The national standard for galvanized steel pipes has very strict quality control requirements, which are mainly reflected in the following aspects:
1. Appearance quality: The surface of galvanized steel pipes should be flat and smooth, without cracks, spots, oxide scales, oil stains, etc., and the internal and external surfaces should be consistent. The coating should be uniform and free from obvious defects and bubbles.
2. Mechanical properties: The mechanical properties of galvanized steel pipes should meet the requirements of national or industry standards, such as tensile strength, yield strength, elongation, and other indicators, to ensure that the steel pipes can withstand various external forces during use.
3. Coating quality: The thickness of the galvanized layer should meet the standard requirements. Usually, the average thickness of the galvanized layer should not be less than a certain value (specific values vary according to different standards), and it should have good adhesion and corrosion resistance. The coating should be uniform and continuous, without the need for peeling, missing plating, etc.
4. Size deviation: The size deviation of galvanized steel pipes should comply with the requirements of national or industry standards, including the deviation range of outer diameter, wall thickness, length, and other dimensions. This helps to ensure that the steel pipe matches other components or equipment during installation and use.
5. Physical properties: The physical properties of galvanized steel pipes, such as density, coefficient of thermal expansion, etc., should also comply with relevant standards to ensure the stability and reliability of steel pipes under various environmental conditions.
In addition, the marking and packaging of galvanized steel pipes must also comply with relevant national standards. Steel pipes should be marked with hot forging or oxidation printing, and packaging should comply with relevant national technical standards, including product identification, length, quantity, and other information. The method and content of marking and packaging must be clear, accurate, easy to identify, and traceable.
In short, the national standard requirements for quality control of galvanized steel pipes cover many aspects, such as appearance quality, mechanical properties, coating quality, dimensional deviation, and physical characteristics, to ensure that the quality and safety performance of the steel pipes meet the standard requirements. When producing, purchasing, and using galvanized pipes, relevant standards must be followed to ensure that they meet national requirements and practical application needs.
