Bellows parallel gate valve

Abstract

The invention relates to a bellows parallel gate valve. Bellows wedge-shaped gate valves and bellows stop valves exist and are originally applied in present market, and have the defects of poor sealing property and short service life. The bellows parallel gate valve comprises a valve body and a valve cover, wherein a valve rod is arranged in the valve body; a bellows is arranged outside the valve rod in a sleeving mode; a valve element is arranged at the lower part of the valve rod. The bellows parallel gate valve is characterized in that a flow passage is arranged in the valve element; two flashboards parallel to each other are arranged on the flow passage; an elastic part is arranged between the two flashboards; the flashboards are fixed on a valve seat. A bellows structure is combined with a parallel gate valve, the performance requirement of zero leakage can be reached, the defects of the stop valves and the wedge-shaped gate valves are also avoided, and the bellows parallel gate valve is higher in sealing property and longer in service life.

Description

technical field [0001] The invention relates to a bellows parallel gate valve. Background technique [0002] With the rapid development of science and technology and the rapid development of industrial level, the higher the sealing and reliability requirements of the valve, the sealing failure will not only cause huge economic losses, but also pollute the environment and even cause major casualties. Therefore, It is of great significance to the research and application of valve sealing technology under special service conditions. The bellows is used as the valve stem sealing element. It is often used in occasions with strict requirements on valve stem sealing, such as high vacuum occasions and nuclear industry or flammable, explosive, toxic, permeable, nuclear radiation, etc. Special media and industrial pipelines under harsh working conditions. Due to the simple structure of the stop valve, the stroke is short, the switching time is short, and the friction of the sealing ...

AI Technical Summary

Problems solved by technology

[0003] like figure 1 As shown in the figure, the bellows globe valve has an S-shaped flow path and a large flow resistance. Because the valve stem is under the pressure of the medium, it is easy to bend, and the operating torque is relatively large when switching.

And there are also the problems of inconvenient disassembly and assembly, poor interchangeability of parts and short service life

[0004] like figure 2 The bellows wedge gate valve shown has the following problems: 1. Because the angle between the gate plate and the valve seat is inconsistent, it is easy to cause leakage, and it will also cause more labor to close the valve.

[0005] 2. When the bellows wedge gate valve is heated and cooled, the wedge gate tends to be stuck. Due to design defects, the valve stem is limited in up and down movement. When the medium expands and contracts, the valve stem will be deformed and twisted

[0006] 3. Although the bellows wedge gate valve uses "flexible" materials to make the wedge gate, it is difficult to achieve real "flexibility". The so-called "flexible" gate often appears very rigid

[0007] 4. Because the bellows wedge gate valve has a slope, when the wedge gate slides over the valve seat, there is no "cleaning" effect, but dirt will be embedded in the mating surface

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