Galvanized Steel Pipe Hot Dip Anti-corrosion GI Pipe
Hot dip galvanized steel pipe, also named GI pipe, is carbon welded pipe coated with uniform zinc alloy layer, covering ERW, LSAW, SSAW three welding types. Comply with ASTM A53, EN10219, GB/T3091 standards. Featuring full-surface anti-rust, easy machining and long service life. We supply pre-galvanized & hot dipped galvanized pipes, offer threading, grooving and custom size service for water supply, fire protection and outdoor structural projects.
Available Grades
- Q195 Pre-galvanized GI Pipe: Light zinc coating economical grade, smooth bright surface, mainly used for indoor wire conduit, greenhouse frame and low-load indoor structural support.
- Q235B / S235JR Hot Dipped GI Pipe: Most popular universal grade, standard zinc coating, balanced toughness and anti-corrosion performance for general water and fire piping projects.
- Q355B / S355JR High Strength Galvanized Pipe: Low alloy upgraded grade, higher compression and bending resistance, ideal for heavy-duty scaffolding, bridge guardrail and load-bearing outdoor structures.
- ASTM A53 Gr.B Schedule Galvanized Pipe: US standard schedule graded pipe, standardized wall thickness, matched with standard pipe fittings for overseas municipal fluid pipeline engineering.
- API 5L Gr.B Anti-corrosion Galvanized Pipe: Thickened zinc coated welded pipe, excellent salt spray resistance, customized for coastal buried water delivery and medium corrosive pipeline projects.
Product Features
- Dual Zinc Anti-corrosion Protection: Integrated metallurgical bonded zinc layer achieves sacrificial anti-rust effect, effectively isolate moisture, oxygen and salt fog to avoid pipe rusting.
- Complete Welding Process Coverage: Available ERW small-bore, LSAW high-pressure, SSAW large-bore galvanized pipe, meet full-diameter pipeline and structural usage demands.
- Excellent On-site Processability: Support cutting, threading, grooving, bending and flange connection, no coating peeling during secondary machining for fast installation.
- Uniform & Dense Zinc Coating: Automated hot dipping process ensures even zinc thickness, no dead angle coating, stable anti-corrosion performance on pipe inner and outer wall.
- Weather & Abrasion Resistance: Hardened outer zinc layer resists outdoor sunlight aging and surface scratch, adapt open-air, buried and coastal harsh service environment.
- Standard Dimensional Accuracy: Unified pipe roundness, caliber and wall thickness tolerance, perfectly compatible with global standard elbows, tees and joint fittings.
Applications
- Municipal Domestic Water Supply: Hot dipped galvanized pipe for buried urban tap water delivery pipeline, prevent pipe inner wall rust to guarantee water quality safety.
- Building Fire Protection System: Threaded galvanized ERW pipe for building fire sprinkler, hydrant piping, meet fire engineering anti-rust and pressure-bearing standards.
- Outdoor Municipal Infrastructure: Galvanized pipe for road guardrail, municipal fence, street light pole and landscape support structure for long-term outdoor anti-rust use.
- Construction Scaffolding Works: Thick-wall hot dipped galvanized pipe for building construction scaffolding, improve site safety and reduce regular anti-rust maintenance.
- Agricultural Greenhouse & Breeding House: Anti-ammonia galvanized pipe for farm greenhouse frame and breeding barn ventilation pipeline, resist corrosive gas erosion.
- Electrical Wire Conduit: Pre-galvanized round pipe for indoor and outdoor cable protection conduit, prevent wire damage and improve circuit safety durability.
Product Advantages (Customer Value)
- Cut Long-term Maintenance Expense: Factory integrated galvanizing cancels on-site painting work, reduce later periodic anti-rust repair, renovation and replacement cost greatly.
- Extend Whole Project Service Life: 3-5 times longer lifespan than black welded pipe, lower pipeline failure rate, reduce project hidden safety risks for contractors.
- Improve Construction Efficiency: Pre-finished galvanized surface + optional factory threading/grooving, shorten on-site secondary processing time and shorten project period.
- Flexible Grade & Cost Matching: Pre-galvanized for low-budget indoor use, hot dipped thick zinc pipe for coastal outdoor use, optimize overall procurement budget reasonably.
- High Project Acceptance Pass Rate: Standard zinc weight and mechanical data meet international building codes, easily pass third-party inspection and engineering bidding audit.
Technical Data Table
| Technical Item | Pre-galvanized GI Pipe | Hot Dipped GI Pipe | High Strength GI Pipe |
| Material Density | 7.85 g/cm³ | 7.85 g/cm³ | 7.85 g/cm³ |
| Yield Strength | ≥195 MPa | ≥235 MPa | ≥355 MPa |
| Tensile Strength | 330–450 MPa | 375–500 MPa | 470–620 MPa |
| Elongation | ≥22% | ≥20% | ≥17% |
| Standard Zinc Coating | 60-120g/m² | 180-275g/m² | 200-275g/m² |
| Available OD Range | 21.3mm – 219mm(ERW) | 21.3mm – 610mm(ERW/LSAW) | 219mm – 1620mm(SSAW) |
Why Choose Us
- Full Series GI Pipe Inventory: Stock pre-galvanized & hot dipped ERW/LSAW/SSAW galvanized pipes, support mixed caliber container shipment for distributors and contractors.
- Strict Zinc Layer & Weld Inspection: Test zinc thickness, weld compactness and salt spray resistance per batch, guarantee no coating peeling and pipe leakage during usage.
- Integrated Deep Processing Service: Provide factory threading, grooving, end flatting, fixed-length cutting and customized logo printing for direct site installation.
- Free Environmental Grade Recommendation: Professional team match proper zinc coating grade based on inland/coastal climate, help clients control procurement cost scientifically.
Packaging & Shipping
- Standard Seaworthy Anti-scratch Package: Small caliber GI pipes bundled by high-strength steel strips; large caliber pipes fitted with plastic end caps; wrapped waterproof woven cloth for long sea transportation protection.
- Permanent Standard Pipe Marking: Print grade, zinc weight, outer diameter, wall thickness, batch number and standard logo on pipe surface for easy receiving and quality tracing.
- Customized Special Packing: Extra anti-rust oil coating, sealed plastic film packing, private brand printing for high-grade threaded finished galvanized pipes.
FAQ
- Q: Difference between pre-galvanized and hot dipped galvanized pipe?
A: Pre-galvanized pipe has thin zinc layer for indoor dry use; hot dipped GI pipe has thick compact zinc layer, suitable for outdoor, buried and coastal anti-corrosion scenarios. - Q: Can galvanized pipe be used for drinking water pipeline?
A: Food-grade hot dipped galvanized pipe meets water supply standard, available for municipal tap water delivery piping system. - Q: Can you make thread and groove on galvanized pipe end?
A: Yes, we complete anti-rust treated threading and grooving in factory, match standard pipe fittings for quick on-site connection. - Q: What zinc coating weight is most popular?
A: Z180 hot dipped galvanized pipe is the best-selling grade, balanced anti-corrosion performance and purchase cost for most engineering projects.
