Refrigerant oils: general information

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

To extend the life of refrigeration equipment, various means are used. With them, it will be possible to reduce the wear of rubbing elements and reduce the friction force of parts. Refrigeration oils are used for this. Lubrication is needed, since it improves the tightness of the device, eliminates particles that have penetrated inside. Also, the lubricant removes excess heat from the parts. Read more about this tool in the article.

Manufacturers use synthetic oils in installations, as well as mineral fluids. If you compare the characteristics, then the first type is considered the best. Liquids have a low pour point, high hermetic stability. Synthetic-based refrigeration oils are used to lubricate parts, and when mixed with refrigerants, they are stable. They do not destroy the materials from which the elements of refrigeration units are made.

Destination

Refrigerant oils not only reduce the wear of parts, but are also designed toother uses:

1. Partial heat dissipation. The oil has good heat capacity.
2. Removing small particles. Dust and other particles are trapped in the oil and therefore do not harm the equipment.
3. Improve tightness. A viscous liquid fills the gaps between the elements so that moisture and air do not get inside.

Therefore, it is important to perform fluid changes. Moreover, you can do this both on your own and by contacting a service center.

Features

When choosing an oil, it is necessary to consider not only the brand and cost. Each equipment requires its own products, taking into account its properties. The main parameters include density, pour point. Also important to know:

1. Refrigerant oil acidity.
2. Cloud point.
3. Chemical stability.
4. Surface tension.
5. Solubility.
6. Miscibility.
7. Viscosity.

Since there is a compressor in the refrigerator, you need to choose oil with a suitable consistency. For example, for equipment R134a, an agent with astringent properties in the range of 15-68 centistokes is used.

Choice

When choosing refrigeration oils, it must be taken into account that refrigerants are compatible with synthetic agents. There is also a certain dependence. Since oils come into contact with refrigerants, they are subject to certain requirements:

1. Quality product does not accumulate in the evaporator. Itcirculates through the system, and even at low temperatures will be liquid.
2. The product should be viscous. The product to be poured into the refrigeration unit must have a system sealing function. Keep in mind that compressor temperatures are high.
3. The tool must be suitable for a certain type of refrigerant.
4. The flocculation temperature of quality oil is quite low.
5. Means must have a minimum acid number. This applies to refraction, toxicity, temperature.

In most installations, the refrigerant is freon and freon. Properly selected refrigeration oil ensures that the compressor will function without failure. The component is mixed with the refrigerant. If it has CFC, HCFC, HFC classes, then different types of refrigerant fluids must be used in the installation.

Such products are presented in the form of mixtures made from synthetic hydrocarbons and mineral oils. There are no additives in these products. These are special refrigeration oils for which standard mineral fluids cannot be used. Semi-synthetic products are suitable for almost all equipment used in everyday life and industry.

Bitzer refrigeration oils suitable for modern equipment are in demand. They reduce wear on moving parts. With them, it will be possible to extend the life of the installations.

Mineral oils

Refrigerants R12 and R22 are used with mineral products. These products are inexpensive. Naphthenic-based refrigeration oils are refined, sothey are of better quality.

Product does not include additives. For its manufacture, base oils are used. They are refined, resulting in a product that is excellent for lubrication. To date, the following fluids are Shell Clavus G and Mobil Gargoyle Arctic, Lunaria FR and Suniso GS. These products are approved by leading compressor manufacturers.

Semi-synthetic and synthetic products

Virginia AB, Shell Clavus SD 22-12 is suitable for pouring. The devices work great with them. Synthetic oils for refrigeration compressors have low hygroscopicity and are compatible with polymers. From the characteristics, excellent thermal stability can be distinguished.

Liquids in contact with non-ferrous metals create their protection against corrosion. The product has excellent electrical insulating properties. The oil has excellent resistance to hydrolysis. New synthetic fluids were created at the same time as HFC refrigerants. They are considered safe for the ozone layer. These include:

1. R23.
2. R134a.
3. R404a.
4. R407c.
5. R410a.
6. R507.

This synthetic-based product guarantees a long service life of the equipment, since no insoluble residue is formed. This means that the internal parts of the system will be clean. For piston mechanisms, it is necessary to buy products with a viscosity according to ISO 22, 32. Liquids 46 and 68 are also used. They are mixed with freon, can be used for mixing with freon. When applied to systems with dry evaporators, the liquid is returned to the compressor.

Preparation

Repair should be done after consulting a specialist. You need to read the instructions. This must be done without fail in the event of warranty service, because then you can contact the service center. Everything you need to prepare:

1. Charging hose.
2. Reliable pressure gauge.
3. Vacuum pump.

Fluid change

Refilling is performed based on the following steps:

1. Vacuum must be created in the compressor. Therefore, the 2 service valves on the system must be closed. A vacuum pump is connected to one, it must work until the minimum positive pressure is set. If the value reaches 0.1 bar, the pump must be switched off. Then you need to remove the oil plug. It is necessary to screw on the hose equipped with shut-off valve.
2. You need to open the suction valve a little so that the refrigerant vapor enters the compressor. When there is slight positive pressure, the valve must be closed.
3. On the rear hose, which is needed to remove air, it is important to open the shut-off valve. The end of the hose must be lowered to the bottom of the oil container, shut off valve.
4. Then the vacuum pump starts. When the pressure is less than atmospheric, the shut-off valve must be opened. Oil is being supplied to the unit, this can becheck with a viewing window. You need to close the shut-off valve when the oil rises to the required level.
5. The pump stops. Open the valve to create positive pressure. The charging hose must be disconnected. At the end, you need to tighten the oil plug.

Conclusion

If the technology is followed, moisture and air will not appear in the installation. Need to add liquid? Use a syringe for this. The system needs an oil change, for refrigeration compressors you need to buy it in special stores. Work is also carried out in service centers. Properly carried out prolongs the life of refrigeration equipment.