Galvanized steel pipe is one of the most common, proven and standardized products in metal applications. Used in water supply networks, fire protection, compressed air, industrial piping, and structural constructions. Behind an apparently simple product lie many standards and options that determine if it will work properly in your application.
Types per DIN 2440 / EN 10255
DIN 2440 (Older, still in use)
- Medium duty: Standard wall thickness for water supply/gas up to 25 bar pressure
- Diameters: ½”, ¾”, 1″, 1¼”, 1½”, 2″, 2½”, 3″, 4″, 5″, 6″
- Wall thickness: 2.3 to 5.4 mm depending on diameter
EN 10255 (Modern European standard)
Replaces DIN 2440. Divides pipes into three categories:
- L (Light): Thin wall for general low-pressure use
- M (Medium): Standard for water supply, gas, fire protection
- H (Heavy): Increased wall for high pressures or structural applications
Zn Coating Thickness
Protection depends on galvanic layer thickness, typically:
| Standard | Zn thickness (interior) | Zn thickness (exterior) | Use |
|---|---|---|---|
| DIN 2444 (light) | 70 g/m² | 200 g/m² | General water supply |
| EN 10255 Medium | 400 g/m² min | 400 g/m² min | Fire protection, industrial |
| EN 10240 A1 | 500–800 g/m² | 500–800 g/m² | High-corrosion zones |
Note: 1 g/m² Zn ≈ 0.14 μm coating thickness.
Uses
Fire Protection Networks
Mandatorily galvanized pipes per NFPA 13 (and Greek PD 71/1988). Interior Zn protects from stagnant water, fire protection networks are stagnant 99% of the time, where non-galvanized pipe would quickly rust.
Outdoor Water Supply & Irrigation
Irrigation networks in farms, outdoor building networks. Galvanized pipe withstands frost and UV radiation better than unprotected.
Compressed Air Networks
In factories and industrial units, galvanized pipe is the typical choice for compressed air systems. The advantage: interior Zn prevents oxidation from compressed air moisture.
Gas (Natural / LPG)
For surface installations (not underground), galvanized pipe is a common solution. EN 10255 is the applicable standard.
Structural Constructions
Guardrails, stairs, handrails, wrought iron, metal structure frames. Galvanized pipe replaces black pipe where paint is insufficient (outdoor).
HVAC & Electrical Supports
Racks for outdoor AC units, lighting masts, cable trays in industrial installations.
When It’s NOT the Best Choice
- Potable water: In older installations with galvanized pipes for potable water, elements (Pb, Cd) may leach from old galvanizing. Modern practice: plastic pipes (PPR, PEX) or inox for potable water.
- Heating: Temperatures above 60°C trigger electrochemical reactions, prefer copper or inox.
- Underground installations: Galvanizing isn’t sufficient for serious soil exposure. Additional epoxy coating or replacement with HDPE is needed.
- Chemical solutions: Zn is attacked by acidic and basic solutions. Inox 316L or special alloy is needed.
Comparison with Other Protective Methods
| Method | Durability | Cost | Ideal Use |
|---|---|---|---|
| Hot-dip galvanizing | 25–75 years | Medium | Fire protection, industrial water, structural |
| Electro-galvanizing | 3–10 years | Low | Interior, non-critical networks |
| Epoxy coating | 15–30 years | High | Underground, chemical environments |
| Cold galvanizing (paint) | 3–7 years | Low | Repair, local protection |
| Inox 304/316L | 50+ years | Very high | Potable water, food, chemicals |
Additional Standards and Certifications
- ASTM A53: Widely used American standard for welded and seamless steel pipes.
- BS 1387: British standard for steel pipes suitable for welding and threading.
- NSF: Certification for contact with potable water (lead-free). In modern practice, however, galvanized steel pipe is not recommended for indoor potable water piping.
Additional Applications
- Agricultural installations: Greenhouses (frame), animal shelters, outdoor irrigation systems.
- HVAC: Ventilation ducts, refrigerant lines, outdoor unit supports.
- Outdoor plumbing: Outdoor taps, downspouts, gray water lines.
- Structural elements: Scaffolding, retaining walls, fences.
Underground Installations, Additional Protection
When galvanized pipe is placed underground, additional protection is needed:
- Wrapping with corrosion-resistant tape.
- Protection from aggressive soils (acidic or high salt content).
- Sealing cut edges so ungalvanized core is not exposed.
Galvanizing alone is not sufficient for long-lasting underground use.
AXINAR galvanizes pipes, fittings and whole products per EN 10255. For complete constructions (piping kits), we provide cutting, welding + galvanizing in one service.
- Galvanizing on complete pipes
- Zn thickness 400+ g/m² for industrial
- Certificates per batch
Request a Quote for Your Project
Send us sketches, CAD drawings, or a description of your project, and we’ll respond within 24 hours with a technical estimate. We cover everything from prototypes to mass OEM production.
See also hot-dip vs cold galvanizing or industrial galvanizing applications.
