The contribution of carbon graphite in the sealing industry

Carbon graphite is the most widely used friction pair material in the mechanical seal industry, and has good self-lubricating properties. The carbon graphite sealing ring is a ring-shaped object made of carbon graphite as a raw material, which can play a sealing role. The carbon graphite sealing ring has a wide range of uses, mainly using the high temperature resistance and elasticity of carbon graphite, so it can play a sealing role in a high temperature environment without melting.

The carbon graphite sealing ring produced by Franli’s carbon graphite has excellent thermal stability, chemical corrosion resistance, good compression and resilience, small thermal stress relaxation, strong ability to compensate for unevenness of the sealing surface, and long service life. To make various cylinder gaskets and high-strength carbon graphite gaskets for compressors and internal combustion engines, instead of metal wound gaskets. It is used for sealing the flanges of various pipes, valves, pumps, heat exchangers, towers, manholes, hand holes, etc.

Characteristics of carbon graphite sealing ring

It is made of carbon graphite through special chemical treatment and heat treatment, which can maintain the original characteristics of carbon graphite material and has good sealing performance. There are four main types of carbon graphite seals produced by the Franli factory:

1.High temperature resistance and low temperature resistance, the use range is Celsius in non-oxidizing media, and can reach 400 °C in oxidizing media;

2.Corrosion-resistant and resistant to various corrosive media, but it has certain limitations when used in strong oxidizing media;

3. It can ensure a good seal even in the case of severe temperature and pressure changes;

4. Due to capillary action, the liquid medium often leaks, so it has good impermeability.

The production process of carbon graphite

1.Roasted carbon graphite: Roasted carbon graphite is divided into hard carbon graphite and soft electrochemical carbon graphite. They are made of petroleum carbon black and soot carbon black mixed with tar, pitch, etc., which are crushed and pressed into green bodies, which are roasted at high temperature. The large carbon-graphite sealing ring replaces the imported spare parts and is applied to the sealing of the steam calciner in the production of soda ash, which not only realizes the long-term operation of the equipment, reduces the maintenance man-hours, increases the production of soda ash, but also saves the cost of spare parts and achieves significant economic benefits.

2.Resin-bonded carbon graphite: It is to pulverize the sintered carbon graphite, use phenolic resin or epoxy resin as a binder, and then press and sinter it into a product after mixing. The resin in the matrix becomes carbon particles after sintering, so it is carbon graphite with gas impermeability.

3.Pyrolytic carbon graphite: domestic pyrolytic carbon graphite is pyrolyzed with hydrocarbons such as propylene at high temperature, so that carbon vapor penetrates into the pores of the carbon graphite body, which plays a role in blocking pores and forms high density, few pores, Pure carbon graphite material with low air permeability.

Carbon graphite materials are usually used as wear-resistant lubricating materials. Carbon graphite is often used as a lubricant in the machinery industry. Lubricating oil often cannot be used under the conditions of high speed, high temperature and high pressure, while carbon-graphite wear-resistant materials can work at a high sliding speed at a temperature of 200~2000 °C without lubricating oil. Many equipment for conveying corrosive media widely use carbon graphite materials to make piston cups, sealing rings and bearings. They do not need to add lubricating oil during operation.

The above carbon-graphite materials used in the mechanical seal industry have made great progress in application technology due to the joint efforts of my country’s carbon-graphite industry and machinery manufacturing industry, and the market pattern has also been greatly changed. Carbon graphite is perfectly fine for the machinery manufacturing industry. This also provides new opportunities for my country’s carbon and graphite industry to develop new markets in this regard. As an important basic equipment material for mechanical seals and mechanical lubrication, carbon graphite requires the Franli factory to continuously improve its technology.