How to judge the quality of copper pipe?

Judging the quality of copper pipes can be started from the following aspects:

1. Appearance:

- Color: for copper pipes, high-quality copper pipes are generally red copper color, uniform color and luster; If the color is dark, black or has other variegated colors, it may contain more impurities and poor quality. For brass pipes, the relative quality of light, uniform and metallic luster is better, and the color is too dark or uneven.

- Surface smoothness: the surface of high-quality copper pipe should be smooth and flat, without obvious bumps, holes, pinholes, cracks, peeling, bubbles, inclusions, green rust, bruises, mold marks and other defects. You can touch the surface with your hand to feel whether it is smooth or not; You can also use the light to observe the reflection of the copper tube surface from different angles to check if there is an uneven place.

- Cleanliness: The inner and outer walls of copper pipes should be kept clean, free from oil, dust, rust and other pollutants. If there is more dirt or rust on the surface of the copper pipe, it may affect its performance and service life.

2. Material purity:

- Composition testing: If conditions permit, the composition of the copper pipe can be tested by professional chemical analysis methods to determine its copper content and whether it contains other impurity elements. For copper pipes, the higher the content of pure copper, the better the quality, such as the copper content of oxygen-free copper ≥99.97%, its electrical conductivity, thermal conductivity and other properties are better.

- Extensibility judgment: pure copper has good extensibility, and high-quality copper pipes can be deformed to a certain extent without breaking when subjected to external force. You can use a sharp tool to gently draw on the surface of the copper pipe, a good copper pipe will appear a deep line, and the scratched part is consistent with the outer wall material; If the internal color or material is different from the outer wall after being scratched, the purity of the copper pipe may not be high enough, and other metals are added inside.

3. Thickness and strength:

- Thickness measurement: Use professional measuring tools, such as micrometers, to measure the wall thickness of copper pipes. The wall thickness of the copper pipe should meet the relevant standards and requirements, if the wall thickness is not uniform or too thin, it may affect the strength and pressure resistance of the copper pipe. For example, in some application scenarios with high pressure requirements, such as copper pipes in air conditioning refrigeration systems, there needs to be enough wall thickness to withstand the pressure of the refrigerant.

- Strength test: gently tap the copper pipe to hear whether the sound is even and crisp. If the sound is dull or noisy, there may be defects or impurities inside the copper pipe, affecting its strength; Or perform a certain degree of bending test on the copper pipe (pay attention to the degree of bending not to exceed the limit of the copper pipe), the high-quality copper pipe can be restored to its original state after bending, and the surface will not crack or fracture, and the poor quality copper pipe may break when bending.

4. Corrosion resistance:

- Anti-corrosion treatment: Know whether the copper pipe has been treated with anti-corrosion treatment, and the anti-corrosion treatment method used. For example, some copper pipes will be tinned and other treatments to improve their corrosion resistance. If the copper pipe is not subjected to any anti-corrosion treatment, it is vulnerable to corrosion during use and affects its service life.

- Corrosion resistance test: the copper pipe can be placed in a certain corrosive environment, such as humid air, acidic or alkaline solution, and the corrosion of the copper pipe can be observed after a period of time. If there are obvious corrosion marks on the surface of the copper pipe, it means that its corrosion resistance is poor.

5.Specifications and standards: Check whether the identification on the copper pipe, such as the manufacturer, specifications, models, implementation standards and other information is clear and accurate. High-quality copper pipe should meet the relevant national standards or industry standards, and the reputation and qualification of the manufacturer is also an important factor in judging the quality of copper pipe.