In industrial engineering, the quality of steel pipes is directly related to the safety and service life of the entire pipeline system. However, even experienced purchasers often encounter problems that make it difficult to distinguish the quality of products. Therefore, when selecting steel pipes, understanding and implementing the following 8 key inspection standards will help you identify high-quality products more effectively and ensure the long-term stable operation of the project.
1. Prefer newly produced steel pipes
Why is it important?
Newly produced steel pipe fittings have better surface integrity and roundness. Long-term storage may not only cause steel to rust and produce elliptical deformation, but may even cause mechanical damage due to improper stacking.
Recommendation:
Choose a steel pipe supplier with “Just-in-Time” production capabilities, such as our company can quickly deploy production lines according to customer orders, reduce the risk of storage aging, and ensure that you get fresh and high-quality products.
2. Check the condition of the outer surface
The cleanliness and integrity of the outer surface not only affect the adhesion effect of the anti-corrosion coating, but also directly affect the long-term stability of use.
Reference standard: ISO 8501 Surface rust grade
- Grade A: Slight rust with original oxide scale
- Grade B: Oxide scale peeling off, surface rusting
- Grade C: Obvious rust with slight pitting
Grade D: Severe pitting, oxide scale completely falling off
Recommendation:
Preferably choose steel pipes that reach Grade A or Grade B, and avoid using Grade C/D products to reduce surface treatment costs (such as sandblasting and rust removal).
3. Verify the cleanliness of the inner wall
If there is rust, welding slag or impurities on the inner wall, it will not only affect the fluid transmission efficiency, but also may cause local corrosion of the pipeline system.
Detection method:
Use a strong light flashlight to check the inner wall, which should be smooth and free of obvious impurities or foreign matter residues.
4. Whether the coating quality meets the standard
The anti-corrosion coating on the surface of the steel pipe (such as hot-dip galvanizing, epoxy resin, etc.) is an important barrier to prevent environmental corrosion.
Key parameters include:
- Coating thickness: recommended to be no less than 20 microns, 4-6 points for each pipe
- Adhesion: no peeling or bulging after cross-cutting test
- Surface finish: uniform coating without cracks and bubbles
We use a fully automatic continuous hot-dip galvanizing process line for galvanizing to ensure galvanized malleable iron fittings traceability of coating quality and batch consistency, meeting the needs of highly corrosive environments such as marine, chemical, and outdoor transportation systems.
5. Is the label clear and durable?
Correct labeling is essential for later product tracking, quality review, and installation.
Standard requirements:
- The font should be clear and indelible, and the labeling should include product grade, size, batch, and manufacturer information
- The labeling position should appear uniformly at both ends of the pipe for easy identification
6. Are the pipe end protection measures in place?
The threaded or beveled ends of steel pipes are prone to bumping or deformation during transportation.
Recommended solution:
Use plug-in or external snap-on plastic pipe caps, or add steel end rings to prevent coating damage and pipe end deformation during transportation. Our products are all shipped with standard pipe caps to ensure that the ports are delivered intact.
7. Are the bundling method and weight distribution reasonable?
Reasonable bundling not only improves handling efficiency but also prevents steel pipes from scratching or slipping during transportation.
Bundling standards:
- Use 6-8 steel straps per bundle (three at each end and two in the middle)
- It is recommended that the weight of a single bundle does not exceed 1 ton for easy lifting and loading, and unloading
- The edges of the bundling straps should be bent to avoid damage to the coating
8. Are the storage conditions standardized?
Moisture, dust, and climate change will accelerate the rust on the surface of the steel pipe, affecting long-term quality.
Recommended storage method:
- Use dry and ventilated indoor warehouses, equipped with moisture-proof wooden mats and layered stacking
- If stored outdoors for a short period, cover with a waterproof cloth and check the surface condition regularly
✅ Summary of quality self-inspection list
| Inspection items | Core indicators |
| Production freshness | Avoid long storage time, give priority to purchasing new products |
| External surface condition | Meet ISO 8501 A/B level, no obvious rust and pitting |
| Inner wall cleanliness | Smooth without welding slag and oil pollution, ensure smoothness |
| Coating quality | Thickness ≥ 20 µm, no cracks and bubbles |
| Marking clarity | Labels are wipe-resistant and have complete information |
| Pipe end protection | Pipe caps and steel rings are complete to prevent bumps and deformations |
| Bundling standard | Each bundle has 6-8 steel strips, safe and convenient |
| Storage environment | In a dry room, cover and protect when necessary |
Why choose us? ——Professional steel pipe and pipe fittings supplier from China
We not only provide high-quality welded steel pipes (ASTM/EN standards), grooved pipe fittings, forged high-pressure elbows and tees, threaded steel pipe joints, liquid PTFE tape and other full-category accessories, but also focus on the field of stainless steel pipe fittings, such as 304/316 stainless steel elbows, tees, cross joints, etc., which are widely used in water supply and drainage, chemical, petroleum, electricity, food hygiene and other industries.
Product advantages:
- Support OEM customization and international standard docking
- Full range of pipe thread standards (ASME B1.20.1, ISO7/1, DIN2999, etc.)
- Pressure level up to 150LB/2.0MPa, suitable for high-pressure systems
- All factory products are equipped with complete MTC (material certification) and batch records
Welcome to visit our official website or contact us directly for detailed quotation information. We will recommend the most suitable product solution for your project!