摘要 |
The present invention pertains to a double shut-off valve device which is specifically intended to eliminate the consequences of erosion and the resulting lack of perfectly tight sealing. This device consists of two concentric valve components, namely an inner component, (3), and an outer component, (4), which, in a closed position, respectively rest upon seats, (5) and (6), so as to halt the flow of fluid between sections of a pipe, (1) and (2). Functioning of these components is controlled by a rod (10) which is directly connected to the outer valve component (4), and by a flexible bellows (7) attached to the inner valve component (3). Under these circumstances, the inner valve component (3) halts the flow of fluid, and the outer valve component (4), which is not subject to fluid pressure, can provide tight sealing without erosion. Opening of both valve components occurs simultaneously on account of the accompanying shoulders, (8) and (9).
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