HOW TO CORRECTLY CHOOSE THE FILLER SEALING MATERIAL SUITABLE FOR SPECIFIC WORKING CONDITIONS

In industrial production, filler sealing, as an important sealing method, is widely used in various mechanical equipment. Correct selection of filling and sealing materials suitable for specific working conditions is of great significance for ensuring the normal operation of equipment, improving production efficiency and reducing maintenance costs.

1. Understand the working principle of packing seal

The packing seal mainly relies on the pressure cover to press the packing in the sealing cavity, so that the appropriate pressure force is generated between the packing and the surface of the shaft or sleeve. During the rotation of the shaft, an extremely thin liquid film is formed between the filler and the surface of the shaft, which plays a sealing role. At the same time, the filler can also play the role of shock absorption, heat insulation and leakage prevention.

2. Consider the factors of working conditions

1. Pressure

Under different working conditions, the equipment is under different pressure. For high-pressure conditions, it is necessary to choose filler sealing materials with good pressure resistance, such as graphite fillers, metal fillers, etc. For low-pressure conditions, you can choose some softer non-metallic fillers, such as PTFE fillers, rubber fillers, etc.

2. Temperature

Temperature is one of the important factors in choosing filler sealing materials. Under high temperature conditions, high-temperature-resistant fillers, such as graphite, ceramic fiber, etc., should be selected. These materials can still maintain good stability and sealing performance at high temperatures. For low-temperature working conditions, it is necessary to choose low-temperature-resistant materials, such as polytetrafluoroethylene.

3. Medium

The nature of the sealing medium also has a great impact on the choice of filler sealing material. For example, for corrosive media, corrosion-resistant materials should be selected, such as PTFE, ceramics, etc. For flammable and explosive media, it is necessary to choose fillers with flame retardant properties, such as graphite. For food, pharmaceutical and other industries, non-toxic and non-polluting materials should be selected.

4. Rotation speed

The rotation speed of the shaft is also an important consideration in the selection of filler sealing material. For high-speed shafts, fillers with good wear resistance and small friction coefficient should be selected, such as graphite, polytetrafluoroethylene, etc. For low-speed shafts, you can choose some softer fillers to improve sealing performance.

3. Types and characteristics of packing and sealing materials

1. Non-metallic filler

(1) Polytetrafluoroethylene: It has excellent corrosion resistance, high temperature resistance, low friction coefficient, etc., and is suitable for various corrosive media and high-temperature working conditions.

(2) Rubber: It has good elasticity and sealing, and is suitable for low-pressure and room temperature conditions. However, rubber is not corrosion-resistant and easy to age.

(3) Graphite: high temperature resistance, corrosion resistance, good self-lubrication, suitable for high temperature, high pressure, corrosive media and other working conditions.

2. Metal filler

(1) Copper wire: It has good thermal conductivity and wear resistance, and is suitable for high temperature and high pressure conditions.

(2) Stainless steel wire: corrosion resistance, high temperature resistance, high strength, suitable for various harsh working conditions.

4. Precautions for choosing packing and sealing materials

1. Refer to the recommendations of equipment manufacturers

Equipment manufacturers usually recommend suitable packing and sealing materials according to the characteristics and usage requirements of the equipment. When choosing the filler sealing material, you can refer to the recommendations of the equipment manufacturer.

2. Conduct experimental verification

In practical application, different packing and sealing materials can be tested and verified to determine the most suitable material. The test can include sealing performance test, temperature resistance test, wear resistance test, etc.

3. Consider the cost factor

The prices of different packing and sealing materials vary greatly, and the cost factors need to be comprehensively considered when choosing materials. However, poor-quality materials cannot be selected just to reduce costs, otherwise it may lead to equipment leakage, failure and other problems, and increase maintenance costs.

In short, the correct selection of filler sealing materials suitable for specific working conditions requires comprehensive consideration of pressure, temperature, medium, rotational speed and other factors, understand the characteristics and scope of application of different filler sealing materials, and refer to the suggestions and test verification of equipment manufacturers. Only by selecting the right packing and sealing material can we ensure the normal operation of the equipment, improve production efficiency and reduce maintenance costs.