Inserting-type emergency cut-off valve for liquefied natural gas cylinder

Abstract

The invention relates to an inserting-type emergency cut-off valve for a liquefied natural gas cylinder. The inserting-type emergency cut-off valve has the main technical characteristic of comprising a distributing head, a seal element, a plug screw pressing cover, an adjusting nut, a bolt, a screw seat, a spring and a valve sheet, wherein the screw seat is an externally-threaded cylinder with a cylindrical surface, six through holes mutually forming 60-degree angles mutually and a center through hole are formed on the screw seat, and a step limiting opening is formed at the middle part of the inner wall of the center through hole. The bolt is sleeved with the valve sheet and the spring; the external diameter of the valve sheet is less than the diameter of the inner cavity of the distributing head; the valve sheet can overcome the reacting force of the spring under the action of external force to make an upward motion along the bolt; the separation distance (d) between the upper surface of the valve sheet and the lower surface of the screw seat ranges from 2.5 mm to 4 mm; the external thread of the screw seat is installed in the inner cavity of the distributing head so as to divide the inner cavity into an A cavity and a B cavity; and a C thread connecting opening formed on the side end surface of the distributing head is communicated with the A cavity. The inserting-type emergency cut-off valve has the advantages of compact and reasonable structure, small abrasion, long service life, high reliability, good safety performance, convenience in detection and maintenance, and the like.

Description

technical field [0001] The invention relates to a plug-in type emergency shut-off valve for liquefied natural gas cylinders, which is especially suitable for gently balancing the internal and external pressure difference at the moment of liquid consumption when the liquefied natural gas shut-off valve is opened, and automatically blocking the large amount of liquefied natural gas when the liquid pipeline for liquefied natural gas bursts unexpectedly. Leaked. Background technique [0002] Liquefied natural gas (LNG) is a low-temperature liquefied natural gas. Its storage, transportation and use must use special liquefied natural gas cylinders or tanks. Among them, the flow limiting valve plays a role of safety protection in the gas supply system. In the background technology, the restrictor valves used in the domestic liquefied natural gas field are vertically installed on the external pipeline of the distribution head, that is, a stainless steel pipe with an internal thread ...

AI Technical Summary

Problems solved by technology

This connection and function method has defects such as cumbersome assembly and maintenance, and is not suitable for system integration, especially at the moment when the stop valve is opened and starts to use liquid, because there is a pressure difference between the inside of the gas cylinder and the external vaporizer, the vertical tube inside the restrictor valve Under the action of the instantaneous impact force formed by the pressure difference, the steel ball in the road will quickly move to the horizontal pipeline, block the horizontal pipeline, close the valve, and prevent the liquid natural gas from entering the vaporizer

At present, some flow limiting valve manufacturers simply cancel the flow limiting steel ball, which makes the flow limiting valve lose its due function and leaves a safety hazard at the same time.

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