NONRETURN-SHUTOFF OR SHUTOFF VALVE Russian patent published in 2003 - IPC

FIELD: mechanical engineering; valves and fittings. SUBSTANCE: invention relates to pipeline devices designed for control of transported working medium flow and its parameters such as velocity, pressure, flow rates, etc, by cutting off flow or opening passage for flow. Proposed valve contains housing, seat, spool, servodrive, cover and control drive. Bellows is made in form of servodrive piston. Said piston is installed coaxially with control drive and is connected with spool. One end face of bellows piston is fixed. Other end is made for displacement. Guaranteed clearance is set between contact surfaces of both drives. Said clearance-provides building of working forces at opening of nonreturn-shutoff valve or closing of shutoff valve which do not depend on each other and are directed in opposite sides. Effective area of corrugated envelope of bellows should exceed area of valve seat. Invention is aimed at reducing mass and dimensional characteristics, increasing reliability of sealing unit with valve closed owing to energy of working medium and enlarging operating capabilities, both of nonreturnshutoff valves and shutoff valve, for instance, for operation as regulators. EFFECT: enlarged operating capabilities. 4 dwg