Double-eccentric ultralow temperature butterfly valve

Abstract

A double-eccentric ultralow temperature butterfly valve comprises a valve body, a valve rod and a butterfly plate. The double-eccentric ultralow temperature butterfly valve is characterized in that a manhole is formed in the valve body, and an upper maintenance cover is arranged at the position of the manhole; a sealing component composed of a sealing ring, a pressing ring and a jacking and pressing component is included; the inner side face of the sealing ring is sealed with the butterfly plate, the jacking and pressing component comprises a locking ring, a plurality of jacking and pressing screws arranged on the locking ring and locking nuts connected with the jacking and pressing screws, the end portions of the jacking and pressing screws are pressed on the outer end face of the pressing ring, a circular bead face is arranged at the end, away from the pressing ring, of the locking ring, and a compression ring compressed on the circular bead face is inserted in the inner cavity wall of the valve body. Through the structure, the sealing ring is convenient to replace online, and the online maintenance of the valve body is more convenient and faster. In the maintenance process, only the upper maintenance cover needs to be opened, and the sealing component is dismounted one by one. In addition, the position of the pressing ring is controlled by adjusting the jacking and pressing screws, the compression amount of the sealing ring can be adjusted, and therefore the sealing performance of the valve is guaranteed, and the safe reliability of the valve is improved.

Description

technical field [0001] The invention relates to a butterfly valve, in particular to a double eccentric ultra-low temperature butterfly valve suitable for ultra-low temperature conditions. Background technique [0002] LNG double eccentric ultra-low temperature butterfly valve has connection methods such as flange, lug, clamp and butt welding according to the requirements of the working conditions. However, due to the ignitability and explosiveness of LNG, the safety and reliability of the LNG cryogenic valves for the system equipment are higher than those of ordinary cryogenic valves, and they are required to have a fire-resistant design. Therefore, the main pipeline of LNG ultra-low temperature butterfly valve mostly adopts butt welding structure design. [0003] The sealing pair of the LNG double eccentric ultra-low temperature butterfly valve is located in the fluid. Long-term operation will inevitably lead to wear of the sealing ring, followed by a decrease in the seali...

AI Technical Summary

Problems solved by technology

Obviously, when the butt welding structure is adopted, the former type of valve can only be repaired by cutting the pipe, which has high cost and poor effect; while the latter type of valve is also more difficult to maintain, and it is not easy to ensure the accuracy

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