GATE VALVE WITH UNLOADING SHUT-OFF UNIT Russian patent published in 1999 - IPC

FIELD: manufacture of fittings; shutting-off working medium in pipe lines at increased pressures. SUBSTANCE: gate valve has body with cylindrical cavity where shut-off unit is located. Shut-off unit consists of three ceramic elements lapped to one another. Ceramic elements are engageable by their ends working surfaces. One ceramic element is swivel in construction and is provided with drive; two other ceramic elements are immovable in tangential direction. Swivel and immovable shut-off ceramic elements are provided with straightway ports. Gate valve has ball unit and pressure unit. Shut-off unit is located between pressure flexible units balancing each other. End surface of flanged cover of body is provided with axial support mounted under circular projection of swivel shut-off member. Element of shut-off unit is made in form of ring on inlet side of gate valve. As a result, bearing and pressure units are isolated from action of working media. EFFECT: enhanced operational reliability of gate valve. 5 cl, 3 dwg