Fluid medium stop valve

Abstract

The invention discloses a fluid medium stop valve. The fluid medium stop valve effectively prevents medium from leaking from a thin position of a seal between a valve stem and a bonnet during plugging and also prevents the inconvenience caused by the fact that the medium in the valve body needs to be completely drained for corresponding operation during maintenance. The fluid medium stop valve comprises a valve stem which a bonnet is sleeved on. Sealing filler is arranged between the valve stem and the bonnet. A force application member is arranged at one end of the bonnet, the valve body penetrates through the other end of the bonnet, and contact surfaces of the bonnet and the valve body are hermetically connected. A valve seat is disposed in a cavity of the valve body and is divided into an upper cavity and a lower cavity by the valve seat. One end of the valve stem is connected with the application member which can drive the valve stem to axially move. The other end of the valve stem sequentially penetrates through the upper cavity inside the valve body and the valve seat and extends into the lower cavity. A spool is arranged at the end of the valve stem of the lower cavity. The lower surface of the valve seat and the upper surface of a spool serve as plugging surfaces. When the spool is driven by the fore application member, the upper surface of the spool can be pressed back to the lower surface of the valve seat to achieve plugging.

Description

technical field [0001] The invention relates to a sealing structure for fluid medium, in particular to a cut-off valve for fluid medium. Background technique [0002] For fluid media, especially low-temperature flammable, explosive and toxic media like LNG (liquefied natural gas), tank trucks equipped with low-temperature emergency shut-off valves are required for transportation. The medium flow direction of the existing cut-off valve adopts the form of high inlet and low outlet. A structure that implements this is of the form figure 1 As shown in , including the valve stem 8 sleeved in the bonnet. One end of the valve rod 8 is provided with a valve core 13 , and the valve core 13 is arranged in the valve body 11 . The valve body 11 is divided into upper and lower cavities by the valve seat 12 . Wherein, the upper cavity 18 includes the upper surface of the valve seat 12 , the medium inlet 17 and the through end of the valve body 11 and the valve stem 8 ; the lower cavit...

AI Technical Summary

Problems solved by technology

[0003] But the problem that exists in the prior art is: from figure 1 It can be seen that in order to prevent the medium from flowing out of the shut-off valve, although a valve cover gasket 10 is provided between the valve cover and the valve body 11 to form a sealed connection, and a valve stem packing 7 is provided between the valve stem 8 and the valve cover

The whole process takes a long time, and there are many operating steps. There are many production safety factors that need to be considered during the replacement, which brings great inconvenience to the operators.

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