Low-temperature gas return valve on LNG storage tank

Abstract

The invention discloses a low-temperature gas return valve on an LNG storage tank. The low-temperature gas return valve comprises a valve body arranged on a gas return hole of the storage tank, a valve body passage communicated with the inner cavity of the storage tank and the valve body outlet is arranged in the valve body, a valve core with a sealing ring is arranged in the valve body passage, a push guide device capable of pushing the valve core towards the outside is arranged between the valve core and valve body, a conical sealing surface capable of closely fitting with the sealing ring on the valve core is arranged on the side wall of the valve body passage, the sealing ring closely fits and seals with the conical sealing surface after the push guide device pushes the valve core towards the outside, a locating pin capable of screwing into a spiral locating guide groove in the front end of a gas return gun is arranged at each of two sides of the valve body, a movable sleeve sleeves each locating pin, and the movable sleeves are capable of freely rolling on the locating pins. According to the low-temperature gas return valve on the LNG storage tank, the movable sleeves sleeve the locating pins, and accordingly the friction on the locating pins when screwing into the spiral locating guide groove in the front end of the gas return gun is greatly reduced, and the service life of the low-temperature gas return valve is prolonged.

Description

technical field [0001] The invention relates to a low-temperature gas return valve on an LNG storage tank for exhausting the storage tank. Background technique [0002] LNG is the English abbreviation of liquefied natural gas. There is a low-temperature return valve on the LNG storage tank. When it is necessary to exhaust the storage tank, connect the return air gun to the low-temperature return valve. At this time, the return air gun can push the low-temperature return valve open. The spool in the tank is opened to open the low temperature return valve to achieve the purpose of degassing the storage tank. The shortcoming of the low-temperature return valve on the existing LNG storage tank is: since the valve body both sides of the low-temperature return valve are respectively provided with positioning pins that can be screwed into the spiral positioning guide groove at the front end of the return gun; During the docking process of the air valve, the locating pin will rub a...

AI Technical Summary

Problems solved by technology

The shortcoming of the low-temperature return valve on the existing LNG storage tank is: since the valve body both sides of the low-temperature return valve are respectively provided with positioning pins that can be screwed into the spiral positioning guide groove at the front end of the return gun; During the docking process of the air valve, the locating pin will rub against the inner wall of the helical locating guide groove, which will cause the screwing process to be unsmooth, and as the number of times of use increases, the locating pin will bend or even fall off. As a result, the air return gun cannot be accurately docked with the low temperature return air valve, so that the LNG storage tank cannot be exhausted

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