DEVICE FOR SHUTTING-OFF BRANCH OF PIPE LINE Russian patent published in 1999 - IPC

FIELD: repair of pipe lines used for transportation of oil and petroleum products; removal of gate valves at branches. SUBSTANCE: device includes change head with drive located in adapter chamber. Change head is provided with retainer made in form of spring-loaded lever and flexible sealing ring fitted between pressure cones. Change head is located in adapter chamber secured on flange of pipe line branch. Change head is shifted to branch by means of drive trill lever enters interior of pipe line. Under action of spring, lever turns and takes position which is transversal relative to branch. During further operation of drive, pressure cones come closer together compressing the flexible sealing ring till it gets in contact with inner wall of branch. EFFECT: enhanced reliability; safety in conducting such jobs as gas cutting and electric welding. 2 cl, 1 dwg