Patent ID: 6123102
Filing Date: 2000-09-26
Classification: F16K,Y10T

Abstract:
A shut-off valve for liquid under relatively high pressure in a pressure system, of a type having a valve body which shuts off the through opening at a valve seat in the shut-off position under a shut-off pressure through a pressure device pressing against the valve body until the liquid pressure is higher than the shut-off pressure, lifting the valve body from the valve seat, wherein the pressure device has a number (n) of back support rings arranged next to one another or stacked one above the other in such a way that the axial direction (R) of the in stack or of the back support rings corresponds generally to the direction of the shut-off pressure (P.sub.2) of the liquid under pressure on the valve body against the valve seat, and can be moved generally in the axial direction (R) in such a way that neighboring back support rings are axially displaceable sufficiently to permit the valve body to lift from the valve seat wherein a minimum axial clearance is established between adjacent ones of the back support rings, the valve body being movable to a shut-off position, by contrast, when the shut-off pressure becomes sufficiently great causing the fluid pressure to increase along successive back support rings leading to the valve body, the minimum axial clearance between adjacent ones of the back support rings being sufficient such that the successive increases in fluid pressure provide a fluid pressure differential across the back support rings, the fluid pressure differential decreasing toward the valve body providing successive increases in the axial clearance between adjacent ones of the back support rings, the fluid pressure differential being for a limited time period and the fluid pressure increase being sufficiently large to limit the increase in the axial clearances, the successive increases in the axial clearances displacing the back support ring toward the valve body to displace the valve body into seating engagement with the valve seat.