Xenith Steel
Xenith Steel

For gas and water conveyance requiring galvanized seamless pipe with no weld seam, a 610 g/m² hot-dipped zinc coating per ISO 1461 delivers 50+ year service life in rural atmospheric exposure per ISO 9224 — compared to pre-galvanized (180-275 g/m²) which suits interior dry applications at lower cost. ASTM A53 Table X3.1 sets 490 g/m² minimum; Xenith Steel targets ≥610 g/m² verified per ASTM A90 with 3-point sampling per 100 pipes. Unlike welded galvanized pipe where the weld zone loses zinc during forming, seamless galvanized pipe maintains coating integrity over the full circumference — a critical differentiator for gas utilities and fire protection systems per NFPA 13. Produced at our seamless pipe mill in Cangzhou, our HDG seamless pipe complies with ASTM A53 Type S, BS 1387 Class C, and EN 10255 Class A.

Welded Steel Pipe

Seamless Steel Pipe

OCTG

Structural Steel Section

Stainless Steel Pipe

Coating Steel Pipe

Steel Metal

Pipe Fittings

Special Products

Galvanized seamless pipe with zinc coating
Seamless pipe wall thickness
Galvanized pipe bundle

Galvanized Seamless Pipe



Size

O.D.

1/8"- 8" (5.15mm-219.1mm)

DN 6 - DN200

Max. → 24"(609.6mm)  DN 600

Wall

Thickness

0.4mm - 26mm

SCH20, SCH40, STD, XS, SCH80, SCH160, XXS

Length

Max. Length: 12m

Material

ASTM, Grade B, Grade C, Grade D, Grade 50,EN, S185, S235JR, S235JO, E335, S355JR, S355J2,JIS, SS330, SS400, SPFC590


  • Products details
  • Tolerance table
  • Chemical composition
  • Specification

Galvanized Seamless Pipe Specification:



Size

O.D.

1/8"- 8" (5.15mm-219.1mm)

DN 6 - DN200

Max. → 24"(609.6mm)  DN 600

Wall

Thickness

0.4mm - 26mm

SCH20, SCH40, STD, XS, SCH80, SCH160, XXS

Length

Max. Length: 12m

Material

ASTM, Grade B, Grade C, Grade D, Grade 50

EN, S185, S235JR, S235JO, E335, S355JR, S355J2

JIS, SS330, SS400, SPFC590


Ends

1) Plain

2) Beveled

3) Thread

4) Chamfer

5) Groove


Usage of Galvanized Seamless Steel Pipe

1) Low Pressure Liquid, Water, Gas, Oil, Line  Pipe
2) Construction Site
3) Fence, Scaffold


Surface Treatment of Galvanized Seamless Steel Pipe

1) Bared
2) Black Painted
3) Galvanized
4) Oiled
5) Corrosion Resistant Coating, Anti Corrosion Coating.

  • Process

  • Tests

Surface quality requirements of galvanized layer:

The galvanized layer on the inner and outer surfaces of the seamless steel pipe should be complete, no black spots and air bubbles without zinc plating are allowed, and small rough surfaces and local zinc tumors are allowed. The surface of the steel pipe can be passivated after galvanizing.


Weight determination of galvanized coating:

For galvanized steel pipes, the weight of the zinc layer shall be measured. The total weight per unit area of the galvanized layer on the inner and outer surfaces of the steel pipe shall not be less than 300g/m2.

According to the requirements of the buyer, the supplier can supply galvanized steel pipes with the total weight per unit area of the galvanized layer on the inner and outer surfaces not less than 500g/m2 after negotiation between the supplier and the buyer and indicate in the contract. When the total weight of the galvanized layer per unit area is 500g/m2, the total weight of the galvanized layer of one of the samples is allowed to be less than 500g/m2, but not less than 480g/m2.


Zinc coating uniformity test:

The galvanized steel pipe shall be subjected to the uniformity test of the zinc layer. During the test, the sample (except for the weld) should not be red (copper-plated color) after being continuously immersed in copper sulfate solution for 5 times.


Adhesion test of galvanized layer:

After galvanizing steel pipes with an outer diameter of not more than 60.3mm, a bending test shall be used to test the adhesion of the galvanized layer. During the test, the bending sample shall be without filler, the bending radius shall be 8 times the outer diameter of the steel pipe, the bending angle shall be 90°, and the weld shall be located on the outer side of the bending direction. After the test, the sample is not allowed to peel off the zinc layer.

According to the requirements of the buyer, after negotiation between the supplier and the buyer, and it is indicated in the contract, the flattening test can be used to test the adhesion of the galvanized layer after the steel pipe with an outer diameter greater than 60.3mm is galvanized. The length of the flattened specimen shall not be less than 64mm. During the test, when the distance between the two flat plates is 3/4 of the outer diameter of the steel pipe, the zinc layer is not allowed to peel off on the sample.

  • Packing & Delivery
  • Tolerance table

Element Material Standard

Mechanical Property


Yield Point

(Mpa)

Tensile Strength

(Mpa)

Elongation

(%)

ASTM Gr.B

>195

315-430

32-33

GB/T 700-2006

>235

375-500

24-26

GB/T1591—1994

>345

470-630

21-22

  • Chemical composition

Element Material Standard

Chemical Composition%



C%


Mn%


S%


P%


Si%

ASTM Gr.B

0.06-0.12

0.25-0.50

<0.050

<0.045

<0.30

GB/T 700-2006

0.12-0.20

0.30-0.70

<0.045

<0.045

<0.30

GB/T1591—1994

<0.20

1.0-1.6

<0.040

<0.040

<0.55

Frequently Asked Questions

What is the difference between pre-galvanized and hot-dipped galvanized seamless pipe?

• Pre-galvanized: steel strip coated before pipe forming via continuous hot-dip per EN 10143 (180-275 g/m²), then formed into pipe. Suits interior/dry applications at lower cost.
• HDG per ISO 1461: pipe fabricated first, then dipped in molten zinc at 450°C, coating weight 610-1100 g/m² depending on wall thickness. 2-4x thicker coating for outdoor/underground service.
• Xenith Steel supplies both types: HDG seamless for water/gas utilities and structural outdoor use (BS 1387 Class C/EN 10255 Class A), pre-galvanized for conduit and light-duty applications.

What standards apply to galvanized seamless steel pipe?

• Pipe standards: ASTM A53 Type S (seamless, black and hot-dipped), BS 1387 (steel tubes for screwing), EN 10255 (non-alloy steel tubes for welding/threading).
• Coating standards: ISO 1461 (hot-dip galvanized coatings), ASTM A123 (zinc coating on steel products), ASTM A153 (zinc coating on hardware).
• Testing: ASTM A90/A90M (coating weight by gravimetric), ASTM A239 (coating uniformity by Preece copper sulfate test per Table 1). Seamless-specific: hydrostatic test per ASTM A53 Section 14 at 2,500 psi minimum, flattening test per Section 12.

What coating weight does ASTM A53 require for galvanized seamless 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 seamless 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 below 430 g/m².

Can galvanized seamless pipe be threaded and coupled?

• Yes. Per ASME B1.20.1 (Pipe Threads, General Purpose), galvanized seamless pipe can be threaded to NPT standard. BS 1387 and EN 10255 specify threading for screwing pipe.
• Post-threading: threading exposes bare steel at cut surfaces. Per ASTM A780, apply zinc-rich paint (minimum 95% zinc dust by weight, 100 µm DFT) to exposed threads.
• Xenith Steel supplies T&C with plastic thread protectors on all orders. For gas utility applications, we recommend HDG seamless with T&C per NFPA 54 for leak-tight joints.

How does galvanized seamless pipe compare to galvanized welded pipe?

• Seamless has no weld seam, eliminating weld-zone corrosion risk and allowing higher pressure ratings per ASME B31.3 Table A-1B (seamless 0.85 quality factor E vs welded 0.75-0.85 E).
• For fire protection systems per NFPA 13: seamless galvanized permitted at higher pressure classes than welded. Hydraulic design advantages: seamless handles 10-20% higher operating pressure for same wall thickness.
• Cost trade-off: seamless galvanized typically costs 20-35% more than welded due to SMLS billet piercing/rolling process vs coil-fed ERW. Applications requiring 100% weld-zone integrity justify the premium.

What sizes and end finishes are available for galvanized seamless pipe?

• OD range: 21 mm (1/2″) to 610 mm (24″). Wall thickness: Schedule 10 (2.1 mm) through Schedule XXS (18.3 mm), plus custom up to 70 mm for heavy-duty industrial 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 on all T&C orders.