RETURN VALVE FOR CASING STRINGS Russian patent published in 2017 - IPC E21B34/10 E21B33/14 F16K15/06 

FIELD: mining.

SUBSTANCE: return valve consists of a housing, a saddle for ball valve in the axial channel, the sleeve with the sealing ring and the ball in the axial channel, stopper with holes, overlapped by a spring loaded with ring partition. In the axial channel of the housing there is the cup with longitudinal edges at the inner surface. The ball valve is made in the form of a hemisphere of an elastic material, covering the core, provided with a nozzle, passed through a stoper and an ring partition in axial channel. In the axial channel of the nozzle there is the limiting protruberance and the inner groove with arranged therein the retaining ring. The sleeve, connected with nozzle by shear element, is placed over the limiting protruberance. The saddle with a ball is installed in the sleeve axial channel, over which in the sleeve body there are bypass holes, hydraulically connecting its axial channel with the housing axial channel above the ball lock saddle in the initial position.

EFFECT: efficiency increase of the return valve for the casing strings.

3 dwg