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What is the top entry ball valve?

The top entry ball valve uses a sphere with a circular through hole as the opening and closing part, and the sphere rotates with the valve stem to realize the opening and closing action. The ball valve evolved from the plug valve, also known as the spherical plug valve. As a ball, the opening and closing part of the top-mounted ball valve rotates 90 degrees around the stem axis to achieve the purpose of opening and closing.

The top entry ball valve is mainly used to cut off, distribute and change the flow direction of the medium in the pipeline. The ball valve with V-shaped opening also has a good flow adjustment function. The ball valve can be closed tightly with only a 90-degree rotation and a small torque. The completely equal inner cavity of the valve body provides a direct flow channel with almost no resistance for the medium. The ball valve is not only simple in structure, good in sealing performance, but also small in size, light in weight, low in material consumption, small in installation size, small in driving torque, simple in operation, easy to realize rapid opening and closing, easy to operate and maintain, and suitable for water, solvents, and acids Common working media such as natural gas and natural gas are also suitable for media with poor working conditions such as oxygen, hydrogen peroxide, methane and ethylene. The valve body can be integral or combined.

The top entry ball valve is widely used, and its variety and quantity continue to expand. It is developing in the direction of high temperature, high pressure, large warpage, high sealing, long life, excellent adjustment performance, and one valve for multiple purposes. Their reliability and other performance indicators have reached a higher level, and have partially replaced gate valves, globe valves and throttle valves. It has been widely used in many aspects such as aerospace, petrochemical industry, long-distance pipeline, light industry food, construction and so on. This is because, compared with other valves, ball valves have many outstanding advantages.

The top entry ball valve adopts integral forging. Compared with casting, the mechanical performance is more stable and reliable when the gas medium is minus 60 degrees. All processed parts are processed by CNC lathes and machining centers to ensure the tolerance and accuracy of the shape and position of the processed parts. In addition, the ball and valve seat products adopt cemented carbide spraying technology, which has the excellent characteristics of high sealing surface hardness, wear resistance, high temperature resistance, and corrosion resistance. After assembly, the finished product is tested to simulate the working conditions of the user's gas. After the nitrogen high-pressure gas test, the hard sealing surface reaches the zero leakage standard.

Top entryball valves are mainly used in pipelines and industrial systems. On the basis of the traditional full bore ball valve, it has the advantages of online maintenance and reducing leakage. The operation mode can be manual, gearbox, pneumatic, electric, gas-liquid linkage, electro-hydraulic linkage, etc.

The difference between top entry ball valves and ordinary valves is that they can be maintained online without disassembly from the pipeline. The maintenance cost is reduced and the service life is prolonged. The pipeline is installed with a welded end structure, which is not affected by pipeline stress, objectively reducing external leakage points and ensuring sealing reliability.

Top entry ball valve seals include valve seats, valve seat inserts and other components. The valve seat insert can float independently in the axial position, and the valve seat can be sealed under zero pressure and low pressure through the pre-tensioned spring. This design is used to achieve the ability to shut off mass under working pressure and high pressure conditions. Outside the seat insertion ring, we put in an O-ring and an elastic ring to ensure the seal between the seat and the valve body. When a fire occurs at the use site of expanded graphite, the sealing performance can be maintained to ensure the reliability of the valve seat fire prevention.

When the valve seat and valve stem seal is damaged and leaks, the sealing grease injected into the grease injection valve can achieve an emergency sealing effect. In the normal working state of the top entry ball valve, grease can be injected through the grease injection valve to lubricate the valve stem and spherical surface, making the opening and closing of the valve more flexible and light.

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