Xenith Steel
Xenith Steel

How long does hot-dipped galvanized pipe last in outdoor construction? Per ISO 9224, a 610 g/m² zinc coating (ASTM A53 minimum) delivers 50+ years in rural atmosphere, 30-50 years urban, 20-30 years industrial — compared to bare steel which corrodes within 1-5 years without protection. ASTM A53 Table X3.1 sets minimum 490 g/m²; Xenith Steel targets ≥610 g/m² verified per ASTM A90 with 3-point sampling per 100 pipes, applied at 450°C immersion per ISO 1461 on ERW substrate from our pipe coating facility in Cangzhou. For water supply and fencing projects requiring BS 1387 Class B or EN 10255 heavy-grade certification, our galvanized welded pipe has been supplied to Middle East infrastructure and African water projects.

Galvanized welded pipe with zinc coating
Galvanized pipe weld seam and zinc layer
Pre-galvanized pipe bundle
Galvanized pipe threaded end
Hot dip galvanizing process

Galvanized Welded Pipe

Product:

galvanized pipe, galvanized steel pipe, hot dipped galvanized steel pipe,pre-galvanized steel pipe

Application:

Used for transporting low pressure liquid, gas and heating.

Size:

OD: 21.3mm ~ 406.4mm

WT: 0.5mm ~ 20mm

LENGTH: 0.3mtr ~ 18mtr, Ramdon Length, Fixed Length, SRL, DRL

Standard

GB/T 3091 Q195/Q215/Q235/Q345, BS 1387, EN 39, EN 1139 S235JR/S275JR, ASTM A53 GR. A/B/C, JIS G3444 STK 400/STK 500

Pipe tape

Seamless & Welded Steel Pipe (Round/Square/Rectangular)

  • Products details
  • Tolerance table
  • Chemical composition
  • Specification

Galvanized Welded Pipe Introduction

Product:

galvanized pipe, galvanized steel pipe, hot dipped galvanized steel pipe,pre-galvanized steel pipe

Application:

Used for transporting low pressure liquid, gas and heating.

Size:

OD: 21.3mm ~ 406.4mm

WT: 0.5mm ~ 20mm

LENGTH: 0.3mtr ~ 18mtr, Ramdon Length, Fixed Length, SRL, DRL

Standard

GB/T 3091 Q195/Q215/Q235/Q345, BS 1387, EN 39, EN 1139 S235JR/S275JR, ASTM A53 GR. A/B/C, JIS G3444 STK 400/STK 500

Pipe tape

Seamless & Welded Steel Pipe (Round/Square/Rectangular)

End

Square Cut/Threaded, Burr Removed



Galvanized Welded Pipe is suitable for use in environments that require high resistance to chemical environments, marine environments or high temperatures.

Product Display & Application


specifications are as follows:

Standard

ASTM A-53

BS 1387-1985

JIS G 3452

Size Range(OD)

21.3mm to 609.6 mm

21mm to 166 mm

21.3 mm to 460.8 mm

Thickness

2.77mm -> 15mm

2mm to 5.4mm

2.8mm -> 7.9mm

  • Process
  • Tests

Tensile Testing

In order to measure the strength of the pipe material, a set of three sub-size tensile testing specimens were tested. The specimens were cut longitudinally of a pipe piece. Sub-size tensile specimens were chosen to account for the pipe curvature. Geometry, dimensions and orientation of the tensile specimens are shown in Fig. 1.

Figure 1 Sampling the tensile specimens of the tube: (a) and the specimen's geometry and dimensions and (b) specimen orientation.


Structural integrity of welded structures depends largely on the mechanical properties of the weld metal. In order to measure the strength of the weld metal, used in the current study, a bock of weld metal was manufactured by a series welding beads deposited one above another, see Fig. 2a. Careful cleaning of the weld surface after each bead was done. The used welding electrode was designated as AWS E 6013. Standard tensile testing specimens were cut out of the weld metal block in the welding direction, see Fig. 2. Those specimens were then tested on a universal testing machine.

All the tensile testing of the pipe material and on the weld metal was carried out on a universal testing machine TM-300 with dual-column, stand-alone system with 300 kN maximum loading capacity.


Pipe Bending Testing

The welded pipes were subjected to bending tests. The pipes were cut longitudinally to four equal segments, as shown in Fig. 3. This is to ease the testing procedure and to characterize the difference between bending through the face and bending through the root. Fig. 4 illustrates the experimental setup for the three-point bending tests. Geometry and dimensions of the pipe specimens along with the bending test layout are shown in Fig. 5. The face- bending test was performed such that the weld face was on the outside of the bend radius. The root-bending test was performed such that the weld root was on the outside of the bend radius.


Figure 2 Sampling the tensile specimen of the weld metal. (a) In-house made block of weld metal. (b) Sampling the specimen out of the weld metal block. (Dimensions in mm)

Figure 3 Sampling of bending specimen of the welded pipes

  • Packing & Delivery

  • Tolerance table
  • Chemical composition

ASTMA53/A53M-07 American Society for Testing and Materials:

Standard

Chemical Composition

Mechanical Properties


C

Si

Mn

P

S

Yield Strength

Tensile Strength

Elongation

2in (50mm)


Max%

Max%

Max%

Max%

Max%

(Min)

(Min)

(Min)

Grade A

0.25

-

0.95

0.05

0.045

205

330

-

Grade B

0.30

-

1.20

0.05

0.045

240

415

-


Standard JIS G 3452-2004 Japanese Industrial Standard Specifies:

Standard

Chemical Composition

Mechanical Properties


C

Max%

Mn

Max%

P

Max%

S

Max%

Yield Strength MPa

Tensile Strength

MPa

Elongation


Min

SGP

-

-

0.040

0.040

-

290

30


EN 10255:2004 (BS 1387-1985) British Standard:

Standard

Chemical Composition

Mechanical Properties

Hydrostatic Test

(Bar)


C

Max%

Mn

Max%

P

Max%

S

Max%

Yield Strength

(Min)

Tensile Strength

(Min)

Elongation

(Min)

Class Light

0.20

1.40

0.035

0.030

195

320-520

20

50

Class Medium

0.20

1.40

0.035

0.030

195

320-520

20

50

Class Heavy

0.20

1.40

0.035

0.030

195

320-520

20

50

Frequently Asked Questions

What is the difference between hot-dipped galvanized (HDG) and pre-galvanized welded pipe?

• HDG per ISO 1461: pipe fabricated first, then dipped in molten zinc at 450°C, minimum coating weight 610 g/m² (>6mm WT) to 1100 g/m² (over 6mm). Suitable for outdoor/underground service with 50+ year life per ISO 9224.
• Pre-galvanized: steel strip zinc-coated before forming via continuous hot-dip per EN 10143, 180-275 g/m² coating, then slit and formed into welded pipe. Lower cost for interior/dry applications; coating damaged at weld zone (zinc-free seam).
• Xenith Steel supplies both: HDG for structural/water/fencing (BS 1387 Class B/C), pre-galvanized for greenhouse/conduit (EN 10255 Class A/B).

Can galvanized welded pipe be welded without damaging the zinc coating?

• Welding burns off zinc in the weld zone (zinc vaporizes at 907°C), exposing bare steel. Per AWS D1.1 Clause 5.15: adequate ventilation required to avoid zinc oxide fume inhalation.
• Post-weld coating repair per ASTM A780: apply zinc-rich paint (minimum 95% zinc dust by weight, 100 µm DFT) or zinc spray metalizing. For critical structural assemblies, specify pre-galvanized sections and minimize weld length.
• Alternative: use mechanical couplings (per AWWA C606) instead of welding for galvanized water pipe ≤300 mm OD.

What standards govern galvanized welded pipe manufacturing and testing?

• Pipe standards: ASTM A53 (welded & seamless galvanized), BS 1387 (steel tubes for screwing), EN 10255 (non-alloy steel tubes for welding/threading).
• Coating standards: ISO 1461 (hot-dip galvanized coatings on fabricated iron/steel), ASTM A123 (zinc coating on steel products), ASTM A153 (zinc coating on hardware).
• Testing: ASTM A90/A90M (coating weight by gravimetric method), ASTM A239 (coating uniformity by Preece copper sulfate test per Table 1), bend test per ASTM A53 Section 13, hydrostatic test per ASTM A53 Section 14 at 2,500 psi minimum.

What is the minimum zinc coating weight required per ASTM A53 for galvanized pipe?

• ASTM A53 Table X3.1: minimum average coating weight 490 g/m² (1.5 oz/ft²) for all pipe sizes. Individual specimen minimum 430 g/m² (1.3 oz/ft²).
• BS 1387 Table 5: heavy grade (Class C) 610 g/m², light grade (Class A) 460 g/m². EN 10255 Table 3: Class A (heavy) 610 g/m², Class B (light) 460 g/m².
• Xenith Steel targets ≥610 g/m² on all HDG pipe, verified per ASTM A90 with 3-point sampling per 100 pipes. Coating thickness measured per ISO 2808 at 5 points per pipe; rejection if any point below 430 g/m².

How does galvanized pipe compare to black steel pipe for outdoor and corrosive environments?

• Service life per ISO 9224 for HDG (610 g/m²): rural 50+ years, urban 30-50 years, industrial 20-30 years, marine 15-25 years. Black steel pipe in same environment requires painting every 3-5 years or fails within 1-5 years bare.
• Cost analysis: HDG adds 30-60% to pipe cost vs black steel but eliminates painting/long-term maintenance. 30-year total cost of ownership (TCO) per NACE 10A392: HDG 25-40% lower than black steel + regular painting.
• For buried service at >60°C or highly acidic soil (pH <5), HDG alone insufficient → specify HDG + FBE dual system per ISO 21809-2.

What sizes, wall thicknesses, and end finishes are available for galvanized welded pipe?

• OD: 21.3 mm (1/2″) to 660 mm (26″). Wall thickness: Schedule 10 (2.1 mm) through Schedule 80 (12.7 mm), plus custom up to 20 mm for structural applications.
• Length: random 5.8-6.1 m, double random 11.8-12.2 m, or cut-to-length ±3 mm per customer spec.
• End finishes: plain end (PE), beveled end (BE) per ASTM A53 Section 18, threaded and coupled (T&C) per ASME B1.20.1 for BS 1387/EN 10255 screwing pipe. Xenith Steel supplies with thread protectors (plastic caps) on all T&C orders.

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