SPHERICAL BLOWOUT PREVENTER Russian patent published in 2008 - IPC E21B33/06 

FIELD: mining, equipment.

SUBSTANCE: invention relates to the drilling and well operation. It ensures increased operational reliability, overhaul period, service life and maintainability of a blowout preventer. Said preventer includes housing with a cavity and centre hole. A cover with centre hole, spherical cavity and sealing ring is mounted onto said housing. The spherical cavity of said cover receives a sealing element made of a flexible material and reinforced with rigid inserts. A piston is arranged in the housing and provided with a surface for receiving said sealing element, a working chamber and a return chamber, fluid passages for connecting said working and return chambers with a hydraulic pressure source. Between the housing, cover and piston there is a separating sleeve provided with a sealing ring with respect to the housing. Sealing cups of the housing come into contact with the inner surface of the piston, and sealing caps of the separating sleeve come into contact with its outer surface. The preventer is also equipped with a cylinder being rigidly connected to the piston and sealed with respect to the latter or made integral with the separating sleeve. The separating sleeve is provided with additional sealing caps coming into contact with the inner surface of the cylinder. The return chamber is formed by the piston surface, the inner surface of the cylinder and the bottom surface of the separating sleeve. The separating sleeve has a fluid passage leading from the inside to the return chamber and from the outside - to the cylindrical or end surface of the separating sleeve.

EFFECT: increasing the operational reliability, overhaul period, service life and maintainability of blowout preventers.

6 cl, 3 dwg