WELL VALVE UNIT Russian patent published in 2000 - IPC

FIELD: oil-producing industry; equipment of wells provided with electric submersible pumps. SUBSTANCE: device has body with seat and radial holes and movable bush with check valve. Outer surface of upper portion of movable bush is made in form of truncated cone. This bush forms valve pair together with seat located above radial holes. Check valve is of spool type. Check valve is mounted in inner cavity of movable bush and is loaded with spring relative to it. In lower position, bush is below radial holes of body. Bush and check valve are made for motion till bush gets on seat and opening of radial holes of check valves in case of rise of pressure of liquid. EFFECT: enhanced reliability; extended functional capabilities during operation in well equipped with lined pipes. 2 dwg