Silicone waterproof sealing ring includes gas insulating material, liquid insulating material and solid insulating material. Involving electrical, petrochemical, light industry, building materials, textiles and many other industries.

Gas insulating material

Under normal circumstances, dry gases under normal temperature and pressure have good insulation performance. As an insulating material, gas dielectric also needs to meet the requirements of physical, chemical properties and economy. Air and sulfur hexafluoride gases are commonly used as gas insulation materials.

Air has good insulation performance, its insulation performance can be instantaneous automatic recovery after breakdown, stable electrical and physical performance, extremely rich source, wide application. But the breakdown voltage of air is relatively low, sharp electrode, short distance, voltage waveform steep, high temperature, high humidity and other factors can reduce the breakdown voltage of air, often use compressed air or vacuum method to improve the breakdown voltage of air.

Sulfur hexafluoride (SF6) gas is a non-flammable, non-explosive, colorless and tasteless inert gas, it has good insulation performance and arc extinguishing ability, far higher than air, has been widely used in high voltage appliances. Sulfur hexafluoride gas also has excellent thermal stability and chemical stability, but under the action of high temperature above 600℃, sulfur hexafluoride gas will decompose, will produce toxic substances. Therefore, the following aspects should be paid attention to in use.

(1) Strictly control water content and do a good job of dehumidification and moisture-proof measures.

(2) Use appropriate absorbents to absorb harmful substances and water.

(3) The pressure of sulfur hexafluoride gas in the circuit breaker can not be too high and the phenomenon of liquefaction.

(4) The place where the sulfur hexafluoride equipment is placed should have good ventilation conditions.

(5) Necessary and reliable labor protection measures should be taken for operation and maintenance personnel.

Liquid insulating material

Insulating oil includes natural mineral oil, natural vegetable oil and synthetic oil, as shown in the figure. Natural mineral oil is widely used. It is obtained from petroleum crude oil by refining in different degrees

A neutral liquid with a golden color and good chemical stability

Properties and electrical stability. Mainly used in power transformers, less oil circuit breakers, high voltage cables, oil - immersed capacitors and other equipment. Natural vegetable oil castor oil, soybean oil and so on. Synthetic oil has dibenzyl methyl silicone oil, benzyl silicone oil and so on, mainly used in power transformers, high-voltage cables, oil-immersed paper capacitors.

Insulation oil will be affected by various factors during storage, transportation and operation, resulting in pollution and aging. Heat and oxygen play a major role in the aging of oils. The measures taken to prevent oil aging in industry are: strengthen heat dissipation to reduce oil temperature; With nitrogen, film to isolate transformer oil from air; Use a desiccant to remove moisture; Adding antioxidants; Protection from sunlight, etc. After the oil is polluted, it can be purified and regenerated by pressure filtration or electric purification.

In order to ensure the safe operation of oil-filled equipment, it is necessary to regularly check the temperature rise of the oil, the height of the oil surface, the flash point of the oil, the acid value, the breakdown strength and the tangent value of the dielectric loss Angle, and if necessary, the chromatographic analysis of the transformer oil. When you need to replenish oil, try to use the original model or similar model, and should be mixed test.

Solid insulating material

There are many kinds of solid insulating materials, which have excellent insulation performance and are widely used in power system. Commonly used solid insulating materials are: insulating paint, insulating adhesive; Fiber products; Rubber, plastics and their products; Glass and ceramic products; Mica, asbestos and its products, etc.

Insulating paint and adhesive are important insulating materials which are based on high polymer and can be solidified into insulating hard film or insulating whole under certain conditions.

Insulating paint is mainly composed of paint base, solvent, thinner, filler and other parts. After curing, insulation strength of insulating paint is high. It can be used as impregnated insulation or coated insulation for motor and electrical coil. It can be divided into impregnated paint, enameled wire paint, covering paint, silicon steel sheet paint and anti-corona paint, etc.

Insulation glue is similar to insulation paint, generally with filler, widely used for casting cable joints, bushings, 220kV and below current transformers, 10kV and below voltage transformers. The insulation adhesive is yellow cable adhesive, black cable adhesive, epoxy cable adhesive, epoxy resin adhesive, epoxy polyester adhesive and so on.

Insulating fiber products refer to insulating materials made of insulating paper, cardboard, paper tubes and various fiber fabrics. Impregnated fiber products are made with insulating fiber products as the base material, immersion made with insulating paint, it has a certain mechanical strength, electrical strength, moisture resistance performance, still have a few mildew, electricity, radiation and other special functions. Insulating electrical laminating products is made of fiber as the base material, dip coated with different adhesives, by hot pressing or rolling laminated structure insulating materials, its performance depends on the base material and adhesives and their forming process, can be made with excellent electrical properties, mechanical properties and heat resistance, mildew resistance, arc resistance, corona resistance and other characteristics of the products.