ERW Steel Pipe Manufacturer in China | API Certified Welded Pipe Factory
Introduction
ERW steel pipes (electric resistance welded steel pipes) are among the most widely used welded steel pipes in modern industry. As a professional Chinese manufacturer of ERW steel pipes, we supply high-quality steel pipe products to oil and gas, water conservancy, building structure, and fire protection system projects worldwide.
Compared to seamless steel pipes and spiral-welded steel pipes, ERW steel pipes strike the optimal balance between cost, strength, and production efficiency, making them widely used in various engineering projects.
What is ERW Steel Pipe?
ERW steel pipes are manufactured by rolling steel strips into a tubular shape and welding the seam using high-frequency resistance welding technology.
Key Features:
- High production efficiency
- Consistent weld quality
- Lower cost
- Suitable for medium- and low-pressure transmission systems
ERW Steel Pipe Specifications & Size Chart
|
Item |
Range |
|---|---|
|
OD |
1/2” – 24” (DN15 – DN600) |
|
Wall Thickness |
1.5mm – 20mm |
|
Length |
6m / 12m / custom |
|
Standard |
API 5L / ASTM A53 / EN10219 |
ERW steel pipes are available in a wide range of specifications to meet various engineering needs and are commonly used in structural engineering, fluid conveyance, and industrial piping systems.
ERW Steel Pipe Size Chart
|
NPS (inch) |
DN (mm) |
OD (mm) |
Wall Thickness (mm) |
Weight (kg/m) |
|---|---|---|---|---|
|
1/2" |
DN15 |
21.3 |
1.5 – 3.0 |
0.75 – 1.27 |
|
3/4" |
DN20 |
26.7 |
1.5 – 3.0 |
1.10 – 1.68 |
|
1" |
DN25 |
33.4 |
1.5 – 4.0 |
1.27 – 2.50 |
|
1 1/4" |
DN32 |
42.2 |
1.5 – 4.5 |
1.68 – 3.40 |
|
1 1/2" |
DN40 |
48.3 |
1.5 – 5.0 |
2.00 – 4.50 |
|
2" |
DN50 |
60.3 |
1.8 – 5.5 |
2.50 – 6.50 |
|
2 1/2" |
DN65 |
73.0 |
2.0 – 6.0 |
3.80 – 9.50 |
|
3" |
DN80 |
88.9 |
2.0 – 6.5 |
5.00 – 12.00 |
|
4" |
DN100 |
114.3 |
2.0 – 8.0 |
7.50 – 20.00 |
|
5" |
DN125 |
141.3 |
2.5 – 9.0 |
11.00 – 28.00 |
|
6" |
DN150 |
168.3 |
2.5 – 10.0 |
15.00 – 38.00 |
|
8" |
DN200 |
219.1 |
3.0 – 12.0 |
22.00 – 60.00 |
|
10" |
DN250 |
273.0 |
3.0 – 14.0 |
32.00 – 85.00 |
|
12" |
DN300 |
323.9 |
4.0 – 16.0 |
45.00 – 110.00 |
|
14" |
DN350 |
355.6 |
5.0 – 18.0 |
55.00 – 135.00 |
|
16" |
DN400 |
406.4 |
5.0 – 20.0 |
70.00 – 165.00 |
|
18" |
DN450 |
457.0 |
6.0 – 22.0 |
90.00 – 210.00 |
|
20" |
DN500 |
508.0 |
6.0 – 24.0 |
110.00 – 250.00 |
|
24" |
DN600 |
610.0 |
8.0 – 25.0 |
160.00 – 350.00 |
ERW steel pipes follow strict dimensional tolerance standards such as:
- OD tolerance: ±0.5% to ±1%
- Wall thickness tolerance: ±10%
- Length tolerance: ±50mm
ERW Steel Pipe Standards
Cortec Steel ERW steel pipes are manufactured in strict accordance with international standards, including:
· API 5L (Line pipe for the oil and gas industry)
· ASTM A53 (General-purpose piping)
· ASTM A500 (Structural steel tubing)
· EN 10219 / EN 10217 (European standards)
ERW Steel Pipe Manufacturing Process
The ERW steel pipe manufacturing process includes:
- Steel coil preparation
- Strip forming into tube shape
- High-frequency welding (HFW)
- Weld seam heat treatment (if required)
- Sizing and straightening
- Cutting to length
- Hydrostatic testing
- Non-destructive testing (UT / Eddy current)
ERW Steel Pipe Applications Across Industries
- Oil & Gas Transportation
- Water Supply & Municipal Engineering
- Structural Steel Construction
- Fire Fighting Systems
- Industrial Fluid Transportation
Before selecting ERW steel pipes for use in various engineering projects, engineers and procurement personnel typically evaluate the following key technical factors to ensure safety and cost-effectiveness in actual projects.
1. Pressure Level
ERW steel pipes are mainly suitable for low to medium pressure applications.
· Low pressure: ≤ 2.5 MPa (water supply, drainage, air)
· Medium pressure: 2.5 – 10 MPa (industrial fluids, oil & gas transmission)
· High pressure: not recommended (seamless pipe preferred)
2. Standard Compliance
Different engineering projects must comply with the corresponding international standards:
· API 5L → Oil and gas transmission pipelines
· ASTM A53 → General-purpose piping systems
· ASTM A500 → Structural engineering
3. Working Environment
Underground installation → Requires anti-corrosion coating
Marine environment → High-grade anti-corrosion system
Corrosive environment → Hot-dip galvanizing or FBE/3LPE anti-corrosion treatment
Size Suitability
· DN15–DN50 → Building services, plumbing, fire protection
· DN50–DN300 → Municipal water systems, structural use
· DN300–DN600 → Large-scale infrastructure (limited ERW usage)
ERW vs Seamless vs SSAW
|
Feature |
ERW Steel Pipe |
||
|---|---|---|---|
|
Manufacturing Process |
Electric resistance welding of steel coil |
Hot piercing & extrusion (no weld seam) |
Spiral submerged arc welding |
|
Weld Seam |
Longitudinal weld seam |
No weld seam |
Spiral weld seam |
|
Strength Level |
Medium |
High |
High |
|
Pressure Rating |
Low – Medium pressure |
High pressure |
Medium – High (depends on thickness) |
|
Diameter Range |
DN15 – DN600 (1/2”–24”) |
DN6 – DN600+ |
DN200 – DN3000+ |
|
Wall Thickness |
1.5 – 20 mm |
2 – 50 mm+ |
6 – 25 mm+ |
|
Cost Level |
⭐ Low (most economical) |
⭐⭐⭐ High |
⭐⭐ Medium |
|
Production Efficiency |
High |
Low |
Medium |
|
Common Standards |
API 5L / ASTM A53 / EN10219 |
API 5L / ASTM A106 |
API 5L / EN10217 |
|
Main Applications |
Water, structure, oil & gas (low-medium pressure) |
High-pressure oil & gas, boiler systems |
Large diameter pipelines, water & oil transmission |
How to Choose an ERW Steel Pipe Manufacturer
When selecting an ERW steel pipe manufacturer, you should focus on four key factors: production capacity, quality certifications, quality control systems, and industry experience.
A reliable supplier should have advanced ERW production lines that comply with international standards such as API 5L and ASTM, and implement strict quality control measures, including hydrostatic testing and non-destructive testing.
Manufacturers such as Cortec Steel typically have stable production capacity, extensive export experience, and a comprehensive quality management system, enabling them to ensure a steady supply for global projects.
FAQ
1. What is ERW steel pipe?
ERW steel pipe is a welded pipe produced by electric resistance welding of steel coils.
2. What is the difference between ERW and seamless pipe?
ERW is welded, while seamless pipe is manufactured without welding.
3.Is ERW pipe suitable for oil and gas?
Yes, ERW pipes can be used in oil and gas transmission under API 5L standards.
4. Can ERW steel pipe be galvanized?
Yes, ERW pipes can be hot-dip galvanized for corrosion protection.
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This article was originally created by CORTEC STEEL LIMITED and first published on the official website www.cortecsteel.com.
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