| 主权项 |
1. In a gas flow duct system which includes (a) a gas flow duct with a central bore, (b) a valve in said gas flow duct to be blocked from gas leakage therefrom, (c) a vent duct which has proximal and opposite distal ends, said distal end intersecting and being in fluid communication with the central bore said duct, (d) a vent duct valve in said vent duct having open and closed states, and (e) a source of compressed gas and a compressed gas valve to selectively allow flow of said gas, the improvement of a valve isolation tool to block leakage gas flow through said valve to be blocked,
said valve isolation tool comprising:
(1) an outer tube having proximal and distal ends,(2) an inner tube having proximal and distal ends and movable axially within said outer tube, said proximal end fluid coupled to said source of compressed gas,(3) an inflatable balloon attached to said distal end of said inner tube and inflatable with gas flowed from said source of compressed gas, and(4) a balloon deflection device having a first part secured to said inner tube, and a second part that extends distally from said first part to lie adjacent said balloon, said device being spring biased to bend in a predetermined inclination from the axis of said inner tube to deflect said balloon after said balloon is transported through said outer tube and into the bore of said gas duct,
wherein said isolation tool is insertable through said vent duct valve when said valve is in its open state, and thence through said the vent duct to said gas flow duct, and said inner tube is axially movable through said outer tube until said balloon is situated within gas duct where said balloon is inflatable and said second part of said valve isolation tool deflects said balloon in said predetermined direction toward the valve to be blocked. |
