Pressurizing pilot-operated type high-temperature and high-pressure labyrinth valve

Abstract

The invention belongs to the technical field of pipeline engineering, and particularly relates to a pressurizing pilot-operated type high-temperature and high-pressure labyrinth valve. According to the technical scheme, a pressurizing type pilot structure is introduced, a pilot valve is closed, unbalanced force acts on the upper surface of a main valve element when the valve is in a closed state,the sealing specific pressure of a sealing pair is increased, and the sealing grade is improved; by opening the pilot valve, pressure balance of the upper and lower surfaces of a main valve element inan adjusting state is achieved, the size of an executing mechanism is reduced, and action time is shortened; a flow equalizing sleeve is introduced to realize uniform circumferential flow of a mediumand prevent the medium from directly impacting a valve rod; and the flow equalizing sleeve and a valve element guide face form guiding, and the valve is stable in action and free of jamming.

Description

technical field [0001] The invention belongs to the technical field of pipeline engineering, and in particular relates to a pressure-charging pilot type high-temperature and high-pressure labyrinth valve. Background technique [0002] In industries such as petroleum, chemical industry, and offshore platforms, the following requirements are often required for regulating valves at stations represented by steam venting: [0003] 1. The valve can withstand high temperature and high pressure. The medium is mainly superheated steam, which requires the valve to be able to withstand high temperature; due to the large temperature and pressure changes, the use of ordinary wound gaskets at the outer sealing position has a shorter life, requiring a more reliable sealing method. [0004] 2. The valve has a good decompression effect. Due to the large pressure difference of the medium, the internal parts are required to have a better decompression effect, and the multi-stage decompressio...

AI Technical Summary

Problems solved by technology

[0005] 3. High sealing level of valve seat

In terms of external sealing, the commonly used structure is the Wood seal, but the structure is relatively complicated, and maintenance and replacement are inconvenient; in order to realize the rapid opening of the valve, it is necessary to reduce the unbalanced force of the medium to reduce the size of the actuator

There are two commonly used structures: one is the general balance type, which uses the main valve core to open holes to achieve the pressure balance of the upper and lower chambers, but the sealing performance of this structure cannot be guaranteed, and the sealing level often fails to meet the requirements; the other is the pressure relief pilot Balanced type, by opening the pilot pressure relief valve to realize high-pressure relief and balance the pressure of the upper and lower chambers, the sealing effect of this structure is better than that of the ordinary balanced type, but it is necessary to install multiple metal guide rings on the guide groove of the main valve core to realize the guidance and control of the valve. Auxiliary seal, limited by the high temperature expansion of the sealing ring, is very easy to get stuck during the action process, resulting in the valve not being able to open normally

[0008] In terms of realizing the decompression function, some use multi-stage sleeves, because the number of decompression stages is less, and the decompression effect is poor; there are also maze decompression internal parts, which is not a problem at all, but in order to ensure the function of the pilot valve at the same time (The structure requires that the medium can only enter high and exit low, and the flow direction is closed), and the medium can only flow from the outside to the inside of the labyrinth core bag, which does not conform to the principle of fluid decompression: after multi-stage decompression, the pressure of the medium decreases and the density decreases. Small, the flow area should be expanded, but the inner area of ​​the labyrinth core bag of this structure is much smaller than the outer area, the area does not increase but decreases, and the medium is compressed again, resulting in secondary acceleration; a large part of the pressure difference of the valve is absorbed by the valve with larger flow resistance. Bearing the seat, it is equivalent to the medium is directly vented from the valve seat at a relatively high pressure, and the medium flows at supersonic speed, forming secondary noise, and the decompression and noise reduction effect of the labyrinth internals is greatly reduced

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