Double-seal stop valve

Abstract

The invention discloses a double-seal stop valve. A valve base comprises a valve base conical surface and a valve base annular surface which is arranged along a moving direction of a valve clack, thevalve clack comprises a valve clack conical surface and a valve clack annular surface which is arranged along the moving direction of the valve clack, the valve base conical surface and the valve clack conical surface are mutually cooperate to form a conical surface sealing pair, the valve base annular surface and the valve clack annular surface are mutually cooperate to form a ring surface sealing pair, relative to the annular surface sealing pair, the conical surface sealing pair is arranged on the side closer to an outlet cavity. The double-seal stop valve has a dual-sealing auxiliary structure, in a valve closing process, the annular surface sealing pair is firstly sealed, the effect of the pressure reducing throttling in advance is achieved, and then impurities are blocked from entering the area of the conical surface sealing pair, then a small amount of medium after throttling is used for flushing, so that the sealing surface is self-cleaned, and the impurities are effectively prevented from remaining on the sealing surface; and meanwhile, the problem that the valve is not tightly closed or the sealing surface is damaged by pressing is effectively solved, the flushing of thehigh-speed medium on the sealing surface is avoided as well, and the working reliability of the stop valve is greatly improved.

Description

technical field [0001] The invention relates to a stop valve, in particular to a double-seal stop valve. Background technique [0002] The opening and closing part of the globe valve is a plug-shaped disc, the sealing surface is flat or sea-cone, and the disc moves linearly along the centerline of the valve seat. In the globe valves used today, the valve seat has only one sealing surface that acts as a seal. When the valve is closed, the pressure difference of the medium is all concentrated on the sealing surface, so the medium has a greater scouring force on the sealing surface of the valve seat, thereby accelerating the valve. The wear of the sealing surface of the seat reduces its service life. In addition, most structures ignore the damage of solid particles in the medium to the sealing surface. Impurities contain a lot of solid particles. When the valve is closed, the particles are easily caught between the sealing surfaces, crushing the sealing surfaces or causing th...

AI Technical Summary

Problems solved by technology

In the globe valves used today, the valve seat has only one sealing surface that acts as a seal. When the valve is closed, the pressure difference of the medium is all concentrated on the sealing surface, so the medium has a greater scouring force on the sealing surface of the valve seat, thereby accelerating the valve. The wear of the sealing surface of the seat reduces its service life

In addition, most structures ignore the damage of solid particles in the medium to the sealing surface

There are many solid particles in the impurities. When the valve is closed, the particles are easily caught between the sealing surfaces, crushing the sealing surfaces or causing the valve to close laxly, causing high-speed media to wash the sealing surfaces for a long time, resulting in internal leakage of the valve.

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