SHUT-OFF VALVE Russian patent published in 2002 - IPC

FIELD: power engineering, chemical oil and gas industries and other industries. SUBSTANCE: shut- off valve has body with inlet and outlet branch pipes and seat closed by shut-off member provided with piston which forms above-piston and under-piston chambers inside body. Under-piston chamber is connected via prechamber with inlet branch pipe and second chamber is connected with outlet branch pipe. This connecting line is provided with control shut-off member. Line connecting the prechamber with under-piston chamber is provided with system of branch pipes and separation chamber mounted is succession. First (from prechamber) branch pipe is located at acute angle relative to axis of inlet branch pipe and is provided with inlet opening in section located inside prechamber on side of this branch pipe opposite to inlet branch pipe. EFFECT: avoidance of use of foreign medium but for working medium for efficiency operation on contaminated medium. 3 cl, 3 dwg