In the global high-end steel pipe market, Europe and America have established strict technical barriers to entry. As a key component in oil & gas, chemical, and new energy sectors, ASTM A778 Electric Resistance Welded (ERW) threaded pipes must pass verification of three core inspection indicators to enter European and American markets – this is not only a mandatory standard requirement but also a "safety code" to avoid trade risks.
1. Chemical Composition Compliance: The "Genetic Code" for Corrosion Resistance
The ASTM A778 standard clearly specifies that ERW threaded pipes shall be made of austenitic stainless steel, and their chemical composition must strictly meet the requirements of respective Grade classifications. Taking the widely used TP316L as an example, the chromium content shall be controlled between 16.0%-18.0%, nickel content between 10.0%-14.0%, and carbon content shall not exceed 0.030%. This indicator directly determines the durability of products under high-humidity and high-corrosion conditions in Europe and America. For instance, in gas transmission pipelines in the marine climate of Northern Europe, if the chromium content is less than 16%, the risk of corrosion failure within 3 years will increase by 40%.
The environmental protection requirements in European and American markets further amplify the importance of this indicator. The EU REACH Regulation explicitly restricts the content of heavy metals, and the ASTM A778 standard’s requirements (phosphorus ≤ 0.045%, sulfur ≤ 0.030%) align perfectly with this regulation. Data from Huayu Testing shows that in 2024, a Chinese enterprise had 1,200 tons of ASTM A778 steel pipes detained at the Port of Rotterdam due to non-compliant nickel content, resulting in a direct loss of over 8 million RMB.
2. Welded Joint Mechanical Properties: The "Lifeline" for Structural Safety
As the weak link of ERW threaded pipes, the mechanical properties of welded joints are the top priority in European and American market audits. The ASTM A778 standard mandates transverse tensile tests and transverse guided bend tests for welded joints, while the EU EN 10217 standard further adds weld hardness mapping requirements on this basis. For pipes with a nominal diameter of 200mm, the tensile strength of the welded joint shall not be less than 515MPa, and no cracks shall occur when the bending angle reaches 180° in the bend test.
This indicator is particularly critical in high-pressure scenarios. ASTM A778 pipes used in chemical parks in the Ruhr region of Germany need to withstand a working pressure of 10MPa; if the yield strength of the welded joint is less than 205MPa, leakage accidents may occur. In 2025, Tianjin Pipe Group’s export order to the Netherlands successfully obtained a subsequent 3-year long-term contract precisely because 100% of its welded joints passed the bend test.
3. Nondestructive Testing (NDT) Integrity: The "Keen Eye" for Defect Detection
The zero-tolerance policy for pipe defects in European and American markets has made NDT a mandatory requirement for ASTM A778 certification. The standard requires ultrasonic testing (UT) to detect internal weld defects and radiographic testing (RT) to verify weld fusion quality, with the length of defect indications not exceeding 1/3 of the wall thickness. This is fully consistent with the requirement of "100% NDT for high-risk equipment" in the EU Pressure Equipment Directive (PED 2014/68/EU).
Practical cases show that strict implementation of NDT can significantly reduce trade risks. In the first half of 2025, a Shandong-based enterprise’s ASTM A778 steel pipes exported to Italy were deemed non-compliant by an EU notified body due to tiny cracks not detected by eddy current testing (ET), with rectification costs accounting for 27% of the order value. In contrast, enterprises adopting the "UT + RT" dual-testing mode have a product return rate of only 0.3% in European and American markets, far lower than the industry average of 2.1%.
Compliance Is the Key to "Customs Clearance": The Solution for Enterprises
Facing the technical barriers of European and American markets, enterprises need to establish a "standard pre-positioning + full-process control" system: conduct spectral analysis against the ASTM A778 composition table in the raw material stage, strictly control parameters based on Welding Procedure Qualification Records (WPQR) in the welding stage, and entrust EU notified bodies to conduct NDT before delivery. As Huayu Testing points out, meeting the dual requirements of ASTM standards and European harmonized standards is the "double key" to unlocking European and American markets.
Sources:
- Huayu Southern Measurement & Control: EU Access Standards for Gas Steel Pipes
- ASTM International: ASTM A778 Standard Specification
- Huayu Testing Network: CE Certification Requirements for Pipeline Steel Pipes
