What are Pneumatic Seals?

Seals are materials or parts that prevent fluid or solid particles from leaking from adjacent joint surfaces and prevent foreign impurities such as dust and moisture from invading parts inside the machine. The storage temperature of the seals is preferably below 30 ° C to avoid high temperature aging of the seals.

Although the rubber seal is small, its role makes it a

1. Classified by function: Divided into shaft seal, hole seal, dust seal, guide ring, fixed seal, rotary seal; 2. Classified by material: divided into nitrile rubber, EPDM rubber,

1. The storage temperature of the seals should be below 30 to avoid high temperature aging of the seals. 2. The seals must be stored in sealed packages to avoid contact with moisture or dust in the air. Light exposure to prevent seals from being attacked by ozone in the air or prematurely aging. The factors affecting the performance of various seals are different, such as mechanical seals (filler seals, etc.).

(1) Select the appropriate seal material and hydraulic oil, as well as the adaptability to the working temperature and the compatibility with the oil. (2) The geometric position accuracy (concentricity) of the sliding part relative to the seal is high, the material is good (such as hard chrome plating), and the surface roughness is thin, which can prolong the service life. The oil seals used for hydraulic pumps and motor journals not only require that the roughness of the sliding surface is within Ra of 0.25m, but also require hard chromium plating on the surface. In the specific use, the diameter of the lip of the oil seal needs to be appropriately adjusted according to the specific situation. To the spring force, make it moderately tight, and also use a mounting sleeve or a thin gasket to protect the seal ring during installation to prevent the lips from rolling and twisting, causing the spring to slide out. Rolling processing method is commonly used on the inner surface of the hydraulic cylinder barrel, which not only improves the surface roughness, but also makes its surface cold-hardened, which is beneficial to extend the service life of the seal ring. In addition, the pressure used, the length and type of the sliding surface also have a great impact on the service life. Therefore, the "scheduled inspection" time should be determined based on these conditions. Required sealing surface

Hydraulic seals play a vital role in the integration of hydropneumatics. If the seal of a hydropneumatic component product is not close, then this hydropneumatic component product is not a good product. There are many factors that affect seals. First of all, pressure is an important factor that affects the quality of seals. The level of pressure and the length of the pressure cycle change have a great impact on seal damage (such as extrusion). The higher the pressure, the greater the impact of other factors on the performance of the seal, such as temperature, speed, material of the seal, the gap between the piston and the cylinder, and the gap between the piston and the cylinder head. Another is temperature and friction. It is difficult to describe the maximum and minimum use temperatures of a seal material, because this is the result of a combination of factors. As the working temperature of the piston and the piston rod are different, they must be selected differently. There is also the surface roughness, surface characteristics, pressure, medium, temperature, seal material, seal type and movement speed of the seal product. These are the factors that affect the seal. The last one is surface treatment. Experience shows that the characteristics of the surface of the cylinder piston and piston rod have a very large impact on the life of the seal. Surface characteristics are usually defined by the value of surface roughness RA, which is the arithmetic mean of the absolute value of the surface shape off the centerline. However, these values do not fully represent the effect of surface conditions on the seal, because even under the same roughness, different surface shape characteristics can cause seal wear to different degrees to the seal.

1. Please read the descriptions of each series of products before designing the grooves, and make sure that the product uses integral grooves or split grooves. In the process of installing the seals, pay attention to avoid the sharp edges. The seals must be installed in the overall grooves. With the help of installation tools, the designer must consider parameters such as groove dimensional accuracy, surface roughness, and extrusion clearance. For details, please refer to the product instructions, diagrams, and size tables. 2. Before installing the seals, make sure that there are no impurities and cracks in the seal grooves, and apply operating oil to the surfaces of the seal grooves and seals respectively; install the seals gradually in order; avoid the sharp edges and straighten the seals during the installation process Avoid twisting and skewing; if it is a split slot, tighten the gland finally.

Seals, packings, mechanical seals,

In recent years, the production and quality of China's rubber sealing products have gradually entered a new stage and new period. However, these alone are far from meeting the needs of other industries for the standardization and serialization of various types of rubber sealing products, especially compared with the advanced countries in the world. Our products are both in terms of product quality and product varieties. Considerable gap. In this issue of the Hundreds of Forums, the concept, research content and research significance of sealing science are explained, the current status of rubber and plastic sealing, mechanical sealing and packing sealing technology is reviewed, and the research level and new products of advanced sealing technologies in China and the world are analyzed. Development gap, and put forward a number of suggestions on the focus of future research in the field of sealing.

It is well known that the overall competitiveness of China's sealing industry is not strong. In our country, the sealing industry can be said to be the smallest industry, but the products can be used in conjunction with large industries. Whether in aviation, marine, petroleum, chemical, or machinery, power generation, metallurgy, mining, etc., seals are inseparable. In short, everything that is organic, pumps, pipes, valves depends on seals. Therefore, although the industry is small, it involves a wide range. In recent years, with the development of the economy, the sealing industry has also developed rapidly. But unlike other industries, although the sealing industry is developing fast, the sealing companies are changing slowly. For example, in the late 1970s and early 1980s, there were only a few manufacturers in Jiangsu, Zhejiang, and Shandong. Whether it is coastal, inland, or southern or northern, there are seals factories everywhere. The entire sealing industry has been developed from the previous ones. With as many as 300 homes, this development rate can be said to be fast. However, as far as individual enterprises are concerned, many enterprises have not changed much, the production scale has been detoured, and some have even retrogressed. Not only has there not been a large increase in scientific and technological strength, but some have weakened. Many manufacturers still hold the "four old" , Namely old products, old technology, old equipment, old scale. Of course, there are some companies that have a strong ability to imitate and imitate some products, but there are not many companies in the industry that have the ability to independently develop new products. In terms of products, most manufacturers still have some old products such as wound gaskets, packing rings, packings and high-strength gaskets. The slightly innovative PTFE products lag far behind foreign countries in terms of technology and quality, such as PTFE packing and expanded PTFE tape. Looking around, there are very few new products. In terms of technical strength, most companies have a relatively small proportion of scientific and technological personnel. Many enterprises lack technical personnel with a genuine scientific background and weak technical strength, so enterprises lack the corresponding development and transformation capabilities. Since the establishment of the European Union, the strength brought by the union has prompted the European Union to improve and establish new European seal quality standards, replacing the series of standards previously relied on by the American Fluid Association. Emergence and emphasis on leakage rates in new European seal quality standards. The leakage rate of products in China is generally 10-1mg / s, and high-strength graphite composite plates with leakage rates of 10-4mg / s have already appeared in Europe! As far as equipment is concerned, most companies have only a few old ones. Knitting machines, several winding machines made of earth, simple tooth punching machines and shearing machines, etc., rely on the ability of old workers to organize production; and the equipment of many manufacturers has been in a state of unsaturated production tasks for a long time. As far as quality management is concerned, most companies rely on the proficiency of their operators to make good products, and they do not produce according to standardized process standards, which is also a necessary management method. Although many manufacturers have obtained ISO9000 series certification, the internally stipulated process documents, quality control plans or operation guidance documents and equipment management documents are often weak and far from the international level. In terms of scale, the vast majority of enterprises have sales of less than 5 million yuan, 10 million are few, and more than 10 million are few. Frankly speaking, a large part of the sales of many manufacturers is outsourced procurement parts, and the proportion of genuine production is not very high. Therefore, it is difficult for many small enterprises to compete with some famous foreign companies and manufacturers.

Analysis of the advantages and disadvantages of China's sealing industry among its international counterparts. In summary, our sealing industry has weak competitiveness, but this refers to some small enterprises, and we also have some powerful companies or factories. Although there are several well-known large enterprises abroad, there are also many small enterprises. There are also many commercial companies specializing in sealed businesses that buy products from China and sell them in their home countries or other countries. The advantages and disadvantages are different. In terms of advantages, we have advantages in three main areas: raw material advantages. Whether it is asbestos, graphite, and other non-metal materials, we are a major producer, and many countries lack this resource. Price advantage At present, the seal is still a labor-intensive product, and the manufacturing cost in China is low. Below 1,000 yuan / person · month is mostly), the current victory of the seal competition is 60% depending on price factors. In the domestic market, this phenomenon of host supporting (OEM form) is already obvious, especially in the international market. With the further deepening and improvement of domestic reforms. The role of price in the maintenance market is becoming increasingly apparent. Humanistic advantages At present, the marketing of the domestic market of seals mainly depends on interpersonal relationships. We are uniquely endowed by nature and harmony. We have many advantages under the same quality conditions in the domestic market. From the perspective of market competition, with these three advantages, we can embark on the road to competition.

Conversely, there may be more disadvantages

The first is technical backwardness. On the one hand, in order to meet the increasing requirements of humans for environmental protection, the ISO14000 standard has begun to be taken seriously by Chinese enterprises, and people's requirements for sealing have become increasingly strict. Just as the entry of a large number of joint ventures has brought new quality requirements and new environmental protection concepts. On the other hand, the new standards objectively bring about market redistribution. The new and stricter quality standards will become the biggest obstacle to the export of sealed products in China; it will also become a killer for foreign companies to enter the Chinese market. Companies that do not value technological progress will be eliminated in the next five years. The main body of technology is people. As far as the status quo is concerned, the sealing industry is relatively loose and the individual scale is small, so the ability of the hidden dragon and crouching tiger is small, and the overall quality of enterprise employees is low. In addition, there may be a need for correctness in business philosophy. Capitalism has been in existence for more than 200 years. Many of our peers, that is, competitors, have experienced the continuation of 4 generations. They have already shaken off the mentality of seeking wealth from poverty and prosperity, moving to a mature state of mind, doing market, managing, and doing Brand and culture. The reason why our company has so many repetitive establishments at this stage is because many people are eager to get rich while taking advantage of the various irregularities in the reform process. This is a very natural alternating process, and the capitalist countries have experienced the same. But what is before us is how to accelerate the evolution, from eager for wealth and entrepreneurship, to a mature business culture. Based on this scrutiny, it is not difficult to see all the shortcomings in our individual corporate behavior. Insufficient alliances and increased competition have resulted in a market decline and are the number one problem in operation. In fact, blindly lowering prices and blindly pursuing orders will eventually destroy the market. The market is not a cake, but a field. It takes effort, cultivation, and love. In terms of quality awareness, after-sales service, product packaging, equipment investment, etc., reference is made to ISO9000 standards, and each company naturally has its own evaluation. Although there are management problems with "three-point technology and seven-point management", it is easy to improve if you have confidence.