STRAIGHTWAY VALVE-SHUTOFF DEVICE Russian patent published in 2002 - IPC

FIELD: intrawell equipment, drilling and running of oil and gas wells. SUBSTANCE: straightway valve-shutoff device has body housing upper valve comprising plunger, seat, clap valve on axle, spring and sealing elements. It is fitted with lower valve comprising plunger, seat, clap valve on axle, spring and sealing elements. Outer diameter of upper part of plunger exceeds outer diameter of lower part. Groove to accommodate spring lock installed in seat and fixing plunger in lower position OPEN is cut in outer surface of plunger. Ring pocket to catch tool for forced displacement of plunger to upper position CLOSED is made in inner surface of plunger. Upper valve has larger orifice than lower valve has. EFFECT: increased operational reliability of straightway valve-shutoff device installed and operating under pressure. 1 cl, 4 dwg