A high temperature gate valve hard seal structure

Abstract

The invention discloses a high-temperature gate valve hard seal structure, and belongs to the technical field of high-temperature gate valve seal structures in the oil refining and chemical engineering industry. The hard seal structure comprises valve bases, guide rails, an upper valve rod, a lower valve rod, a first valve plate, a second valve plate and a wedge-shaped block. The first valve plate and the second valve plate are oppositely arranged and connected with the guide rails. The opposite surfaces of the first valve plate and the second valve plate are provided with inclined faces correspondingly. The inclined faces are oppositely combined to form a wedge-shaped space. The back-to-back surfaces of the first valve plate and the second valve plate are attached to the surfaces of the valve bases to form seal pairs; one end of the upper valve rod is connected with the first valve plate and the second valve plate, and the other end of the upper valve rod is connected with a driving system; the surface of the wedge-shaped block is matched with the surface of the wedge-shaped space; and one end of the lower valve rod is connected with the lower end of the wedge-shaped block, and the other end of the lower valve rod is connected with the driving system. The high-temperature gate valve hard seal structure is good in sealing performance, capable of meeting the sealing requirements of high-temperature gate valves with the nominal diameter being 1.5 m or larger, and lasting in sealing effect.

Description

technical field [0001] The invention relates to the technical field of high-temperature gate valve sealing structure in oil refining and chemical industry, in particular to a hard sealing structure of high-temperature gate valve. Background technique [0002] High temperature gate valve is a commonly used supporting control valve in oil refining and chemical equipment, and it is used in high temperature working conditions. The high temperature gate valve is a cut-off valve, the valve plate is fully opened during normal operation, and quickly closed when a fault occurs. Therefore, the high temperature gate valve needs to have excellent sealing performance, so as to ensure that the equipment or high temperature pipeline connected with the high temperature gate valve will not be damaged in the event of an accident or emergency shutdown. [0003] At present, there are two types of high temperature gate valves commonly used: high temperature flat gate valve and electric high tem...

AI Technical Summary

Problems solved by technology

The above two high-temperature gate valve seals have a good sealing effect for high-temperature gate valves with small diameters, but when the high-temperature gate valves have a large diameter (for example, when the nominal diameter is greater than 1.5 meters), the sealing effect of the above-mentioned sealing structure will decrease, mainly because :

[0004] 1. When the caliber of the high-temperature gate valve is large, due to the limitation of the structure and equipment processing capacity, it is difficult to guarantee the flatness and parallelism of the sealing surface of the valve plate and the valve seat, and the processing error of the sealing surface is relatively large, which is easy to cause leakage;

[0005] 2. When the sealing structure is in a high temperature environment for a long time, the deformation of the sealing surface such as the valve plate and the valve seat is relatively large, resulting in a large change in the gap between the sealing surfaces, and medium leakage is prone to occur

[0006] 3. For the soft seal structure, when the valve diameter is large, it becomes difficult to assemble and disassemble the seal ring in cold state, and it is difficult to control the seal pre-pressure and pre-load

And when the valve is operated at high temperature for a long time, the sealing surface and the sealing ring are easily deformed, causing the graphite on the sealing ring to be eroded by the flue gas to form a cavity, causing the gap between the sealing surfaces to expand and causing the seal to fail

[0007] To sum up, in the process of realizing the present invention, the inventors found that there are at least the following problems in the prior art: when the high-temperature gate valve has a large diameter, the existing high-temperature gate valve sealing structure cannot achieve a good sealing effect

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