CASING PIPE VALVE Russian patent published in 2007 - IPC E21B34/10 

FIELD: oil production industry, particularly means for casing pipe centering.

SUBSTANCE: valve comprises limiter with seat and axial side channels, hollow bush and spring-loaded disc slide. Spring-loaded disc slide may cooperate with seat in air-tight manner. Hollow bush is installed in axial channel of the limiter through shear members and is arranged over the side channels to provide side channel sealing. Limiter has through channels located between axial channel and seat. Axial channel is closed with cap from below. Disc slide may move in axial direction without side limiter channels closing.

EFFECT: simplified structure and increased operational reliability of casing pipe valve, possibility of cement grout injection without casing pipe throat loss.

1 dwg