Steel Pipe Procurement FAQ: Top 6 Questions Answered | Hebei Metal

        In the international steel trade, attention to detail determines the success or failure of a project. As a professional steel pipe manufacturer in China, Hebei Metal has compiled the 10 most critical questions that global buyers frequently encounter during the inquiry and import processes. Whether you are sourcing seamless pipes or stainless steel products, this guide will help you avoid pitfalls and optimize your budget.

        Ⅰ. What are the fundamental differences in application between seamless steel pipes and welded steel pipes (ERW)?

        This represents the most fundamental—yet most critical—consideration in the pipe selection process.

        • Seamless Steel Pipe:Produced by perforating a solid round steel billet,it features no welded seams. Its primary advantage lies in its exceptionally high pressure-bearing capacity and uniform structural integrity, making it the preferred choice for high-pressure boilers, oil and gas transmission, and hydraulic systems.

        • Welded Steel Pipe (ERW/LSAW): Manufactured by rolling and welding steel plates. Thanks to advancements in welding technology, its strength now closely rivals that of seamless pipes; moreover, it offers lower costs and shorter lead times, making it suitable for low-pressure fluid conveyance and structural construction applications.

        Ⅱ. How to Verify an MTC Provided by a Chinese Supplier?

        Fraudulent material certificates represent a persistent pain point within the industry.As a Verified Steel Pipe Supplier,Metal recommends that you pay close attention to the following two points:

        • Heat Number Verification: Verify that the Heat Number listed on the Material Test Certificate (MTC) corresponds exactly with the stencil markings applied to the surface of the steel pipe.

        • Standard Compliance: Confirm that the certificate complies with EN 10204 3.1 (issued by the manufacturer's internal quality control department) or the higher-level standard, 3.2 (verified by a third party).

        Ⅲ. What is the SCH of steel pipe? How is the wall thickness calculated?

        "Schedule" (SCH) is a standard designation for wall thickness widely used in North America and internationally; it does not represent a specific measurement in millimeters. For instance,when comparing a 10-inch SCH 40 pipe with a 10-inch SCH 80 pipe,the latter features a significantly thicker wall and offers superior pressure bearing capacity.

        Note: For a given SCH number, the actual wall thickness varies depending on the nominal pipe size (diameter). When making a purchase, please be sure to consult the latest ASME B36.10 standard tables.

        Ⅳ. How does Hebei Metal prevent rust during sea transport?

        A sea voyage lasting up to 40 days poses a severe challenge to steel products. As a Direct Factory Exporter, we provide the following protective measures:

        • Surface Treatment:Painting (Black Painting), hot-dip galvanizing,or application of anti-rust oil.

        • Pipe End Protection: Installation of plastic caps on beveled ends to prevent moisture ingress.

        • Packaging: Full wrapping in waterproof woven bags or reinforcement with wooden crates.

        Ⅴ. What are Beveled Ends? Do I need them?

        If your steel pipes require installation via butt welding, beveling is mandatory. Common bevel angles are 30℃ or 37.5℃. If a threaded connection is required, Threaded Ends (NPT/BSPT) must be specified.

        Ⅵ. What is the difference between the NB/DN and the OD of a steel pipe?

        • NB (Nominal Bore) / DN (Diameter Nominal): A nominal value representing the approximate internal diameter of the pipe.

        • OD (Outside Diameter): The actual external dimension of the steel pipe; this serves as the precise reference data for manufacturing and installation purposes.

        Important Tip: When making a purchase, be sure to clearly specify whether you are providing the OD or the DN to avoid compatibility issues that could prevent mating components from being installed.

        Conclusion

        As your trusted Global Steel Piping Partner, Hebei Metal is more than just an ISO-certified steel pipe mill—we serve as your technical consultants.

        If you have any questions regarding your ongoing projects, or if you require the latest wholesale pricing for seamless steel pipes and stainless steel products, please do not hesitate to contact our technical experts.