas.

3. Threaded vs grooved ends – which is better for installation?
Threaded ends are traditional for small diameters (≤100mm) and low-pressure systems. Grooved ends allow faster, flexible assembly with mechanical couplings, ideal for larger diameters and fire protection systems.