ポンプバルブシール：液漏れを防ぐ重要な部品

Valve is a control component in the fluid transportation system, which has the functions of shutting off, regulating, diverting flow, preventing reverse flow and stabilizing pressure, diverting flow or overflow pressure relief, etc. Valves can be used to control the flow of various types of fluids such as air, water, steam, various corrosive media, mud, oil, liquid metal and radioactive media. Pump valve seals play a vital role in pumps and valves. Their main function is to prevent fluid leakage and external impurities from entering the interior of the pump or valve.

機能

1. Prevent fluid leakage: Pump valve seals can tightly fit the internal parts of the pump or valve to ensure that fluid does not leak to the outside when circulating inside the pump or valve. This sealing effect can reduce fluid loss and prevent external impurities from entering the pump or valve, ensuring the normal operation of the equipment.

2. Improve equipment efficiency: Since seals can effectively prevent fluid leakage, the fluid circulates more smoothly inside the pump or valve, reducing the resistance of the fluid during the circulation process and improving the equipment’s delivery efficiency. At the same time, because the seal can prevent external impurities from entering the pump or valve, it avoids clogging and wear inside the equipment and extends the service life of the equipment.

3. Ensure equipment safety: In some specific application scenarios, such as chemical industry, petroleum and other fields, fluid transportation needs to ensure high standards of safety. If there is a problem with the seals in the pump or valve, it may cause fluid leakage, causing fires, explosions and other safety incidents. Therefore, the quality and reliability of seals are crucial to ensuring the safety of equipment.

4. Adapt to different working environments: In different application scenarios, pumps and valves need to face different fluid media, temperatures, pressures and other environmental conditions. Seals can use different materials, structures and designs according to different working environment requirements to ensure effective sealing under various conditions. For example, for high or low temperature situations, you can choose materials with good thermal stability and low temperature toughness such as titanium alloys; for some special application scenarios such as flammable, explosive, toxic and harmful situations, you can choose materials with better fire and explosion protection.

Types and characteristics

According to different application scenarios and needs, pump valve seals can be divided into various types, mainly including: mechanical seals, packing seals, air seals and liquid seals, etc. Each type of seal has its own unique characteristics and range of applications.

1. Mechanical seal: Mechanical seal is a common pump and valve seal. It has the advantages of high precision, high strength, high wear resistance, etc., and is suitable for high-speed rotation and high-pressure sealing occasions. The mechanical seal adopts the structure of dynamic and static ring friction pairs. The end faces of the dynamic and static rings are perpendicular to each other and make relative sliding friction, which can achieve zero leakage effect. Mechanical seals have a long service life and low maintenance costs.

2. Packing seal: Packing seal is a simple pump valve seal. It has the advantages of simple structure and easy maintenance. It is suitable for normal pressure or low pressure sealing occasions. Packing seals use soft packing materials, such as asbestos fiber, graphite, etc., which are compressed and tightly fitted to the internal parts of the pump or valve to achieve a sealing effect. Packing seals are relatively cheap and suitable for some low-demand applications.

3. Air seal and liquid seal: Air seal and liquid seal are a special pump valve seal that can prevent the leakage of gas or liquid media. The gas seal and liquid seal adopt a special structural design, which can keep the pressure of the gas or liquid medium within a certain range, thereby achieving a sealing effect. Air seal and liquid seal are suitable for some special application scenarios such as flammable, explosive, toxic and harmful occasions.

Materials and processes

The materials and processes of pump valve seals have an important impact on their performance and service life. Common sealing materials include metal, non-metal, composite materials, etc. Metallic materials such as stainless steel and titanium alloys have the advantages of high strength and high corrosion resistance, but are easily affected by temperature and pressure; non-metallic materials such as rubber and polytetrafluoroethylene have good elasticity and corrosion resistance, but are easily affected by temperature and pressure susceptible to chemical corrosion and wear; composite materials combine the advantages of multiple materials to have better overall performance.

1. Metal materials: Common metal materials include stainless steel, titanium alloy, nickel-based alloy, etc. These materials have high strength and high corrosion resistance to maintain good performance under high temperatures and pressures. However, they also have some disadvantages such as being susceptible to friction and wear and requiring regular maintenance and replacement.

2. Non-metallic materials: Common non-metallic materials include rubber, polytetrafluoroethylene, etc. They have good elasticity and corrosion resistance and can adapt to various complex fluid media and working environments. However, they also have some disadvantages such as being susceptible to chemical corrosion and wear and requiring regular replacement and maintenance.

3. Composite materials: Composite materials combine the advantages of multiple materials and have better comprehensive properties such as corrosion resistance, wear resistance, high temperature resistance, etc. Common composite materials include silicon carbide composite materials, titanium alloy composite materials, etc. They can effectively improve the life and performance of pump valve seals.

In addition, the manufacturing process of the seal also affects its performance and service life, such as precision casting, heat treatment and surface treatment. These processes can improve the accuracy and quality of the parts and thereby improve the performance and service life of the entire equipment.

Selection and application

When selecting pump valve seals, you need to consider the actual needs and application scenarios of the equipment, including parameters such as fluid medium, temperature, and pressure. Different seals have different advantages, disadvantages and application ranges, so selection needs to be based on specific circumstances.

1. Selection of mechanical seal: For high-speed rotation and high-pressure situations, mechanical seals have better applicability. When selecting a mechanical seal, factors such as the speed, pressure, and medium properties of the pump or valve need to be considered. For occasions where the medium is highly corrosive, materials with strong corrosion resistance such as polytetrafluoroethylene can be selected; for high or low temperature applications, materials with good thermal stability and low-temperature toughness can be selected, such as titanium alloys.

2. Selection of packing seal: Packing seal has the advantages of simple structure and easy maintenance, and is suitable for normal pressure or low pressure sealing occasions. When selecting a packing seal, factors such as the corrosion resistance, wear resistance, compressibility and applicable pressure of the packing material need to be considered. For some application scenarios with low requirements, you can choose cheaper filler materials; for some special application scenarios such as flammable, explosive, toxic and harmful situations, you can choose NBR rubber, a filler material with better fire and explosion-proof performance and corrosion resistance.

3. Selection of air seal and liquid seal: Air seal and liquid seal can prevent the leakage of gas or liquid media, and are suitable for some special application scenarios such as flammable, explosive, toxic and harmful occasions. When selecting an air seal or liquid seal, factors such as the structural form, applicable medium, and working pressure of the air seal and liquid seal need to be considered. For different application scenarios and needs, you can choose different air seal and liquid seal structures and materials such as rubber and polytetrafluoroethylene.

In addition to selecting the appropriate seal type, there are considerations during seal installation and use. When installing, you need to pay attention to the correct installation direction and position of the seal to avoid problems such as distortion and offset; during use, you need to pay attention to the operation and maintenance specifications of the pump or valve to avoid overloading, over-pressure and other problems that may cause damage to the seal.

In short, when selecting and applying pump valve seals, you need to consider the actual needs and application scenarios of the equipment. Choosing the appropriate seal type and material as well as the correct installation and use methods can improve the performance and service life of the equipment, and at the same time ensure the safety of the equipment.

For some special application scenarios such as chemical and petroleum fields, special attention needs to be paid to the selection, use and maintenance of pump valve seals to ensure safety and stability during the production process.