High-pressure stop valve - has truncated-cone sealing faces coated with high-grade non-corroding steel

摘要

The stop valve is for a pipe handling a high-pressure medium, particularly oil or natural gas. The seal is pressed into place by the medium, and the sealing member is an annular piston, radially adjustable to leave a clearance between it and a guide chamber. Its movement is effected by a seat sealing ring and an actuating piston. Both pistons are regulated by a control valve and when opening a rotary plug at right angles to the flow direction sealing faces operate concentric to the plug and to the flow direction. On shutting by turning the plug through 90 deg., sealing faces of solid cross-section come into use. The sealing faces are truncated-cones at right angles and concentric to the flow directions (x-x), and are formed by a relatively thin but non-corroding layer of high-grade steel on a conventional base material.