Red Copper Tube- For Refrigeration | Air Conditioning

Because of its strong and wear-resistant properties, Copper Tubes are often used in electrical, industrial and construction industries. Copper tubes can be produced by extrusion, continuous casting and rolling, and up-drawing methods. Copper Tube is an important raw material for the processing and manufacturing of refrigeration equipment, and it has two main uses:

• Making heat exchangers
• Make connecting tubes and Fittings

The copper tube used in the refrigeration industry is red copper, with a copper content of more than 99.90%, which is widely used in various fields of industry and civil use, and plays an important role. Air conditioning copper tube is made of pure copper, with excellent physical and chemical properties, pure copper texture gives the copper tube unique flexibility and ductility, so that it can adapt to a variety of complex installation environment. In the air conditioning system, copper tubes are mainly responsible for the transmission of refrigerant (freon, commonly known as snow). It acts as an efficient transport channel, allowing the refrigerant to flow freely between the evaporator, condenser and other components, thereby enabling the exchange of heat and providing us with comfortable temperature regulation.

There are three main types of copper tubes for air conditioners: TP2, T2, and TU1.

• TP2 is phosphorus deoxidized copper, containing 0.015-0.04% phosphorus, with good welding and cold bending properties, in the air conditioning refrigeration connection tube, stove gas tube connection tube, electric heater and other manufacturing fields are widely used.
• T2 is pure copper, copper content is higher than 99.90%, when the user has high electrical conductivity requirements for the material, T2 copper pipe will be the first choice.
• TU1 is oxygen-free copper, copper content ≥99.97%, oxygen and impurity content is very low, high purity, excellent electrical and thermal conductivity, good ductility, processing performance and welding, corrosion resistance, cold resistance are good. Due to the high requirements and high costs of its production, the price of its products is much higher than that of other categories of red copper tubes.

The specific classification of air conditioning copper tube

By material

1. Oxygen-free copper: including high purity oxygen-free copper (TU0, TU1, TU2) and phosphorus deoxidized copper (TUP, TP1, TP2, etc.), characterized by very little oxygen content, a small amount of deoxidizer remains in deoxidized copper;
2. Aerobic copper: mainly ordinary pure copper (T1, T2, T3, etc.) and tough copper, characterized by high oxygen content;
3. Special copper: there are arsenic copper, silver copper, tellurium copper, etc., which are characterized by adding different trace alloying elements to achieve the purpose of improving the comprehensive performance of the material.
4. Brass tube: copper-zinc alloy tube. The number after the H letter in the grade often represents the middle value of its copper content, and the zinc content is the remaining amount. Brass Tubes of different grades, as the copper content becomes higher and higher, generally show better quality and elongation performance, and are mainly used as water tubes and water-related connectors.

According to the hardness: soft copper tube and hard copper tube

1. Copper tube, also known as flexible copper tube, is a copper tube that has been annealed to enhance its flexibility. This type of copper tube is easy to bend and form by hand and is suitable for situations that require complex wiring, such as residential water mains or HVAC systems.
2. Hard copper tubes, with thicker walls, are suitable for higher pressure and temperature environments and are commonly used in main water supply, gas lines and industrial applications.

Divided by refrigerant: ordinary air conditioning copper pipe and degreased air conditioning copper pipe

1. Ordinary air conditioning copper tube is mainly used for R22, the pressure is controlled at 0.98MPa.
2. Degreasing air conditioning copper tube: also called "degreasing air conditioning copper tube", mainly used for R410 and other new refrigerant, pressure control at 1.8MPa.

The price of 410 air conditioning copper tube on the market is generally more expensive than the price of R22 air conditioning copper tube. In fact, not necessarily. Since most of the 410 air conditioning copper tubes use extrusion technology, the wall thickness of the copper tubes can be made thinner while withstanding high pressure. This reduces the weight of the copper tube per meter, making the copper tube lighter in weight with the same number of meters.

Judgment of Copper Tube Quality

Appearance observation

The more intuitive way to judge the quality of copper tubes is to observe its appearance. Looking at the color of the copper tubes first, and make different color judgments based on the type of copper tubes purchased. For example, red copper tubes. Generally, reddish copper is of better quality, while inferior copper generally contains more impurities.

Internal and external identification

Good quality copper tubes have a higher copper content and will have better extensibility, so good copper tubes have a deep line. We can use tools to cut open the outer wall of the copper tube to see if the inside and outside are consistent. If the inside and outside walls are made of the same material, it means that the overall quality of the copper tube is high relatively; but if the color or other aspects are different inside and outside, indicating that its purity is not high enough and some other metals are added to it.

Bending test

The processed copper tubes are mainly divided into three types: hard, semi-hard and soft. Different forms of copper tubes have different flexibility. Therefore, it is a simple and easy method to judge the quality of copper tubes by bending them. Better quality copper tubes are easier to bend. If bending is difficult or cracks appear on the surface of the copper tube after bending, it indicates that the quality of the copper tube is not very good.

Comprehensive inspection

The three methods introduced above are simple and easy to implement and can be used for daily judgment. But if you want to obtain accurate and strict data, you need to conduct comprehensive inspections through various instruments and equipment. The inspection items include dimensional deviation, mechanical properties, process performance, chemical composition, grain size, eddy current flaw detection, etc.

Characteristics of Air Conditioning Copper Tube

1. Material advantages: Copper is a highly stable metal, which allows air conditioning copper tubes to maintain their performance under various environmental conditions. It has good plasticity and can be easily processed into different shapes and sizes to meet diverse air conditioning design needs.
2. Thermal conductivity: The thermal conductivity of air conditioning copper tubes is excellent. It can quickly conduct heat from one end to the other, allowing the refrigerant to efficiently exchange heat within the copper tube. This efficient thermal conductivity greatly improves the cooling and heating efficiency of the air conditioner and shortens the time required to reach a comfortable temperature.
3. Corrosion resistance: In humid and complex environments, air conditioning copper tube can maintain a good condition. A thin oxide film will be formed on its surface. This oxide film is like a layer of strong protective armor, effectively resisting the erosion of corrosive substances from the outside and extending the service life of the copper tube.
4. Service life: Combining its material advantages, thermal conductivity and corrosion resistance, air conditioning copper tubes have a long service life. It can work stably in the air conditioning system for many years, bringing users a long-lasting comfortable experience and reducing the trouble of frequent parts replacement.

The Difference between R22 Refrigerant and R410A Refrigerant

R22 refrigerant is one of the most widely used refrigerants in the past. The chemical name of R22 refrigerant is difluorochloromethane and it belongs to the hydrochlorofluorocarbons. Because R22 refrigerant is very harmful to the ozone layer, the Montreal Protocol stipulates that it will be completely phased out by 2020. Now many manufacturers have stopped producing air conditioners which using R22 refrigerant.

R410A refrigerant is recognized currently in the world as the most suitable and environmentally friendly refrigerant that can replace R22. It has been popularized in Europe, the United States, Japan, China and other countries. R410A refrigerant is a new type of refrigerant. R410A refrigerant is composed of two quasi-azeotropic mixtures, mainly composed of hydrogen, fluorine and carbon elements. R410A refrigerant has the characteristics of stability, non-toxicity and superior performance. Since R410A refrigerant does not contain chlorine, it will not destroy the ozone layer. And the performance of air conditioners using R410A refrigerant will be better.